Relationship Between Health Literacy in Parents and Asthma Control in Their Children: A Prospective Study in a Diverse Suburban Population

Abstract

Background:

Patients with low health literacy may not have an adequate understanding of basic health information, and were more likely to skip necessary tests and treatments, or wrongly administer medications. There are limited studies on rapid assessment of health literacy in parents and its impact on asthma control in their children.

Materials and Methods:

This study involves prospective assessment of health literacy in parents and asthma control in their children, age ≥2 years. Primary caregivers completed the Short Assessment of Health Literacy (SAHL) and the Newest Vital Signs (NVSs) questionnaires. Scores of ≤14 on the SAHL or ≤3 on the NVS were considered indicative of low health literacy and/or numeracy. Asthma control was assessed with the Asthma Control Test (ACT), Child ACT (cACT), or the Test for Respiratory and Asthma Control in Kids (TRACK). Scores of ≤19 on the ACT or cACT, and <80 on the TRACK were considered indicative of not well-controlled asthma.

Results:

Two hundred sixty-four children were enrolled, with mean age of 8.9 + 4.4 years. Sixty-three percent were male. Seventy-seven percent of parents identified themselves as White, 18% Black/African American, and 7% Asian. Twenty-five percent had state-supported health insurance. Seventy-eight parents (30%) were assigned to the low health literacy group. There were no differences between the 2 groups in age, race, or sex. Those with low health literacy were more likely to have state-supported health insurance, P < 0.0001. Fifty-four percent of the children whose parents had low health literacy had asthma not well controlled as compared with 30% of those with health literacy scores in the normal range, odds ratio: 2.66 (95% confidence interval: 1.55–4.56). This relationship persisted on multivariate analysis after accounting for health insurance and age.

Conclusion:

Low health literacy in primary caregivers is associated with not well-controlled asthma in children in a diverse, suburban population.

Introduction

Asthma is a major health care problem for children in the United States with an estimated 7 million (10%) with current asthma and 10 million (14%) with ever asthma according to the National Health Interview Survey.¹ It is more likely in children with disparities, including inner-city children and those with lower socioeconomic status.^2–4

Health literacy refers to the degree to which patients and caregivers can obtain, process, and understand basic health information to make appropriate health decisions.⁵ Without an adequate understanding of basic health information, patients and caregivers are more likely to skip necessary tests and treatments, and to wrongly administer medications.^5,6 Adequate health literacy is thought to be fundamental to medication adherence and noticing warning signs, thereby complicating self-management and decision making.⁶ Health numeracy involves basic skills such as arithmetic computation and percentages. These are important in adhering to medication dosage and frequency, converting units of dosage, and understanding test results.⁶ More complex skills such as risk assessment and estimation are essential for appropriate long-term care.^5,6

Studies in adults with asthma suggest that lower health literacy is associated with worse asthma control outcomes, including medical decision making, knowledge, and self-management skills, and communicating with their health care providers.^7–9 Increased emergency department (ED) visits and hospitalizations have been reported.^10,11 An estimated 28.5% of parents have low health literacy in the United States.¹² There are limited studies evaluating the relationship between pediatric asthma outcomes and health literacy of parents.^13–19 Some reported increased asthma health care utilization.^15,16 One study demonstrated a clear relationship between parental health literacy and asthma control in 6- to 12-year-old predominantly African American urban sample.¹⁷ There are limited studies including younger children in diverse populations using rapid assessment tools for parental health literacy.

The hypothesis for this study was that children of all ages are less likely to have well-controlled asthma if their parents had low health literacy and/or numeracy.

Materials and Methods

This was a prospective, cross-sectional, single-site study derived from a convenience sample of children 2–18 years of age attending a pediatric pulmonology clinic over a 4-month period March–May 2016, in a predominantly suburban population from the Hudson Valley region of NY state, with a physician diagnosis of asthma. Parents were interviewed at the time of routine asthma follow-up visits. Inclusion criteria were as follows: literate in English and/or Spanish, physician diagnosis of persistent asthma,¹⁹ on a controller therapy for asthma at the time of the visit, and at least 1 asthma exacerbation in the previous year. Information on demographics including age, gender, race/ethnicity, and health insurance status (state supported versus private) as a surrogate of socioeconomic class was collected. Parents completed 2 questionnaires to assess health literacy and numeracy: (1) Short Assessment of Health Literacy (SAHL)²⁰ and (2) Newest Vital Sign (NVS).²¹ Subjects and/or their parents completed an age-appropriate questionnaire to assess their asthma control during the previous 4 weeks: Asthma Control Test (ACT)²² for children ≥12 years of age, Child Asthma Control Test (cACT)²³ for children 5–11 years of age (completed by child and parent/caregiver), or Test for Respiratory and Asthma Control in Kids (TRACK)²⁴ for children <5 years of age (completed by parent/caregiver). A Spanish version of all questionnaires was used when requested after enquiry for preference of language. The minimum requirement for a completed interview was completion of at least 1 literacy test and a test of asthma control.

