Document Type : Original Article
Authors
1
Department of Fundamental Nursing, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
2
Clinical Research Center, NHO Nagasaki Medical Center, Omura, Japan
3
Healthcare Management Research Center, Chiba University, Chiba, Japan
4
Department of Cardiology, Chiba University Graduate School of Medicine, Chiba, Japan
5
Department of Healthcare Management Research Center, Chiba University Hospital, Chiba, Japan
Abstract
Background
Temporal variation in healthcare delivery is well documented, yet its implications for financing under hybrid payment systems remain unclear. Weekday differences in care processes may generate payment variation without corresponding outcome differences, raising efficiency and equity concerns. We examined weekday variation in per-diem reimbursement after hip fracture surgery under Japan’s Diagnosis Procedure Combination (DPC) system and whether it was accompanied by clinical-outcome differences.
Methods
We conducted a multicenter retrospective cohort study using nationwide DPC data from 185 acute care hospitals in Japan (April 2014–July 2025), including patients undergoing open reduction and internal fixation (ORIF) or hemiarthroplasty for proximal femoral fracture. The exposure was day of surgery (Monday–Friday); the primary outcome was per-diem fee-for-service (FFS) reimbursement (an FFS equivalent valuation of services, not realized revenue). Multivariable linear regression with cluster-robust standard errors, clustered at the hospital level, was fitted separately by procedure, adjusting for patient and admission characteristics. We assessed weekday patterns and a prespecified Monday–Friday comparison.
Results
Of 41 362 patients analyzed (ORIF, n = 25 779; hemiarthroplasty, n = 15 583), per-diem reimbursement showed a consistent weekday pattern, highest on Friday in both groups. Compared with Friday, Monday surgery was associated with lower adjusted per-diem reimbursement in both ORIF (β = −578.1 JPY; 95% CI, −1021.7 to −134.6; P = .010) and hemiarthroplasty (β = −736.4 JPY; 95% CI, −1389.5 to −83.2; P = .027). Surgery- and anesthesia-related services showed the largest Friday–Monday differences, whereas diagnostic testing differed minimally. Length of stay and recorded clinical indicators (discharge functional status and 7- and 28-day readmission) were broadly similar across weekdays.
Conclusion
Weekday variation in reimbursement was observed alongside broadly similar measured clinical indicators, suggesting that routine differences in care processes may be associated with reimbursement differences under hybrid financing systems. Routine monitoring of temporal payment patterns may help align reimbursement design more closely with observed care delivery.
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