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Abstract

Objective

To determine the generalizability of randomized controlled trials (RCTs) in the treatment of systemic sclerosis (SSc) using the Canadian Scleroderma Research Group (CSRG) database.

Methods

We identified articles related to SSc published from 1958 to 2006. Key points on trial design were recorded. The inclusion/exclusion criteria were used in conjunction with the CSRG database to determine the proportion of patients with SSc who would theoretically be eligible for these trials. Articles were classified into subcategories according to the target system. The CSRG database contains 438 patients with SSc from 14 Canadian centers. Results were in median (%) and mean (%) with 95% confidence intervals (95% CIs).

Results

In total, 210 articles were evaluated and 73 were selected for inclusion in this study. The mean percentage of eligible patients with SSc associated with other conditions was 35% (95% CI 17–53) for Raynaud's phenomenon, 24% (95% CI 1–47) for digital ulcers, 48% (95% CI 27–68) for gastrointestinal (GI) involvement, 32% (95% CI 20–43) for overall disease modification, 6% (95% CI 4–8) for pulmonary arterial hypertension, 2% (95% CI 0–4) for interstitial lung disease, and 38% (95% CI 12–64) for other categories.

Conclusion

Except for GI trials, <38% of the identified patients with SSc would have been suitable to enter the RCTs. Although some patients would be ineligible because they lack certain organ involvement, RCTs designed to include appropriate patients with SSc are needed; there are few proven treatments and trials typically do not include the majority of those who could potentially benefit from the intervention.