The Optimal Length of Stay Associated With the Lowest Readmission Risk Following Surgery

Index length of stay (LOS) and readmissions are viewed as important quality measures. However, these metrics represent competing demands as an inordinate reduction in LOS may lead to unplanned readmissions. We sought to assess the optimal LOS associated with the lowest 90-d readmission rate following discharge after common surgical procedures.

This was a retrospective study relying on Tricare claims. We identified all eligible adult patients (18-64 y) receiving a series of common surgical procedures between 2006 and 2014. We used a generalized additive model with spline regression to determine the optimal LOS associated with the lowest 90-d risk of readmission.

Ninety-day readmission rates varied from 6.03% to 34.69%. Most procedures exhibited a logit linear relationship, with the lowest risk of readmission evident on postoperative day-1 and increasing thereafter. Among the more invasive procedures (e.g., esophagectomy and radical cystectomy), a U-shaped relationship was realized, indicating that expedited discharge would increase the potential for readmission as would any extended hospital LOS. For these procedures, the ideal index LOS appeared to be 6-7 d for radical cystectomy and 12-13 d for esophagectomy.

Our results support the practice of discharging patients as soon as clinically feasible after hip and knee arthroplasty, lumbar spine surgery, hernia repair, appendectomy, nephrectomy, and colectomy. Among esophagectomy or radical cystectomy, there is a well-defined optimal index admission period and discharge outside this window appears to be detrimental. Our results suggest that invasive procedures appear to possess a unique "signature" when it comes to optimal LOS.