Unmet Need for Drug Therapy in Hospital-Visited Patients This research aimed to analyze the issue of unmet need for drug therapy in hospital-visited patients. Methods used in the study varied from physician interview, hospital policy survey, analysis of hospital databases, individual patient evaluation, to medical chart review. Based on opinions of prescribing physicians, the unmet drug need problem tended to focus on expensive or newly marketed drug products, which were considered the target group in this study. Results from the hospital survey showed that some of the study drugs were not covered in drug formularies of several hospitals; whereas some were listed in restricted formularies. In ten therapeutic drug classes, hospital database analysis revealed that out-patients under Low-Income Scheme were less likely to receive and to continue receiving the drugs as compared with those covered by Civil Servant Medical Benefit Scheme. Disparity in the unmet drug need across patient payment schemes varied widely with respect to the drug classes and study hospitals. This study confirmed adverse consequences due to inaccessibility to certain therapeutic modalities. A case study on patients with end stage renal disease found that accessibility to renal replacement therapy by the Low-Income patients was much lower than in the Civil Servant Medical Benefit recipients, thus the former group faced a higher mortality rate. Inaccessibility to appropriate choice of antibiotics would increase risk of death due to the fatal infectious disease like melioidosis in another case study. Four major policy recommendations were generated from this study. First, standard data sets for drug prescribing and dispensing as well as drug coding harmonization should be developed. All three health care financing agencies: Civil Servant Medical Benefit Scheme, Social Security Scheme, and Universal Health Care Coverage Scheme should set common structures of electronic files for recording drug utilization data. Second, prior to use of the stored information, a set of criteria for drug use quality based on up-to-date medical knowledge should be established. Information on the quality criteria could lead to an agreement among medical communities on variables needed to be specified in the standard data sets and on the way to measure quality of care. Third, for the issue of health equity monitoring, this study showed high feasibility to assess the extent to which a need for drug therapy was unmet, especially for the drug products that were proven in their effectiveness and efficiency. Lastly, it is possible to evaluate a policy aiming to increase health care productivity in the future. The approach used in this study should be disseminated through hospital networks in order that results generated from analyses of drug use databases can be used for quality of care development.