Epidemiology and effect of psychiatric comorbidities on survival rates in patients with systemic sclerosis: A nationwide population-based cohort study

Background

Systemic sclerosis (SSc) is a chronic, disabling connective tissue disease with a considerable psychological burden. While studies suggest a higher prevalence of psychiatric disorders in SSc, most have small sample sizes.

Methods

Using Taiwan's National Health Insurance Research Database, we identified 3270 SSc patients from the catastrophic illness registry and matched them 1:4 by age and sex with 13,080 controls. We compared the incidence rate ratios (IRRs) of new psychiatric disorder diagnoses between the two groups and analyzed risk factors using a Cox proportional hazards model. Kaplan–Meier analysis and log-rank test were used to compare survival in SSc patients with and without psychiatric conditions (matched at a 1:4 ratio by age, sex and CCI).

We compared psychiatric disorder incidence rates.

Results

The SSc group had a significantly higher incidence of psychiatric disorders than controls (IRR = 1.66, p < 0.001). In SSc patients, treatment with an oral daily steroid dose of ≥7.5 mg (hazard ratio [HR] = 1.71, p = 0.010), intravenous steroid pulse therapy (HR = 2.34, p < 0.0042), or D-penicillamine (HR = 1.60, p < 0.001) served as an independent risk factor for psychiatric comorbidities. SSc patients with psychiatric comorbidities had significantly lower survival rates than those without.

Conclusions

Patients with SSc are at an increased risk of psychiatric comorbidities, which can negatively affect their survival rates. Treatment with a daily oral steroid dose of ≥7.5 mg, intravenous steroid pulse therapy, or D-penicillamine is a risk factor for psychiatric comorbidities in SSc.