Collaborative care for common mental disorders in low- and middle-income countries: A systematic review and meta-analysis

Background: Low- and middle-income countries (LMICs) face high burden of common mental disorders (CMDs). Most of the evidence for the Collaborative Care (CC) model effectiveness comes from high-income countries (HICs) and may not generalise to LMICs. A systematic review was conducted to assess effectiveness of CC for CMDs in LMICs. Methods: We searched eight-databases, two trial registries (2011-November 2023). Randomised controlled trials (RCTs) of adults (>18 years) with depression/anxiety diagnosis, reporting remission/change in symptom severity were eligible. Random effects meta-analyses were conducted for: short-(0-6 months), medium-(7-12 months), long-(13-24 months), and very long-term (>25 months) follow-up. Quality was assessed with Cochrane RoB2 tool. PROSPERO registration: CRD42022380407. Results: Searches identified 7494 studies, 12 trials involving 13,531 participants were included; nine had low-risk of bias. CC was more effective than usual care for depression: dichotomous outcomes (short-term, 7 studies, relative risk (RR) 1.39, 95%CI 1.31, 1.48; medium-term, 6 studies, RR 1.35, 95%CI 1.28, 1.43); and continuous outcomes (short-term, 8 studies, standardised mean difference (SMD) -0.51, 95%CI -0.80, -0.23; mediumterm, 8 studies, SMD -0.59, 95%CI -1.00, -0.17). CC was found to be effective at long-term (one study), but not at very long-term. Improvement in anxiety outcomes with CC (2 studies, 340 participants) reported up to 12-months; improvements in quality-of-life were not statistically significant (3 studies, 796 participants, SMD 0.62, 95%CI -0.10, 1.34). Limitations: Pooled estimates showed high heterogeneity. Conclusions: In LMICs, CC was more effective than usual care for improving depression outcomes at short and medium-term follow-up. A similar improvement was found for anxiety outcomes, but evidence is limited.