Jacqueline Boehme, BS1, Sophia K McKinley, MD, EdM1, L. Michael Brunt, MD2, Tina D Hunter, PhD3, Daniel B Jones, MD, MS, FACS1, Daniel J Scott, MD4, Steven D Schwaitzberg, MD1. 1Harvard Medical School, 2Washington University School of Medicine, 3CTI Clinical Trials and Consulting, 4UT Southwestern Medical Center
Background: A dearth of literature exists concerning the association between distinct comorbidities and resource utilization in patients undergoing cholecystectomy. This study aimed to review resource utilization trends of laparoscopic and open cholecystectomies from a comprehensive payer database in order to characterize patient factors associated with increased resource utilization. As healthcare payment models move towards bundled payments, group pricing, and Accountable Care Organizations (ACOs), the importance of determining patient factors and how case mix affects resource utilization becomes increasingly relevant in order to create optimal clinical care and overall net savings, yet maintain financial margins for provider revenues.
Methods: A total of 53,632 open and laparoscopic cholecystectomies were reviewed from July 2009 to December 2010 from a large private payer claims database. ICD-9 and CPT codes were available for each event, as well as basic demographics including sex and age group. Data regarding 30 day postoperative resource utilization metrics (emergency, clinic, office, home, outpatient, short procedure unit visits, inpatient hospitalizations, and readmissions) were analyzed and stratified by patient comorbidities as presence or absence of diabetes mellitus, hypertension, or hyperlipidemia. Differences were evaluated with Pearson’s chi-squared tests.
Results: Of the 53,632 patients studied, 71.2% (38,171) were female and 28.8% (15,461) male. The principal comorbidities were: 13.7% (7,354) had diabetes mellitus, 34.2% (18,324) hypertension, and 30.6% (16,436) hyperlipidemia. In terms of resource utilization within 30 days of surgery, 0.1% (59) had a short procedure unit visit, 6.6% (3,538) an ER visit, 7.7% (4,103) a 30-day readmission, 4.0% (2,140) a home visit, and 29.7% (15,900) an outpatient hospital visit. All three comorbidities showed a significantly positive difference between the number of certain visits within 30 days of surgery for patients with vs. without the respective conditions: home visits (diabetes 10.6% versus 2.9%, p<0.0001; hypertension 7.2% versus 2.3%, p<0.0001; hyperlipidemia 6.4% versus 2.9%, p<0.0001), and outpatient hospital visits (diabetes 36.1% versus 28.6%, p<0.0001; hypertension 33.4% versus 27.7%, p<0.0001; hyperlipidemia 33.0% versus 28.2%, p<0.0001). Patients with diabetes and hypertension were significantly more likely to have an ER visit within 30 days of surgery (diabetes 7.4% versus 6.5%, p=0.0018; hypertension 7.0% versus 6.4%, p=0.0090). Finally, all three comorbidities demonstrated a positive association with having an inpatient hospitalization within 30 days of surgery (p<0.0001 for all).
Conclusions: Patient comorbidity indexing plays a major role in clinical risk stratification and resource utilization for both open and laparoscopic cholecystectomy. These factors should be considered in bundled reimbursement packages given their role in determining potential resource utilization in the postoperative setting.