Objective: To determine the prevalence and confirmation rate of autoimmune diseases reported by relatives of patients with lupus and controls.
Methods: Medical histories were obtained by self-report from 626 first-degree relatives of lupus patients and 267 population controls.
Results: Of 178 reports of an autoimmune disease, 44% were confirmed by medical records; excluding those whose medical records were unavailable, the confirmation rate was 76%. The prevalence of at least one confirmed autoimmune disease was 12% in lupus relatives and 2% in controls.
Conclusion: Methods to improve the reliability of self-reported autoimmune disease history could enhance population and clinic-based research.