Mortality and causes of death among Danish medical doctors 1973-1992.

BACKGROUND: To examine the mortality pattern of Danish doctors for the period 1973-1992. METHODS: A historical prospective cohort study based on the membership register of the Danish Medical Association. The study population consisted of 21,943 medical doctors, 6012 of whom were women. The doctors' cause-specific mortality was compared with that of the general population. RESULTS: The study covered about 277,000 person-years. A total of 2387 deaths occurred from 1 January 1973 to 31 December 1992. The doctors' mortality was lower than that of the general population. Both sexes showed a standardized mortality ratio (SMR) below one for cancer, circulatory diseases and other natural causes. Mortality due to lung cancer was particularly low. The SMR for suicide was significantly increased, 1.6 for males (95% CI: 1.4-1.9) and 1.7 for females (95% CI: 1.1-2.5). The suicide rate was increased, in particular because of an increased number of suicides by poisoning. In addition female doctors displayed a relatively high mortality due to accidents and other types of violent death. CONCLUSIONS: Compared with the general population the doctors' mortality was low, but the mortality from external causes was increased, mainly due to an excess number of suicides.

[Mortality and cause of death among Danish physicians 1973-1992]. / Dødelighed og dødsårsager blandt danske laeger 1973-1992.

This study examines mortality rates of Danish doctors and describes pattern and causes of death for the period 1973-1992. The study comprises 21,943 medical doctors, 6012 of whom were women. At the end of 1992 there were 2387 recorded deaths. The doctors had lower mortality rates than the general population. A significant lower mortality was seen for male medical specialists compared to general practitioners. A gender-difference was seen among the youngest doctors with the female doctors suffering a considerably higher mortality than the male doctors did. Both sexes showed SMR below unity for cancer, circulatory diseases and other natural causes. Mortality due to lung cancer was particularly low. The suicide mortality was increased for both sexes, in particular because of an increased number of suicides by poisoning. Compared with the general population the doctors' mortality was low, but the mortality from external causes was increased, mainly due to an excess number of suicides.

[The national patient registry. Evaluation of data quality]. / Landspatientregisteret. Evaluering af datakvaliteten.

The Danish National Patient Register, which includes information on all patients admitted to hospitals, has been evaluated as concerns the quality of the data included. The material examined consisted of a representative sample of 1094 patients from departments all over the country (gynaecology and obstetrics, medicine, surgery and paediatrics). Recoding of data, clinical as well as administrative, based on copies of the case records from the hospitals was carried out by two clinically working physicians (registrars). For the administrative data e.g. length of stay, satisfactory concordance was found. The validity of clinical information depended on clinical speciality and degree of diagnostic specificity. Based on the international classification the agreement on the three digit diagnostic level was better than on the five digit diagnostic level. For surgery the agreement was better than for medicine. The agreement between the diagnostic information (primary diagnosis) and the recoder in choosing primary diagnosis varied from 66-83 percent on the five digit level and between 73-89 percent on the three digit diagnostic level. If cases where the diagnosis in the registry could be regarded as an acceptable alternative were included, the agreement between the registry and recoding was 75-90%. In a subsample of the material double coding by the two coders was carried out and it was remarkable that, taken as a whole, the degree of agreement between the two coders was of the same size as between recoder and the registry. It is anticipated, however, that introduction of ICD-10 with more clear-cut rules for choice of primary diagnosis in morbidity coding will contribute to better validity and consequently improved hospital statistics.

[Deaths due to paracetamol poisoning in Denmark 1979-1992]. / Dødsfald af paracetamolforgiftning i Danmark 1979-1992.

A significant relationship between the amount of paracetamol (acetaminophen) sold in Denmark after the drug became available on an over-the counter basis in 1984 and an increase in paracetamol (acetaminophen) related deaths has been demonstrated.

Use of cimetidine and other peptic ulcer drugs in Denmark 1977-1990 with analysis of the risk of gastric cancer among cimetidine users.

