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Parental Understanding of Infant Health Information: Health Literacy, Numeracy, and the Parental Health Literacy Activities Test (PHLAT)

  • Disha Kumar
    Affiliations
    Departments of Medicine and Pediatrics (Ms Kumar, Drs Patterson and Rothman), and the Department of Biostatistics (Dr Choi) Vanderbilt University Medical Center, Nashville, Tenn; Department of Pediatrics, University of Miami, Miami, Fla (Dr Sanders and Ms Franco); Department of Pediatrics, Division of General Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC (Dr Perrin and Ms Finkle); Department of Pharmacy, University of Wisconsin Hospital and Clinics, Madison, Wis (Dr Lokker); and Department of Health, State of Tennessee, Nashville, Tenn (Dr Gunn)
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  • Lee Sanders
    Affiliations
    Departments of Medicine and Pediatrics (Ms Kumar, Drs Patterson and Rothman), and the Department of Biostatistics (Dr Choi) Vanderbilt University Medical Center, Nashville, Tenn; Department of Pediatrics, University of Miami, Miami, Fla (Dr Sanders and Ms Franco); Department of Pediatrics, Division of General Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC (Dr Perrin and Ms Finkle); Department of Pharmacy, University of Wisconsin Hospital and Clinics, Madison, Wis (Dr Lokker); and Department of Health, State of Tennessee, Nashville, Tenn (Dr Gunn)
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  • Eliana M. Perrin
    Affiliations
    Departments of Medicine and Pediatrics (Ms Kumar, Drs Patterson and Rothman), and the Department of Biostatistics (Dr Choi) Vanderbilt University Medical Center, Nashville, Tenn; Department of Pediatrics, University of Miami, Miami, Fla (Dr Sanders and Ms Franco); Department of Pediatrics, Division of General Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC (Dr Perrin and Ms Finkle); Department of Pharmacy, University of Wisconsin Hospital and Clinics, Madison, Wis (Dr Lokker); and Department of Health, State of Tennessee, Nashville, Tenn (Dr Gunn)
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  • Nicole Lokker
    Affiliations
    Departments of Medicine and Pediatrics (Ms Kumar, Drs Patterson and Rothman), and the Department of Biostatistics (Dr Choi) Vanderbilt University Medical Center, Nashville, Tenn; Department of Pediatrics, University of Miami, Miami, Fla (Dr Sanders and Ms Franco); Department of Pediatrics, Division of General Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC (Dr Perrin and Ms Finkle); Department of Pharmacy, University of Wisconsin Hospital and Clinics, Madison, Wis (Dr Lokker); and Department of Health, State of Tennessee, Nashville, Tenn (Dr Gunn)
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  • Baron Patterson
    Affiliations
    Departments of Medicine and Pediatrics (Ms Kumar, Drs Patterson and Rothman), and the Department of Biostatistics (Dr Choi) Vanderbilt University Medical Center, Nashville, Tenn; Department of Pediatrics, University of Miami, Miami, Fla (Dr Sanders and Ms Franco); Department of Pediatrics, Division of General Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC (Dr Perrin and Ms Finkle); Department of Pharmacy, University of Wisconsin Hospital and Clinics, Madison, Wis (Dr Lokker); and Department of Health, State of Tennessee, Nashville, Tenn (Dr Gunn)
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  • Veronica Gunn
    Affiliations
    Departments of Medicine and Pediatrics (Ms Kumar, Drs Patterson and Rothman), and the Department of Biostatistics (Dr Choi) Vanderbilt University Medical Center, Nashville, Tenn; Department of Pediatrics, University of Miami, Miami, Fla (Dr Sanders and Ms Franco); Department of Pediatrics, Division of General Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC (Dr Perrin and Ms Finkle); Department of Pharmacy, University of Wisconsin Hospital and Clinics, Madison, Wis (Dr Lokker); and Department of Health, State of Tennessee, Nashville, Tenn (Dr Gunn)
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  • Joanne Finkle
    Affiliations
    Departments of Medicine and Pediatrics (Ms Kumar, Drs Patterson and Rothman), and the Department of Biostatistics (Dr Choi) Vanderbilt University Medical Center, Nashville, Tenn; Department of Pediatrics, University of Miami, Miami, Fla (Dr Sanders and Ms Franco); Department of Pediatrics, Division of General Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC (Dr Perrin and Ms Finkle); Department of Pharmacy, University of Wisconsin Hospital and Clinics, Madison, Wis (Dr Lokker); and Department of Health, State of Tennessee, Nashville, Tenn (Dr Gunn)
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  • Vivian Franco
    Affiliations
    Departments of Medicine and Pediatrics (Ms Kumar, Drs Patterson and Rothman), and the Department of Biostatistics (Dr Choi) Vanderbilt University Medical Center, Nashville, Tenn; Department of Pediatrics, University of Miami, Miami, Fla (Dr Sanders and Ms Franco); Department of Pediatrics, Division of General Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC (Dr Perrin and Ms Finkle); Department of Pharmacy, University of Wisconsin Hospital and Clinics, Madison, Wis (Dr Lokker); and Department of Health, State of Tennessee, Nashville, Tenn (Dr Gunn)
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  • Leena Choi
    Affiliations
    Departments of Medicine and Pediatrics (Ms Kumar, Drs Patterson and Rothman), and the Department of Biostatistics (Dr Choi) Vanderbilt University Medical Center, Nashville, Tenn; Department of Pediatrics, University of Miami, Miami, Fla (Dr Sanders and Ms Franco); Department of Pediatrics, Division of General Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC (Dr Perrin and Ms Finkle); Department of Pharmacy, University of Wisconsin Hospital and Clinics, Madison, Wis (Dr Lokker); and Department of Health, State of Tennessee, Nashville, Tenn (Dr Gunn)
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  • Russell L. Rothman
    Correspondence
    Address correspondence to Russell Rothman, MD, MPP, Departments of Internal Medicine and Pediatrics, Suite 6000 Medical Center East, Vanderbilt University Medical Center, Nashville, Tennessee 37232-8300.
    Affiliations
    Departments of Medicine and Pediatrics (Ms Kumar, Drs Patterson and Rothman), and the Department of Biostatistics (Dr Choi) Vanderbilt University Medical Center, Nashville, Tenn; Department of Pediatrics, University of Miami, Miami, Fla (Dr Sanders and Ms Franco); Department of Pediatrics, Division of General Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC (Dr Perrin and Ms Finkle); Department of Pharmacy, University of Wisconsin Hospital and Clinics, Madison, Wis (Dr Lokker); and Department of Health, State of Tennessee, Nashville, Tenn (Dr Gunn)
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Published:August 02, 2010DOI:https://doi.org/10.1016/j.acap.2010.06.007

      Abstract

      Objective

      To assess parental health literacy and numeracy skills in understanding instructions for caring for young children, and to develop and validate a new parental health literacy scale, the Parental Health Literacy Activities Test (PHLAT).

