Time to Diagnosis in Systemic Sclerosis: Is Gender a Factor?

Background SSc affects mainly women. In the general patient population, medically unexplained symptoms are more prevalent among women than men and are sometimes mistakenly understood as psychosocial in nature, which can result in less vigorous efforts to seek a medical reason for complaints. The objective of this study was to assess whether gender plays a role in the length of time to diagnosis of SSc.
Methods Participants in the study were patients from the Canadian Scleroderma Research Group Registry with baseline visitis from September 2004 to August 2006. The Registry includes adult patients diagnosed with SSc by referring rheumatologists from 14 centers across Canada. Registry patients undergo extensive clinical history, physical evaluation, and laboratory investigations. Physicians document the dates of onset of Raynaud’s phenomenon and the first non-Raynaud’s disease symptom and the date patients were first diagnosed with SSc. The unadjusted association between gender and time to diagnosis was assessed using Kaplan-Meier curves and the log-rank test. A multivariate Cox proportional hazards model was used to test the association after adjusting for limited versus diffuse skin involvement, age, education, and marital status.
Results Of the 359 patients studied, the mean age was 55.4 years, 85.8% were women, 72.1% were married, 44.0% had education beyond high school, and 50.1% had diffuse SSc. Mean time to diagnosis from onset of Raynaud’s phenomenon was 6.1 years, but was significantly (p < .001) longer for women (6.7 years) than for men (2.9 years). Mean time to diagnosis from onset of non-Raynaud’s symptoms was 2.7 years, also significantly (p < .001) longer for women (2.9 years) than for men (1.4 years). Time to diagnosis was significantly longer for women in Kaplan-Meier (log-rank p= .027) and Cox regression analyses (hazard ratio = 1.38, 95% CI 1.02 to 1.87, p = .038).
Conclusion In SSc, the time to diagnosis is long, and it is longer for women than men. It is possible that there are differences in early disease progression between men and women with SSc, although there is currently no evidence for this. Another possibility is that women in the early stages of SSc who present with non-specific symptoms are not as likely to be evaluated as promptly as men with similar symptoms. Based on current prevalence estimates, SSc likely affects close to 100,000 Americans, the majority women. In diffuse SSc, skin thickening and severe internal organ involvement generally occur in the first 3 years of disease. Thus, earlier diagnosis could potentially allow many women with SSc to benefit from available treatments in a timely manner.

 M. Hudson, None; B. Thombs, None; M. Baron, None.