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. 2025 Dec 13:27:101193.
doi: 10.1016/j.resplu.2025.101193. eCollection 2026 Jan.

Dispatcher-assisted cardiopulmonary resuscitation for out-of-hospital cardiac arrest patients: a site-level analysis of the PAROS trial

Fahad Javaid Siddiqui  1 , Stephanie Fook-Chong  1 , Nur Shahidah  1   2 , David Pflug  3 , Benjamin Sieu-Hon Leong  4   5 , Sang Do Shin  6   7 , Hyun Wook Ryoo  8 , Hyun Ho Ryu  9 , Chih-Hao Lin  10 , Chan-Wei Kuo  11 , Marcus Eng Hock Ong  2   12 ; PAROS Clinical Research Network
Collaborators, Affiliations

Dispatcher-assisted cardiopulmonary resuscitation for out-of-hospital cardiac arrest patients: a site-level analysis of the PAROS trial

Fahad Javaid Siddiqui et al. Resusc Plus. .

Abstract

Objectives: The study aimed to examine the influence of contextual settings on the complex OHCA intervention outcomes thereby providing evidence to guide managers and policymakers in optimizing implementation strategies. Our secondary analysis of an international multi-site trial examined site-level effectiveness of comprehensive versus basic Dispatcher-Assisted CPR (DACPR) interventions on bystander CPR rates, hypothesizing site-specific variation and declining variability as an early sign.

Methods: Using 2009-2018 data from the Pan-Asian Resuscitation Outcomes Study (PAROS), we compared monthly and quarterly trends in BCPR rates at selected PAROS sites before and after the intervention. Interrupted time series analysis was performed using regression of monthly BCPR rates for the pre- and post-intervention periods.

Results: Six PAROS sites contributed 37,872 out-of-hospital cardiac arrest (OHCA) cases from January 2009 to June 2018. Comprehensive package sites showed consistent improvement in average monthly BCPR rates, with absolute increases ranging from 4.2 to 30.8 percentage points. Sharper post-intervention increases in DACPR rates were observed, indicated by positive site-wise regression coefficient differences (0.07-0.38). However, some sites experienced an initial post-intervention slowdown of the pre-existing trend. The two Basic package sites also improved their BCPR rates by 9.3 and 25.1 percentage points, though the shorter pre-intervention periods limited meaningful interpretation of the rate of change (0.22 & -0.33).

Conclusion: Both intervention packages improved BCPR rates, with most sites showing steeper improvements post-intervention. However, variations in timing and magnitude between sites highlight differing levels of system readiness and implementation rigor. Reduced variability has been observed post-intervention.

Keywords: Bystander CPR; Dispatcher-assisted cardiopulmonary resuscitation; PAROS; Telephone instructions.

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Conflict of interest statement

MEH Ong is a member of the Editorial Board of Resuscitation. MEH Ong reports grants from the Laerdal Foundation, Laerdal Medical, and Ramsey Social Justice Foundation for funding of the Pan-Asian Resuscitation Outcomes Study; an advisory relationship with Global Healthcare Singapore (SG), a commercial entity that manufactures cooling devices. MEH Ong has a licensing agreement with ZOLL Medical Corporation and patent filed (Application no: 13/047,348) for a “Method of predicting acute cardiopulmonary events and survivability of a patient”. He is also the co-founder and scientific advisor of Technology Innovation in Medicine (TIIM) Healthcare, a commercial entity which develops real-time prediction and risk stratification solutions for triage. All other authors have no conflict of interest to declare.

Figures

Fig. 1
Fig. 1
Patient selection flow chart.
Fig. 2
Fig. 2
Quarterly trend of bystander CPR prevalence during the observation period for PAROS network cities included in the analysis by intervention package. Panel A: Comprehensive DACPR; B: Basic DACPR; C: Control (No DACPR). Four quarters on the x-axis represents 1 year.
Fig. 2
Fig. 2
Quarterly trend of bystander CPR prevalence during the observation period for PAROS network cities included in the analysis by intervention package. Panel A: Comprehensive DACPR; B: Basic DACPR; C: Control (No DACPR). Four quarters on the x-axis represents 1 year.
See this image and copyright information in PMC

References

    1. Yan S., Gan Y., Jiang N., Wang R., Chen Y., Luo Z., et al. The global survival rate among adult out-of-hospital cardiac arrest patients who received cardiopulmonary resuscitation: a systematic review and meta-analysis. Crit Care. 2020;24(1):61. - PMC - PubMed
    1. Parvez S.S., Parvez S., Ullah I., Parvez S.S., Ahmed M. Systematic review on the worldwide disparities in the frequency and results of Emergency Medical Services (EMS) and response to Out-of-Hospital Cardiac Arrest (OHCA) Cureus. 2024;16(6) - PMC - PubMed
    1. Shekhar A., Narula J. Globally, GDP per capita correlates strongly with rates of Bystander CPR. Ann Glob Health. 2022;88:36. - PMC - PubMed
    1. Ong M.E.H., Shin S.D., Ko P.C., Lin X., Ma M.H., Ryoo H.W., et al. International multi-center real world implementation trial to increase out-of-hospital cardiac arrest survival with a dispatcher-assisted cardio-pulmonary resuscitation package (Pan-Asian resuscitation outcomes study phase 2) Resuscitation. 2022;171:80–89. - PubMed
    1. Okada Y., Hong K.J., Lim S.L., Hong D., Ng Y.Y., Leong B.S., et al. The “invisible ceiling” of bystander CPR in three Asian countries: descriptive study of national OHCA registry. Resuscitation. 2024;206 - PubMed

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