Subjects were placed into 2 groups based on the assessment of their health literacy. A SAHL score of ≤14 (out of 18) was considered a measure of low health literacy.²¹ A NVS score of 0–1 (out of 6) suggests a high likelihood of limited literacy and numeracy, 2–3 indicates the possibility of limited literacy and numeracy, and a score of 4–6 indicated adequate literacy and numeracy.²² Subjects were placed into the low literacy group if their parents scored either ≤14 on SAHL or ≤3 on NVS.^21,22 Asthma control was assessed as “not well-controlled” if ACT or Child-ACT scores were ≤19, or the TRACK scores <80.^22–24

The study was approved by the Institutional Review Board, and a waiver for informed consent obtained.

Data analysis

Demographics and proportions of the 2 groups, low health literacy and normal health literacy, with not well-controlled asthma were compared with chi-square or Fisher's Exact tests when appropriate, with calculation of odds ratios [OR; with 95% confidence interval (CI)]. Ordinal data for the 2 groups were compared with Student's t-tests. Subjects were further divided into 3 age ranges, <5, 5–11, and ≥12 years, based on the test of asthma control used: TRACK for <5, Child ACT for 5–11, and ACT for ≥12 years; and the 3 age groups were compared for differences in the relationship between parental health literacy and asthma control in children. Multivariate logistic regression analysis was performed to correct for potentially confounding variables, defined as variables found to be associated with poor asthma control in univariate analyses with P values <0.20. Two-sided P values <0.05 were considered statistically significant for all tests. Data were analyzed using STATA, version 15.1 (StataCorp LLC, College Station, TX).

Results

Two hundred sixty-four parent/children dyads were enrolled. Mean age was 8.9 ± 4.4 years with 16% of children ≤5 years of age. Sixty-three percent were male. Seventy-seven percent of parents identified themselves as White, 18% Black or African American, 7% Asian and 2% other. Fifty-nine (22%) identified themselves as Hispanic or Latino. Sixty-six (25%) had state-supported health insurance. Parents of 16 subjects (6%) selected Spanish as their primary language, and 18 subjects (7%) completed the questionnaires in Spanish. All but 8 of the parents were mothers.

Seventy-eight (30%) were placed into the low health literacy group based on their scores on either NVS or SAHL. Seventy (27%) parents scored ≤3 on NVS. Twenty-two (8%) parents scored ≤14 on SAHL. Ten of 14 parents who scored <14 on SAHL also scored ≤3 on NVS; the other 4 did not complete the NVS. Mean SAHL for the low health literacy group was 15.1 ± 4.3 and 17.4 ± 0.90 for the adequate health literacy group, P < 0.0001. Mean NVS for the low health literacy group was 2.25 ± 1.34 and 5.31 ± 0.76 for the adequate health literacy group, P < 0.0001.

Patient characteristics for the 2 groups are compared in Table 1. There were no differences between the 2 groups in age, race, or sex. The parents in the low health literacy group were more likely to identify as Hispanic or Latino, choose Spanish as their primary language, and had state-supported health insurance, all P < 0.0001.

Table 1.

Patient Characteristics

	Low health literacy/numeracy, N = 78 (30%)	Adequate health literacy/numeracy, N = 186 (70%)	P
Age, mean (SD)	8.5 (4.1)	9.1 (4.5)	0.272
<5 years	13 (0.16)	32 (0.17)	0.823
5–11 years	50 (0.63)	91 (0.50)	0.051
≥12 years	17 (0.21)	61 (0.33)	0.052
Race
White	52 (0.65)	141 (0.77)	0.050
Black	19 (0.23)	28 (0.15)	0.096
Asian	6 (0.08)	12 (0.07)	0.862
Other	3 (0.04)	3 (0.02)	0.371
Hispanic	32 (0.40)	22 (0.12)	<0.0001
Sex, female	27 (0.34)	72 (0.39)	0.406
Spanish as primary language	14 (0.18)	2 (0.01)	<0.0001
State-assisted health insurance	36 (0.45)	30 (0.16)	<0.0001

All values expressed as n (proportion).

