救急・集中治療領域の終末期治療における代理意思決定支援実践尺度の開発

Development of a Nursing Practice Scale for Measuring Support for Surrogate Decision-makers of Terminal Care in the Intensive and Critical Care Unit

要旨

目的：救急・集中治療領域における終末期治療の代理意思決定支援実践尺度を開発し信頼性および妥当性を検証する．

方法：尺度原案は文献検討および内容妥当性を検討し作成した．全国の救命救急センター病床/ICUにて，看護師473名に質問紙調査を実施した．項目分析，IT相関，GP分析，探索的因子分析，基準関連妥当性の検証，既知集団法，および再テスト法を行った．外的基準は看護師の倫理的行動尺度を用いた．

結果：探索的因子分析の結果，4因子18項目が抽出され，第1因子から順に【他職種連携】【代理意思決定の準備】【偏りのない姿勢と説明の確認】【代理意思決定を考える促し】と命名した．尺度全体のクロンバックαは0.89（下位因子0.74〜0.84）であった．再テスト法の級内相関係数は0.71で，看護師の倫理的行動尺度との相関係数ρは0.54であった．資格および学習経験のある群が有意に高値であった．

結論：救急・集中治療領域の終末期治療における代理意思決定支援実践尺度の信頼性および妥当性が確認された．

Purpose: The aim of this study was to develop a valid and reliable new nursing practice scale for measuring support for surrogate decision-makers, such as family members and close relatives, of terminal care in the intensive and critical care unit.

Methods: Based on a review of the literature, a new scale was drafted and its content validity was evaluated. Next, a survey using an self-administered questionnaire was conducted at intensive and critical care units in emergency and critical care centers in Japan on 473 clinical nurses. All responses were then subjected to statistical analysis, including item analysis, item-total correlation, good-poor analysis, exploratory factor analysis, validation of criterion-related validity, knowngroups method, and the test-retest method. The ethical behavior scale for nurses was used for criterion-related validity.

Results: Exploratory factor analysis using the maximum likelihood method and promax rotation was performed to extract factors, resulting in a four-factor solution with 18 items. The four extracted factors were named as follows based on their content: Factor 1, “Interprofessional Collaboration”; Factor 2, “Preparation for surrogate decision-making”; Factor 3, “Evenly unbiased attitudes and checks on Doctor's explanation”; and Factor 4, “Facilitation of surrogate decisionmaker thinking”. Cronbach's alpha coefficient was 0.89 for the total score and varied between 0.74-0.84 for the four factors. The correlation coefficient for the retest survey was 0.71, while that for the ethical behavior scale for nurses was 0.54. Known-groups method resulted that the group of certified nurse specialists and certified nurses showed significantly higher score than nurses except them, and so did the group with learning experience.

Conclusion: The validity and reliability of the nursing practice scale developed in this study to measure support for surrogate decision-makers of terminal care in the intensive and critical care unit were confirmed.