Outcomes for Arthroplasties in Military Health: A Retrospective Analysis of Direct Versus Purchased Care

The Department of Defense is reforming the military health system where surgeries are increasingly referred from military treatment facilities (MTFs) with direct care to higher-volume civilian hospitals under purchased care. This shift may have implications on the quality and cost of care for TRICARE beneficiaries. This study examined the impact of care source and surgical volume on perioperative outcomes and cost of total hip arthroplasties (THAs) and total knee arthroplasties (TKAs).

We examined TRICARE claims for patients who underwent THA or TKA between 2006 and 2019. The 30-day readmissions, complications, and costs between direct and purchased care were evaluated using the logistic regression model for surgical outcomes and generalized linear models for cost.

We included 71,785 TKA and THA procedures. 11,013 (15.3%) were performed in direct care. They had higher odds of readmissions (odds ratio, OR 1.29 [95% CI, 1.12-1.50]; P < 0.001) but fewer complications (OR 0.83 [95% CI, 0.75-0.93]; P = 0.002). Within direct care, lower-volume facilities had more complications (OR 1.27 [95% CI, 1.01-1.61]; P = 0.05). Costs for index surgeries were significantly higher at MTFs $26,022 (95% CI, $23,393-$28,948) vs. $20,207 ($19,339-$21,113). Simulating transfer of care to very high-volume MTFs, estimated cost savings were $4,370/patient and $20,229,819 (95% CI, $17,406,971-$25,713,571) in total.

This study found that MTFs are associated with lower odds of complications, higher odds of readmission, and higher costs for THA and TKA compared to purchased care facilities. These findings mean that care in the direct setting is adequate and consolidating care at higher-volume MTFs may reduce health care costs.