Evaluating bias with loss to follow-up in a community-based cohort: empirical investigation from the CARRS Study.

BACKGROUND: Retention of participants is a challenge in community-based longitudinal cohort studies. We aim to evaluate the factors associated with loss to follow-up and estimate attrition bias. METHODS: Data are from an ongoing cohort study, Center for cArdiometabolic Risk Reduction in South Asia (CARRS) in India (Delhi and Chennai). Multinomial logistic regression analysis was used to identify sociodemographic factors associated with partial (at least one follow-up) or no follow-up (loss to follow-up). We also examined the impact of participant attrition on the magnitude of observed associations using relative ORs (RORs) of hypertension and diabetes (prevalent cases) with baseline sociodemographic factors. RESULTS: There were 12 270 CARRS cohort members enrolled in Chennai and Delhi at baseline in 2010, and subsequently six follow-ups were conducted between 2011 and 2022. The median follow-up time was 9.5 years (IQR: 9.3-9.8) and 1048 deaths occurred. Approximately 3.1% of participants had no follow-up after the baseline visit. Younger (relative risk ratio (RRR): 1.14; 1.04 to 1.24), unmarried participants (RRR: 1.75; 1.45 to 2.11) and those with low household assets (RRR: 1.63; 1.44 to 1.85) had higher odds of being lost to follow-up. The RORs of sociodemographic factors with diabetes and hypertension did not statistically differ between baseline and sixth follow-up, suggesting minimal potential for bias in inference at follow-up. CONCLUSION: In this representative cohort of urban Indians, we found low attrition and minimal bias due to the loss to follow-up. Our cohort's inconsistent participation bias shows our retention strategies like open communication, providing health profiles, etc have potential benefits.

The Impact of a Collaborative Care Model on Health Trajectories among Patients with Co-Morbid Depression and Diabetes: The INDEPENDENT Study.

Context: Collaborative care models for depression have been successful in a variety of settings, but their success may differ by patient engagement. We conducted a post-hoc analysis of the INDEPENDENT trial to investigate the role of differential engagement of participants on health outcomes over 3 years. Settings and Design: INDEPENDENT study was a parallel, single-blinded, randomised clinical trial conducted at four socio-economically diverse clinics in India. Participants were randomised to receive either active collaborative care or usual care for 12 months and followed up for 24 months. Method: We grouped intervention participants by engagement, defined as moderate (≤7 visits) or high, (8 or more visits) and compared them with usual care participants. Improvements in composite measure (depressive symptoms and at least one of three cardio-metabolic) were the primary outcome. Statistical Analysis: Mean levels of depression and cardio-metabolic measures were analysed over time using computer package IBM SPSS Statistics 25. Results: The composite outcome was sustained the highest in the moderate engagers [27.5%, 95% confidence interval (CI): 19.5, 36.7] and the lowest in high engagers (15.8%, 95% CI: 8.1, 26.8). This pattern was observed for individual parameters - depressive symptoms and glycosylated haemoglobin. Progressive reductions in mean depressive symptom scores were observed for moderate engagers and usual care group from baseline to 36 months. However, in high engagers of collaborative care, mean depressive symptoms were higher at 36 months compared to 12 months. Conclusion: Sustained benefits of collaborative care were larger in participants with moderate engagement compared with high engagement, although a majority of participants relapsed on one or more outcome measures by 36 months. High engagers of collaborative care for co-morbid depression and diabetes may need light touch interventions for longer periods to maintain health and reduce depressive symptoms.

Couple concordance in diabetes, hypertension and dyslipidaemia in urban India and Pakistan and associated socioeconomic and household characteristics and modifiable risk factors.

