Standardized mortality ratios in systemic sclerosis: a meta-analysis assessing overall and sex- and disease subtype-specific differences.

OBJECTIVE

This study aims to evaluate the overall and sex- and illness subtype-specific standardized mortality ratios (SMRs) in patients with systemic sclerosis (SSc).

METHODS

We searched and examined studies that compared the overall and sex- and illness subtype-specific SMRs in patients with SSc to those in the general population using MEDLINE, EMBASE, and Cochrane databases (until May 2023). We then conducted a meta-analysis of the overall and sex- and illness subtype-specific SMRs in patients with SSc.

RESULTS

Overall, 29 studies including 30,673 patients with SSc and 5582 deaths met the inclusion criteria. Patients with SSc had a higher overall SMR than that in the general population (SMR: 2.742, 95% confidence interval [CI]: 2.224-3.38091, p < 0.001). The SMR significantly increased in populations from Europe, North America, Asia, and Oceania according to regional stratification. A sex-specific meta-analysis revealed a substantial increase in the SMR in both men and women (SMR: 3.598, 95% CI: 3.097-4.180, p < 0.001; SMR: 2.833, 95% CI: 2.4384-3.292, p < 0.001, respectively) and the mortality rate was higher in men compared to women. A substantial increase in the SMR in diffuse cutaneous SSc (dcSSc) and limited cutaneous SSc (lcSSc) was observed in a disease subtype-specific meta-analysis. In addition, the SMR in the dcSSc group was higher than that in the lcSSc group (SMR: 4.726, 95% CI: 3.795-5.885, p < 0.001; SMR: 1.987, 95% CI: 1.586-2.489, p < 0.001, respectively).

CONCLUSION

Our findings demonstrated that the mortality rate in patients with SSc was 2.74-times greater than that in the general population. The mortality rate was higher in men compared to women. Additionally, compared to patients with lcSSc, those with dcSSc showed much higher fatality rates.