Long-term effects of a Collaborative Care Model on Depressive Symptoms and Metabolic Outcomes in India: The INDEPENDENT Randomized Clinical Trial Open Access

Suvada, Kara (Spring 2021)

Permanent URL: https://etd.library.emory.edu/concern/etds/1r66j245h?locale=en


Background: Chronic diseases are responsible for 60% of deaths worldwide. Multiple chronic conditions, such as comorbid type 2 diabetes (T2D) and depression, are increasingly prevalent and are made worse by fragmented medical care. Fragmented medical care is a major barrier to the treatment of multiple chronic conditions in low-and-middle income countries, such as India. This study examined the long-term effects of a collaborative care model on metabolic indicators and depressive symptoms among adults in India with poorly-controlled T2D and comorbid depression.

Methods: The Integrating Depression and Diabetes Treatment (INDEPENDENT) trial was a multicenter, open-label, pragmatic clinical trial comparing a 12-month active collaborative care intervention with usual care for patients with poorly-controlled diabetes and comorbid depression. At baseline, 404 patients at 4 clinic sites were randomized. At 36-months following randomization, N = 331 intervention participants (n=156 collaborative care model and n=175 usual care) were assessed for target outcomes. Long-term intervention effects were estimated at 36-months as risk differences and risk ratios comparing the collaborative care group to the usual care group on the primary composite outcome, comprised of ≥50% improvement in the 20-item Symptom Depression Checklist (SCL-20) scores since baseline and one or more of the following: 0.5-percentage point reduction in HbA1C, 5 mmHg or more reduction in SBP, or a 10 mg/dL reduction in LDL cholesterol. Secondary outcomes included change since baseline in HbA1c, SBP, LDL, and SCL-20, separately. We also evaluated heterogeneity in treatment effects by socioeconomic and health characteristics at baseline.

Results: At 36-months, among 331 patients randomized (mean [SD] age: 52.6 [8.4]; 207 [62.5%] female), there was not a statistically significant difference between the percentage of patients who attained the primary outcome in the collaborative care group vs. usual care group (62.1% vs. 57.8%; RD, 4.3 [95% CI: -6.2%-1.5%]; RR: 1.07 [95% CI: 0.90, 1.27]).

Conclusion: At 36 months following randomization, there were no improvements in metabolic parameters or depressive symptoms associated with a proven-effective collaborative care model. Continued active intervention may be needed to achieve sustained control of metabolic disease and depression in low-resource settings. 

Table of Contents

Table of Contents

Chapter I: Introduction. 1

Chapter II: Literature Review.. 3

The Epidemiologic Transition in India. 3

Global Burden of Type 2 Diabetes. 3

Global Burden of Depression. 5

Impact of Comorbid Type 2 Diabetes & Depression. 6

Access to Medical Care for Chronic Conditions. 7


Chapter III: Manuscript 10

Abstract 10

Key Points. 12

Introduction. 13

Methods. 14

Intervention Components & Study Population. 14

Recruitment and Randomization. 16

Assessments. 16

Outcomes. 17

Statistical Analysis. 18

Results. 19

Discussion. 21

Conclusions. 24

Tables and Figures. 25

Table 1. Baseline Characteristics of Participants Assessed at 36 Months (N=331) 25

Table 2. Adjusted Differences in Means of Key Treatment Targets Between Collaborative Care and Usual Care at 36 Months^. 29

Table 3: Primary Outcome at 36 Months by Socioeconomic and Clinical Characteristics Between Collaborative Care vs. Usual Care Groups. 31

Figure 1: INDEPENDENT Participant Eligibility and Collaborative Care Component 32

Figure 2: Proportion of Participants Achieving Treatment Targets by Arm at 36 Month Follow-Up. 33

Figure 3. Mean Outcomes for Depression and Cardiometabolic Indicators at Baseline and 36 Months. 34

Supplemental Material 35

Supplemental Figure 1: Participants Lost to Follow-Up from Baseline to 36 Months. 35

Supplemental Table 1. Differences Between Participants Not Assessed at 36 months and Completing Participants (N = 404) 36

Chapter III: Summary, Implications, & Future Directions. 41

Summary. 41

Implications & Future Directions. 42

References. 44

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