Disparities in Parental Health Literacy at a Pediatric Cystic Fibrosis Center

Abstract

Background:

Hispanic cystic fibrosis (CF) patients experience higher morbidity and mortality than non-Hispanic patients, even after adjustment for socioeconomic status. Reduced parental health literacy is associated with adverse child health outcomes in chronic disease, but has not been characterized in CF.

Methods:

Twenty-five parents of Hispanic children and 63 parents of non-Hispanic children with CF participated in the study. Health literacy was assessed using the English or Spanish version of a validated instrument according to each parent's preference.

Results:

Average health literacy fell in the adequate range for parents of both Hispanic and non-Hispanic CF patients, and was not significantly different between groups (p=0.17). Four parents of Hispanic CF patients (16%) demonstrated inadequate or marginal health literacy compared to zero parents of non-Hispanic CF patients (p=0.005).

Conclusions:

While parents of Hispanic children with CF were at higher risk for reduced health literacy, median health literacy was similar to parents of non-Hispanic patients. Low parental health literacy is therefore unlikely to affect outcomes in Hispanic children with CF strongly. Multicenter studies linked to patient outcome measures are required to confirm this hypothesis.

Introduction

Health literacy is defined by the Institute of Medicine as “The degree to which individuals can obtain, process, and understand the basic health information and services they need to make appropriate health decisions.”¹ In pediatrics, low parental health literacy is associated with reduced knowledge of health outcomes, behaviors, and services, as well as worse outcomes in children with diabetes, asthma, and depression.^2–5 However, health literacy among parents of children with cystic fibrosis (CF) has not been reported. As the treatment regimen in CF is complex, the ability to access and understand health information is crucial for the appropriate delivery of care in the home. Knowledge of the CF treatment regimen has long been recognized as necessary for adherence,^6–9 which in turn is the strongest factor influencing treatment failure in chronic disease.¹⁰

Parental health literacy may be particularly important in the Hispanic CF population. Hispanic CF patients have an annual risk of mortality that is 85% greater than that of non-Hispanic patients.¹¹ This risk persists after adjustment for socioeconomic status and despite the fact that Hispanic CF patients are more likely to be pancreatic sufficient and have a higher body mass index, two factors associated with milder disease.^12,13 While some risk factors associated with poorer CF outcomes among Hispanic patients appear to be biological in nature,¹⁴ the need to elucidate the role of social and environmental influences in outcome disparities is critical in order to design interventions.^15,16 Health literacy is one potential contributor, as adults of Hispanic ethnicity have reduced health literacy scores compared to non-Hispanic adults, even when tested using Spanish-language instruments.^17,18

The aims of this pilot study were to assess health literacy in parents of children with CF, and to compare the health literacy of parents of Hispanic and non-Hispanic patients. We hypothesized that health literacy would be reduced in parents of Hispanic children with CF.

Methods

This cross-sectional study utilized a convenience sample of 88 parents of children with CF who attended routine outpatient clinic visits at the Ann and Robert H. Lurie Children's Hospital of Chicago Cystic Fibrosis Center. A CF Center research professional recruited parents at the child's clinic appointment. Written, informed consent was obtained using English or Spanish language forms per each parent's preference. A qualified medical interpreter was utilized in person or by telephone to translate for Spanish-speaking families. The Lurie Children's Institutional Review Board approved the research plan.

Parents of children up to 18 years old with a confirmed CF diagnosis were eligible for the study; only one parent per family was permitted to participate. Hispanic CF patients were identified through the Cystic Fibrosis Foundation (CFF) Patient Data Registry, with a patient defined as Hispanic if one or both parents self-identified as Hispanic. For two patients not listed in the registry, the child's ethnicity was determined through parental report at the time of enrollment. Parents of non-Hispanic children were recruited and enrolled as a comparison group.

Parents were asked for their age, ethnicity, primary language spoken at home, and preferred language in which to complete the health literacy assessment. The Short Test of Functional Health Literacy in Adults (S-TOFHLA; Peppercorn Books, Snow Camp, NC)¹⁹ was then administered in each participant's preferred language. This instrument abbreviates a full, 22-minute assessment into a 7-minute version that is more practical for clinical use. The S-TOFHLA consists of 36 reading comprehension test items distributed between two prose passages. Participants received a total S-TOFHLA score between 0 and 36, and were stratified into one of three categories—inadequate (0–16), marginal (17–22), or adequate (23–36) functional health literacy—indicating relative inability, difficulty, or ability in reading and interpreting most health texts, respectively.²⁰

The CFF Patient Data Registry was queried to assess insurance status (private or public), highest parental educational achievement, total household income, and number of children with CF in the family. For six patients enrolled in the study, annual registry data were unavailable, and only insurance information available in the medical record was used. Total reported household income was recorded in $10,000 increments up to a threshold of ≥$90,000; the data were then restratified into income levels of <$30,000, $30,000–59,999, $60,000–89,999, and ≥$90,000.

