DEVELOPMENT AND CONSTRUCT VALIDATION OF QUESTIONNAIRE ASSESSING THE ADULT IMMUNISATION PERCEPTIONS AMONG MALAYSIAN POPULATION

Introduction: Immunisations are one of the most effective public health interventions, reducing or eliminating the burden of many infectious diseases. This study aims to establish the construct validity of a newly developed adult immunisation perceptions questionnaire among Malaysians. Methods: The Adult Immunisation Perceptions-Questionnaire (AIP-Q) was created following literature reviews on The Health Belief Model. Primarily, 64 questions were pooled, followed by face validity by experts, pretested via 20 healthcare personnel and later translate into the Malay language. A total of 305 respondents were selected for the construct validation process. Varimax rotation method used in the analysis for exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) done using AMOS software. Results: Ten constructs were produced as predicted in EFA: health believes, experience, knowledge, attitude, perceived severity, perceived susceptibility, perceived benefits, perceived barriers, and 2 cues for action. Thirteen items with low factor loading and unrelated to the recovered domains were removed from being included in CFA. In path analysis, the scale fitted ?2/df=1.943 (n=305) =p<0.001, CFI=0.908, IFI=0.909, TLI=0.901 and RMSEA=0.056. Strong factor loading was found across the final items, ranged from 0.53 to 0.94 with a good reliability test (Cronbach Alpha, AVE and CR values) for all constructs. Conclusion: The final AIP-Q consists of 10 domains with 45 items that give a promising psychometric property. This questionnaire can measure the perceptions of adult immunisation among the Malaysian population and can be utilized for the nationwide study.