SMR (standardized mortality ratio) standardized mortality ratio = observed deaths / expected deaths
① factory 30 to 40 age group 500 workers, two people a year die from lung cancer, known mortality rate in the whole population of the age group 30 to 40 %% 2 lung cancer, find the SMR
SMR = 2 / (500 * 2 %%) = 2 shows that the age group of 30 to 40 workers died of lung cancer risk of up to 2 times the general population.
② factory proportion of 30 to 40 age group, the total number of workers killed 100 people, including five people died of lung cancer, the whole population in the age group of 30 to 40 lung cancer deaths accounted for 2.2% of death cause of death, the
SMR = 5 / (100 * 2.2%) = 2.27 indicates that the risk of 30 to 40 workers died of lung cancer in the age group of up to 2.27 times the general population.
RR (relative risk) used for cohort study in , the risk represented by non-exposure of the corresponding disease who are exposed many times
AR (attributable risk) attributable risk , represent relatively exposed and non-exposed population groups, the increase in disease occurrence number