      Methods

      Caregivers of infants (age <13 months) were recruited in a cross-sectional study at pediatric clinics at 3 academic medical centers. Literacy and numeracy skills were assessed with previously validated instruments. Parental health literacy was assessed with the new 20-item PHLAT. Psychometric analyses were performed to assess item characteristics and to generate a shortened, 10-item version (PHLAT-10).

      Results

      A total of 182 caregivers were recruited. Although 99% had adequate literacy skills, only 17% had better than ninth-grade numeracy skills. Mean score on the PHLAT was 68% (standard deviation 18); for example, only 47% of caregivers could correctly describe how to mix infant formula from concentrate, and only 69% could interpret a digital thermometer to determine whether an infant had a fever. Higher performance on the PHLAT was significantly correlated (P < .001) with education, literacy skill, and numeracy level (r = 0.29, 0.38, and 0.55 respectively). Caregivers with higher PHLAT scores were also more likely to interpret age recommendations for cold medications correctly (odds ratio 1.6, 95% confidence interval 1.02, 2.6). Internal reliability on the PHLAT was good (Kuder-Richardson coefficient of reliability = 0.76). The PHLAT-10 also demonstrated good validity and reliability.

      Conclusions

      Many parents do not understand common health information required to care for their infants. The PHLAT and PHLAT-10 have good reliability and validity and may be useful tools for identifying parents who need better communication of health-related instructions.

      Keywords

      What's New
      This study develops and validates the first health literacy scale designed for parents with young children. The study demonstrates that many parents struggle to perform daily tasks required for the care of young children.
      In 2003, the National Assessment of Adult Literacy found that approximately 90 million Americans have basic or below basic literacy skills, and 110 million people have basic or below basic quantitative (numeracy) skills.

      Kutner M, Greenburg E, Jin Y, Paulson C. The health literacy of america's adults: results from the 2003 national assessment of adult literacy. September 2006. National Center for Education Statistics. Available at: http://nces.ed.gov/pubsearch/pubsinfo.asp?pubid=2006483. Accessed July 2, 2010.

      Lower literacy and numeracy skills have been associated with poorer understanding of health information, poorer health behaviors, and worse clinical outcomes.
      Institute of Medicine Committee on Health Literacy
      Health Literacy: A Prescription to End Confusion.
      • Dewalt D.A.
      • Berkman N.D.
      • Sheridan S.
      • et al.
      Literacy and health outcomes. a systematic review of the literature.
      • Schillinger D.
      • Grumbach K.
      • Piette J.
      • et al.
      Association of health literacy with diabetes outcomes.
      • DeWalt D.A.
      • Dilling M.H.
      • Rosenthal M.S.
      • Pignone M.P.
      Low parental literacy is associated with worse asthma care measures in children.
      • Baker D.W.
      • Gazmararian J.A.
      • Williams M.V.
      • et al.
      Functional health literacy and the risk of hospital admission among Medicare managed care enrollees.
      • Huizinga M.M.
      • Beech B.M.
      • Cavanaugh K.L.
      • et al.
      Low numeracy skills are associated with higher BMI.
      • Cavanaugh K.
      • Huizinga M.M.
      • Wallston K.A.
      • et al.
      Association of numeracy and diabetes control.
      • Rothman R.L.
      • Housam R.
      • Weiss H.
      • et al.
      Patient understanding of food labels the role of literacy and numeracy.
      • Sanders L.M.
      • Federico S.
      • Klass P.
      • et al.
      Literacy and child health: a systematic review.
      • Yin H.S.
      • Dreyer B.P.
      • Foltin G.
      • et al.
      Association of low caregiver health literacy with reported use of nonstandardized dosing instruments and lack of knowledge of weight-based dosing.
      • Lokker N.
      • Sanders L.
      • Perrin E.M.
      • et al.
      Parental misinterpretations of over-the-counter pediatric cough and cold medication labels.
      • Davis T.C.
      • Crouch M.A.
      • Wills G.
      • et al.
      The gap between patient reading comprehension and the readability of patient education materials.
      • Davis T.C.
      • Mayeaux E.J.
      • Fredrickson D.
      • et al.
      Reading ability of parents compared with reading level of pediatric patient education materials.
      For parents or caregivers, poor literacy and numeracy skills may create difficulties in understanding and applying health information to the care of their children. In order to care adequately for their children, parents must be able to comprehend common food and medication labels, medical provider recommendations, and health education materials. However, most written child health information is too complex for caregivers to understand and use appropriately.
      • Davis T.C.
      • Crouch M.A.
      • Wills G.
      • et al.
      The gap between patient reading comprehension and the readability of patient education materials.
      • Davis T.C.
      • Mayeaux E.J.
      • Fredrickson D.
      • et al.
      Reading ability of parents compared with reading level of pediatric patient education materials.
      • Arnold C.L.
      • Davis T.C.
      • Frempong J.O.
      • et al.
      Assessment of newborn screening parent education materials.
      • Davis T.C.
      • Bocchini Jr., J.A.
      • Fredrickson D.
      • et al.
      Parent comprehension of polio vaccine information pamphlets.
      • D'Alessandro D.M.
      • Kingsley P.
      • Johnson-West J.
      The readability of pediatric patient education materials on the World Wide Web.
      • Davis T.C.
      • Humiston S.G.
      • Arnold C.L.
      • et al.
      Recommendations for effective newborn screening communication: results of focus groups with parents, providers, and experts.
      Although the average adult reads at the eighth-grade level, a large portion of parent education materials, including some materials produced by the American Academy of Pediatrics (AAP), the Centers for Disease Control and Prevention (Vaccine Information Sheets), and state newborn screening programs, remain above the tenth-grade level.
      • Davis T.C.
      • Crouch M.A.
      • Wills G.
      • et al.
      The gap between patient reading comprehension and the readability of patient education materials.
      • Davis T.C.
      • Mayeaux E.J.
      • Fredrickson D.
      • et al.
      Reading ability of parents compared with reading level of pediatric patient education materials.
      • Arnold C.L.
      • Davis T.C.
      • Frempong J.O.
      • et al.
      Assessment of newborn screening parent education materials.
      • D'Alessandro D.M.
      • Kingsley P.
      • Johnson-West J.
      The readability of pediatric patient education materials on the World Wide Web.
      • Davis T.C.
      • Humiston S.G.
      • Arnold C.L.
      • et al.
      Recommendations for effective newborn screening communication: results of focus groups with parents, providers, and experts.
      A few studies have shown that caregivers with lower literacy are less likely to understand important aspects of pediatric anticipatory guidance, including weighing risks and benefits of routine vaccinations, performing home safety checks, and handling common household emergencies.
      • Davis T.C.
      • Crouch M.A.
      • Wills G.
      • et al.
      The gap between patient reading comprehension and the readability of patient education materials.
      • Davis T.C.
      • Bocchini Jr., J.A.
      • Fredrickson D.
      • et al.
      Parent comprehension of polio vaccine information pamphlets.
      • Llewellyn G.
      • McConnell D.
      • Honey A.
      • et al.
      Promoting health and home safety for children of parents with intellectual disability: a randomized controlled trial.
      In general, lower caregiver health literacy is associated with worse family health behaviors and worse child health outcomes.
      • Sanders L.M.
      • Federico S.
      • Klass P.
      • et al.
      Literacy and child health: a systematic review.
      • Armar-Klemesu M.
      • Ruel M.T.
      • Maxwell D.G.
      • et al.
      Poor maternal schooling is the main constraint to good child care practices in Accra.
      • Levandowski B.A.
      • Sharma P.
      • Lane S.D.
      • et al.
      Parental literacy and infant health: an evidence-based healthy start intervention.
      Currently, there are no scales specifically designed for measuring the health literacy of parents of young children. Previous studies examining parent literacy have used scales that assess general literacy or that primarily assess health literacy in the context of adult medical care. For example, the Short Test of Functional Health Literacy for Adults (S-TOFHLA), one of the most common measures of adult health literacy, includes a section that assesses an adult's ability to read and understand how to prepare for a contrast radiograph of the upper gastrointestinal tract. Several recent studies have demonstrated that young adults tend to score very highly on the S-TOFHLA, even when they are from lower socioeconomic backgrounds that should correlate with low literacy.
      • Janisse H.C.
      • Naar-King S.
      • Ellis D.
      Parent's health literacy among high-risk adolescents with insulin dependent diabetes.
      • Oettinger M.D.
      • Finkle J.P.
      • Esserman D.
      • et al.
      Color-coding improves parental understanding of body mass index charting.
      • Tran T.P.
      • Robinson L.M.
      • Keebler J.R.
      • et al.
      Health literacy among parents of pediatric patients.
      Recently, some of the developers of the S-TOFHLA have recognized this ceiling effect and have suggested that the current scoring of the S-TOFHLA (to form the categories “inadequate,” “marginal,” and “adequate”) are probably insufficient for many analyses.
      • Pandit A.U.
      • Tang J.W.
      • Bailey S.C.
      • et al.
      Education, literacy, and health: mediating effects on hypertension knowledge and control.
      • Wolf M.S.
      • Feinglass J.
      • Thompson J.
      • Baker D.W.
      In search of “low health literacy”: threshold vs gradient effect of literacy on health status and mortality.
      Given the potential limitations of current health literacy scales, as well as the lack of one specific to the pediatric setting, we sought to develop a new health literacy scale specifically for parents that focused on the ability of parents to understand and apply common child-health-related information. The objectives of this study were 1) to assess parental health literacy and numeracy skills and 2) to develop and validate a new parent health literacy scale related to the care of young children, the Parental Health Literacy Activities Test (PHLAT).

