Immunization knowledge and practice among Malaysian parents: a questionnaire development and pilot-testing

Background: Parents are the main decision makers for their children vaccinations. This fact makes parents' immunization knowledge and practices as predictor factors for immunization uptake and timeliness. The aim of this pilot study was to develop a reliable and valid instrument in Malaysian language to measure immunization knowledge and practice (KP) of Malaysian parents. Methods: A cross-sectional prospective pilot survey was conducted among 88 Malaysian parents who attended public health facilities that provide vaccinations. Translated immunization KP questionnaires (Bahasa Melayu version) were used. Descriptive statistics were applied, face and content validity were assessed, and internal consistency, test-retest reliability, and construct validity were determined. Results: The mean +/- standard deviation (SD) of the knowledge scores was 7.36 +/- 2.29 and for practice scores was 7.13 +/- 2.20. Good internal consistency was found for knowledge and practice items (Cronbach's alpha = 0.757 and 0.743 respectively); the test-retest reliability value was 0.740 (p = 0.014). A panel of three specialist pharmacists who are experts in this field judged the face and content validity of the final questionnaire. Parents with up-to-date immunized children had significantly better knowledge and practice scores than parents who did not (p < 0.001 and p = 0.001 respectively), suggesting a good construct validity. A significant difference was found in knowledge and practice scores among parents' age (p = 0.006 and p = 0.029 respectively) and place of living (p = 0.037 and p = 0.043). The parents' knowledge level was positively associated with their practice toward immunization (Spearman's rank correlation coefficient 0.310, p = 0.003). Conclusions: The pilot study concluded that the Bahasa Melayu version of the immunization KP questionnaire has good reliability and validity for measuring the knowledge and practices of Malaysian parents and therefore this version can be used in future research.