The impact of minimally invasive surgery on complex DRG assignments

Purpose: Minimally invasive surgery is associated with improved clinical outcomes and reduced costs. We hypothesize that in patients with similar preoperative characteristics, hysterectomy, colectomy, and thoracic resection performed via minimally invasive surgery (MIS) approach would be associated with fewer complex Diagnosis Related Group (cDRG) assignments and subsequently result in reimbursement savings. Methodology: Premier hospital database was used to examine inpatient discharges of open and MIS colectomy, hysterectomy and thoracic resection. Open and MIS groups were matched based on propensity score. Descriptive statistics and regression analysis were used to assess the impact of MIS on cDRG assignment. Potential reimbursement savings to the U.S. health care system, assuming a 10% increase in MIS utilization, was estimated using Medicare's Fiscal Year (FY) 2013 national average reimbursement data and Premier's procedure volume projections. Results: Compared with open surgery, the MIS group had a statistically significantly lower percentage of cDRG assignment (colectomy, 57% vs. 71%; hysterectomy, 15% vs. 19%; thoracic resection, 62% vs. 70%; P<.001 for each). Open surgery, when compared to MIS, increased the odds of cDRG assignment by 67% (odds ratio [OR], 1.67; 95% confidence interval [CI], 1.62-1.71). We estimated that a 10% increase in MIS utilization would lead to annual payer reimbursement savings of about $24.4 million (colectomy, $17 million; hysterectomy, $5 million; thoracic resection, $2.4 million). Conclusion: Health care reform laws and economic pressures are causing a shift in focus from volume-based to value-based care. MIS approaches reduce payer expense based on fewer expensive cDRG assignments. Further adoption of MIS may lead to improved outcomes and additional savings.