      Methods

      A cross-sectional study was performed at pediatric clinics at 3 academic institutions to examine caregiver literacy and numeracy skills related to the understanding of common health tasks in caring for infants, and to validate the PHLAT. The institutional review boards for all 3 institutions approved the study. All participants provided informed consent and were given a nominal reimbursement for their time.

      Scale Development

      The PHLAT is a 20-item assessment scale designed to investigate the health literacy and numeracy skills of caregivers to infants (birth to 1 year of age). Items in the scale test common literacy- and numeracy-related tasks that parents perform when caring for young children, including mixing infant formula, understanding breastfeeding recommendations, making up doses of over-the-counter (OTC) and prescription medicines, and understanding nutrition labels.
      For content validity, the scale was developed through an iterative process that included item generation from experts and parents, and cognitive interviewing to assess item comprehension. A group of experts in general pediatrics, pediatric health services research, pediatric pharmacy, pediatric psychology, public health, and health literacy were assemble to generate a list of initial possible scale items. Item content was derived from commonly available health information materials, including recommendations and parent-centered information from the AAP and Bright Futures (National Center for Education in Maternal and Child Health).
      Bright Futures: Guidelines for Health Supervision of Infants, Children, and Adolescents.
      Question development was also guided by reviewing previously validated math and literacy tests (including the Test of Functional Health Literacy in Adults,
      • Baker D.W.
      • Williams M.V.
      • Parker R.M.
      • et al.
      Development of a brief test to measure functional health literacy.
      Diabetes Numeracy Test,
      • Cavanaugh K.
      • Huizinga M.M.
      • Wallston K.A.
      • et al.
      Association of numeracy and diabetes control.
      • Huizinga M.M.
      • Elasy T.A.
      • Wallston K.A.
      • et al.
      Development and validation of the Diabetes Numeracy Test (DNT).
      Wide Range Achievement Test,
      • Wilkinson G.S.
      WRAT3: Wide Range Acheivement Test Administration Manual.
      Woodcock Johnson,
      • Woodcock R.W.
      • McGrew K.S.
      • Mather N.
      Woodcock Johnson Tests of Acheivement.
      and Keymath
      • Connolly A.J.
      • Natchman W.
      • Pritchett E.M.
      Key Maths, Diagnostic Arithmetic Test.
      ).
      In the initial development phase, 26 items were generated. This was then reduced to 25 items through an iterative process involving input from the expert group and parents of young children. In the second phase of development, these 25 items were administered to caregivers of infants (age <13 months) who attended the pediatric clinics. By means of cognitive interviewing, participants were asked questions about each scale item to assess the clarity and understandability of the scale items. If the item was unclear, the interviewee was encouraged to suggest an alternative format or wording. In response to the parent interviews, and in an effort to eliminate item redundancy and emphasize the most important content areas, the expert panel reduced the scale to 20 items.
      The 20 items on the PHLAT cover 3 clinical domains: nutrition/growth/development (9 questions), injury/safety (2 questions), and medical/preventive care (9 questions) (see the online Appendix). The PHLAT assesses a range of literacy and numeracy skills, including document literacy, addition, multiplication, division, fractions and percentages, multistep mathematics, and numeration/number hierarchy. All of these domains and skills may be required of parents on a daily basis during their infant's first year of life. There is no set time limit for completion of the PHLAT.
      The third phase of development assessed the reliability and construct validity of the PHLAT. Reliability was evaluated through internal consistency testing with the Kuder-Richardson formula.
      • DeVellis R.F.
      Scale Development: Theory and Applications.
      There is no criterion (ie, “gold standard”) validity for parental health literacy and numeracy. Therefore, an a priori model of correlations was determined by the expert panel to assess construct validity. We hypothesized that higher levels of education, income, literacy, and math skills would all be associated with improved PHLAT scores. We also hypothesized that a higher PHLAT score would be associated with a higher understanding of the age indications for pediatric OTC cough and cold medications.

