Mortality rates for common respiratory diseases in an English population 1979-1998: artefact and substantive trends.

We analysed a mortality database in which all causes of death on each death certificate were coded, as well as underlying cause, to study trends from 1979 to 1998. Multiple-cause-coded death rates for pneumonia and acute bronchitis fell steadily and consistently. There were complementary rises and falls in death rates for individual chronic obstructive pulmonary diseases (COPD)--chronic bronchitis, emphysema, chronic obstructive airways disease--attributable to changes in clinical terminology. Judged by underlying cause, death rates for COPD were lower than those for lung cancer; but, judged by all mentions, death rates for COPD were appreciably higher than for lung cancer. Death rates for COPD, like lung cancer, fell over time in women under 65 years of age and in men; and increased in older women. For all respiratory diseases studied, except lung cancer, the underlying cause of death alone considerably underestimated the extent of their certification on death certificates.