Quality of health literacy instruments used in children and adolescents: a systematic review.

OBJECTIVE: Improving health literacy at an early age is crucial to personal health and development. Although health literacy in children and adolescents has gained momentum in the past decade, it remains an under-researched area, particularly health literacy measurement. This study aimed to examine the quality of health literacy instruments used in children and adolescents and to identify the best instrument for field use.

DESIGN: Systematic review.

SETTING: A wide range of settings including schools, clinics and communities.

PARTICIPANTS: Children and/or adolescents aged 6-24 years.

PRIMARY AND SECONDARY OUTCOME MEASURES: Measurement properties (reliability, validity and responsiveness) and other important characteristics (eg, health topics, components or scoring systems) of health literacy instruments.

RESULTS: There were 29 health literacy instruments identified from the screening process. When measuring health literacy in children and adolescents, researchers mainly focus on the functional domain (basic skills in reading and writing) and consider participant characteristics of developmental change (of cognitive ability), dependency (on parents) and demographic patterns (eg, racial/ethnic backgrounds), less on differential epidemiology (of health and illness). The methodological quality of included studies as assessed via measurement properties varied from poor to excellent. More than half (62.9%) of measurement properties were unknown, due to either poor methodological quality of included studies or a lack of reporting or assessment. The 8-item Health Literacy Assessment Tool (HLAT-8) showed best evidence on construct validity, and the Health Literacy Measure for Adolescents showed best evidence on reliability.

CONCLUSIONS: More rigorous and high-quality studies are needed to fill the knowledge gap in measurement properties of health literacy instruments. Although it is challenging to draw a robust conclusion about which instrument is the most reliable and the most valid, this review provides important evidence that supports the use of the HLAT-8 to measure childhood and adolescent health literacy in future school-based research.