Out-of-hospital cardiac arrest (OHCA) remains a global public health challenge with high mortality and poor neurological outcomes.[1,2] Early bystander cardiopulmonary resuscitation (CPR) substantially improves survival,[3] yet bystander CPR rates remain low in many regions, including China.[4]
Dispatcher-assisted CPR (DA-CPR) has been widely implemented to address low bystander intervention rates.[5] While compared with no CPR, DA-CPR generally improves outcomes, audio-guided DA-CPR has inherent limitations, including delayed dispatcher assessment, prolonged hands-off periods, and inconsistent compression quality,[6,7] and may yield inferior outcomes compared with spontaneous CPR by trained rescuers.[8,9] In China, language barriers, variable dispatcher training, and low public CPR literacy further complicate its effectiveness.[10]
Video-guided DA-CPR (V-DA-CPR) has emerged as a potential optimization.[11] In late 2024, Zhejiang Province established China’s first provincial full-coverage V-DA-CPR system, yet real-world clinical evidence remains scarce. This study aimed to evaluate the association between V-DA-CPR and OHCA outcomes using province-wide registry data.
This was a retrospective population-based cohort study using the 2025 Zhejiang Provincial OHCA Registry, which prospectively collects data on all EMS-managed OHCA cases in Zhejiang Province, adhering to the Utstein standard.[12] This study was approved by the Ethics Committee of Zhejiang Provincial People’s Hospital (Approval No: QT2026084); written informed consent was waived because of the retrospective use of anonymized data.
We included adults with presumed medical-origin witnessed OHCA who received EMS intervention. The exclusion criteria included traumatic or non-medical causes, no on-scene EMS intervention, missing core data, and arrests witnessed by EMS providers. Missing data for model variables were <5%; complete-case analysis was used.
Patients were divided into the following groups: (1) no bystander CPR; (2) self-led bystander CPR—CPR initiated spontaneously without dispatcher guidance; and (3) V-DA-CPR—CPR under real-time two-way video guidance from dispatchers. Audio-only DA-CPR cases (failed video connection) were excluded because of small numbers. Rural areas were defined as regions not designated as urban districts by the National Bureau of Statistics of China.
The primary outcomes were 30-day survival and favorable neurological recovery (cerebral performance categories 1-2). Secondary outcomes were bystander automated external defibrillator (AED) use and prehospital return of spontaneous circulation (ROSC).
Continuous variables are presented as medians (interquartile ranges [IQRs]), and categorical variables are presented as counts (percentages). Groups were compared using the Kruskal-Wallis H test and Chi-square test. Multivariable logistic regression adjusted for age, sex, cardiac etiology, arrest location, initial rhythm, EMS response time, and prehospital interventions (epinephrine, advanced airway management, mechanical CPR). No bystander CPR or self-led bystander CPR served as references in separate models. Absolute risk differences (ARDs) and a rurality × CPR type interaction test were reported. A two-tailed P-value<0.05 was considered to indicate statistical significance. SPSS 26.0 was used for the analyses, and the figures were generated using Python 3.13.12 with Matplotlib 3.10.3.
Among the 29,314 OHCA patients screened, 7,240 witnessed adult medical-origin OHCA cases were included: no bystander CPR (n=3,083), self-led bystander CPR (n=2,295), and V-DA-CPR (n=1,862).
Baseline characteristics differed significantly across groups (Table 1). The outcomes improved sequentially (Table 1).
Table 1.
Baseline characteristics and clinical outcomes among groups with different bystander CPR types
| Parameters | No bystander CPR (n=3,083) | Self-led CPR (n=2,295) | V-DA-CPR (n=1,862) | P-value |
|---|---|---|---|---|
| Age (years), median (IQR) | 70 (57, 79) | 67 (54, 78) | 63 (51, 76) | <0.01 |
| Male, n (%) | 2,139 (69.38) | 1,640 (71.46) | 1,302 (69.92) | 0.25 |
| Rural region, n (%) | 1,948 (63.19) | 1,311 (57.12) | 978 (52.52) | <0.01 |
| Cardiac etiology, n (%) | 2,325 (75.41) | 1,820 (79.30) | 1,509 (81.04) | <0.01 |
| Home location, n (%) | 2,175 (70.55) | 1,410 (61.44) | 1,251 (67.19) | <0.01 |
| Shockable rhythm, n (%) | 252 (8.17) | 375 (16.34) | 381 (20.46) | <0.01 |
| EMS response time (min), median (IQR) | 9.20 (6.87, 12.51) | 9.37 (6.90, 12.57) | 9.06 (6.73, 12.32) | 0.19 |
| Bystander AED use, n (%) | 7 (0.23) | 14 (0.61) | 23 (1.24) | <0.01 |
| Prehospital ROSC, n (%) | 224 (7.27) | 263 (11.46) | 289 (15.52) | <0.01 |
| 30-day survival, n (%) | 64 (2.08) | 104 (4.53) | 142 (7.63) | <0.01 |
| Favorable neurological outcome, n (%) | 40 (1.30) | 77 (3.36) | 114 (6.12) | <0.01 |
CPR: cardiopulmonary resuscitation; V-DA-CPR: video-guided dispatcher-assisted CPR; EMS: emergency medical service; IQR: interquartile range; AED: automated external defibrillator; ROSC: return of spontaneous circulation.
