Incidence and considerations of 90-day readmissions following posterior lumbar fusion.

BACKGROUND CONTEXT: Posterior lumbar fusion (PLF) is a commonly performed procedure. The evolution of bundled payment plans is beginning to require physicians to more closely consider patient outcomes up to 90 days after an operation. Current quality metrics and other databases often consider only 30 postoperative days. The relatively new Healthcare Cost and Utilization Project Nationwide Readmissions Database (HCUP-NRD) tracks patient-linked hospital admissions data for up to one calendar year.

PURPOSE: To identify readmission rates within 90 days of discharge following PLF and to put this in context of 30 day readmission and baseline readmission rates.

STUDY

DESIGN

Retrospective study of patients in the HCUP-NRD.

PATIENT SAMPLE: Any patient undergoing PLF performed in the first 9 months of 2013 were identified in the HCUP-NRD.

OUTCOME MEASURES: Readmission patterns up to a full calendar year after discharge.

METHODS

PLFs performed in the first 9 months of 2013 were identified in the HCUP-NRD. Patient demographics and readmissions were tracked for 90 days after discharge. To estimate the average admission rate in an untreated population, the average daily admission rate in the last quarter of the year was calculated for a subset of PLF patients who had their operation in the first quarter of the year. This study was deemed exempt by the institution's Human Investigation Committee.

RESULTS

Of 26,727 PLFs, 1,580 patients (5.91%) were readmitted within 30 days of discharge and 2,603 patients (9.74%) were readmitted within 90 days of discharge. Of all readmissions within 90 days, 54.56% occurred in the first 30 days. However, if only counting readmissions above the baseline admission rate of a matched population from the 4th quarter of the year (0.08% of population/day), 89.78% of 90 day readmissions occurred within the first 30 days.

CONCLUSIONS

The current study delineates readmission rates after PLF and puts this in the context of 30-day readmission rates and baseline readmission rates for those undergoing PLF. These results are important for patient counseling, planning, and preparing for potential bundled payments in spine surgery.