Failure of cigarette smoking to explain international differences in mortality from chronic obstructive pulmonary disease.

STUDY OBJECTIVE

The study aimed to explain international differences in rates and trends of chronic obstructive pulmonary disease (COPD) using two measurements of cigarette smoking, the major risk factor for this disease.

DESIGN

Mortality data for COPD were obtained from the World Health Organisation for 31 countries from 1979 to 1988. Smoking data were obtained for most countries. COPD rates were compared to the percentage of current smokers and past levels of cigarette consumption. COPD trends were compared to past consumption trends.

MAIN RESULTS

In men, Romania had the highest COPD mortality and Greece the lowest throughout the period. English speaking countries occupy most of the other top positions, and southern European countries and Japan the low positions. Women show a similar ranking to men (r = 0.75; p < 0.01 (1988)). Mortality rates in men are, in general, two to four times those in women. Most countries show either a decrease or no change in COPD mortality over the period. In women the opposite is true--no clear relationships are seen when comparing rates and trends of COPD with measures of smoking.

CONCLUSION

This failure to explain international COPD differences suggests that national data on COPD may be unreliable or national cigarette smoking data are inadequate, or both.