Statistical analyses

Data analyses were conducted using SPSS Statistics for Windows v22.0 (IBM Corp., Armonk, NY) and Stata v12.0 (StataCorp, College Station, TX). For continuous variables, the one-sample Kolmogorov–Smirnov and Shapiro–Wilk tests were used to assess goodness-of-fit to a normal distribution. Based on the results, a two-tailed t-test was conducted to compare parental age between two groups; comparisons of all other variables between two groups, including S-TOFHLA score, were performed using the nonparametric two-tailed Mann–Whitney U-test. Comparisons of health literacy scores between more than two groups were assessed using a two-tailed Kruskal–Wallis test; where differences were significant, post-hoc Mann–Whitney U pairwise comparisons were completed with a Bonferroni adjustment.²¹ All categorical data were analyzed using chi-square and Fisher's exact tests. For stratified analysis of health literacy score and classifications by child's Hispanic origin and parent's primary language, further stratification by insurance type was performed. Additional multivariable linear and logistical regression analyses predicting S-TOFHLA performance by child's Hispanic origin, parent's primary language, and other demographic characteristics were attempted. All results were considered significant at p<0.05.

Results

Participants

Demographic characteristics, classified by child's ethnicity, are given in Table 1. The distributions of primary language spoken in the home (p<0.001), insurance type (p<0.001), educational achievement (p<0.001), and total combined household income (p=0.001) differed significantly between parents of Hispanic and non-Hispanic patients. Parental gender, parental age, patient age, and number of children with CF were not significantly different between cohorts.

Table 1.

Family Demographic Characteristics by Child's Hispanic Origin

	Hispanic (n=25)	Non-Hispanic (n=63)	Total (n=88)	p
Parental age in years, mean (SD)	35.3 (6.8)	38.4 (7.8)	37.6 (7.6)	0.08
Child's age, median (IQR)	6.1 (4.8–10.3)	10.7 (2.6–13.8)	8.3 (3.1–13.5)	0.43
Gender, n (%) female	20 (80)	48 (76)	68 (77)	0.78
Primary spoken language, n (%)				<0.001
English	10 (40)	63 (100)	73 (83)
Spanish	15 (60)	0 (0)	15 (17)
Educational achievement, n (%)				<0.001
Less than high school	7 (32)	0 (0)	7 (9)
High school diploma or equivalent	4 (18)	8 (14)	12 (15)
Some college	4 (18)	13 (23)	17 (22)
College graduate	7 (32)	24 (43)	31 (40)
Masters/doctoral level degree	0 (0)	11 (20)	11 (14)
Insurance type, n (%)				<0.001
Public	17 (68)	11 (17)	28 (32)
Private	8 (32)	52 (83)	60 (68)
Total combined household income, n (%)^a				0.001
<$30,000	7 (37)	2 (5)	9 (15)
$30,000–59,000	6 (32)	7 (17)	13 (21)
$60,000–89,999	3 (16)	10 (24)	13 (21)
≥$90,000	3 (16)	23 (55)	26 (43)
Number of children with CF, n (%)				0.74
1	21 (84)	55 (87)	76 (86)
2	4 (16)	8 (13)	12 (14)

Due to rounding, percentages may not equal 100%.

IQR, interquartile range; SD, standard deviation.

Health literacy performance

The median overall S-TOFHLA score was 35.0 out of 36 (interquartile range [IQR]=34.0–36.0), near the top of the range of adequate functional health literacy. Eighty-four of the 88 participants (95%) attained adequate health literacy scores.

Table 2 compares S-TOFHLA performance by child's Hispanic origin and parent's primary language. The median scores for parents of Hispanic children and parents of non-Hispanic children were identical at 35.0. While parents of Hispanic children had a broader score distribution than parents of non-Hispanic children, the difference was not statistically significant.

Table 2.

