Population density, call-response interval, and survival of out-of-hospital cardiac arrest
2011

Population Density and Survival Rates in Cardiac Arrest Cases

Sample size: 101287 publication 10 minutes Evidence: high

Author Information

Author(s): Yasunaga Hideo, Miyata Hiroaki, Horiguchi Hiromasa, Tanabe Seizan, Akahane Manabu, Ogawa Toshio, Koike Soichi, Imamura Tomoaki

Primary Institution: Department of Health Management and Policy, Graduate School of Medicine, The University of Tokyo

Hypothesis

The study investigates the relationship between population density, call-response interval, and survival of out-of-hospital cardiac arrest (OHCA).

Conclusion

Living in a low-density area was associated with a higher risk of delayed ambulance response and lower survival rates in cases of OHCA.

Supporting Evidence

  • 1-month survival was 7.8% and neurologically favorable survival was 3.6%.
  • In very low-density areas, the mean call-response interval was 9.3 minutes.
  • Patients in very high-density areas had a significantly higher survival rate (OR, 1.64).
  • The proportion of elderly people in neighborhoods was associated with lower survival rates.

Takeaway

If you live in a crowded city, you're more likely to survive a heart attack than if you live in a quiet, rural area because help gets to you faster.

Methodology

The study analyzed data from 101,287 bystander-witnessed OHCA patients who received EMS in Japan between 2005 and 2007, using logistic regression to assess survival outcomes.

Potential Biases

Potential biases may arise from the registry-based nature of the study and the arbitrary categorization of population density groups.

Limitations

The study's data may not be generalizable to other countries due to unique geographic characteristics of Japan, and it lacked detailed data on patient comorbidities.

Participant Demographics

The average age of patients was 73.2 years, with a significant proportion being elderly (≥65 years) in low-density areas.

Statistical Information

P-Value

p<0.001

Confidence Interval

95% CI: 1.44 - 1.87

Statistical Significance

p<0.001

Digital Object Identifier (DOI)

10.1186/1476-072X-10-26

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