Children with special health care needs (CSHCN) are defined by the Maternal and Child Health Bureau as those who have or are at increased risk for a chronic physical, developmental, behavioral or emotional condition(s) and require healthcare services beyond that required by children generally [1, 2]. It is estimated that between 13-18 % of children in the United States are CSHCN and their diagnoses can encompass a wide range of pediatric diagnoses, including: autism, asthma, diabetes, sickle cell disease, cystic fibrosis, cerebral palsy, congenital heart disease, developmental delay, diseases due to prematurity, etc. [1, 3]. Among children’s health expenditures, CSHCN account for between 40 to 70 % of all health care expenditures among children [1, 3–6]. CSHCN often have multiple providers, complex treatment regimens, and high financial burden to the family, including out-of-pocket costs [7]. Additionally, they are a particularly vulnerable patient population due to the fact that they encompass a heterogeneous diagnostic group, often with multiple co-morbidities. Because their classification is not disease-specific, they are commonly encountered in health care settings, yet overlooked in terms of research and translational implications.

In adults, limited health literacy (the ability to obtain, integrate and appraise health-related knowledge) has emerged as a key indicator of adverse health outcomes including: increased measures of morbidity, poor adherence to medications, limited levels of shared decision-making, more unintended readmissions and higher utilization of health care resources compared to those with functional health literacy [8]. Health literacy is recognized by the Institute of Medicine as an integral component of high quality health care and it is estimated that nearly 36 % of adults in the United States have limited health literacy, and the prevalence rises to closer to 50 % among those from low-income backgrounds [9, 10].

While the concept of health literacy has received attention in adult populations with chronic disease, it has been substantially less studied among parents and caregivers of children. When it has been studied among parents and caregivers of children, it’s been primarily limited to health promotion, delivery of health information of well-child practices (e.g., immunization information), medication knowledge (e.g., dosing of acetaminophen), and health literacy of parents presenting to the emergency department (ED) [11–13]. There have been comparatively few studies that assess parental/caregiver health literacy of CSHCN, even though they may be at particular risk for inadequate information exchange, confusion regarding complex home medication regimens and treatment instructions, and non-adherence to medication or recommendations. Additionally, because of the chronicity of their diagnoses, it is particularly important to assess parent/caregiver health literacy across the treatment continuum. This gap in assessment and knowledge of the impact of parental/caregiver health literacy on health outcomes of CSHCN is particularly concerning and a needed area of future research. Therefore, the purpose of this systematic literature review was to assess the available evidence of studies investigating parent/caregiver health literacy of CSHCN and the effect on pertinent health outcomes.

This systematic review was conducted using the available biomedical literature in accordance with the guidelines outlined by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement (PRISMA) [14].

Study selection

The PRISMA flow diagram detailing study selection and inclusion is found in Fig. 1. All studies were independently assessed for eligibility by two reviewers (JKM and LL). Once articles were identified from the database searches, duplicates were removed, then all remaining abstracts were reviewed for eligibility. Full-text articles were assessed for eligibility with only two articles excluded at this stage (because there was no assessment of parent/caregiver health literacy). Fifteen studies were included for thematic and contextual purposes, and of these, thirteen studies were included in the final analysis and systematic review. Two studies were eliminated because they were reviews and not empirical studies.

The data presented in the 13 studies included in this review highlight the future directions needed in parental/caregiver health literacy among CSHCNs. While numerous studies demonstrated a relationship between parental/caregiver health literacy and outcomes pertinent to CSHCNs, several gaps in the literature remain. All studies utilized valid and reliable instruments to assess for parental/caregiver health literacy, however there was a wide range of health literacy estimates. This can likely be explained due to the heterogeneity in sampling strategies and locations. A defined need in the literature is health literacy assessment of the child/adolescent themselves – particularly among older school age and adolescent children who are likely engaging in some form of self-management of their own disease. For example, the Newest Vital Sign (NVS) has been administered in children as young as seven [32] and the Rapid Estimate of Adolescent Literacy in Medicine (REALM)-Teen was specifically validated as a version of the REALM to be used among adolescents age 10–19 years of age [33]. Very few studies have assessed adolescent health literacy. In previous research, Dharmapuri and colleagues [34] were not able relationship between adolescent health literacy and medication adherence. However, more adolescent-specific health literacy studies are needed with more diverse populations and among CSHCNs, where medication regimens are often chronic in nature, rather than episodic. There has been a limited discussion about the importance of a developmentally appropriate approach to health literacy among children and adolescents as well as the proposed importance of the health literacy of the child/parent dyad and these should be considered gaps in the current state of the literature [11].

The majority of the parental/caregiver health literacy studies included in this review focused on asthma. While asthma provides a concrete disease model for self-management of chronic disease in childhood and adolescence, more studies are needed from other representative special health care needs diagnoses. A defined need in this body of literature includes studies that encompass comprehensive symptom management approaches among families with limited health literacy. CSHCN often have multiple co-morbid conditions, and none of the included studies involved samples with more than one condition. Along with more representative CSHCN diagnoses, another defined gap is the focus of limited health literacy families in the acute or critical care inpatient hospital setting. There are no identified studies that assess parental/caregiver health literacy in this setting and there are likely many relationships between limited health literacy and communication between providers, information appraisal, and transition from hospital to the home care setting.

While there was a range in study quality, several studies included in this review demonstrated relationships between parental/caregiver health literacy and outcomes that are meaningful for families of CSHCN. Even so, very few studies actually assessed the impact of parental/caregiver health literacy on health care utilization. DeWalt and colleagues [15] found that children from parents with low health literacy with asthma had greater incidence of ED visits and hospitalizations, while Wood and colleagues [27] were not able to establish any relationship between caregiver health literacy on utilization variables related to asthma visits. The commonly proposed pathway of limited health literacy inhibiting medication adherence, which ultimately may cause an increase in overall emergent, ED and hospital utilization exits, alternative causal mechanisms must also be considered. Additionally, no studies assessed the relationship of parental/caregiver health literacy on identification of early warning signs of uncontrolled symptoms or disease progression, and these concepts are incredibly central to self-management of CSHCN in the home setting, which may also impact utilization. Finally, no studies included in this review assessed the impact of health literacy on cost, cost-savings, or cost-utility of chronic disease management. The relationship between health literacy and the direct financial impact on families, payers, and health systems are not yet fully understood, particularly among the pediatric population.

Very few studies included in this review appropriately considered the confluence of health literacy among other social determinants of health that may lead to adverse health outcomes for CSHCN. Sanders and colleagues have described that due to the dependence of children on many caregivers, researchers in pediatric health literacy may want to consider the collective health literacy of all responsible for the care of that child, including the child, parent, siblings, family members, daycare or school staff, etc. [11]. Collective health literacy of the child may be operationalized as a form of social capital and has broad implications for clinical and research outcomes [11].

Assessing for and addressing limited health literacy is a critical component of future research endeavors aimed at improving child health outcomes and health care utilization for vulnerable families. This review of the literature highlights early key concepts that must be further developed into more robust prospective studies as well as intervention-development and testing through RCTs. Interdisciplinary teams are needed to develop innovative modalities to integrate this research into current clinical practice. Finally, clinicians and researchers must work together with policy-makers to advocate for the health of limited health literacy families.