The effect of a total hip arthroplasty bundled payment program on perioperative smoking and obesity

Medicare's Bundled Payments for Care Initiative is a risk-sharing, value-based alternative payment model. As such, Medicare providers are financially responsible for poor outcomes, potentially disincentivizing operating on high-risk individuals, including obese patients and smokers. We sought to describe the change in these modifiable risk factors among Medicare, Medicaid, and commercially insured patients in the 6-year period after implementation of Bundled Payments for Care Initiative.

We analyzed a consecutive series of 11,790 patients who underwent total hip arthroplasty between January 1, 2013, and August 31, 2019. We categorized patients based on smoking status (current, former, or never) and body mass index (BMI; obese if BMI was >30 kg/m2, morbidly obese if BMI was >40 kg/m2, and superobese if BMI was >50 kg/m2). Correlations between each year's proportion of patients in each smoking category and obesity category were evaluated.

We included 11,582 patients with complete demographic and insurance information. There was a statistically significant decrease in the proportion of Medicare patients who were active smokers (7.91% in 2013, 5.99% in 2019, Pearson correlation coefficient = -0.759, P = .048). When looking at patients with BMI >40 kg/m2, commercially insured patients significantly increased (3.64% in 2013, 6.65% in 2019, Pearson correlation coefficient = 0.860, P = .013). Our study also demonstrated a significantly higher rate of active smokers among Medicaid patients compared with other insurance groups (P = .001), which is consistent with the general population.

Our results demonstrated that the proportion of Medicare-insured patients who were active smokers decreased significantly over the study period. In addition, the proportion of obese commercially insured patients increased, but the proportion of obese Medicare patients did not. These findings suggest the possibility that surgeons may be disincentivized to operate on both obese patients and those who are actively smoking who are enrolled in risk-sharing, value-based programs. Notably, we found a potential trickle-down effect to Medicare patients with our smoking cessation program. The same was not observed for patients with Medicaid or Commercial insurance or for weight reduction before surgery for any insurance group. A possible explanation is that obesity is not as modifiable as smoking and increased efforts to address obesity in the arthritis population are needed.

III, retrospective observational analysis.