Cross-Cultural Adaptation and Assessment of the Reliability and Validity of the Thai Hill-Bone Compliance to High Blood Pressure Therapy Scale

Purpose: Cross-cultural adaptation should be considered before applying psychometric instruments to another country. Hypertension is a highly prevalent condition that and contributes to cardiovascular morbidity and mortality among adults globally. Compliance to high blood pressure therapy is an essential part of self-management of hypertension. Valid, reliability, and feasible measures of compliance to hypertension therapy are needed for research and clinical practice. The objectives of this study were to adapt, translate and validate the Thai Hill-Bone Compliance to High Blood Pressure Therapy Scale for use in the Thai population.

Methods: For cross-cultural adaptation of the 14 item Hill-Bone Compliance to High Blood Pressure Therapy Scale, the Beaton guideline for cross-cultural adaptation of self-report measures was used. This guideline consisted of 6 stages of the instrument cross-cultural adaptation process as following 1) initial translation; 2) synthesis of the translation; 3) back translation; 4) expert committee; 5) test of the pre-final version and 6) submission of documentation to the developers or coordination committee for appraisal of the adaptation process. The original version was translated into Thai language to produce a Thai language version. The psychometric properties assessed included face validity; content validity; construct validity and criterion validity (concurrent validity) were used to validate the psychometric quality of the Thai language version. Face validity and content validity were determined with consultation with three content experts. For construct validity and reliability, exploratory factor analysis (EFA) was used to assess the structures of the scale and measures of internal consistency. Mean blood pressure and anthropometric measures were used to determine concurrent validity.

Results: 156 participants with hypertension were recruited from a community-based primary

Health care setting to determine the psychometric properties of the Thai version. The mean age of

participants was 70 (S.D = 6.34; range 60-88). 107 of 156 (68.6%) participants were female. The mean

duration of diagnosed hypertension of 10.27 years (SD = 7.22; range 1-40). For the Thai version,

standardized Cronbach’s alpha was 0.64 for all items, 0.61 for the sodium intake subscale, 0.5 for the

appointment-keeping subscale and 0.69 for the medication taking subscale. Pearson’s correlation

coefficient, reflecting inter-item correlation,  values ranged from -0.14 to 0.58. The Thai Hill-Bone

Compliance to High Blood Pressure Therapy Scale was able to discriminate blood pressure and waist

circumference levels.

Conclusions: In this cross-cultural adaptation study, the Thai Hill-Bone Compliance to High Blood

Pressure Therapy Scale demonstrated strong psychometric properties and is a promising instrument to

be used in intervention studies in Thailand.