One hundred seventeen adult patients with SCD (HbSS, HbSb 0 , HbSC, and HbSb 1 ) were eligible for our study. Twenty-three patients were excluded from analysis because they were not able to fill in the SF-36 questionnaire for different reasons (illiterate persons, mental retardation or repeated no show at their appointments). These excluded patients did not differ from the study population concerning outcome variables (pain, disease severity, education, and occupation). QoL was assessed in 51 patients with HbSS, 5 with HbSb 0 , 11 with HbSb 1 , and 27 patients with HbSC.