S-TOFHLA Performance by Child's Hispanic Origin and Parent's Primary Language

	Child's Hispanic origin			Parent's primary language
	Hispanic (n=25)	Non-Hispanic (n=63)	p	Spanish (n=15)	English (n=73)	p
S-TOFHLA, Median (IQR)
Overall	35.0 (28.0–36.0)	35.0 (34.5–36.0)	0.17	33.0 (22.5–36.0)	35.0 (34.0–36.0)	0.02
Public insurance	34.0 (28.0–36.0)	35.0 (33.5–35.0)	0.74	33.0 (24.5–36.0)	35.0 (34.0–35.5)	0.25
Private insurance	35.5 (27.5–36.0)	35.0 (35.0–36.0)	0.70	22.0 (18.5–29.0)	35.0 (35.0–36.0)	0.15
Adequate S-TOFHLA, n (%)
Overall	21 (84)	63 (100)	0.005	11 (73)	73 (100)	0.001
Public insurance	15 (88)	11 (100)	0.51	10 (83)	16 (100)	0.18
Private insurance	6 (75)	52 (100)	0.02	1 (33)	57 (100)	0.002

S-TOFHLA score classification: 0–22, inadequate/marginal; 23–36, adequate.

S-TOFHLA, Short Test of Functional Health Literacy in Adults.

Twenty-one of 25 parents of Hispanic CF patients (84%) scored at the adequate level compared to all 63 parents of non-Hispanic patients (p=0.005). After stratification by insurance type, this difference was statistically significant only for families with private insurance (p=0.02). When compared by primary language spoken at home, primarily Spanish-speaking parents scored lower on the S-TOFHLA (median=33.0, IQR=22.5–36.0) than primarily English-speaking parents (median=35.0, IQR=34.0–36.0), p=0.02. However, score differences after stratification into public insurance and private insurance were not statistically significant. Eleven of 15 primarily Spanish-speaking parents (73%) attained adequate health literacy scores, compared to all 73 primarily English-speaking parents (p=0.001). After stratification by insurance type, this difference persisted only among families with private insurance (p=0.002).

Table 3 compares S-TOFHLA performance across additional demographic parameters. The Kruskal–Wallis test demonstrated a significant main effect of educational achievement on health literacy score (p=0.03), with S-TOFHLA performance ranked higher at each increment of educational achievement. Post-hoc pairwise comparisons performed using Mann–Whitney U-tests with a Bonferroni correction indicated that parents who had not completed high school scored significantly lower than parents whose highest educational achievement was a college (p=0.03) or master's/doctoral degree (p=0.04); additional pairwise comparisons by education level were not statistically significant. The proportion of parents with adequate health literacy also varied significantly by education level (p=0.002), with a markedly lower rate of adequate literacy (57.1%) among parents who did not complete high school than parents with higher educational achievement. Individuals with public insurance were distributed toward significantly lower S-TOFHLA scores than individuals with private insurance (p=0.04). However, the median health literacy scores were equal at 35.0, and the rate of adequate health literacy was not significantly different. While health literacy scores did not significantly differ when compared by household income level, income level was associated with the rate of adequate health literacy (p=0.04), with all participants scoring in the inadequate/marginal range having household incomes <$60,000. Health literacy scores and categorizations did not significantly differ by parent's gender or the number of children with CF.

Table 3.

S-TOFHLA Performance by Additional Demographic Characteristics

	Median (IQR)	p	Adequate, n (%)	p
Educational achievement		0.03		0.002
Less than high school	23.0 (13.5–31.5)		4 (57.1)
High school diploma or equivalent	35.0 (33.0–36.0)	0.47^a	12 (100)
Some college	35.0 (34.0–36.0)	0.57^a	17 (100)
College graduate	35.0 (35.0–36.0)	0.03^a	30 (96.8)
Masters/doctoral level degree	35.0 (35.0–36.0)	0.04^a	11 (100)
Insurance type		0.04		0.59
Public	35.0 (30.5–36.0)		58 (96.7)
Private	35.0 (34.5–36.0)		26 (92.8)
Total combined household income		0.29		0.04
<$30,000	33.0 (26.0–36.0)		7 (77.8)
$30,000-$59,999	35.0 (34.0–36.0)		12 (92.3)
$60,000-$89,999	35.0 (34.0–36.0)		13 (100)
≥$90,000	35.0 (35.0–36.0)		26 (100)
Parent's gender		0.72		1.00
Male	35.0 (34.0–36.0)		19 (95.0)
Female	35.0 (34.0–36.0)		65 (95.6)
Number of children with CF		0.32		1.00
1	35.0 (34.0–36.0)		72 (94.7)
2	35.0 (33.5–35.0)		12 (100)

p-Values adjusted for multiple comparisons correspond to post-hoc Dunn–Bonferroni tests performed vs. less than high school.

