Epidemiological study in Switzerland

A study group of originally 623 employed women of Northwestern Switzerland who were aged 30 to 49 yr and showing objective evidence of intake of phenacetin-containing analgesics, and a control group of 621 comparable women showing no such intake, were examined in 1968 and followed-up five times from 1969 to 1975 for laboratory evidence of urorenal disorders. Mortality was higher in the study group, with 21 deaths, compared to the control group, with 5 deaths, and was higher than expected in a comparative population in Switzerland (P less than or equal to 0.05). In both study and control groups, morbidity was low. There was no difference between the study and control groups with respect to subsequent proteinuria and hematuria. The seven-year incidence of low urine specific gravity after overnight thirsting was higher in the study group than in the control group (2.9% vs. 1.0%), and the incidence of raised serum creatinine was also significantly higher in the study group (2.9% vs. 0%). However, when the study group was further subdivided into a subgroup showing evidence of high intake of phenacetin-containing analgesics and one showing low-intake, only the high-intake subgroup had an incidence of raised serum creatinine concentrations (5.3%), significantly higher than the control group (0%), whereas the low-intake subgroup had an incidence (0.4%) similar to the control group. Also the high-intake subgroup showed significantly higher rates of bacteriuria than the controls (P less than or equal to 0.004).