      Study Setting and Participants

      A convenience sample of participants was recruited from pediatric clinic sites at 3 academic medical institutions where faculty and residents care for a socioeconomically diverse range of patients. From September 2006 to October 2007, potential participants were approached in the clinic and asked to participate if they were the primary caregivers for infants (≤13 months) and spoke English. Exclusion criteria included corrected vision worse than 20/50 as assessed by a Rosenbaum Pocket Vision Screener or severe psychiatric illness.

      Measures

      Participants were given the following survey instruments: 1) a demographic questionnaire to assess basic patient characteristics, 2) a previously validated health literacy measure (Short Test of Functional Health Literacy in Adults, S-TOFHLA),
      • Baker D.W.
      • Williams M.V.
      • Parker R.M.
      • et al.
      Development of a brief test to measure functional health literacy.
      3) a validated measure of mathematics skills (Wide Range Achievement Test—Third Edition, WRAT-3),
      • Wilkinson G.S.
      WRAT3: Wide Range Acheivement Test Administration Manual.
      4) the PHLAT, and 5) a survey to assess caregiver perception of the age indication of pediatric OTC cold medications.
      • Lokker N.
      • Sanders L.
      • Perrin E.M.
      • et al.
      Parental misinterpretations of over-the-counter pediatric cough and cold medication labels.
      If a participant achieved a score of ≤22 on the S-TOFHLA (consistent with inadequate or marginal literacy), the research assistant read the demographic questionnaire aloud to the participant. (This occurred for 2 parents.) Other participants had the choice of completing the questionnaire on their own or participating verbally.
      Trained research assistants administered all survey instruments in a private area in the clinic. Each research assistant was trained to be sensitive to the context of testing literacy instruments in a pediatric setting. Training included reflective discussions during survey pretesting, with a focus on remaining nonjudgmental and encouraging each participant to try their hardest on each skills test. For some PHLAT items, participants were given a product, chart, or label corresponding to a specific test question. Participants were encouraged to examine the product, chart, or label fully before determining an answer. In addition, a separate survey was administered to gauge how well caregivers understood and characterized the labeling on 4 OTC cold and cough medication products that were marketed for infant children at the time the study was performed. Results of this survey have been previously reported.
      • Lokker N.
      • Sanders L.
      • Perrin E.M.
      • et al.
      Parental misinterpretations of over-the-counter pediatric cough and cold medication labels.
      The products all recommended consulting a physician before providing the medicine to children <24 months of age. Participants were asked, “Looking only at the front of this product, what age group is this medicine for?” Participants were then asked to view the entire label and were asked, “Would you give this product to a 13-month-old child with cold symptoms?.”

      Analyses

      All analyses were performed by Stata 9.2 (StataCorp, College Station, Tex). Descriptive statistics of all variables, including the individual items of the PHLAT, were calculated. Literacy, measured with the S-TOFHLA, was examined as a continuous variable (raw score) and a categorical variable (inadequate ≤16, marginal ≤22, or adequate ≥23). Numeracy, measured with the WRAT-3, was also examined as a continuous variable (standard score) and a categorical variable (corresponding grade level).
      Total PHLAT performance was calculated as the percent of questions answered correctly (score 0% to 100%). For construct validity, bivariate analyses examined the relationship between caregiver characteristics, literacy and numeracy level, and performance on the PHLAT.
      • DeVellis R.F.
      Scale Development: Theory and Applications.
      Correlations between performance on the PHLAT and continuous outcomes, including literacy (S-TOFHLA raw score) and numeracy (standardized WRAT-3 score), were performed by Spearman rank correlation coefficients. For categorical variables, average score on the PHLAT was compared by Student t tests or 1-way analysis of variance.
      Relationships between the PHLAT and patient understanding of the 4 OTC labels were examined by generalized estimating equations with logit link to adjust for clustering at the caregiver level. Analyses examined the relationship between PHLAT score (dichotomized at the median to be high or low) and each of the following: 1) caregiver response that products were appropriate for age <24 months when looking at the front of the package, and 2) caregiver response that they would give the product to a 13-month-old with cold symptoms when looking at the entire package.
      The Kuder-Richardson coefficient of reliability (KR-20), a variation of Cronbach's alpha for dichotomous outcomes, was used to measure internal reliability of the PHLAT.
      • DeVellis R.F.
      Scale Development: Theory and Applications.
      Psychometric analyses were performed to examine the factor loading by means of principal factors analysis and principal component factors analysis. A 10-item abbreviated PHLAT scale (the PHLAT-10) was created by retaining items with the highest factor loadings and those questions deemed a priori to be of most clinical significance. The abbreviated scale was analyzed for internal reliability using the KR-20. Correlation between the PHLAT-10 and the PHLAT was assessed by Spearman rank correlation. Construct validity of the PHLAT-10 was examined by assessing the relationships between PHLAT-10 score and caregiver characteristics, literacy, and numeracy.

