Device implantation rates during inpatient surgery differ among payers at critical access versus other hospitals

Abstract

BackgroundUnited States critical access hospitals are paid by Medicare at 101% of reasonable costs, not based on Diagnosis Related Groups (i.e., not a preset payment and thus not an incentive to constrain costs). We hypothesized that critical access hospitals would perform disproportionately more surgical procedures involving implanted devices among patients with Medicare as the primary payer than would other hospitals. MethodsThis retrospective, observational cohort study examined all 272,553 major therapeutic procedures performed during inpatient surgery, October 1, 2015, to June 30, 2017, at Iowa's 82 critical access and 41 other non-federal hospitals. ResultsAs hypothesized, among patients with Medicare as the primary payer, there were proportionately more procedures with implanted devices performed at critical access versus other hospitals (relative risk 1.14). Similarly, among patients with Medicare not being the primary payer, there were proportionately fewer procedures with devices performed at critical access versus other hospitals (relative risk 0.48). However, unexpectedly, many more of the procedures performed at critical access hospitals (73.2%) with an implantable device were lower limb joint replacement than at other hospitals (31.6%). The relative risks for lower joint replacement at critical access versus other hospitals were >1 both for patients with Medicare (2.46) and without Medicare (1.17) as primary payer. These 4 relative risks were all P < .00001. ConclusionsCritical access hospitals perform disproportionately more surgical procedures with implantation of devices among Medicare patients as compared with other hospitals. However, this is an indirect effect and caused mostly by the single class of procedure of hip or knee arthroplasty, not opportunistic decision-making.