S-TOFHLA score classification: 0–22, inadequate/marginal; 23–36, adequate.

Due to the limited sample size of the study and the lack of variability in the outcome, the multivariable linear and logistic regressions were not justified (i.e., model assumptions were violated, and estimates were unstable) and therefore inconclusive.

Discussion

We believe that this is the first investigation of parental health literacy in CF. The S-TOFHLA was chosen in part because of its availability in both English and Spanish, demonstrated validity in research settings,^19,20,22 and, in contrast to the Rapid Estimate of Adult Literacy in Medicine (REALM), measurement of reading comprehension rather than merely word recognition.²³ We found that 95% of parents demonstrated adequate health literacy, consistent with other studies employing the S-TOFHLA in pediatric populations, in which 89.5–100% of parents scored at the “adequate” health literacy level.^24–27

In our single-center pilot study, parents of Hispanic CF patients demonstrated a broader distribution of health literacy scores than parents of non-Hispanic CF patients, and a higher proportion of parents of Hispanic CF children scored in the inadequate or marginal range. However, the median S-TOFHLA scores were identical between the two cohorts such that the difference in average health literacy was not statistically significant. Moreover, because Hispanic parents were more likely to have public insurance, lower educational attainment, and lower household incomes—demographic factors that were associated with reduced S-TOFHLA performance in this study—the wider range of scores among these parents likely reflects a discrepancy in socioeconomic status rather than a deficit specific to the navigation of health information. On the whole, these findings suggest that while parents of Hispanic CF children are at risk for low health literacy, this may not be a main cause of disparate outcomes in Hispanic CF patients.

When compared by the primary language spoken at home, Spanish-speaking parents demonstrated lower health literacy performance, even when asked to complete the assessment in their preferred language. However, this difference did not persist with stratification by insurance type, suggesting that this discrepancy is also attributable to socioeconomic status. Nonetheless, when working with Spanish-speaking parents, it is important for CF providers to recognize that translation does not guarantee adequate comprehension of health information.

The primary limitations of this study were its relatively small sample size and completion at a single site, reducing both statistical power and external validity. A larger sample size would also enable multivariate analyses that can further investigate the intricate relationship observed between health literacy, socioeconomic status, and Hispanic origin. Additionally, the S-TOFHLA has a widely acknowledged ceiling effect that disproportionately affects young adults.^27–29 The Spanish version of the instrument was also developed using a translation and back-translation rather than psychometric approach, and therefore does not consist of test items identical to those on the English version.^22,30

In conclusion, our pilot study at a single CF center demonstrated that median health literacy was adequate and similar for parents of both Hispanic and non-Hispanic children with CF. These findings suggest that parental health literacy is unlikely to contribute strongly to the outcome disparities observed among Hispanic children with CF. Larger multicenter studies linking health literacy scores to patient outcomes should be conducted to confirm this hypothesis.

Footnotes

Acknowledgments

The authors thank the team members of the Lurie Children's CF Center for their assistance with patient recruitment, particularly Adrienne Savant, MD, MS, and Eileen Potter, MS, RD. The authors are also appreciative of David Baker, MD, MPH, for his consultation on the selection and implementation of the health literacy instrument.

Author Disclosure Statement

No competing financial interests exist.

References

Health Literacy: A Prescription to End Confusion. Washington, DC: Institute of Medicine, 2004.

DeWalt

, Dilling

, Rosenthal

, Pignone

. Low parental literacy is associated with worse asthma care measures in children. Ambul Pediatr, 2007; 7:25–31.

DeWalt

, Hink

. Health literacy and child health outcomes: a systematic review of the literature. Pediatrics, 2009; 124:S265–274.

Ross

, Frier

, Kelnar

, Deary

. Child and parental mental ability and glycaemic control in children with Type 1 diabetes. Diabet Med, 2001; 18:364–369.

Zaslow

, Hair

, Dion

, Ahluwalia

, Sargent

. Maternal depressive symptoms and low literacy as potential barriers to employment in a sample of families receiving welfare: are there two-generational implications?. Women Health, 2001; 32:211–251.

Henley

, Hill

. Errors, gaps, and misconceptions in the disease-related knowledge of cystic fibrosis patients and their families. Pediatrics, 1990; 85:1008–1014.