SD, standard deviation.

Table 2 describes the relationship between health literacy and asthma control. Forty-three (54%) of children whose parents had low health literacy had not well-controlled asthma (ie, ACT or cACT scores <19 or TRACK score <80), compared with 56 (30%) children whose parents had health literacy in the adequate range, P = 0.0003, OR: 2.66 (95% CI: 1.55–4.56). There was no relationship between health literacy and asthma control in children <5 years of age, as determined by either the proportion with a TRACK score <80 or comparison of mean scores. The OR (95% CI) for having not well-controlled asthma as measured by Child ACT in children 5–11 years of age was 3.61 (1.73–7.56), P = 0.0005 and 4.11 (1.34–12.89) as measured by ACT in children ≥12 years of age, P = 0.016. There were significant differences in the mean ACT and cACT scores between those with well-controlled asthma and those not well controlled, though these differences were small.

Table 2.

Relationship Between Health Literacy/Numeracy, Age, and Asthma Control

	Low health literacy/numeracy, N = 78 (30%)^a	Adequate health literacy/numeracy, N = 186 (0.7)^a	P	Odds ratio (95% CI)
Total not well-controlled^a	43 (0.54)	56 (0.30)	0.0003^b	2.66 (1.55–4.56)
0–4 years (TRACK <80)^a	8 (0.62)	22 (0.69)	0.732^b	0.727 (0.190–2.79)
Mean (SD) score^c	70.9 (19.3)	62.6 (16.1)	0.204^c
5–11 years (cACT ≤19)^a	26 (0.56)	21 (0.23)	0.0005^b	3.61 (1.73–7.56)
Mean (SD) score^c	19.8 (4.0)	22.2 (3.4)	0.0003^c
≥12 years (ACT ≤19)^a	9 (0.53)	13 (0.21)	0.016^b	4.15 (1.34–12.89)
Mean (SD) score^c	20.6 (2.6)	21.7 (2.9)	0.038^c

n (proportion).

Chi-square test.

Student's t-test.

ACT, Asthma Control Test; cACT, Child Asthma Control Test; CI, confidence interval; TRACK, Test for Respiratory and Asthma Control in Kids.

Factors affecting asthma control are described in Table 3. Seventy-seven percent of children <5 years of age had not well-controlled asthma, compared with 33% of children 5–11 years and 28% of children ≥12 years, P < 0.001. Race, ethnicity, sex, and type of health insurance were not different between children with or without well-controlled asthma. Thirty percent of children with not well-controlled asthma were <5 years of age compared with 15% of children with well-controlled asthma, P < 0.0001. The mean (standard deviation) NVS score in subjects with not well-controlled asthma was 3.80 (1.78) as compared with 4.74 (1.54) in those with well-controlled asthma, P < 0.0001. In multivariate analysis (Table 4), the association between low health literacy/numeracy of parents and not well-controlled asthma in their children persisted despite accounting for child age group and type of health insurance, P < 0.001.

Table 3.

Factors Affecting Asthma Control

	Not well controlled, N = 99	Well controlled, N = 165	P^a
Age, mean (SD)	7.8 (4.4)	9.6 (4.2)	<0.0001
<5 years	30 (0.30)	15 (0.09)	<0.0001
5–11 years	47 (0.47)	94 (0.57)	0.134
≥12 years	22 (0.22)	56 (0.34)	0.047
Race
White	69 (0.70)	124 (0.75)	0.332
Black	17 (0.17)	30 (0.18)	0.841
Asian	9 (0.09)	9 (0.05)	0.250
Other	4 (0.04)	2 (0.01)	0.201
Hispanic	21 (0.21)	33 (0.20)	0.806
Sex, female	36 (0.36)	63 (0.38)	0.764
Spanish as primary language	4 (0.04)	12 (0.07)	0.237
State-assisted health insurance	30 (0.30)	66 (0.25)	0.172

All values expressed as n (proportion).

