試題反應理論協助醫院之成本分析

Item Response Theory to Provide Cost Analyzers with Rasch-KIDMAP to Monitor Unusual

醫院內的部門多且複雜，不同部門間的成本如何比較？同一部門內又是如何與過去成本或是其標準成本做比較？如何「有效率」且「有效果」地提出成本異常報表供成本分析管理者「主動」採取行動以進一步分析與檢討，即是本研究之目的。針對某一區域級醫院的異常指標—電話費用，以丹麥數學家Rasch（1960）的試題反應理論單參數洛基模式，對各部門的電話費用，客觀科學地挑出最是非預期的費用偏高部門做篩選，並以網頁KIDMAP報表，提示部門主管「進一步分析與檢討」。結果顯示，Rasch分析可以（1）單向度分析部門電話費用特質與異樣，（2）篩選「最是非預期」費用偏高部門的檢討名單，（3）繪製出KIDMAP通知應受檢討部門提出改善計劃。本研究示範出即便是書記也能勝任而科學挑出費用非預期反應偏高的部門，提出改善建議的模式建立。

Hospital managers usually encounter such problems as how to make cost comparisons between departments, and how to compare the past cost with the present one or the standard one at the same department. The purpose of the study is to explore an effective way to propose unusual cost reports for further study. We picked up telephone fees as the indicator in a regional hospital, scientifically sifting out the departments with unexpectedly-high telephone fees. We used Rasch analysis (Rasch, 1960) to transform raw data with natural logarithm (Ln) function into a Likert-type scoring scales to examine whether all items meet model’s expectation. WINSTEPS computer software was performed and the rating scale model was applied to investigate the unidimensionality of measured characteristics (consumption of telephone fees) and to generate easily-read reports, on which items (months in this study) with Outfit and Infit MNSQ beyond 0.05 and 1.5 are deemed as misfits to the Rasch model and considered for deletion from the assessed sequence. Successive Rasch analyses were performed until a final set of items satisfied the model fit requirements. The results show that Rasch analysis could (1) pick up abnormally suspected departments for further examination in telephone cost consumption per month, (2) disclose the most unexpected units for responding to monthly telephone fees for further improvement, and (3) illustrate a visual KIDMAP diagram to explain the most unexpected units in telephone fees across months. KIDMAP can help managers detect the suspicious units for consuming telephone fees in a month effectively.