Ethnic difference in the prevalence of systemic lupus erythematosus

A retrospective study of systemic lupus erythematosus (SLE) was carried out in Auckland, New Zealand, for the years 1975 to 1980 inclusive. One hundred and fifty-one patients were found of which 106 fulfilled the American Rheumatism Association criteria. There were 15 deaths. Age-adjusted prevalence rates per 100 000 were estimated for all cases at the end of 1980 as follows: white 14.6, Polynesian 50.63, and other 19.11. There was a preponderance of females in each ethnic group, average 87% of all cases. Age-adjustment mortality rates per million patient years were: white 2.5 and Polynesians 13.0. Survival curves for both ethnic groups were similar. The prevalence rate in New Zealand Polynesian is significantly higher than in white counterparts which confirms the observation that the disease is commoner in the pigmented races.