Is the current referral trend a threat to the Military Health System? Perioperative outcomes and costs after colorectal surgery in the Military Health System versus civilian facilities.

BACKGROUND: TRICARE military beneficiaries are increasingly referred for major surgeries to civilian hospitals under "purchased care." This loss of volume may have a negative impact on the readiness of surgeons working in the "direct-care" setting at military treatment facilities and has important implications under the volume-quality paradigm. The objective of this study is to assess the impact of care source (direct versus purchased) and surgical volume on perioperative outcomes and costs of colorectal surgeries. METHODS: We examined TRICARE claims and medical records for 18- to 64-year-old patients undergoing major colorectal surgery from 2006 to 2015. We used a retrospective, weighted estimating equations analysis to assess differences in 30-day outcomes (mortality, readmissions, and major or minor complications) and costs (index and total including 30-day postsurgery) for colorectal surgery patients between purchased and direct care. RESULTS: We included 20,317 patients, with 24.8% undergoing direct-care surgery. Mean length of stay was 7.6 vs 7.7 days for direct and purchased care, respectively (P = .24). Adjusted 30-day odds between care settings revealed that although hospital readmissions (odds ratio 1.40) were significantly higher in direct care, overall complications (odds ratio 1.05) were similar between the 2 settings. However, mean total costs between direct and purchased care differed ($55,833 vs $30,513, respectively). Within direct care, mean total costs ($50,341; 95% confidence interval $41,509-$59,173) were lower at very high-volume facilities compared to other facilities ($54,869; 95% confidence interval $47,822-$61,916). CONCLUSION: Direct care was associated with higher odds of readmissions, similar overall complications, and higher costs. Contrary to common assumptions regarding volume and quality, higher volume in the direct-care setting was not associated with fewer complications.