Racial disparities, comorbidities, and low body mass index reduce survival after cardiopulmonary resuscitation: a systematic review and meta-analysis

Introduction CPR is crucial for the management of cardiac arrest. However, the impacts of certain individualized factors, such as different ethnicities, body weights, and medical histories, on the efficacy of CPR remain unclear. This meta-analysis clarifies the associations between three individualized factors and the outcomes of CPR, aiming to optimize resuscitation strategies. Methods We systematically searched eight databases—PubMed, Web of Science, Scopus, Embase, Cochrane Library, VIP, Wan Fang, and CNKI—for studies that explored the associations between ethnicity, past medical history, body mass index (BMI), and CPR outcomes. Separate meta-analyses were then conducted for each of these three individualized factors. Results Eleven studies evaluated ethnicity, nine assessed medical history, and eight analyzed BMI. White patients exhibited significantly higher survival rates than Black patients (OR = 1.36, 95% CI 1.22–1.50, p 0.00001). Compared to patients with a medical history, patients without a medical history have a higher survival rate (OR = 0.51, 95% CI 0.37–0.70, p 0.0001). Compared to standard weight groups (BMI 18.5–24.9 kg/m 2 ), underweight individuals (BMI 18.5 kg/m 2 ) had lower survival (OR = 0.64, 95%CI0.51–0.80, p = 0.0001) and poorer neurological outcomes in underweight individuals (BMI 18.5 kg/m 2 ) (OR = 0.72, 95%CI0.55–0.94, p = 0.01). No significant differences were observed in overweight/obese versus normal-weight patients. Discussion This study demonstrates that ethnicity differences, pre-existing comorbidities, and low BMI can affect survival rates after CPR. These results are of great significance for clinical practice, suggesting that it is necessary to reduce inequalities in the distribution of medical resources in response to racial differences, optimize disease management for patients with comorbidities, and incorporate underweight status into high-risk assessment. Future research should further explore the underlying mechanisms and expand to more regions, so as to provide evidence for the construction of a personalized resuscitation medicine system and the formulation of guidelines. Systematic Review Registration https://www.crd.york.ac.uk/PROSPERO/view/CRD42025558162 , identifier PROSPERO (CRD42025558162).