Joinpoint regression analysis of lung cancer mortality, Andalusia 1975-2000

Background: Previous analyses of lung cancer mortality were based on models of death rates within one time period, assuming that rates increase or decrease with time at a constant rate. The aim of this work is to analyse recent changes in lung cancer mortality trends in Andalusia (Spain) during the period of 1975-2000 using joinpoint regression models. Patients and methods: Mortality data were obtained from the Death Registry of Andalusia. For each gender, age group-specific and standardised (overall and truncated) rates were calculated by the direct method (using the world standard population). The joinpoint analysis was used to identify the best-fitting points where a statistically significant change in the trend occurred. Results: Lung cancer is the leading cause of cancer mortality in men, with an increasing trend up to 1994. After that year, rates began to decrease significantly (-1.8% yearly from 1994 to 2000). Standardised rates in women exhibited a downward trend until the early 1990s, after which they levelled off (overall standardised rates) or increased significantly (truncated rates 35-64 years). Conclusions: An increase in lung cancer mortality has been observed in young women. There seems to be a relationship with the prevalence in smoking in men and women.