Effectiveness of integrated care for older adults with depression and hypertension in rural China: A cluster randomized controlled trial

Background
Effectiveness of integrated care management for common, comorbid physical and mental disorders has been insufficiently examined in low- and middle-income countries (LMICs). We tested hypotheses that older adults treated in rural Chinese primary care clinics with integrated care management of comorbid depression and hypertension (HTN) would show greater improvements in depression symptom severity and HTN control than those who received usual care.

Methods and findings
The study, registered with ClinicalTrials.gov as Identifier NCT01938963, was a cluster randomized controlled trial with 12-month follow-up conducted from January 1, 2014 through September 30, 2018, with analyses conducted in 2020 to 2021. Participants were residents of 218 rural villages located in 10 randomly selected townships of Zhejiang Province, China. Each village hosts 1 primary care clinic that serves all residents. Ten townships, each containing approximately 20 villages, were randomly selected to deliver either the Chinese Older Adult Collaborations in Health (COACH) intervention or enhanced care-as-usual (eCAU) to eligible village clinic patients. The COACH intervention consisted of algorithm-driven treatment of depression and HTN by village primary care doctors supported by village lay workers with telephone consultation from centrally located psychiatrists. Participants included clinic patients aged ≥60 years with a diagnosis of HTN and clinically significant depressive symptoms (Patient Health Questionnaire-9 [PHQ-9] score ≥10). Of 2,899 eligible village residents, 2,365 (82%) agreed to participate. They had a mean age of 74.5 years, 67% were women, 55% had no schooling, 59% were married, and 20% lived alone.

Observers, older adult participants, and their primary care providers (PCPs) were blinded to study hypotheses but not to group assignment. Primary outcomes were change in depression symptom severity as measured by the Hamilton Depression Rating Scale (HDRS) total score and the proportion with controlled HTN, defined as systolic blood pressure (BP) <130 mm Hg or diastolic BP <80 for participants with diabetes mellitus, coronary heart disease, or renal disease, and systolic BP <140 or diastolic BP <90 for all others. Analyses were conducted using generalized linear mixed effect models with intention to treat.

Sixty-seven of 1,133 participants assigned to eCAU and 85 of 1,232 COACH participants were lost to follow-up over 12 months. Thirty-six participants died of natural causes, 22 in the COACH arm and 14 receiving eCAU. Forty COACH participants discontinued antidepressant medication due to side effects. Compared with participants who received eCAU, COACH participants showed greater reduction in depressive symptoms (Cohen’s d [±SD] = −1.43 [−1.71, −1.15]; p < 0.001) and greater likelihood of achieving HTN control (odds ratio [OR] [95% CI] = 18.24 [8.40, 39.63]; p < 0.001).

Limitations of the study include the inability to mask research assessors and participants to which condition a village was assigned, and lack of information about participants’ adherence to recommendations for lifestyle and medication management of HTN and depression. Generalizability of the model to other regions of China or other LMICs may be limited.

Conclusions
The COACH model of integrated care management resulted in greater improvement in both depression symptom severity and HTN control among older adult residents of rural Chinese villages who had both conditions than did eCAU.

Trial registration
ClinicalTrials.gov Identifier NCT01938963 https://clinicaltrials.gov/ct2/show/NCT01938963.