Background and objective: In 1981, toxic oil syndrome (TOS) appeared in Spain, affecting more than 20,000 persons and causing over 2500 deaths to date. Previous studies have addressed mortality only by gender and age. We analyzed possible prognostic factors in the survival of the cohort.
Methods: The study period was 1 May 1981 to 31 December 1995 (31 December 1995 was the cut-off date for survivors). The study population consisted of the entire cohort. Overall mortality and TOS-related deaths were studied. Kaplan-Meier method and Cox regression were used in the analyses.
Results: Among the 20,084 subjects in the cohort, 12,164 (60.6%) were women, and 7917 (39.4%) were men. Of the 1799 deaths, 958 (53.3%) were women, and 841 (46.71%) were men; of the 356 TOS-related deaths, 234 (65.7%) were women, and 122 (34.3%) were men. TOS was the leading cause of death among subjects <40 years of age. Among the TOS-related deaths, the shortest survival times were for women and subjects <40 years of age. The major disease manifestations had the highest relative risks (RR) (liver disease, RR 3.83; pulmonary infection, RR 1.54; motor neuropathy, RR 2.24; pulmonary hypertension, RR 3.19; and eosinophilia, RR 1.14.).
Conclusions: The major clinical manifestations showed worse prognosis for overall and TOS-related mortality. Application of these results to the survivors will help clarify the validity of these conclusions.