BACKGROUND: Concordance in chronic disease status has been observed within couples. In urban India and Pakistan, little is known about couple concordance in diabetes, hypertension, and dyslipidaemia and associated socioeconomic characteristics and modifiable risk factors. METHODS: We analysed cross-sectional data from 2548 couples from the Centre for cArdio-metabolic Risk Reduction in South Asia cohort in Chennai, Delhi and Karachi. We estimated couple concordance in presence of ≥1 of diabetes, hypertension and dyslipidaemia (positive concordance: both spouses (W+H+); negative concordance: neither spouse (W-H-); discordant wife: only wife (W+H-); or discordant husband: only husband (W-H+)). We assessed associations of five socioeconomic and household characteristics, and six modifiable risk factors with couple concordance using multinomial logistic regression models with couples as the unit of analysis (reference: W-H-). RESULTS: Of the couples, 59.4% (95% CI 57.4% to 61.3%) were concordant in chronic conditions (W+H+: 29.2% (95% CI 27.4% to 31.0%); W-H-: 30.2% (95% CI 28.4%- to 32.0%)); and 40.6% (95% CI 38.7% to 42.6%) discordant (W+H-: 13.1% (95% CI 11.8% to 14.4%); W-H+: 27.6% (95% CI 25.9% to 29.4%)). Compared with couples with no conditions (W-H-), couples had higher relative odds of both having at least one condition if they had higher versus lower levels of: income (OR 2.03 (95% CI 1.47 to 2.80)), wealth (OR 2.66 (95% CI 1.98 to 3.58)) and education (wives' education: OR 1.92 (95% CI 1.29 to 2.86); husbands' education: OR 2.98 (95% CI 1.92 to 4.66)) or weight status (overweight or obesity in both spouses ORs 7.17 (95% CI 4.99 to 10.30)). CONCLUSIONS: Positive couple concordance in major chronic conditions is high in urban India and Pakistan, especially among couples with relatively higher socioeconomic position. This suggests that prevention and management focusing on couples at high risk for concordant chronic conditions may be effective and more so in higher socioeconomic groups.

The role of age inequalities in cause of death in the slow pace of epidemiological transition in India.

In developed countries, low disparity in lifespan contributed by the reduction in the burden of noncommunicable diseases (NCDs) is the key to advances in epidemiological transition. Contrarily, India passing through a phase of the dual burden of CDs and NCDs shows a heavy burden of NCDs responsible for the high disparity in lifespan. The Gini coefficient was decomposed for examining the contribution of 22 causes of death and their repercussions for inequality in age at death for 30 years between 1990-1994 and 2015-2019, using Global Burden of Disease data. The outcomes of the study reveal that India's epidemiological transition has been just modest on account of high inequality in mortality by NCDs emplaced in the middle through old age despite a consistent mortality decline at infant through old age for communicable diseases (CDs). The structural changes in causes of death structure is shaped by CDs rather than NCDs, but overall bolstered by the adult mortality decline, especially in women. However, the process is restrained by the small contribution of the middle age group and a benign contribution of old mortality decline owing to the low threshold age. India needs to target health interventions in seeking significant mortality decline in the middle age group of 50-69 years that is warranted for epidemiological transition apace as evident in the developed nations.

Association between poor oral health and diabetes among Indian adult population: potential for integration with NCDs.

BACKGROUND: Studies in high-income countries have reported associations between oral health and diabetes. There is however a lack of evidence on this association from low and middle-income countries, especially India. The current study aimed to assess the prevalence of common oral diseases and their association with diabetes. METHODS: This cross-sectional study was nested within the second Cardiometabolic Risk Reduction in South Asia Surveillance Study. A subset of study participants residing in Delhi were administered the World Health Organization's Oral Health Assessment Questionnaire and underwent oral examination for caries experience and periodontal health assessment using standard indices. Diabetes status was ascertained by fasting blood glucose, glycosylated hemoglobin values or self-reported medication use. Information was captured on co-variates of interest. The association between oral health and diabetes was investigated using Multivariable Zero-Inflated Poisson (ZIP) regression analysis. RESULTS: Out of 2045 participants, 47% were women and the mean age of study participants was 42.17 (12.8) years. The age-standardised prevalence (95% confidence interval) estimates were 78.9% (75.6-81.7) for dental caries, 35.9% (32.3-39.6) for periodontitis. Nearly 85% participants suffered from at least one oral disease. Compared to diabetes-free counterparts, participants with diabetes had more severe caries experience [Mean Count Ratio (MCR) = 1.07 (1.03-1.12)] and attachment loss [MCR = 1.10 (1.04-1.17)]. Also, the adjusted prevalence of periodontitis was significantly higher among participants with diabetes [42.3%(40.0-45.0)] compared to those without diabetes [31.3%(30.3-32.2)]. CONCLUSION: We found that eight out of ten participants in urban Delhi suffered from some form of oral disease and participants with diabetes had worse oral health. This highlights the need for public health strategies to integrate oral health within the existing Non-Communicable Disease control programs.