以長期死亡率驗證「簡易營養評估」(MNA)台灣修訂版之評估功能

Validation of the modified MNA with its long-term mortality-predicting ability

楊淑芳(Shu-Fang Yang)

指導教授 ： 蔡仲弘

亞洲大學/健康學院/健康管理研究所/碩士(2009年)

摘要

背景─老人的營養狀況與其健康有密切關係。而營養評估工具為早期偵測所必需。簡易營養評估(Mini Nutritional Assessment, MNA)為一簡單、易用又不俱侵入性指標的工具且也依台灣族群特性加以修訂，但此修訂的評估功能尚須以嚴峻的尺度加以驗證。
目的—本研究目的是分析以「簡易營養評估」(Mini Nutritional Assessment， MNA)台灣修訂版預測台灣老年人存活的情形，並以此驗證量表的評估功能。
方法—本研究以長期追蹤具有族群代表性的樣本，分析MNA長期預測台灣老年人存活的能力，以驗證MNA的營養評估功能。以MNA原量表及兩台灣修訂版分析國民健康局「中老年身心社會狀況長期追蹤調查系列研究」中1999年53歲以上老人之營養狀況及追蹤其後四年的存活情形。MNA台灣修訂一版之小腿圍與臂中圍兩題採具台灣族群代表性的分切點；台灣修訂二版則去除BMI，並調整臂中圍及小腿圍配分以維持相同的總分。以描述性統計分析個案的社會人口學資料。以Friedman Test 和Wilcoxon Signed Rank Test 事後檢定分析 MNA三版本評估結果之差異性。以卡方檢定檢視經MNA各版本評定後四年間按營養狀況分組之死亡率是否有顯著差異。以Pool-T Test及ANOVA檢視個案於1999年及2003年的營養狀況與各項健康指標的差異性。以Spearman相關，分析MNA得分與各健康指標(ADL、CES-D、生活滿意度及住院天數)之相關性。以Kaplan-Meier存活分析檢視各版本四年間依營養狀況分組存活曲線的差異性。以邏輯迴歸分析影嚮四年間死亡的預測因子。
結果—結果顯示MNA原量表與兩修訂版本所判定的營養狀況之分佈在各年齡層均具顯著差異。但兩修訂版本所判定之結果則無顯著差異。整體而言，三版本評定營養不良者的死亡風險，大約是具營養風險者的兩倍，營養良好者的六倍。個案的各項健康指標，依所判定的營養狀況作比較，不同營養狀況皆呈顯著差異，但不同版本則無顯著差異。MNA總分與健康相關指標之Spearman相關分析結果均呈顯著相關，修訂版的相關程度較原量表高。Kaplan Meier生存分析顯示三版本皆有預測死亡的能力。在控制社會人口、生活型態與慢性疾病等自變項後，死亡風險的邏輯迴歸分析結果顯示三個MNA版本皆為死亡風險之顯著預測因子，且以修訂二版的預測力最強。
結論—MNA修訂版具有評估長期死亡風險的功能。從長期存活率比較，兩個MNA台灣修訂版的評估結果相當。MNA台灣修訂版較MNA原量表更適合用來評估台灣老年人的營養狀況，MNA台灣修訂二版不論是死亡率的預測還是與健康相關指標的相關性都和MNA台灣修訂一相同或更強，因此可推論MNA台灣修訂二版可以取代MNA台灣修訂一版。MNA台灣修訂二版雖在操作上較修訂一版少了測量及計算BMI的步驟，但對老年人營養情況的評定和MNA台灣修訂一版有相同的功能，更適合推廣用來評定台灣老年人的營養狀況。定期評估、及時介入可降低老人的罹病風險，增進成功老化。

關鍵字

營養評估 ； 營養狀態 ； 驗證 ； 死亡率

並列摘要

Background: Nutrition is a key element in maintaining health in the elderly whereas assessment is the key in detecting emerging nutritional problems. The Mini Nutritional Assessment (MNA) is a simple and non-invasive assessment tool and it has been modified according to population-specific anthropometric cut-points. However, these modified tools have not yet been tested with robust standards.
Objective: This study attempted to validate the two modified versions of the MNA with a more robust standard, the long-term mortality-predictive ability of the tool.
Methods: Data used in this analysis was the “Survey of Health and Living Status of the Elderly in Taiwan, SHLSET” conducted by the Bureau of Health Promotion of Taiwan. All subjects were rated into three levels of nutritional status, malnourished, at risk of malnutrition or normal, according to either the original or two modified versions of the MNA. Kaplan-Meier survival analysis was performed to determine the differences between the two survival curves for the 4 follow-up years. Regression analysis was also performed to determine the significance of impact of nutritional status on survivability.
Results: During the 4-year follow-up period, subjects rated malnourished by the MNA had a two-fold mortality risk of those rated at risk and 6-7 folds of those rated normal. Survival analysis showed that the survival curves were significantly different from each other among the three rated nutritional groups. Overall, the modified Taiwan version-2 had the best predictive ability whereas the modified version-1 was the next. Regression analysis showed clear significant predictive ability of the MNA.
Conclusion: Results of this study indicate that all three versions of the MNA have fairly good mortality-predicting ability. However, the two modified versions, especially Taiwan version-2, have stronger predictive abilities. These results suggest that the modified MNA may be of value in developing into a tool for predicting the long-term care needs of the elderly.

並列關鍵字

Nutritional assessment ； Nutritional status ； Validation ； Mortality

參考文獻

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Tsai AC, Ku PY & Tsai JD. (2008c). Population-Specific Anthropometric Cutoff Standards Improve the Functionality of the Mini Nutritional Assessment without BMI in Institutionalized Elderly in Taiwan. The Journal of Nutrition, Health & Aging, 12(10), 696-700.

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