Organ damage and sickle cell-related complications were assessed by systematic screening and medical record review and defined as follows: PHT: tricuspid regurgitation jet flow velocity (TRV) equal to or higher than 2.5 m/sec in rest detected by Doppler echocardiography. PHT was considered absent with no or only trace TRV [17] . Renal failure: an estimated creatinine clearance lower than 100 mL/min (Cockcroft and Gault). Microalbuminuria: urinary creatinine (mmol/L) to urinary albumin (mg/L) ratio higher than 3.5 for males and higher than 2.5 for females confirmed with 24 hr urine collection with microalbuminuria higher than 30 mg/24 hr [18] . Retinopathy: presence of at least mild nonproliferative retinopathy [19] . Iron overload: plasma ferritin level higher than 1,000 mmol/L (on at least three occasions during steady state) and a history of more than 20 transfused packed cells [20] . Symptomatic avascular osteonecrosis: local pain and reduced function with documented osteonecrosis of the femoral or humeral head (hip or shoulder X-ray) or a history of surgical intervention for osteonecrosis. Leg ulcers: chronic ulcers of the ankle not otherwise explained. Acute chest syndrome: defined as described by Stuart and Setty [21] occurring between January 2002 and January 2007. Priapism: spontaneous painful erection requiring hospital care. Stroke: history of stroke confirmed by magnetic resonance imaging or computerized tomography. We analyzed the relation between organ damage and QoL both for each form of organ damage or complication separate as well as for groups. Groups were divided in a group with no organ damage or sickle cell-related complications, a group with organ damage or complications due to hemolysis (leg ulcers, PHT, priapism, and stroke), or a group with organ damage related to vaso-occlusion (ACS, retinopathy, avasculair osteonecrosis, renal failure, and microalbiminuria) as proposed previously [11] .