Related Experiment Video
Updated: Apr 16, 2026

Measurement of Lifespan in Drosophila melanogaster
Published on: January 7, 2013
Differences in survival and cause-specific mortality in a culturally diverse Greek population, 1999-2008
Christos Nikolaidis1, Evangelia Nena1, Michalis Agorastakis2
1Laboratory of Hygiene and Environmental Protection, Medical Department, Democritus University of Thrace, Alexandroupolis 68100, Greece.
Background:
Modern urban populations exhibit considerable internal heterogeneity. Several social groups, such as ethnic minorities or immigrants, constitute individual clusters with different demographic and epidemiological characteristics.
Methods:
Death records were collected from the Municipality Registry between 1999 and 2008. Kaplan-Meier survival analysis was conducted for (i) natively born Greeks, (ii) former USSR-repatriated Greeks and (iii) Roma. Further evaluation was conducted by log-rank (Mantel-Cox) test. Relative mortality rates were assessed by means of cross-tabulation (Pearson's χ(2)).
Results:
Statistically significant differences in median survival were observed among the three social groups (P < 0.001). The relative mortality from infectious diseases was higher in the Roma population compared with natively born Greeks, odds ratio (OR) = 8.31 [confidence interval (CI) 95% 3.19-21.61]. More than 70% of these deaths were attributed to respiratory tract infections and were associated with children under the age of 5. Excess mortality due to external causes, injuries and substance abuse was observed in repatriated males compared with their natively born counterparts, OR = 2.27 (CI 95% 1.35-3.81).
Conclusions:
Specific public health interventions are required, to improve the survival of different cultural groups. For example, improvement of immunization status and increase in overall hygiene awareness can ameliorate high infant/childhood mortality in Roma population, while social integration can help reduce acculturation-related mortality among repatriated Greeks.
Related Concept Videos
Comparing the Survival Analysis of Two or More Groups
Assumptions of Survival Analysis
Cancer Survival Analysis
Actuarial Approach
Consider the example of a high-risk surgical procedure with significant early-stage mortality. A two-year clinical study is conducted,...
Introduction To Survival Analysis
The primary goal of survival analysis is to estimate survival time—the time...
Kaplan-Meier Approach

