Addressing competing risks when assessing the impact of health services interventions on hospital length of stay

News

Published: 14Dec2020

The IHSP's Arijit Nandi co-authored an article in Epidemiology:

Batomen B, Moore L, Strumpf E, Nandi A

Addressing competing risks when assessing the impact of health services interventions on hospital length of stay

Epidemiology (Cambridge, Mass.)
November 23, 2020 - Volume Published Ahead of Print
DOI: 10.1097/ede.0000000000001307. PMID: 33284168.

Abstract:

Background: Although hospital length of stay is generally modeled continuously, it is increasingly recommended that length of stay should be considered a time-to-event outcome (i.e., time to discharge). Additionally, in-hospital mortality is a competing risk that makes it impossible for a patient to be discharged alive. We estimated the effect of trauma center accreditation on risk of being discharged alive while considering in-hospital mortality as a competing risk. We also compared these results with those from the "naïve" approach, with length of stay modeled continuously.

Methods: Data include admissions to a level I trauma center in Quebec, Canada between 2008 and 2017. We computed standardized risk of being discharged alive at specific days by combining inverse probability weighting and the Aalen-Johansen estimator of the cumulative incidence function. We estimated effect of accreditation using pre-post, interrupted time series analyses (ITS) and the "naïve" approach.

Results: Among 5,300 admissions, 12% died, and 83% were discharged alive within 60 days. Following accreditation, we observed increases in risk of discharge between the 7, 4.5% (95%CI: 2.3, 6.6) and 30 days since admission 3.8% (95%CI 1.5, 6.2). We also observed a stable decrease in hospital mortality, -1.9% (95%CI -3.6, -0.11) at the 14 day. Although pre-post and ITS produced similar results, we observed contradictory associations with the naïve approach.

Conclusions: Treating length of stay as time to discharge allows for estimation of risk of being discharged alive at specific days after admission while accounting for competing risk of death. 

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