The Chinese Older Adult Collaborations in Health (COACH) Study

Using a cluster randomized controlled design, the Chinese Older Adult Collaborations in Health (COACH) Study compared the COACH intervention to enhanced Care-as-Usual (eCAU) for the treatment of comorbid depression and HTN in older residents of rural Chinese villages. Study measures were administered in the subject’s home or the clinic by unblinded, trained research assistants at study entry and 1-, 3-, 6-, 9-, and 12-months later. Sociodemographic information obtained at baseline included age, sex, education level, marital status, living condition, employment status, religion and economic satisfaction. Our primary outcome variables were depression symptom severity, and HTN control. The measure of depressive symptom change was a valid and reliable Chinese translation of the 17-item Hamilton Depression Rating (HDRS). Items for analysis included response to treatment, defined as a ≥50% change in the HDRS score from baseline, and remission of depression defined as a total HDRS score <10 at follow-up. BP was measured at baseline and each follow-up point according to standards developed by the Center for Disease Control and Prevention in China. The primary variable for analysis was dichotomous – controlled vs. uncontrolled HTN. Consistent with the Hypertension Treatment Guidelines, uncontrolled HTN was defined as systolic BP ≥ 130 or diastolic BP ≥ 80 for patients with diabetes mellitus, coronary heart disease or renal disease, and BP ≥ 140 or diastolic BP≥90 for all others. Variables known to influence response to treatment of depression or HTN were included as covariates: the Body Mass Index (BMI), which is associated with hypertension treatment response, and the WHOQOL-BREF for quality of life, which is a widely used measure and the Chinese version of which has shown very good psychometric properties. As a measure of functioning independent of the WHOQOL-BREF physical domain score, we assessed the subject’s impairment in basic (ADL) and instrumental activities of daily living (IADLs). We measured social support with the Chinese version of the Medical Outcomes Study Social Support Survey (MOS-SSS-C)42 and social network size.