Meta-analysis of systemic sclerosis and exposure to solvents

Background Although systemic sclerosis is a rare disease, incidence rates h ave increased recently in the United States. This study investigated the as sociation between systemic sclerosis and exposure to solvents. Methods A Medline search of articles published between 1966 and 2000 dealin g with solvent exposure and systemic sclerosis identified eight studies tha t met inclusion criteria of the meta-analysis. The studies included seven c ase-control studies and one cohort study published between 1989 and 1998. A series of meta-analyses of studies on systemic sclerosis and solvent expos ure were performed for all studies and for case-control studies. A random e ffect model was used to calculate a combined estimator of relative risk. Results The combined estimator of relative risk for all studies was 2.91, w ith a 95% confidence interval (CI) of 1.60 to 5.30. The combined estimator of relative risk for the seven case-control studies was 3.14 (95% CI, 1.56- 6.33). Conclusion A statistically significant increased relative risk for all stud ies and for case-control studies suggests that exposure to organic solvent may be a risk factor for developing systemic sclerosis. Further studies usi ng other study designs and better control of confounders are needed. (C) 20 01 Wiley-Liss, Inc.