Objectives: Differences in mortality rates within Europe might be partly due to the quality of mortality statistics. The present article summarizes the available data on the quality of cancer death certification in Spain. A short description of the temporal distribution of the proportion of deaths due to ill-defined tumors in Spain -an indirect indicator of the quality of cancer death certification- is also provided.
Methods: Relevant studies were identified from electronic databases (MEDLINE, EMBASE, IME and IBECS) and from manual searches of the references contained in the articles retrieved. Quality data on death certificates for all tumors and for each specific cancer location were summarized, and all main cancer sites were classified according to their pooled accuracy indicators. Trends for the percentage of deaths due to ill-defined tumors and conditions were studied for the period from 1980 to 2002.
Results: In Spain, deaths from cancer as a whole and leading cancer sites (lung, colon-rectum, prostate, stomach, pancreas, female breast, uterus, brain, leukemia, lymphomas and myeloma) were well-certified. However, other frequent locations, such as the larynx, esophagus and liver were overcertified, while deaths from bladder, kidney and ovarian cancer were undercertified. The percentage of deaths due to ill-defined tumors and causes was regularly higher in females and decreased in both sexes during the study period. However, the recent introduction of the International Classification of Diseases (ICD)-10 has reversed this trend.
Conclusions: Spanish death certificates can be considered as accurate and useful to estimate the burden of cancer, though certification of some frequent sites should be improved. The possible effect of the introduction of the ICD-10 requires careful surveillance.