      Results

      From September 2006 through October 2007, a total of 413 eligible caregivers were referred, of which 261 consented (63%) and 182 participated (70% of those consenting and 44% of those initially referred). The primary reason for nonparticipation was lack of time because recruitment occurred in a busy clinical setting. Baseline characteristics are presented in Table 1. Participants had similar characteristics to the families that seek care in our clinics, except that we excluded Spanish-speaking patients for the purposes of this study. Most caregivers interviewed were mothers, and the youngest child in the family was an average of 4.5 months old (range 0–13 months). Most study participants had completed at least twelfth grade or attained a GED. Although only 1% of participants had inadequate or marginal literacy skills (as measured by the S-TOFHLA), 83% had lower than ninth-grade math skills (as measured by the WRAT-3). Most participants reported that they had received health information about their new baby and had read books or magazines about parenting. Most participants also reported that they fed their infant either formula only or a combination of formula and breast milk. Over half of caregivers reported providing OTC medications to children to treat fever, and 29% of caregivers had provided OTC cold medications to children.
      Table 1Characteristics of 182 Caregivers
      WIC = Special Supplemental Nutrition Program for Women, Infants and Children; S-TOFHLA = Short Test of Functional Health Literacy in Adults; WRAT-3 = Wide Range Achievement Test—Third Edition; OTC = over the counter. Data are presented as n (%) or mean (SD).
      Caregiver CharacteristicValue
      Caregiver age, y25.6 (6.1)
      Female sex162 (89.0%)
      Race/ethnicity
       White66 (36.5%)
       Black93 (51.4%)
       Hispanic19 (10.5%)
       Other3 (1.7%)
      Relationship to child is mother157 (86.7%)
      No. of children in the family2.3 (1.5)
      Age of youngest child, mo4.5 (3.7)
      Annual family income
       ≤$19 99978 (42.9%)
       $20 000–39 99962 (34.1%)
       ≥$40 00019 (10.4%)
       Do not know/refused23 (12.5%)
      Participates in WIC program142 (78.0%)
      Education
       Less than high school28 (15.5%)
       High school or GED76 (42.0%)
       Some college or above77 (42.5%)
      Literacy status (S-TOFHLA)
       Inadequate1 (0.55%)
       Marginal1 (0.55%)
       Adequate180 (98.9%)
      Numeracy skills (WRAT-3)
       Fifth grade or less64 (35.6%)
       Sixth to eighth grade85 (47.2%)
       High school or above31 (17.2%)
      Since baby was born, received written information from a doctor or nurse about caring for new baby162 (89.0%)
      Has read books about babies or parenting152 (84.0%)
      Has read magazines about babies or parenting171 (94.0%)
      Child receives:
       Infant formula only115 (63.5%)
       Breast milk only32 (17.7%)
       Infant formula and breast milk34 (18.8%)
      Uses OTC medications to treat fever in children94 (52.2%)
      Uses OTC medications to treat a cold in children53 (29.1%)
      WIC = Special Supplemental Nutrition Program for Women, Infants and Children; S-TOFHLA = Short Test of Functional Health Literacy in Adults; WRAT-3 = Wide Range Achievement Test—Third Edition; OTC = over the counter. Data are presented as n (%) or mean (SD).
      Overall, participants correctly answered 68% of the PHLAT questions (standard deviation [SD] 18%, range 10%–100%). The average time to administer the PHLAT was 21 minutes (SD 6.9). Table 2 lists several sample questions and results on the PHLAT, and Table 3 demonstrates the range of topics covered. For example, only 73% of respondants were able to correctly set up the dose of a prescription for liquid amoxicillin medication with a syringe. Only 69% were able to correctly read a digital thermometer to determine whether they should call their pediatrician for fever (after being given a specific temperature to use as a threshold for fever); only 53% were able to determine the proper dose with a liquid acetaminophen dosage chart. Only 64% could correctly determine whether a juice had an adequate amount of vitamin C to be eligible for the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) program (after being instructed on what amount was sufficient). Only 51% could interpret a percentile on a growth curve. Very few (18%), after reading a brief breastfeeding guide, could determine how much time spent breastfeeding was less than normal.
      Table 2Sample Parental Health Literacy Activities Test (PHLAT) Questions and Results
      Table thumbnail fx1
      Table 3Sample Parental Health Literacy Activities Test Topics and Results
      No.Question TopicCorrect
      1Demonstrates how to make a 4-oz bottle of formula using powder-based formula.90%
      2Demonstrates how to make a 4-oz bottle of formula using concentrated formula.47%
      4Reads a digital thermometer to determine if a baby has a temperature of 100.4°F or greater.69%
      5Uses a car seat guidelines table to determine appropriate car seat and location for a 10-month-old weighing 23 pounds.79%
      6Interprets a growth chart where the baby is at the 25th percentile for weight.51%
      7Interprets an acetaminophen dosage chart to determine how much medicine to give based on the weight of the child.53%
      10Refers to an ibuprofen container and medicine cap to determine how many milliliters are in ½ teaspoon of medicine.60%
      16Reads a liquid antibiotic prescription and demonstrated with a syringe how to administer a dose of the medicine.73%
      17Calculates the number of 2-oz servings of juice in a 32-oz can of juice.73%
      18Interprets a food label to determine whether it meets WIC
      WIC = Special Supplemental Nutrition Program for Women, Infants and Children.
      program guidelines of being 100% fruit or vegetable juice and contains at least 30 mg of vitamin C per 100 mL of juice, or 120% of the daily value of vitamin C.
      64%
      20Reads and comprehends instructions regarding breastfeeding (brochure from the Department of Health and Human Services).18%
      WIC = Special Supplemental Nutrition Program for Women, Infants and Children.
      The framing of health information appeared to influence a caregiver's ability to understand an item. For example, although 90% of caregivers could explain how to make a 4-oz bottle using powdered formula (which included a table with mixing instructions), only 47% could correctly explain how to make a 4-oz bottle using concentrated formula (which recommended to “mix equal amounts of formula and water”) (Table 2).
      Correlations between caregiver characteristics and total PHLAT score are shown in Table 4. Higher performance on the PHLAT was significantly correlated (P < .001 for all comparisons) with increased education (r = 0.29), literacy skill (r = 0.38), and numeracy level (r = 0.55). Participants who were African American or Hispanic, had lower income, or reported participation in the WIC program had significantly lower average PHLAT scores. Participants with less than ninth-grade numeracy skills performed worse on the PHLAT than participants with higher numeracy skills (P < .0001).
      Table 4Relationship of Characteristics of 182 Caregivers to PHLAT and PHLAT-10 Scores
      PHLAT = Parental Health Literacy Activities Test; PHLAT-10 = shortened, 10-item version of the Parental Health Literacy Activities Test; WIC = Special Supplemental Nutrition Program for Women, Infants and Children; S-TOFHLA = Short Test of Functional Health Literacy in Adults; WRAT-3 = Wide Range Achievement Test—Third Edition.
      PHLAT ScorePHLAT-10 Score
      CharacteristicMean (SD) or Correlation (r)P valueMean (SD) or Correlation (r)P value
      Caregiver age (y)0.096.200.078.30
      Age of youngest child (mo)0.007.930.06.40
      Race/ethnicity<.0001<.0001
       White78 (13)78 (17)
       Black63 (16)58 (22)
       Hispanic58 (24)54 (28)
      Annual family income.0004.002
       ≤$19 99961 (19)58 (24)
       $20 000–39 99968 (16)67 (20)
       ≥$40 00074 (16)72 (21)
      Participation in WIC.0001.0004
       No78 (14)77 (18)
       Yes66 (18)62 (24)
      Education.0003.003
       Less than high school64 (18)61 (24)
       High school or GED64 (19)60 (25)
       Some college or above74 (15)72 (20)
      Education level, y0.29.00010.25.0007
      Literacy status (S-TOFHLA).10.12
       Inadequate/marginal48 (4)40 (0)
       Adequate69 (18)66 (23)
      Raw S-TOFHLA score0.38<.00010.36<.0001
      Numeracy skills (WRAT-3)<.0001<.0001
       Less than sixth grade58 (19)53 (23)
       Sixth to eighth grade71 (14)68 (20)
       High school and above83 (11)84 (15)
      Standard WRAT score0.55<.00010.53<.0001
      Total PHLAT ScoreNANA0.91<.0001
      PHLAT = Parental Health Literacy Activities Test; PHLAT-10 = shortened, 10-item version of the Parental Health Literacy Activities Test; WIC = Special Supplemental Nutrition Program for Women, Infants and Children; S-TOFHLA = Short Test of Functional Health Literacy in Adults; WRAT-3 = Wide Range Achievement Test—Third Edition.
      Performance on the PHLAT was also significantly correlated with parental understanding of the age indications for use of child OTC cough and cold medications. When looking at the front of the label, caregivers with higher PHLAT scores were more likely to report correctly that an OTC cold medication was not appropriate for children <24 months of age (odds ratio 2.2, 95% confidence interval 1.2–4.0). When looking at the entire label, caregivers with higher PHLAT scores were more likely to report correctly that they would not give OTC cold medication to a 13-month-old child with cold symptoms unless they first consulted physician (odds ratio 1.6, 95% confidence interval 1.02, 2.6).
      Internal reliability of the PHLAT was good (KR-20 = 0.76). Psychometric analyses suggested that the PHLAT loaded to a single factor. Items with the highest loadings included items related to nutrition (eg, formula mixing, breastfeeding instructions) and medication dosing. The shortened PHLAT, the PHLAT-10, retained 7 items on nutrition, 1 item on understanding a growth chart, 1 item about medication dosing, and 1 item about amoxicillin dosing. The average score on the PHLAT-10 was 65% correct (SD 23, range 0–100). Correlation between the PHLAT-10 and the PHLAT was very high (r = 0.91, P < .0001). Correlation between the PHLAT-10 and other patient characteristics was very similar to the correlations between the PHLAT and other patient characteristics (Table 4). Internal reliability of the PHLAT-10 was also good (KR-20 = 0.70).

