Epidemiology and survival of systemic lupus erythematosus in Hong Kong Chinese

Systemic lupus erythematosus (SLE) is a fairly common rheumatic disease in Hong Kong, China. The prevalence and annual incidence of SLE are estimated to be 0.1% and 6.7/100,000 population, respectively. The 10-year cumulative survival of SLE patients in Hong Kong is 83% and the age and gender-adjusted standardized mortality ratio was 5.25 (1.64-10.4) from 1999 to 2008. The commonest cause of death is infections (60%), followed by cardiovascular complications (16%). Life expectancy analysis reveals a loss of 20 years in women and 27 years in men when SLE develops at birth. The loss in life years is greatest in the younger age groups. Renal damage is the most frequent disease-related damage, whereas musculoskeletal damage is the commonest treatment-related complication. The quality of life of our SLE patients is impaired and declines over time, which is contributed by new organ damage. One-third of our patients lose their ability to work within 5 years of disease onset, which is mainly attributed to musculoskeletal pain, fatigue, anxiety and depression symptoms, and memory deterioration. With the availability of novel therapeutics and an increased awareness of complication prevention in SLE, it is expected that our patients will live longer with a better quality of life in the next decade.