Psychometric Analysis of Hypertension Self-Management Behaviors Questionnaire; an Application of Intervention Mapping Approach in Questionnaire Development

Aims: High blood pressure is one of the common main preventable risk factors for many diseases. This study aimed to psychometric properties of the cognitive determinants of hypertension self-management questionnaire among Iranian hypertensive patients based on the Intervention Mapping approach. Instrument & Methods: This psychometric study was conducted in Abadan in 2019. Content Validity Ratio and Content Validity Index of the questionnaire were calculated by ten hypertensive patients and 12 experts. Construct validity was investigated using Classical Item Analysis and Exploratory Factor Analysis by the participation of 315 hypertensive patients. The internal consistency was measured by using Cronbach’s Coefficient Alpha of the various cognitive determinants of the questionnaire. Data were analyzed by SPSS 16. Findings: The mean age of patients was 57.53±11.30 years, ranging from 30 to 70 years. Five factors (attitude, outcome expectation, self-efficacy, subjective norms, and barriers) and behavior were confirmed. The Kaiser-Meyer Olkin test was generally satisfactory (calculated: 0.817). The factors explained 61.86% of the variance of the hypothesized model. Estimated reliability using alpha Cronbach coefficient for each cognitive determinants were as follows: attitude (α=0.75), outcome expectations (α=0.79), self-efficacy (α=0.80), subjective norms (α=0.85), barriers (α=0.88), behavior (α=0.82). Conclusion: The application of the intervention mapping approach in questionnaire development offers a useful questionnaire to measurement self-management hypertension behaviors, and psychometric analysis shows that it could be useful for related planning programs.