      Discussion

      It is concerning that this study found that many caregivers had difficulty understanding basic health information for the care of infants. For example, 1 in 4 could not properly prepare doses of prescription medication or read a digital thermometer, half could not properly prepare doses of OTC medication or understand a growth chart, and more than 3 in 4 could not understand a commonly used breastfeeding brochure. The PHLAT demonstrated excellent reliability and construct validity, suggesting that it may be a useful measure for assessing parental health literacy in the context of caring for young children. To our knowledge, this is the first study to comprehensively evaluate how literacy and numeracy correlate with basic understanding of health-based instructions related to infant care. It is also the first study to validate a specific parental health literacy and numeracy measure.
      Psychometric analysis of the 20-item version of the PHLAT shows that it has good reliability and validity in testing literacy- and numeracy-related skills of caregivers with young children. Higher PHLAT scores were significantly correlated with higher education level, literacy skill, and numeracy level. Compared with the S-TOFHLA, the PHLAT seems to provide greater sensitivity as a measure of health literacy in the pediatric setting. Although most caregivers had adequate literacy on the commonly used S-TOFHLA, they had a more diverse range in performance when tested with the PHLAT. This may be related to the ceiling effect on the S-TOFHLA, particularly among younger adults,
      • Janisse H.C.
      • Naar-King S.
      • Ellis D.
      Parent's health literacy among high-risk adolescents with insulin dependent diabetes.
      • Oettinger M.D.
      • Finkle J.P.
      • Esserman D.
      • et al.
      Color-coding improves parental understanding of body mass index charting.
      • Tran T.P.
      • Robinson L.M.
      • Keebler J.R.
      • et al.
      Health literacy among parents of pediatric patients.
      • Pandit A.U.
      • Tang J.W.
      • Bailey S.C.
      • et al.
      Education, literacy, and health: mediating effects on hypertension knowledge and control.
      • Wolf M.S.
      • Feinglass J.
      • Thompson J.
      • Baker D.W.
      In search of “low health literacy”: threshold vs gradient effect of literacy on health status and mortality.
      and/or because the PHLAT tests a more robust array of applied skills (both literacy and numeracy) more pertinent to the caregiver with infant children.
      • Nutbeam D.
      Health literacy as a public health goal: a challenge for contemporary health education and communication strategies into the 21st century.
      The shortened 10-item version of the PHLAT, the PHLAT-10, also showed good reliability and construct validity. The PHLAT could be a useful tool for research purposes, while the PHLAT-10 may be a more useful tool in the clinical setting. We are currently testing the validity and reliability of both English- and Spanish-language versions of the PHLAT-10 in a larger study. In this new study, we have adapted the PHLAT-10 to use pictures of labels rather than actual products to make the test more feasible to administer in a busy clinic setting. Future work should focus on validating a variation of the PHLAT for parents with older children, and on identifying meaningful approaches for interpretation and application of the PHLAT results in a clinical setting.
      Results from the PHLAT highlight the many challenges that caregivers face in trying to provide daily appropriate health-related care for their infants. Caregivers were often unable to understand nutrition and medication labels, simple child-health handouts, and basic child-safety recommendations. Many were also unable to mix infant formulas or to create appropriate doses of liquid medication. The framing of health-related instructions, such as 2 different versions of how to mix infant formula, was associated with significantly different rates of parent understanding, suggesting both the effect of individual experience and the importance of clearly presenting health information.
      Recent studies have shown associations between low maternal literacy and a decreased likelihood of breastfeeding, greater likelihood of smoking, and greater likelihood to have depressive symptoms.
      • Baker D.W.
      • Gazmararian J.A.
      • Williams M.V.
      • et al.
      Functional health literacy and the risk of hospital admission among Medicare managed care enrollees.
      • Kaufman H.
      • Skipper B.
      • Small L.
      • et al.
      Effect of literacy on breast-feeding outcomes.
      • Fredrickson D.D.
      • Washington R.L.
      • Pham N.
      • et al.
      Reading grade levels and health behaviors of parents at child clinics.
      • Bennett I.
      • Switzer J.
      • Aguirre A.
      • et al.
      “Breaking it down”: patient-clinician communication and prenatal care among African American women of low and higher literacy.
      • Poresky R.H.
      • Daniels A.M.
      Two-year comparison of income, education, and depression among parents participating in regular Head Start or supplementary Family Service Center Services.
      Also, children of caregivers with lower literacy skills have more unmet health care needs,
      • Broder H.L.
      • Russell S.
      • Catapano P.
      • Reisine S.
      Perceived barriers and facilitators to dental treatment among female caregivers of children with and without HIV and their health care providers.

