Instruments for measuring parents' vaccine hesitancy towards their children based on the COSMIN guidelines: A...

Parental vaccine hesitancy undermines immunization gains, leading to resurgent outbreaks and increased child mortality. Reliable assessment instruments are urgently needed to guide effective interventions and improve coverage. Despite multiple vaccine hesitancy assessment instruments, no systematic reviews have evaluated the measurement properties of these instruments against established methodological standards, limiting evidence-based selection.

To systematically evaluate the methodological quality and measurement properties of vaccine hesitancy assessment instruments for parents of 0-18 children, providing an evidence-based basis for selecting appropriate instruments.

Measurement properties are systematically reviewed according to the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) guidelines.

Six electronic databases were systematically searched from inception until July 15, 2025. Methodological quality was assessed using the COSMIN Risk of Bias Checklist and measurement properties were synthesized according to the COSMIN criteria. A modified Grading, Recommendations, Assessment, Development, and Evaluation system was used to assess the certainty of evidence.

Forty studies evaluating 31 vaccine hesitancy assessment instruments were included. Based on COSMIN evidence grading, the Malay version of the modified vaccine hesitancy scale (MVHS-M), the Vietnamese version of the parent attitudes about childhood vaccines survey (PACV-Viet), and the parental attitude scale towards vaccination (PASV) received Category A recommendation. The general vaccine hesitancy scale (GVHS), vaccination attitudes examination (VAX), vaccine acceptance instrument (VAI), and vaccine barriers assessment tool (VBAT) received Category C recommendation, while others were Category B recommendation.

This systematic review identified MVHS-M, PACV-Viet, and PASV as effective tools for assessing vaccine hesitancy in parents, suitable for both research and clinical use. Future research should comprehensively assess their measurement properties, especially exploring measurement error and responsiveness.

A protocol was registered on the PROSPERO (CRD420251070194).