日本語版NPI-NHの妥当性と信頼性の検討

Validity and Reliability of the Japanese Version of the Neuropsychiatric Inventory-Nursing Home Version (NPI-NH)

Ⅰ．はじめに

　認知症患者は認知機能障害に加え，しばしば幻覚，妄想や不安，焦燥，無為などさまざまな精神症状を呈する^1）。これらの症状は近年behavioral and psychological symptoms of dementia（BPSD）といわれ，症候学的視点や薬物療法，介護負担を増大させる因子として評価の対象となることが多い^2）。BPSDに対する評価尺度は，既に標準化され使用されているものが数種ある。中でも欧米で認知症患者の精神症状の評価法としてCummingsらによって開発されたNeuropsychiatric Inventory（NPI）は，その信頼性と有用性が示されており，その日本語版は国内でも広く利用されている^3－5）。NPIは主たる介護者に対して検者が面接を行い評価する手法をとっているため，在宅認知症患者と介護者である家族を対象としている。本邦では介護保険の導入以後，認知症患者を介護する施設が急増し，施設内においてBPSDを評価し，適切な治療や看護・介護に結びつける必要性が高まっている。しかし本邦に施設内の看護，介護者が施設入所認知症患者のBPSDを評価する標準化された評価尺度はない。

　そこで今回われわれは，NPIと同様にCummingsらによって開発され，施設入院・入所中の認知症患者について，NPIの10項目に睡眠異常，食行動異常の2項目を加えた12項目のBPSDを，家族介護者ではなく施設の看護・介護職員を対象として評価するNeuropsychiatric Inventory in Nursing Home Version（NPI-NH)^6）の日本語版を作成しその信頼性と妥当性を検討した。

Abstract

　Objective　Neuropsychiatric disturbances are common and burdensome symptoms of dementia.　Assessment and measurement of neuropsychiatric disturbances are indispensable to the management of patients with dementia.　Neuropsychiatric Inventory (NPI) is a comprehensive assessment tool that evaluates psychiatric symptoms in dementia.　The Nursing Home Version (NPI-NH) of NPI was developed for use in extended care facilitate caring for residents with dementia.　We translated the NPI-NH into Japanese and examined their validity and reliability.

　Subjects and Methods The subjects were 100demented inpatients and the nurses in charge of them.　The Mini-Mental State Examination (MMSE) was conducted with all patients and NPI-NH, Cohen-Mansfield Agitation Inventory (CMAI), Cornell Scale for Depression in Dementia (CSDD), and Behavior Pathology in Alzheimer's Disease (BEHAVE-AD) Rating Scale were conducted with the nurses.　We examined validity of NPI-NH by comparing its score with the CMAI, CSDD, and BEHAVE-AD.　In order to evaluate test-retest reliability, NPI-NH was re-adopted to 30 randomly selected nurses in charge inpatients by a different examiner 1 week later.

　Results　The frequency score, severity score and occupational disruptiveness score in each NPI-NH item were significantly correlated with the score of the correspondent item in BEHAVE-AD.　The agitation score of NPI-NH was significantly correlated with CMAI and the depression score of NPI-NH was significantly correlated with CSDD.　Test-retest reliability of the scores of NPI-NH was acceptably high.

　Conclusion　The Japanese version of NPI-NH demonstrated sufficient validity and reliability as well as the original version of them.　It is a useful tool for evaluating psychiatric symptoms in demented inpatients.

(Received: November 21,2007,Accepted: July 28,2008)