      Sanders LM, Lewis J, Brosco JP. Low Caregiver Health Literacy: Risk Factor for Child Access to a Medical Home. Pediatric Academic Societies Meeting, May 5–8, 2007, Toronto, Canada.

      more preventable use of the emergency room,
      • DeWalt D.A.
      • Dilling M.H.
      • Rosenthal M.S.
      • Pignone M.P.
      Low parental literacy is associated with worse asthma care measures in children.
      and worse control of asthma and type 1 diabetes.
      • DeWalt D.A.
      • Dilling M.H.
      • Rosenthal M.S.
      • Pignone M.P.
      Low parental literacy is associated with worse asthma care measures in children.
      • Ross L.A.
      • Frier B.M.
      • Kelnar C.J.
      • Deary I.J.
      Child and parental mental ability and glycaemic control in children with type 1 diabetes.
      Infants with parents of lower education or literacy also have worse health outcomes.
      • Armar-Klemesu M.
      • Ruel M.T.
      • Maxwell D.G.
      • et al.
      Poor maternal schooling is the main constraint to good child care practices in Accra.
      • Levandowski B.A.
      • Sharma P.
      • Lane S.D.
      • et al.
      Parental literacy and infant health: an evidence-based healthy start intervention.
      In our current study, caregivers, particularly those with lower literacy and numeracy skills, consistently had problems making formula, understanding breastfeeding instructions, and interpreting nutrition labels. Lower PHLAT score was associated with a higher likelihood of caregivers inappropriately interpreting age indications of OTC cough and cold medications. OTC medication labels contain dense information that can be more challenging, and potentially misleading, for patients with lower health literacy and numeracy skills to understand.
      • Lokker N.
      • Sanders L.
      • Perrin E.M.
      • et al.
      Parental misinterpretations of over-the-counter pediatric cough and cold medication labels.
      The correlation between the PHLAT and these common nutrition and medication activities may relate to clinically relevant outcomes, such as medication administration, although this requires further study.
      This study has several limitations. This cross-sectional study only demonstrates associations and not causation. The utility of the PHLAT for longitudinal study needs to be demonstrated. We recruited a convenience sample of English-speaking caregivers from a population whose children were being seen at academic medical centers. Therefore, our results may not be generalizable to all populations. Our literacy measure, the S-TOFHLA, had little variability among subjects and a ceiling effect, limiting the validation of our new measure against an assessment of caregiver health literacy. Additionally, we examined caregiver skills in a clinical setting, but these paper-and-pencil tests may not reflect actual behaviors at home. Although we demonstrated the PHLAT was correlated with understanding of OTC labels, we did not specifically correlate performance on the PHLAT with any clinical outcomes, such as health status or receipt of preventive services. We established the PHLAT had good construct validity, but future prospective studies will need to demonstrate its predictive utility.
      Our results have important implications for caregivers of young children, health care providers, industry, and federal agencies. All caregivers of young children—particularly the many caregivers with limited literacy and numeracy skills—face significant barriers to comprehending and implementing basic child-health tasks, such as providing appropriate nutrition, safety, and medication. Improving the clarity of child health information may be a critical factor for efforts that aim to improve the pediatric medical home—including preventive care, acute care, and care coordination for children. The PHLAT may be useful to identify families who may benefit from verbal or pictorial instruction in the clinical setting. Our results suggest that pediatricians and health care providers may need to improve how they communicate with and educate caregivers of young children to perform many basic health-related skills. Health departments, pharmaceutical corporations, hospitals, and academic medical centers can also use these results to inform future design improvements for the health system, including interactive health-education materials, user-friendly medication labels, and personal health records.

      Acknowledgments

      We thank Matthew Oettinger and Steven Pattishall for their help with recruitment. We thank Graham Gipson for graphic design assistance with Table 2. Dr Rothman is currently supported by an NIDDK Career Development Award (NIDDK 5K23 DK065294 ). Dr Perrin is currently supported by an NICHD career development award (NICHD K23 HD051817 ). Dr Sanders's work on this study was supported in part by the Robert Wood Johnson Generalist Physician Scholars Program . This research was also supported with funding from the NICHD ( R01 HD059794 ) and the Vanderbilt Program on Effective Health Communication .

      Supplementary Material

      References

      1. Kutner M, Greenburg E, Jin Y, Paulson C. The health literacy of america's adults: results from the 2003 national assessment of adult literacy. September 2006. National Center for Education Statistics. Available at: http://nces.ed.gov/pubsearch/pubsinfo.asp?pubid=2006483. Accessed July 2, 2010.

