Background: Days alive and out of hospital (DAOH) could be an alternative outcome measure for medical [1], and perioperative outcome studies.[2] However, lack of procedure specific data and standardized perioperative care may hinder interpretation. The aim of this study was to investigate DAOH in fast-track total hip (THA) and knee arthroplasty (TKA).

Methods: An 8 center cohort study from 2012-2015 with prospective data on comorbidity and complete follow-up on length of hospital stay (LOS) and 90-days readmissions/mortality using the Danish National Patient Registry and evaluation of discharge records. LOS was counted as postoperative nights in hospital. Readmissions were counted as days in hospital, excluding emergency room/outpatient visits. We compared high vs. low-risk patients according to a previously published preoperative risk-score for medical complications.[3]

Results: Of 16137 procedures, 2889 (19%) were in high-risk and 12633 (81%) in low-risk patients (data missing in 615 patients). Median LOS was 2 days (IQR 2-3), 90-days readmissions were 8.2 % and mortality was 0.3%. Median DAOH was 88 days (IQR 87-88) and >96 % of patients had DAOH of 81-90 days, but reduced in high vs. low-risk patients (91% vs. 97%  p<0.001) (fig. 1 and table 1)

Discussion: We found a high rate of DAOH in fast-track THA an TKA, although less in high-risk patients. In contrast to a study in mixed procedures measuring 30 days DAOH [2], the clinical relevance of 90-days DAOH was limited considering the rarity of DAOH <81, including in high-risk patients. 

Conclusion: The clinical relevance of 90-days DAOH as an outcome measure may be limited in fast-track THA and TKA, although high-risk patients have significantly fewer DAOH. 

References:
[1]Ariti et al. AM Heart J 2011; 162:900-6
[2]Myles et al. BMJ-OPEN;2017-015828
[3]Jorgensen et al. BMJ-OPEN; 2015-009813

03 / Days alive and out of hospital within 90 days after fast-track total hip and knee arthroplasty