Development and psychometric evaluation of the child marriage cognitive determinants questionnaire (CMCDQ): a mixed-methods study

Child marriage (CM) is prevalent in Iran. Family members are most commonly the final decision-makers to accept a marriage proposal, often without girls' involvement. Valid and reliable instruments are needed to assess the contributing factors of CM. This study aimed to develop and evaluate the Child Marriage Cognitive Determinants Questionnaire (CMCDQ). An exploratory sequential mixed methods research design was conducted from 2021 to 2022 in Sanandaj, Iran. The CMCDQ was developed through a qualitative survey of 41 parents, men and women with a history of CM, and experts and a literature review. Then, its primary face, content, construct validity, and reliability were assessed. Construct validity was evaluated by exploratory and confirmatory factor analyses on the data obtained from 500 parents. The primary CMCDQ had 83 items. In face and content validity assessments, 31 items were deleted because their item impact scores were less than 1.5 (n = 3), content validity ratios were less than 0.59 (n = 23), and content validity indices were less than 0.79 (n = 5). Seven items were revised because their content validity indices were 0.7-0.79. In exploratory factor analysis, six items were deleted because their factor loading values were less than 0.3 and the remaining 46 items were loaded on eight factors, namely cultural perception, parenting skills, attitude, situational influences, subjective norms, factual beliefs, neutralization, and personal normative beliefs. These factors explained 56.55% of the total variance. Confirmatory factor analysis confirmed the good fitting of the eight-factor model (CMIN/DF = 1.039, PCFI = 0.938, PNFI = 0.964, NFI = 0.945, IFI = 0.963, CFI = 0.995, RFI = 0.949, GFI = 0.961, AGFI = 0.952 and RMSEA = 0.013). The Cronbach's alpha values and the intraclass correlation coefficients of CMCDQ subscales were 0.7-0.8 and 0.8-0.9, respectively. CMCDQ is a valid and reliable instrument and can be used to assess the parental cognitive determinants of CM and develop effective strategies to minimize CM.