Risk factors for incident cardiovascular events and their population attributable fractions in rural India: The Rishi Valley Prospective Cohort Study

Objective: We prospectively determined incident cardiovascular events and their association with risk factors in rural India. Methods: We followed up with 7935 adults from the Rishi Valley Prospective Cohort Study to identify incident cardiovascular events. Using Cox proportional hazards regression, we estimated hazard ratios (HRs) with 95% confidence intervals (95% CI) for associations between potential risk factors and cardiovascular events. Population attributable fractions (PAFs) for risk factors were estimated using R ('averisk' package). Results: Of the 4809 participants without prior cardiovascular disease, 57.7% were women and baseline mean age was 45.3 years. At follow-up (median of 4.9 years, 23,180 person-years [PYs]), 202 participants developed cardiovascular events, equating to an incidence of 8.7 cardiovascular events/1000 PYs. Incidence was greater in those with hypertension (hazard ratio [HR] [95% CI] 1.73 [1.21-2.49], adjusted PAF 18%), diabetes (1.96 [1.15-3.36], 4%) or central obesity (1.77 [1.23, 2.54], 9%) which together accounted for 31% of the PAF. Non-traditional risk factors such as night sleeping hours and number of children accounted for 16% of the PAF. Conclusions: Both traditional and non-traditional cardiovascular risk factors are important contributors to incident cardiovascular events in rural India. Interventions targeted to these factors could assist in reducing the incidence of cardiovascular events.