Incidence per 1000 patient-years of the use of biguanides (●), sulphonyl urea (○), insulin (△), thiazolidinediones (✕), alpha-glucosidase inhibitors (◇), meglitinides (■) and dipeptidyl peptidase 4 (DPP-4) inhibitors (▲) in Taiwan, Hong Kong, Japan, and the United States.

Panel A shows patients younger than 65 years; Panel B shows patients 65 years or older. † The study population is not representative of the corresponding age group in the general population in the United States (see text for details). # The study population is not representative of the corresponding age group in the general population in Japan (see text for details).