Chi-square test.

Table 4.

Risk Ratios by Univariate Analysis and Multivariate Logistic Regression

		Univariate ^a		Multivariate logistic regression
Patient characteristic	Proportion not well controlled	Odds ratio	P	Odds ratio	P
Low health literacy	0.43	2.66 (1.55–4.56)	<0.001	3.01 (1.57–5.17)	<0.001
Age <5	0.30	4.35 (2.20–8.60)	<0.001	4.77 (2.35–9.65)	0.001
Gender, female	0.36	1.14 (0.68– 1.89)	0.690
Race: other than White	0.30	0.76 (0.45–1.33)	0.410
English not primary language	0.04	0.92 (0.39–2.21)	0.975
State-assisted health insurance	0.30	0.65 (0.37–1.14)	0.172	1.08 (0.57–2.03)	0.807

Chi-square test.

Discussion

This study demonstrates that a substantial number of parents have limited health literacy, and there was an association between health literacy/numeracy in parents and not well-controlled asthma in their children. This association was found in children ≥5 years of age but not in children <5. More than a quarter of parents interviewed scored ≤3 on the NVS test, indicating low health literacy/numeracy, which is consistent with national estimates of low health literacy in adults (28.7%).¹² Factors that affected asthma control were young age of children and low health literacy in their primary caregivers, while race or socioeconomic status (using state-supported insurance as a surrogate) had no impact. It should be noted that mean differences in the asthma control scores between the well-controlled and not well-controlled groups, though statistically significant, are small.

Other studies evaluating parent health literacy and asthma control have yielded conflicting results. Harrington et al.,¹⁷ in a cohort of 281 English-only speaking parents, recently reported that lower parent health literacy was associated with worse asthma control outcomes as rated by both the provider (P = 0.007) and the Asthma Control Questionnaire (P = 0.013). Wood et al.¹⁶ had reported on parent health literacy with the NVS and asthma control in 198 African American children. There was no relationship between parent health literacy and child asthma control or health care utilization in their study. On the contrary, Gandhi et al.²⁵ in a cohort of 160 parent/child sets described an indirect relationship between parent health literacy measured by the s-TOFHLA (short-Test for Functional Health Literacy in Adults) and child asthma control.

The population studied in those studies were all or predominantly African American (56%–87%)^15–18,25 as compared with the more diverse population in our report. The literacy instrument used in the Harrington et al. cohort, the Test for Functional Health Literacy in Adults (TOFHLA), takes on an average 22 min to administer.²⁶ The NVS and SAHL are both short questionnaires, and possible to administer quickly in a busy clinic setting as opposed to other tests, including STOHFLA or Rapid Estimate of Adult Literacy in Medicine (REALM) used in other studies. Further, unlike TOHFLA or REALM, NVS measures numeracy as well as literacy.

As compared with prior studies looking at underprivileged/inner-city parent/child dyads, our report reflects a suburban, private practice setting. We included children from 2 through 18 years of age; other reported studies evaluated only older children (>5 years of age). Unlike other studies, we did not find any association between asthma control and race or socioeconomic status. Our study population was predominantly suburban and of relatively high income status.

The NHLBI/NIH Expert Panel Report-3 guidelines recommend that children and parents be engaged in the decision-making process for effective asthma management and emphasize a well-constructed asthma action plan.¹⁹ An appropriate asthma action plan relies upon parents providing accurate information to the health care provider. Adults with asthma and low literacy may lack these skills,^6–9 hence it is likely that low literacy parents may lack them as well. Although it may not be practical to improve health literacy of the population, physicians caring for children with chronic diseases including asthma should keep this in mind when planning management strategies for their patients.

Our study has several limitations: the study was cross-sectional; longitudinal assessments were not done. There were no formal assessments of general literacy in the parents; it is possible that some parents may not have adequately understood written questionnaires. Adverse health care outcomes to objectively assess asthma control including medication use, ED visits, or hospitalizations were not assessed. Children with mild, intermittent asthma or those with no exacerbations in the previous year were excluded. The study was completed over a 4-month period, and seasonal variations in asthma control in children may not be accounted for.

Conclusion

Low health literacy in primary caregivers is associated with not well-controlled asthma in children in a diverse, suburban population.

Footnotes

Author Disclosure Statement

No competing financial interests exist.

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