Affiliation: | aDepartment of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Health C&C Center, Kubara 1822-1, Hisayama Town, Kasuya-gun, Fukuoka 811-2501, Japan;bBiostatistics Center, Kurume University, 67 Asahi-machi, Kurume, 830-0011, Japan |