ORIGINAL ARTICLE The PREDICTIVE TM Study: a multinational, prospective observational study to evaluate the safety and efficacy of insulin detemir treatment in patients with type 1 and 2 diabetes—data from the Japan cohort Mitsuyoshi Namba • Kohei Kaku • Narihito Yoshioka • Yuichiro Yamada • Hirotaka Watada • Kohjiro Ueki • Yasuo Terauchi • Kazuyuki Tobe • Eiichi Araki • Yujin Shuto • Takashi Kadowaki Received: 10 May 2011 / Accepted: 18 October 2011 / Published online: 12 November 2011 Ó The Japan Diabetes Society 2011 Abstract The PREDICTIVE TM Study of Japan was an open-label, non-randomized 52-week observational study to evaluate the safety and efficacy of insulin detemir when used in routine clinical practice. Patients with either type 1 or 2 diabetes in whom insulin detemir was to be prescribed but without a previous history of using insulin detemir were eligible to participate. The primary endpoint was an inci- dence of serious adverse drug reaction (SADR) for the entire observational period. Data were collected at baseline, 12, 26, and 52 weeks. A total of 3,519 patients were enrolled in 540 institutions between 2008 and 2009. Thirty patients (0.9%) reported 32 SADRs. The rate of total hypoglycemic episodes was 1.51 episodes/patient-year in patients with type 1 dia- betes and 0.23 episodes/patient-year in patients with type 2 diabetes. The rate of total hypoglycemic episodes did not increase during the observational period. Significant reduc- tions were observed at 52 weeks in HbA1c levels (0.51% in type 1 diabetes, P \ 0.001; 0.80% in type 2 diabetes, P \ 0.001), fasting glucose level (reduction of 22.1 mg/dl in type 1 diabetes, P \ 0.001; 25.6 mg/dl in type 2 diabetes, P \ 0.001), and intrapatient fasting glucose variability (coefficient of variance; reduction of 11.4% in type 1 dia- betes, P \ 0.001; 4.1% for type 2 diabetes, P \ 0.001). Our results from the 52-week follow-up data of 3,345 Japanese patients with diabetes demonstrated that insulin detemir contributed to a lower incidence of SADRs ( \ 1%) and suggested that treatment with detemir could provide better glycemic control without increasing hypoglycemic episodes. Keywords Insulin detemir Á Type 1 diabetes Á Type 2 diabetes Á Observational study M. Namba (&) Division of Diabetes and Metabolism, Department of Internal Medicine, Hyogo College of Medicine, Mukogawa-cho 1-1, Nishinomiya, Hyogo 663-8501, Japan e-mail: namba-m@hyo-med.ac.jp K. Kaku Division of Diabetes, Endocrinology and Metabolism, Department of Internal Medicine, Kawasaki Medical School, Kurashiki, Okayama, Japan N. Yoshioka Department of Division of Diabetes and Metabolism, Sapporo Medical Center NTT East Corporation, Sapporo, Hokkaido, Japan Y. Yamada Department of Endocrinology, Diabetes and Geriatric Medicine, Akita University Graduate School of Medicine, Akita, Japan H. Watada Division of Metabolism and Endocrinology, Department of Internal Medicine, Juntendo University, Tokyo, Japan K. Ueki Á T. Kadowaki Department of Metabolic Diseases, Graduate School of Medicine, University of Tokyo, Tokyo, Japan Y. Terauchi Division of Endocrinology and Metabolism, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, Japan K. Tobe Department of Internal Medicine, Faculty of Medicine, University of Toyama, Toyama, Japan E. Araki Department of Metabolic Medicine, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan Y. Shuto Safety Management Department, Novo Nordisk Pharma Ltd., Tokyo, Japan 123 Diabetol Int (2012) 3:11–20 DOI 10.1007/s13340-011-0051-x