Psychometric Properties

HLS-Child-Q15-EN scores increased with age, school year, self-efficacy, parental education, and home literacy environment. Health literacy and self-efficacy were related but distinct constructs in the validation analysis. The English scale exceeded the predefined acceptable internal consistency threshold. The review will examine reliability, validity, sensitivity, specificity, internal consistency, test-retest reliability, construct validity, and responsiveness. Criterion validity and responsiveness were not assessed in any included study. Studies must report at least one measurement property to be eligible. Measurement error was formally evaluated in only two studies. Only ten of the thirty included articles assessed test-retest reliability. The review found widespread methodological deficiencies, especially in instrument development and content validity. Structural validity varied, and three named instruments failed COSMIN CFA thresholds. Most instruments achieved sufficient internal consistency. Test-retest results showed no significant systematic bias between initial and retest scores. Mental health instruments can cause misdiagnosis or missed symptoms when they do not capture…