Abstract 261: Effect of Therapeutic Hypothermia After Out-of-Hospital Cardiac Arrest in Early Phase of Implementation: Propensity-Score Matching and Inverse Probability of Treatment-Weighted Analysis
Introduction: Therapeutic hypothermia (TH) is usually applied to selective patients in the early phase of implementation due to many local barriers. Thus therapeutic effects of TH could be overestimated or underestimated during the period. The objective of this study was to determine whether TH is associated with increased survival to discharge and favorable neurological outcome for adult out-of-hospital cardiac arrest (OHCA) patients during the first five years of implementation in a tertiary teaching hospital.
Hypothesis: We hypothesized that TH would be associated with increased survival and favorable neurological outcome at hospital discharge in adult comatose survivors of OHCA during the early phase of implementation.
Methods: Adult comatose survivors of OHCA from January 2006 to September 2010 were enrolled in the study. Favorable neurologic outcome was defined as cerebral performance category 1 or 2 at the time of hospital discharge. To reduce the effect of treatment-selection bias and potential confounding in the study, we performed rigorous adjustment for significant differences in the baseline characteristics of patients with the use of propensity-score (PS) matching and inverse probability of treatment weighted (IPTW) analysis. The adjusted odds ratio (OR) and its 95% confidence interval (95% CI) for the outcomes between TH and standard care group were calculated.
Results: During the implementation period, 163 OHCA patients (41%) regained spontaneous circulation. Of those patients, 49 (30%) were treated with mild (32-34°C) TH for 24 hours. Using PS matching, 32 patients were equally assigned to each group. The adjusted OR for the survival and favorable neurological outcome at hospital discharge was 9.13 (95% CI 2.92-28.50) and 4.39 (95% CI 1.08-17.89), respectively in the PS-matched patients. Using the IPTW analysis, the adjusted OR for the survival and favorable neurological outcome at hospital discharge was 6.82 (95% CI 3.05-15.24) and 3.27 (95% CI 1.18-9.08), respectively.
Conclusions: TH was associated with significant improvements in survival and neurologic outcomes at hospital discharge in adult comatose survivors of OHCA even in the early phase of implementation.
- © 2011 by American Heart Association, Inc.