Skilled Nursing Facility Network Capacity and Hospital Length of Stay.

Importance: Delays in hospital discharge to skilled nursing facilities (SNFs) are widely viewed by hospital administrators and policymakers as a significant contributor to hospital crowding and adverse patient outcomes. However, the extent to which regional SNF capacity is associated with hospital length of stay (LOS) is not well understood. Objectives: To construct empirically derived hospital-SNF markets using a network science approach and to examine whether variation in SNF capacity within these markets is associated with hospital LOS. Design, Setting, and Participants: This cross-sectional study used 2018 and 2019 Medicare fee-for-service claims linked with publicly available SNF data and included 3.34 million inpatient admissions discharged to SNFs from short-term hospitals in the US. Data were analyzed from October 1, 2024, to February 28, 2026. Exposures: Monthly mean SNF occupancy rates and nurse and therapy staffing levels within an empirically defined regional hospital-SNF market from a patient-sharing network analysis. Main Outcomes and Measures: The main outcome was hospital LOS. Linear regression models estimated associations between market-level SNF capacity measures and LOS, adjusting for patient characteristics, hospital-level postacute care demand, SNF organizational features, and time and hospital-SNF market fixed effects. Analyses were stratified by dual Medicare-Medicaid eligibility. Results: The study sample included 3.34 million Medicare inpatient admissions (mean [SD] age, 78.6 [11.3] years; 60.2% women) discharged to SNFs across 62 303 hospital-SNF dyads, and 421 empirically derived hospital-SNF markets. The mean (SD) hospital LOS was 6.9 (6.8) days (7.4 [7.8] days for dual-eligible patients and 6.7 [6.2] days for non-dual-eligible patients). Within markets, each additional nurse staffing hour per patient-day was associated with a 3.5% shorter LOS (95% CI, -5.5% to -1.4%); associations were also found among dual-eligible patients (-3.9% [95% CI, -6.7% to -0.9%) and non-dual-eligible patients (-3.2% [95% CI, -5.4% to -0.9%]). Differences in occupancy rates and therapy staffing within networks were not associated with differences in LOS after adjusting for patient, hospital, and network factors. Conclusions and Relevance: Hospital-SNF markets defined by the strength of patient-sharing relationships provide a reproducible framework for examining postacute care capacity across payer populations. Within these markets, for the Medicare fee-for-service population, higher nurse staffing levels were associated with shorter hospital LOS. Strategies to reduce discharge delays and hospital crowding may require closer alignment between hospitals and highly connected SNFs to maintain adequate postacute care capacity.