PT  - JOURNAL ARTICLE
AU  - Ryan Ng
AU  - Sasha Bernatsky
AU  - Elham Rahme
TI  - Observation Period Effects on Estimation of Systemic Lupus Erythematosus Incidence and Prevalence in Quebec
AID  - 10.3899/jrheum.121215
DP  - 2013 Aug 01
TA  - The Journal of Rheumatology
PG  - 1334--1336
VI  - 40
IP  - 8
4099  - http://www.jrheum.org/content/40/8/1334.short
4100  - http://www.jrheum.org/content/40/8/1334.full
SO  - J Rheumatol2013 Aug 01; 40
AB  - Objective. To determine how duration of observation affects estimation of incidence and prevalence of systemic lupus erythematosus (SLE). Methods. SLE incidence and prevalence estimates from data periods as brief as 3 years (2001–2003) were compared to estimates from a 15-year period (1989–2003). Results. The 15-year period incidence was 5.6/100,000 (95% CI 5.0–6.1) and the prevalence was 59.1/100,000 (95% CI 57.4–60.8). When a 3-year period was used, incidence was overestimated by 238.1% and prevalence underestimated by 66.0%. Conclusion. SLE incidence and prevalence estimates vary considerably according to the observation period; more than 5 years of data is likely required.