Assessment of Differences in Inpatient Rehabilitation Services for Length of Stay and Health Outcomes Between US Medicare Advantage and Traditional Medicare Beneficiaries

IMPORTANCE: Enrollment in Medicare Advantage (MA) has been increasing and has reached one-third of total Medicare enrollment. Because of data limitations, direct comparison of inpatient rehabilitation services between MA and traditional Medicare (TM) beneficiaries has been very scarce. Subgroups of elderly individuals admitted to inpatient rehabilitation facilities (IRFs) may experience different care outcomes by insurance types. OBJECTIVE: To measure the differences in length of stay and health outcomes of inpatient rehabilitation services between TM and MA beneficiaries in the US. DESIGN, SETTING, AND PARTICIPANTS: This multiyear cross-sectional study used the Uniform Data System for Medical Rehabilitation to assess rehabilitation services received by elderly (aged >65 years) Medicare beneficiaries in IRFs between 2007 and 2016 for stroke, hip fracture, and joint replacement. Generalized linear models were used to assess whether an association existed between Medicare insurance type and IRF care outcomes. Models were adjusted for demographic characteristics, clinical conditions, and facility characteristics. Data were analyzed from September 2018 to August 2019. EXPOSURES: Medicare insurance plan type, TM or MA. MAIN OUTCOMES AND MEASURES: Inpatient length of stay in IRFs, functional improvements, and possibility of returning to the community after discharge. RESULTS: The sample included a total of 1 028 470 patients (634 619 women [61.7%]; mean [SD] age, 78.23 [7.26] years): 473 017 patients admitted for stroke, 323 029 patients admitted for hip fracture, and 232 424 patients admitted for joint replacement. Individuals enrolled in MA plans were younger than TM beneficiaries (mean [SD] age, 76.96 [7.02] vs 77.95 [7.26] years for stroke, 79.92 [6.93] vs 80.85 [6.87] years for hip fracture, and 74.79 [6.58] vs 75.88 [6.80] years for joint replacement) and were more likely to be black (17 086 [25.5%] vs 54 648 [17.9%] beneficiaries) or Hispanic (14 496 [28.5%] vs 24 377 [8.3%] beneficiaries). The MA beneficiaries accounted for 21.8% (103 204 of 473 017) of admissions for stroke, 11.5% (37 160 of 323 029) of admissions for hip fracture, and 11.8% (27 314 of 232 424) of admissions for joint replacement. The MA beneficiaries had shorter mean lengths of stay than did TM beneficiaries for both stroke (0.11 day; 95% CI, −0.15 to −0.07 day; 1.15% shorter) and hip fracture (0.17 day; 95% CI, −0.21 to −0.13 day; 0.85% shorter). The MA beneficiaries also had higher possibilities of returning to the community than did TM beneficiaries, by 3.0% (95% CI, 2.6%-3.4%) for stroke and 5.0% (95% CI, 4.4%-5.6%) for hip fracture. The shorter length of stay and better ultimate outcomes were achieved without substantially compromising the intermediate functional improvements. Facility type (freestanding vs within an acute care hospital) and patient alternative payment sources other than Medicare (none vs other) partially explained the differences between insurance types. CONCLUSIONS AND RELEVANCE: This study suggests that MA enrollees experience shorter length of stay and better outcomes for postacute care than do TM beneficiaries in IRFs. The magnitude of the differences depends on treatment deferability, patient sociodemographic subgroups, and facility characteristics.