Objective¡G The purpose of this research is (1) to find out the overall trends of the common avoidable hospitalization diseases in Taiwan since the implementation of the National Health Insurance (NHI), (2) to compare the different distributions of the common avoidable hospitalization diseases across age groups, genders, regions, and the hospital¡¦s characters, (3) to make the related useful information and suggestions of improving avoidable hospitalizations to the policy makers, hospitals, and the general public. Method¡G Standardized rates of avoidable hospitalization from 1997 to 2004 were derived from the National Health Insurance database and the Taiwan census data. In this research, we focus on the four main diseases¡GAsthma, Pneumonia, Diabetes, Hypertension as the avoidable hospitalization diseases. Logistic regression and chi-squire tests are used to detect and describes trends in data. Results¡G During the 8-year research period, AHCs (Avoidable Hospitalization Conditions)of Asthma and Hypertension decline overall, conversely, AHCs of Pneumonia and Diabetes show increasing trends overall¡Fin the hospital characters aspects, AHCs are mostly occurred in the local hospitals¡Ffrom the viewpoint of the patients¡¦ characters, AHCs of Asthma and Pneumonia are always occurred in children male, on the other hand, AHCs of Diabetes and Hypertension are always occurred in female and above 65 years old¡Fin the regional aspect, the AHCs of Asthma and Pneumonia are comparatively higher in east Taiwan. Conclusion¡G According to the results of this research, we can find that the avoidable hospitalizations in Taiwan still need to be improved. We suggest the policy makers and the hospitals may use the ¡uavoidable hospitalization¡vas an indicator to monitor the quality of care and the outpatient care quality in Taiwan¡¦s healthcare system. Thus can not only reduce the unnecessary expenditure, but also can offer the general public better quality of healthcare and improve their quality of life.

To achieve the goal of universal coverage of health insurance for the Americans, in March 2010, the Patient Protection and Affordable Care Act (ACA) was signed into law. The ACA targets at providing help to improve access to affordable health coverage for everyone and protect consumers from abusive insurance company practices. One of the precedent mandates, implemented in September 2010, is to expand coverage on young adults of age 19 to 26, who may lose insurance coverage due to the remove from their parents’ plan after age 18 and lacking of productivity to bargain with employers in the labor market. This dissertation looks into the impact of the ACA health insurance coverage expansion for young adults on the subsequent health outcomes, health care utilization, and further social impact on traffic fatalities. Difference-in-differences models are used with different treatment groups and corresponding control groups. Chapter I uses survey data (BRFSS) to evaluate health care access, health behavior and self-assessed health status. The results suggest an improvement in health care access and self-assessed health but more risky behavior. Chapter II uses hospital discharge data (NIS) to estimate avoidable hospitalization in order to assess primary care utilization. The result shows that less primary care was consumed, which leads to more avoidable hospitalization but health may have been improved by using more hospital care. The results from both chapters imply potential ex ante moral hazard among young adults in the policy targeting age group. Thus, chapter III uses accident records data (FARS) to examine the impact of the health insurance expansion on traffic fatality for young adults, to see whether young drivers perform ex ante moral hazard through risky behavior like drunk and/or reckless driving after they get covered by the health insurance expansion policy. Primary result shows that there is an increase in traffic accidents and fatalities for those younger adults as a result of the ACA dependent coverage expansion.