Cardiovascular

Influencing factors analysis and prediction model development for ROSC in adult non-traumatic OHCA: a retrospective study based on pre-hospital emergency settings.

TL;DR

This retrospective study of 9,386 adult non-traumatic OHCA patients identified multiple independent predictors of ROSC and developed a nomogram prediction model with an AUC of 0.775 and negligible overfitting that showed good calibration and favorable net clinical benefit.

Key Findings

The overall ROSC rate among adult non-traumatic OHCA patients in this study was 7.2%.

  • 9,386 cases were included from Tianjin Emergency Medical Center from January 1, 2023 to December 31, 2024.
  • 678 patients (7.2%) achieved sustained ROSC up to emergency department arrival and handover to receiving-hospital staff.
  • The primary outcome was defined as sustained ROSC maintained through ED arrival and staff handover.
  • Data were collected retrospectively from electronic medical records.

Shockable initial cardiac rhythm was the strongest single predictor of ROSC, associated with nearly a 3-fold increase in odds.

  • Shockable initial rhythm had an adjusted odds ratio (aOR) of 2.850 (95% CI: 2.390–3.397).
  • This was identified via multivariable mixed-effects logistic regression with clinician ID as a random intercept to adjust for clustering bias.
  • This was the largest effect size among all identified independent predictors.

Endotracheal intubation was independently associated with significantly higher odds of ROSC.

  • Endotracheal intubation had an aOR of 2.294 (95% CI: 1.936–2.718).
  • This was the second largest effect size among identified predictors.
  • The association was identified in multivariable mixed-effects logistic regression adjusting for clustering by clinician.

Longer onset-to-ambulance intervals were progressively and independently associated with lower odds of ROSC.

  • Compared to an interval of ≤5 minutes, intervals of 5–10 min had aOR = 0.758, 10–30 min had aOR = 0.578, and >30 min had aOR = 0.498.
  • This dose-response relationship indicates that each incremental delay in ambulance arrival substantially reduces the probability of ROSC.
  • Prolonged emergency response time was also independently associated with lower ROSC odds (aOR = 0.971, 95% CI: 0.945–0.999).

Epinephrine administration exceeding 5 mg was independently associated with lower odds of ROSC.

  • Epinephrine >5 mg had an aOR of 0.765 (95% CI: 0.626–0.935).
  • This suggests that higher cumulative epinephrine doses, likely reflecting prolonged resuscitation, were negatively associated with ROSC.
  • The finding was identified through multivariable mixed-effects logistic regression.

Public location of cardiac arrest onset was independently associated with higher odds of ROSC compared to non-public locations.

  • Public location had an aOR of 1.285 (95% CI: 1.038–1.592).
  • Cardiac arrest occurring between 06:00–12:00 was also independently associated with higher ROSC odds (aOR = 1.308, 95% CI: 1.018–1.682).
  • Cardiac arrest not having occurred at the time of emergency call (i.e., witnessed or witnessed with bystander CPR) was associated with higher ROSC odds (aOR = 1.540, 95% CI: 1.048–2.262).

Physician characteristics including sex, years of practice, and professional title were independently associated with ROSC outcomes.

  • Male attending physicians were associated with higher ROSC odds (aOR = 1.255, 95% CI: 1.077–1.464).
  • Longer physician practice years were associated with higher ROSC odds (aOR = 1.043, 95% CI: 1.022–1.065).
  • Intermediate physician title (versus other titles) was associated with higher ROSC odds (aOR = 1.236, 95% CI: 1.047–1.459).
  • These factors were adjusted for using clinician ID as a random intercept in a mixed-effects logistic regression model.

The developed nomogram prediction model demonstrated good discrimination, minimal overfitting, good calibration, and favorable net clinical benefit.

  • The nomogram AUC was 0.775 (95% CI: 0.756–0.794) in the training set and 0.775 (95% CI: 0.745–0.805) in the test set.
  • 1000-bootstrap internal validation yielded an optimism-corrected C-index of 0.7679 with minimal optimism of 0.0071, indicating negligible overfitting.
  • Patients were randomly split 7:3 for training and internal testing.
  • Calibration curves and decision curve analysis (DCA) further confirmed predictive consistency and net clinical benefit.
  • The acceptable discrimination threshold was pre-specified as AUC >0.7.

What This Means

This research suggests that many factors — ranging from where and when a cardiac arrest happens, to how quickly emergency services respond, to the specific treatments provided and the experience of the treating physician — all meaningfully affect whether an out-of-hospital cardiac arrest patient achieves return of spontaneous circulation (ROSC), meaning their heart starts beating again before reaching the hospital. The study analyzed nearly 9,400 cardiac arrest cases treated by emergency services in Tianjin, China over two years, finding that only about 1 in 14 patients achieved ROSC. Key factors linked to better outcomes included having a 'shockable' heart rhythm (the type that can be treated with a defibrillator), receiving endotracheal intubation (a breathing tube), having a cardiac arrest in a public place, and having a more experienced physician respond. Factors linked to worse outcomes included longer delays between collapse and ambulance arrival, and receiving high doses of epinephrine (adrenaline), which likely reflects prolonged and difficult resuscitation attempts. Using these findings, the researchers built a predictive scoring tool called a nomogram that can estimate the probability of ROSC for an individual patient based on these factors. The model performed well statistically, with an accuracy score (AUC) of approximately 0.775 in both the group used to build it and a separate test group, and showed very little overfitting — meaning it is likely to generalize to new patients rather than just fitting the original data. This research suggests that pre-hospital emergency systems might improve outcomes by minimizing response times, prioritizing airway management, and accounting for physician experience in dispatch decisions. The prediction model could potentially help clinicians and emergency systems identify which patients are more or less likely to benefit from continued resuscitation efforts.

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Citation

Zhang Q, Pang Z, Yan X, Tang F, Li S, Shao X, et al.. (2026). Influencing factors analysis and prediction model development for ROSC in adult non-traumatic OHCA: a retrospective study based on pre-hospital emergency settings.. Annals of medicine. https://doi.org/10.1080/07853890.2026.2740275