Text message alert system and resuscitation outcomes after out-of-hospital cardiac arrest: A before-and-after population-based study

Introduction; This study aimed to investigate the association of a resuscitation bundle intervention including text message (TM) alert system and bystander cardiopulmonary resuscitation (CPR) and outcomes of out-of-hospital cardiac arrest (OHCA). Methods: A population intervention study was conducted for resuscitation-attempted OHCAs from 2013 to 2017 in selected districts in Seoul, Korea. A bundle intervention consisting of three components was implemented in May 2015:1) community CPR training and organizing volunteer network, 2) installation of public access defibrillators (PAD) and 3) text message (TM) sent to registered volunteers to inform them about the OHCA event and nearest PAD. The study outcomes (bystander CPR, survival to discharge and good neurological outcome at hospital discharge) were compared between intervention period (after-intervention: May 2015 to December 2017) and control period (before-intervention: January 2013 to April 2015). A multivariable logistic regression analysis was performed to determine the effect of the intervention. Adjusted odds ratios (AORs) with 95% confidence intervals (Cis) were calculated, adjusting for potential confounders. As a sensitivity analysis, propensity score matching (PSM) method was used for cases of the before period to the TM sent cases in the after period to balance covariate in the before and after groups. the same logistic regression model was evaluated with this PSM population. Results: A total of 3194 eligible OHCA cases (1498 in before- and 1696 in after-intervention) were evaluated. The bystander CPR rate increased during the study periods (from 54.9% to 59.8%) (p < 0.01). OHCA outcomes improved from 9.0% to 12.7% for survival to discharge and from 4.5% to 8.3% for good neurological outcome (all p < 0.01). Compared with control periods, the AORs (95% Cls) for bystander CPR, survival to discharge and good neurological outcome of the intervention period were 1.25 (1.08-1.44), 1.84 (1.29-2.63) and 2.31 (1.44-3.70), respectively. Similar results were observed in the PSM population. Conclusion: The bundle intervention including TM alert service for OHCA was associated with better survival outcomes through an increase in bystander CPR.