The QoL scores in relation to pain rate are depicted in Table II . With respect to the MCS, the overall score and all subscales, except for mental health, were significantly lower in patients with the highest pain rate (P 5 0.021). Although significantly lower scores were found on the role-physical scale (P 5 0.005) and the general health scale (P 5 0.033) in patients with the highest pain rate, the overall PCS was not determined by the number of admissions for painful crises (P 5 0.110). Also, analysis by linear regression confirmed that pain rate is significantly associated with MCS and is less likely to influence the PCS (data not shown).