The QoL data of our population are presented in Table I . As expected, our patient group scored lower on QoL compared with the healthy Dutch population [7] (see Supporting Information Table IV) . No correlation between the MCS and PCS was found in the sickle cell population (spearman r 5 0.14; P > 0. 20) . When comparing male to female sickle cell patients, the overall PCS appeared to be significantly higher in males when compared with females (P 5 0.015). We found no significant difference in the overall MCS between males and females. Older patients scored lower on the PCS in comparison to younger patients (P 5 0.002) while no significant differences in QoL scores between genotypes was found (data not shown).