        • Institute of Medicine Committee on Health Literacy
        Health Literacy: A Prescription to End Confusion.
        National Academies Press, Washington, DC2004
        • Dewalt D.A.
        • Berkman N.D.
        • Sheridan S.
        • et al.
        Literacy and health outcomes. a systematic review of the literature.
        J Gen Intern Med. 2004; 19: 1228-1239
        • Schillinger D.
        • Grumbach K.
        • Piette J.
        • et al.
        Association of health literacy with diabetes outcomes.
        JAMA. 2002; 288: 475-482
        • DeWalt D.A.
        • Dilling M.H.
        • Rosenthal M.S.
        • Pignone M.P.
        Low parental literacy is associated with worse asthma care measures in children.
        Ambul Pediatr. 2007; 7: 25-31
        • Baker D.W.
        • Gazmararian J.A.
        • Williams M.V.
        • et al.
        Functional health literacy and the risk of hospital admission among Medicare managed care enrollees.
        Am J Public Health. 2002; 92: 1278-1283
        • Huizinga M.M.
        • Beech B.M.
        • Cavanaugh K.L.
        • et al.
        Low numeracy skills are associated with higher BMI.
        Obesity (Silver Spring). 2008; 16: 1966-1968
        • Cavanaugh K.
        • Huizinga M.M.
        • Wallston K.A.
        • et al.
        Association of numeracy and diabetes control.
        Ann Intern Med. 2008; 148: 737-746
        • Rothman R.L.
        • Housam R.
        • Weiss H.
        • et al.
        Patient understanding of food labels the role of literacy and numeracy.
        Am J Prev Med. 2006; 31: 391-398
        • Sanders L.M.
        • Federico S.
        • Klass P.
        • et al.
        Literacy and child health: a systematic review.
        Arch Pediatr Adolesc Med. 2009; 163: 131-140
        • Yin H.S.
        • Dreyer B.P.
        • Foltin G.
        • et al.
        Association of low caregiver health literacy with reported use of nonstandardized dosing instruments and lack of knowledge of weight-based dosing.
        Ambul Pediatr. 2007; 7: 292-298
        • Lokker N.
        • Sanders L.
        • Perrin E.M.
        • et al.
        Parental misinterpretations of over-the-counter pediatric cough and cold medication labels.
        Pediatrics. 2009; 123: 1464-1471
        • Davis T.C.
        • Crouch M.A.
        • Wills G.
        • et al.
        The gap between patient reading comprehension and the readability of patient education materials.
        J Fam Pract. 1990; 31: 533-538
        • Davis T.C.
        • Mayeaux E.J.
        • Fredrickson D.
        • et al.
        Reading ability of parents compared with reading level of pediatric patient education materials.
        Pediatrics. 1994; 93: 460-468
        • Arnold C.L.
        • Davis T.C.
        • Frempong J.O.
        • et al.
        Assessment of newborn screening parent education materials.
        Pediatrics. 2006; 117: S320-S325
        • Davis T.C.
        • Bocchini Jr., J.A.
        • Fredrickson D.
        • et al.
        Parent comprehension of polio vaccine information pamphlets.
        Pediatrics. 1996; 97: 804-810
        • D'Alessandro D.M.
        • Kingsley P.
        • Johnson-West J.
        The readability of pediatric patient education materials on the World Wide Web.
        Arch Pediatr Adolesc Med. 2001; 155: 807-812
        • Davis T.C.
        • Humiston S.G.
        • Arnold C.L.
        • et al.
        Recommendations for effective newborn screening communication: results of focus groups with parents, providers, and experts.
        Pediatrics. 2006; 117: S326-S340
        • Llewellyn G.
        • McConnell D.
        • Honey A.
        • et al.
        Promoting health and home safety for children of parents with intellectual disability: a randomized controlled trial.
        Res Dev Disabil. 2003; 24: 405-431
        • Armar-Klemesu M.
        • Ruel M.T.
        • Maxwell D.G.
        • et al.
        Poor maternal schooling is the main constraint to good child care practices in Accra.
        J Nutr. 2000; 130: 1597-1607
        • Levandowski B.A.
        • Sharma P.
        • Lane S.D.
        • et al.
        Parental literacy and infant health: an evidence-based healthy start intervention.
        Health Promot Pract. 2006; 7: 95-102
        • Janisse H.C.
        • Naar-King S.
        • Ellis D.
        Parent's health literacy among high-risk adolescents with insulin dependent diabetes.
        J Pediatr Psychol. 2010; 35: 436-440
        • Oettinger M.D.
        • Finkle J.P.
        • Esserman D.
        • et al.
        Color-coding improves parental understanding of body mass index charting.
        Acad Pediatr. 2009; 9: 330-338
        • Tran T.P.
        • Robinson L.M.
        • Keebler J.R.
        • et al.
        Health literacy among parents of pediatric patients.
        West J Emerg Med. 2008; 9: 130-134
        • Pandit A.U.
        • Tang J.W.
        • Bailey S.C.
        • et al.
        Education, literacy, and health: mediating effects on hypertension knowledge and control.
        Patient Educ Couns. 2009; 75: 381-385
        • Wolf M.S.
        • Feinglass J.
        • Thompson J.
        • Baker D.W.
        In search of “low health literacy”: threshold vs gradient effect of literacy on health status and mortality.
        Soc Sci Med. 2010; 70: 1335-1441
      2. Bright Futures: Guidelines for Health Supervision of Infants, Children, and Adolescents.
        National Center for Education in Maternal and Child Health, Arlington, VA1994
        • Baker D.W.
        • Williams M.V.
        • Parker R.M.
        • et al.
        Development of a brief test to measure functional health literacy.
        Patient Educ Couns. 1999; 38: 33-42
        • Huizinga M.M.
        • Elasy T.A.
        • Wallston K.A.
        • et al.
        Development and validation of the Diabetes Numeracy Test (DNT).
        BMC Health Serv Res. 2008; 8: 96
        • Wilkinson G.S.
        WRAT3: Wide Range Acheivement Test Administration Manual.
        Wide Range Inc, Wilmington, DE1993
        • Woodcock R.W.
        • McGrew K.S.
        • Mather N.
        Woodcock Johnson Tests of Acheivement.
        3rd ed. Riverside Publishing, Itasca, Ill2001
        • Connolly A.J.
        • Natchman W.
        • Pritchett E.M.
        Key Maths, Diagnostic Arithmetic Test.
        American Guidance Service, Circle Pines, MN1971
        • DeVellis R.F.
        Scale Development: Theory and Applications.
        Sage, Newbury Park, Calif1991
        • Nutbeam D.
        Health literacy as a public health goal: a challenge for contemporary health education and communication strategies into the 21st century.
        Health Promot Int. 2000; 15: 259-267
        • Kaufman H.
        • Skipper B.
        • Small L.
        • et al.
        Effect of literacy on breast-feeding outcomes.
        South Med J. 2001; 94: 293-296
        • Fredrickson D.D.
        • Washington R.L.
        • Pham N.
        • et al.
        Reading grade levels and health behaviors of parents at child clinics.
        Kans Med. 1995; 96: 127-129
        • Bennett I.
        • Switzer J.
        • Aguirre A.
        • et al.
        “Breaking it down”: patient-clinician communication and prenatal care among African American women of low and higher literacy.
        Ann Fam Med. 2006; 4: 334-340
        • Poresky R.H.
        • Daniels A.M.
        Two-year comparison of income, education, and depression among parents participating in regular Head Start or supplementary Family Service Center Services.
        Psychol Rep. 2001; 88: 787-796
        • Broder H.L.
        • Russell S.
        • Catapano P.
        • Reisine S.
        Perceived barriers and facilitators to dental treatment among female caregivers of children with and without HIV and their health care providers.
        Pediatr Dent. 2002; 24: 301-308
      3. Sanders LM, Lewis J, Brosco JP. Low Caregiver Health Literacy: Risk Factor for Child Access to a Medical Home. Pediatric Academic Societies Meeting, May 5–8, 2007, Toronto, Canada.

        • Ross L.A.
        • Frier B.M.
        • Kelnar C.J.
        • Deary I.J.
        Child and parental mental ability and glycaemic control in children with type 1 diabetes.
        Diabet Med. 2001; 18: 364-369