On multivariable analysis with no bystander CPR as a reference, self-led bystander CPR was associated with improved survival (aOR=1.47, 95% CI 1.05-2.07) and neurological outcomes (aOR=1.62, 95% CI 1.07-2.45), whereas V-DA-CPR was strongly associated (survival: aOR=2.38, 95% CI 1.71-3.32; neurological: aOR=2.83, 95% CI 1.89-4.24). In the direct comparison (self-led bystander CPR as a reference), V-DA-CPR remained significantly associated with better survival (aOR=1.62, 95% CI 1.05-2.50) and neurological outcomes (aOR=1.75, 95% CI 1.05-2.92) (Figure 1; Table 2).
Figure 1. Forest plot of adjusted odds ratios (aORs) for 30-day survival and favorable neurological outcomes. A: overall cohort with no bystander CPR as a reference; B: direct comparison with self-led CPR as a reference; C: rural subgroup with no bystander CPR as a reference. Adjusted for age, sex, cardiac etiology, arrest location, initial rhythm, EMS response time, and prehospital interventions (epinephrine, advanced airway management, mechanical CPR). aOR: adjusted odds ratio; CI: confidence interval; EMS: emergency medical service; CPR: cardiopulmonary resuscitation; V-DA-CPR: video-guided dispatcher-assisted CPR.
Table 2.
Multivariable logistic regression analysis of bystander CPR type and outcomes after witnessed out-of-hospital cardiac arrest
| Subgroups | Comparison | Outcome | aOR (95% CI) | P-value |
|---|---|---|---|---|
| Overall cohort | Self-led bystander CPR vs. no bystander CPR | 30-day survival | 1.47 (1.05, 2.07) | <0.05 |
| Favorable neurological outcome | 1.62 (1.07, 2.45) | <0.05 | ||
| V-DA-CPR vs. no bystander CPR | 30-day survival | 2.38 (1.71, 3.32) | <0.05 | |
| Favorable neurological outcome | 2.83 (1.89, 4.24) | <0.05 | ||
| V-DA-CPR vs. self-led bystander CPR | 30-day survival | 1.62 (1.05, 2.50) | <0.05 | |
| Favorable neurological outcome | 1.75 (1.05, 2.92) | <0.05 | ||
| Rural subgroup | V-DA-CPR vs. no bystander CPR | 30-day survival | 2.90 (1.78, 4.70) | <0.05 |
| Favorable neurological outcome | 3.76 (2.07, 6.83) | <0.05 |
Adjusted for age, sex, cardiac etiology, arrest location, initial rhythm, EMS response time, and prehospital interventions (epinephrine, advanced airway management, mechanical CPR). aOR: adjusted odds ratio; CI: confidence interval; CPR: cardiopulmonary resuscitation; V-DA-CPR, video-guided dispatcher-assisted CPR; EMS: emergency medical service. The rurality × V-DA-CPR interaction was not statistically significant (P for interaction=0.18 for 30-day survival; P=0.22 for favorable neurological outcome).
In the rural subgroup, compared with no CPR, V-DA-CPR yielded higher aORs (survival: 2.90, 95% CI 1.78-4.70; neurological: 3.76, 95% CI 2.07-6.83). The rurality × V-DA-CPR interaction was not statistically significant (P=0.18 for 30-day survival; P=0.22 for neurological outcomes), suggesting that point estimates were greater in rural areas but did not reach statistical significance (Figure 1).
This population-based cohort study revealed that compared with self-led bystander CPR and no bystander CPR, V-DA-CPR was associated with a gradual improvement in 30-day survival and favorable neurological outcomes, which persisted after multivariable adjustment, although residual confounding remains a concern.
Several mechanisms may explain these associations. Video guidance enables dispatchers to visually assess and correct compression techniques in real time and may facilitate faster arrest recognition and reduce caller anxiety;[13] however, CPR quality metrics were unavailable, and these mechanisms remain hypothetical. Self-led bystander CPR likely reflects prior CPR training or healthcare worker status, which may partly explain the observed differences.
These findings extend previous reports on dispatcher-assisted CPR. Although audio-guided DA-CPR generally improves outcomes compared with no CPR,[5] comparisons with self-led bystander CPR have been mixed;[8,9] our finding that V-DA-CPR outperforms self-led CPR suggests that real-time visual feedback may overcome the limitations of audio-only instructions. Larger point estimates in rural areas, although not statistically significant, are consistent with reports that rural OHCA patients face greater barriers to timely resuscitation,[14,15] and V-DA-CPR may partially compensate for limited community training and longer EMS response times.
Several limitations merit consideration. Selection bias is inherent: V-DA-CPR requires smartphone ownership, internet access, caller cooperation, and successful video connection, and capable bystanders are likely younger, more educated, and more health literate. Survivorship bias may exist, as patients who survive long enough to achieve video connection may have an inherently better prognosis. Unmeasured confounders (bystander type, prior CPR training, collapse-to-call time) and early-implementation effects may influence the results. Finally, propensity-based methods, clustering analyses, DAG-based adjustment clarification, and CPR quality metrics could not be addressed due to the limited article length and warrant future study.
In conclusion, V-DA-CPR was associated with improved survival and neurological outcomes after OHCA, with numerically larger point estimates in the rural subgroup, although no statistically significant interaction was observed. Given the observational design and substantial residual confounding, these findings require confirmation through well-designed prospective studies, ideally randomized trials.
Funding: This study was supported by Noncommunicable Chronic Diseases-National Science and Technology Major Project (2026ZD0558208).
Ethical approval: This study was approved by the Ethics Committee of Zhejiang Provincial People’s Hospital (Approval No: QT2026084); written informed consent was waived because of the retrospective use of anonymized data.
Conflicts of interest: None declared.
Contributors: HJL conceived the study and drafted the manuscript. JF and LFL collected the data and performed the statistical analysis. XYW and KZ revised the manuscript. WWC supervised the project and was the guarantor. All the authors approved the final manuscript.
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