Non-communicable diseases (NCDs) are important issues in Thailand and health sectors are now focusing on modifiable risks that include cognitive, affective and behavioral factors. This study aimed to develop and validate a questionnaire to assess knowledge about NCDs, threat appraisal, coping appraisal and intention to practice based on protection motivation theory. Content validity was determined by the mean of the item content validity index (I-CVI) from five experts. The questionnaire was pilot tested for difficulty of knowledge items and reliability test using the Kuder-Richardson (KR)-20 and Cronbach's alpha coefficient among 30 Thai adult subjects in the health office for two sub-districts. The mean I-CVI ranged from 0.90-1.00 and difficulty of knowledge ranged from 0.3-0.9. The reliability test of knowledge by KR-20 ranged from 0.648-0.799, while Cronbach's alpha coefficients of threat and coping appraisal and intention to practice ranged from 0.70-0.843. We compared sociodemographic data, knowledge about NCDs, threat appraisal, coping appraisal and intention to practice between 50 diabetic type 2 cases and 50 controls. T2DM cases had higher age, knowledge scores on diabetes and hypertension, threat appraisal scores on hypertension and cardiovascular disease when compared with control (p < 0.05). The questionnaire was valid and sufficiently reliable to use for data collection.
Keywords: NCDs; PMT; reliability test; validation of questionnaire.