目的：以住院病患疾病嚴重度調整醫療支付以降低醫院之財務風險與病患就醫可近性及公平性之議題受到同等重視。本研究旨在分析健保住院診斷關聯群依美國MS-DRGs所定義之主要併發症／合併症分類後，不同醫院特性病患之醫療費用與住院日的變異，俾便對疾病嚴重度的影響能有較為深入的認識。 方法：本研究為回溯性之2006年全民健保資料庫分析。研究樣本為依美國MS-DRGs所定義之主要併發症／合併症重新群分派後，Tw-DRGs案件中併有主要併發症／合併症之案件大於60%之群組，為Tw-DRG 12101、20201、41601與47501等四群，每群分別有2,294，19,411，28,576與33,178案件。比較各群有無主要併發症／合併症之案件的醫療費用，並分析群組醫療費用變異係數與醫院病例組合指標（CMI值）之改變量。 結果：有主要併發症／合併症之案件的平均醫療費用均顯著高於無主要併發症／合併症者的平均醫療費用。以公立醫學中心平均醫療費用（95,611.20點）最高，其次為財團法人醫學中心（89,338.56點），區域醫院與地區醫院。主要併發症／合併症分群後，醫學中心CMI值增加1.099%比區域醫院增加幅度多，但財團法人區域醫院則稍微減少(-0.02%)，地區醫院CMI值減少與其醫療費用較低有對應。本研究結果顯示主要併發症／合併症分群之各群醫療費用變異係數有減少。 結論：結果發現主要併發症／合併症能反應不同醫院之同群DRG醫療費用之變異，若推論至本研究四群Tw-DRGs外之其他DRGs則須謹慎。

Objectives: Adjusting the severity of illness (SOI) for each inpatient service is important for reducing financial risks faced by different hospitals and for maintaining patients' accessibility to and equity in an inpatient payment system. In this study, we analyzed four Tw-DRGs (Taiwan version of Diagnosis-Related Groups) by applying the new Major Complications and Co-morbidity (MCC) standards in the new Medicare Severity-adjusted DRGs (MS-DRG). Variations in medical expenses and length of stay (LOS) among hospitals with different accreditation and ownership status were examined after employing more appropriate SOI standards. Methods: A retrospective study was conducted using the 2006 Taiwan NHI inpatient claim database. After re-grouping Tw-DRGs by MCC, it was found that four DRGs had MCC in over 60% of their claims. These included Tw-DRG 12101 (Circulatory disorders with acute myocardial infarction and major complications, discharged alive with Complications and Comorbidities (CC), 20201 (Cirrhosis and alcoholic hepatitis with CC), 41601 (Septicemia age≧18 with CC) and 47501 (Respiratory system diagnoses with ventilator support with CC) with 2,294, 19,411, 28,576 and 33,178 cases respectively. These four DRGs were selected for comparison of the differences in medical expenses for inpatients with MCC versus those without MCC. The coefficient of variation (CV) of medical expenses was applied to measure intra DRG homogeneity. The hospital case mix index (CMI) and medical expenses were also calculated and compared to examine changes in CMI across hospitals. Results: Public medical centers had the highest average expense per discharge (relative value unit 95,611.20), followed by non-profit medical centers (89,338.56), regional hospitals and district hospitals. The CMI for public medical centers under the Tw-DRGs incorporating the MCCs standards increased by 1.099% more than did the CMI for regional hospitals; however, the CMI for non-profit regional hospitals decreased slightly by -0.02%. CMI reduction corresponded with lower expenses for district hospitals. MCC-split DRGs had a lower CV with respect to medical expenses. Conclusions: The findings of this study indicated that MCCs accounted for variations in medical expenses for patients in the same DRG across different hospitals. Our findings were limited to four Tw-DRGs and should be interpreted cautiously.