Standardized mortality ratio and life expectancy: a comparative study of Chinese mortality.

BACKGROUND Various models have been proposed for rapid conversion of the standardized mortality ratio (SMR) to life expectancy using data from developed countries. METHODS We compared two methods for converting the SMR to life expectancy using mortality data from the largest developing country, China. RESULTS The first model, using the Gompertz function, does not provide a good fit to the life expectancy and SMR of China. The regression lines derived from the second, a log-linear model using parameters estimated from the US white population are not a good fit to Chinese males and older females. However, if the parameters in the log-linear model are estimated using Chinese mortality data, the resultant regression lines fit the data reasonably well. CONCLUSION The relationship between life expectancy and SMR based on mortality data from developed countries may not be valid for developing countries. Based on our empirical study, separate estimates of the coefficients of the model are required for developing countries.