The prevalence of systemic lupus erythematosus in Northern Ireland.

Using six sources of patient ascertainment, 467 patients were initially identified as having a diagnosis of systemic lupus erythematosus (SLE) in Northern Ireland. The diagnosis was subsequently altered in 45 of these, either by the patient, their family, or their physician. The corrected source data were then reanalysed by the 'capture-recapture' technique, which suggested a further 71 patients missed during the initial identification process. Eighty-eight patients underwent physical examination, and 14 were found to have a diagnosis other than SLE. A final estimated figure of 415 patients was obtained, giving a point prevalence on August 1, 1993 of 25.4 per 10,000 for the Province (95% confidence interval 22.1-28.7 per 100,000).