Toxic oil syndrome: health-related quality-of-life assessment using the SF-36 Health Survey

Abstract

Background: Toxic oil syndrome (TOS) is a multisystemic disease due to a massive intoxication that occurred in Spain in 1981 affecting >20 000 persons. This study aims to evaluate the quality of life of the survivors' cohort after 38 years of follow-up using the Short Form 36 (SF-36) Health Survey.

Methods: One thousand patients were selected among the 14 084 alive TOS cohort members in 2018 using a stratified random sampling method. Stratification was performed by the 2017 self-rated health status reported by patients. SF-36 results were compared directly and as standardized (T scores) with the Spanish-population reference values. Relationship between self-rated health status and SF-36 results was assessed.

Results: Overall, 900 cohort members participated and 895 valid responses were included in the study. Participants' average age was 65.2 (standard deviation: 13.8) years and 563 (62.9%) participants were women. Participants' distribution by self-rated health status was: 219 (24.5%) good/very good, 415 (46.4%) fair and 261 (29.1%) poor/very poor. Quality of life was below the Spanish-population reference in 84% of the TOS patients (87.2% for women and 78.6% for men) for the Physical Component Summary (PCS) and in 75.4% (81.7% for women and 64.8% for men) for the Mental Component Summary (MCS). PCS and MCS scores decreased similarly for both sexes with worse self-rated health.

Conclusions: Very low quality of life and self-rated health, especially for women, were found in the total TOS participants that can be extrapolated to the TOS survivors' cohort. The TOS cohort still requires standardization of care with integral plans around the country.

Keywords: SF-36; Toxic oil syndrome; cross-sectional study design; patient-reported outcomes; self-rated health status.