Outcomes in primary Raynaud phenomenon -: A meta-analysis of the frequency, rates, and predictors of transition to secondary diseases

Objective: To summarize the current literature on the frequency, rates, types, and outcome predictors of secondary diseases that develop in patients with primary Raynaud phenomenon. Methods: A structured MEDLINE literature search with the MeSH heading "Raynaud's disease," which was crossed with (1) systemic sclerosis, (2) prognosis, (3) prospective studies, (4) follow-up studies, and (5) retrospective studies, was used to identify 910 articles for possible inclusion. Articles that identified patients with primary Raynaud phenomenon who were followed up and reevaluated at the end of the study, and which used published classification criteria to assess the presence or absence of secondary disease were included. Patient-years of Raynaud disease, patient-years of follow-up, and rates and predictors of transition to secondary disease were calculated from the articles selected. The summary odds ratio and positive predictive value for evaluation criteria at entry were calculated from 2x2 tables generated for each variable. Results: Ten articles identified a total of 639 patients with primary Raynaud phenomenon who were followed up for 2531 patient-years. Eighty-one patients (12.6%) developed a secondary disorder, 80 of which were connective-tissue diseases. Transitions occurred at a mean rate of 3.2 per 100 patient-years of observation. The mean time to develop a secondary disorder was 2.8 years from study entry and 10.4 years from the onset of Raynaud phenomenon. At entry, the best predictor of transition was an abnormal nailfold capillary pattern (positive predictive value, 47%). Antinuclear antibodies in these patients had a positive predictive value of only 30%. Conclusion: Although a variety of clinical and serological abnormalities can be found in patients with primary Raynaud phenomenon, only a small percentage of them develop a connective-tissue disease.