Ievers-Landis

, Drotar

. Parental and child knowledge of the treatment regimen for childhood chronic illnesses: related factors and adherence to treatment. In: Drotar

(ed.). Promoting Adherence to Medical Treatment in Childhood Chronic Illness: Concepts, Methods, and Interventions. Mahwah, NJ: Lawrence Erlbaum, 2000, pp. 259–282.

Koocher

, McGrath

, Gudas

. Typologies of nonadherence in cystic fibrosis. J Dev Behav Pediatr, 1990; 11:353–358.

Ievers

, Brown

, Drotar

, Caplan

, Pishevar

, Lambert

. Knowledge of physician prescriptions and adherence to treatment among children with cystic fibrosis and their mothers. J Dev Behav Pediatr, 1999; 20:335–343.

10.

Quittner

, Modi

, Lemanek

, Ievers-Landis

, Rapoff

. Evidence-based assessment of adherence to medical treatments in pediatric psychology. J Pediatr Psychol, 2008; 33:916–936; discussion 937–918.

11.

O'Connor

, Quinton

, Kahn

, et al. Case-mix adjustment for evaluation of mortality in cystic fibrosis. Pediatr Pulmonol, 2002; 33:99–105.

12.

O'Connor

, Quinton

, Kneeland

, et al. Median household income and mortality rate in cystic fibrosis. Pediatrics, 2003; 111:e333–339.

13.

Schechter

, Shelton

, Margolis

, Fitzsimmons

. The association of socioeconomic status with outcomes in cystic fibrosis patients in the United States. Am J Respir Crit Care Med, 2001; 163:1331–1337.

14.

Watts

, Seshadri

, Sullivan

, McColley

. Increased prevalence of risk factors for morbidity and mortality in the US Hispanic CF population. Pediatr Pulmonol, 2009; 44:594–601.

15.

Watts

, Schechter

. Origins of outcome disparities in pediatric respiratory disease. Pediatr Ann, 2010; 39:793–798.

16.

Watts

. Healthcare inequalities in paediatric respiratory diseases. Paediatr Respir Rev, 2012; 13:57–62.

17.

America's Health Literacy: Why We Need Accessible Health Information: U.S. Department of Health and Human Services, 2008.

18.

Kutner

, Greenberg

, Jin

, Paulsen

. The Health Literacy of America's Adults: Results From the 2003 National Assessment of Adult Literacy. Washington, DC: U.S. Department of Education, 2006.

19.

Baker

, Williams

, Parker

, Gazmararian

, Nurss

. Development of a brief test to measure functional health literacy. Patient Educ Couns, 1999; 38:33–42.

20.

Nurss

, Parker

, Williams

, Baker

. TOFHLA (Test of Functional Health Literacy in Adults). Snow Camp, NC: Peppercorn Books & Press, 2001.

21.

Dunn

. Multiple Comparisons Using Rank Sums. Technometrics, 1964; 6:241–252.

22.

Aguirre

, Ebrahim

, Shea

. Performance of the English and Spanish S-TOFHLA among publicly insured Medicaid and Medicare patients. Patient Educ Couns, 2005; 56:332–339.

23.

Powers

, Trinh

, Bosworth

. Can this patient read and understand written health information?. JAMA, 2010; 304:76–84.

24.

Janisse

, Naar-King

, Ellis

. Brief report: Parent's health literacy among high-risk adolescents with insulin dependent diabetes. J Pediatr Psychol, 2010; 35:436–440.

25.

Lokker

, Sanders

, Perrin

, et al. Parental misinterpretations of over-the-counter pediatric cough and cold medication labels. Pediatrics, 2009; 123:1464–1471.

26.

Oettinger

, Finkle

, Esserman

, et al. Color-coding improves parental understanding of body mass index charting. Acad Pediatr, 2009; 9:330–338.

27.

Tran

, Robinson

, Keebler

, Walker

, Wadman

. Health Literacy among Parents of Pediatric Patients. West J Emerg Med, 2008; 9:130–134.

28.

Kumar

, Sanders

, Perrin

, et al. Parental understanding of infant health information: health literacy, numeracy, and the Parental Health Literacy Activities Test (PHLAT). Acad Pediatr, 2010; 10:309–316.

29.

Wolf

, Feinglass

, Thompson

, Baker

. In search of “low health literacy”: threshold vs. gradient effect of literacy on health status and mortality. Soc Sci Med, 2010; 70:1335–1341.

30.

Lee

, Stucky

, Lee

, Rozier

, Bender

. Short Assessment of Health Literacy-Spanish and English: a comparable test of health literacy for Spanish and English speakers. Health Serv Res, 2010; 45:1105–1120.