The prevalence of use of peptic ulcer drugs in the Danish population is described at two points in time using registrations of applications for reimbursement. In 1977-81, the prevalence of use of cimetidine was 0.4% in men and 0.2% in women. In 1989-90, the prevalence of use of peptic ulcer drugs was 1.3% in men and 1.2% in women. The increase in prevalence was apparent in all age groups, but most pronounced at relatively old age. The median age of users increased from 55 years in 1977-81 to 63 years in 1989-90. The data indicated that a third of those who used peptic ulcer drugs in 1977-81 also used these drugs in 1989-90, conditional on surviving this period. The probability of becoming a long term user was highest for those who were 50-69 years in 1977-81. The incidence of gastric cancer was investigated in the cohort of persons who used cimetidine in 1977-81. An excess risk of gastric cancer was apparent in the first years after start of cimetidine use. This is thought to reflect a selection bias. Significantly increased incidence was also observed in women seven years or longer after start of cimetidine use (RR = 4.7; 95% CI: 1.7-10.3). This estimate was, however, based on only six cases, and a similar pattern was not observed in men.

The pattern of cancer in a large cohort of stroke patients.

A cohort of 113,732 stroke patients from Danish Hospital Discharge Registry were, by linkage to the Danish Cancer Registry, found to have developed a total of 5151 cases of cancer in a mean follow-up time of 2.4 years after the diagnosis of stroke. There was no excess of gastric cancer. The present findings fail to support the existence of a common, strong risk factor for stroke and gastric cancer in individuals. In the cohort, more cancer than expected was observed. In particular, a more than ten-fold increase in risk of brain tumours within the first year after stroke diagnosis was observed, suggesting some diagnostic misinterpretation of a brain tumour as a stroke. Minor excesses of cancer of other sites were also found in the first year of follow-up. They are probably due to increased medical surveillance and diagnostic misinterpretation of an underlying malignancy as an incident of cerebrovascular disease, eg through metastatic spread to the brain.

The WHO principles for registering causes of death: suggestions for improvement.

In the ongoing 10th revision of the International Classification of Diseases, the WHO's rules for registering causes of death are revised. Previous studies have shown that deficiencies in the WHO's rules and basic concepts for registering causes of death impair the quality of cause-of-death statistics. The purpose of the present paper is to elucidate some of these shortcomings and to make suggestions for improvement. Also, the purpose of the WHO's definition of 'the underlying cause of death' is discussed, and a modification suggested. Suggestions are also made for new definitions of the four basic WHO concepts, 'causes of death', 'the underlying cause of death', 'direct cause' and 'contributory conditions'. At the end an account is given of the proposals made within the WHO for changes in the rules for registering causes of death.

Cancer occurrence in a cohort of patients treated with cimetidine.

The possible carcinogenic effects of antisecretory agents used in the treatment of gastric and duodenal ulcer were investigated in a population based cohort study of 16,739 patients who were prescribed the H2-antagonist cimetidine between 1977 and 1981. An excess risk for gastric cancer was observed, with a relative risk of about 10 in the first year after beginning use of the drug, which decreased thereafter. A similar pattern was seen for cancers of the colon, pancreas and gall bladder, and for non-Hodgkin's lymphoma. These increased risks probably represent cases in which a malignancy was misdiagnosed as a gastric ulcer. The excess risk for gastric cancer was unaffected by the method of diagnosis, the risk in those who had undergone an endoscopy being similar to those who had been diagnosed by an x-ray examination. A relative risk of 1.5-2.0 was observed for cancer of the respiratory organs, with no effect of latency, indicating that there are common risk factors for peptic ulcer and for lung cancer. Although the observed increases in cancer risk in persons receiving cimetidine is probably caused by factors other than a carcinogenic action of the drug itself, this possibility cannot be ruled out because of the short period of follow up.

Validity and repeatability of self-reported occupational and industrial history from patients in EEC countries.

The results of a study to assess the feasibility and acceptability of a questionnaire designed to ascertain occupational history and the repeatability of coding occupational and industrial status using an abbreviated version of the coding status are presented for EEC countries. The study demonstrates the difficulty of recruiting cancer patients below age 65. The percentage of useful information among patients who completed a self-administered questionnaire was slightly lower than those who completed an administered questionnaire but in general the response rate for most items in the questionnaires in any group was above 90%. The repeatability of coding occupational status and industrial status for current or last job was satisfactory with Kappa values of 65% and 76% respectively. The within-individual repeatability for these variables had similar Kappa values. The validity of coding occupational status with an abbreviated version of coding status compared to the full instructions was satisfactory for current or last occupation. However, observer variability may be fairly large for the abbreviated version. An increase in the coding repeatability could probably be achieved with few modifications to the description of occupation status groups and clearer headings for each division of the Industrial Occupation Classification and greater training of coders.