わが国における言語聴覚療法のエビデンス—システマティックレビューによる検討—言語聴覚士の摂食嚥下障害に対する介入のエビデンス

A systematic review of evidence on the effectiveness of intervention for dysphagia by speech-language-hearing therapists in Japan

【目的】わが国の言語聴覚士（ST）が実施する摂食嚥下訓練のエビデンスをまとめることを目的としてシステマティックレビューを実施した．

【方法】研究疑問（reserach question：以下，RQ）は，「日本における摂食嚥下障害に対する言語聴覚士が行う介入は摂食嚥下機能の向上/改善にどのようなアウトカムをもたらすか」とした．主な検索語は「嚥下障害」「治療」「介入」「訓練」，研究デザインはランダム化比較試験（以下，RCT），非ランダム化比較試験（非RCT），コホート研究，症例対照研究とした．採択した文献についてRQとの関係を評価した．RCTについてはバイアスリスクも評価した．

【結果】1次スクリーニングでは英語297編，日本語238編を選択し，英語6編，日本語27編を2次スクリーニングの対象とした．最終的に英語6編，日本語6編が採択された．研究デザインはRCT 4編，RCTではない研究（非RCT 6編，症例対照研究2編）であった．介入内容は，介入方法・システム，刺激促通，特定の訓練に分類された．それぞれの介入方法に対し一定の摂食嚥下機能向上/改善が示された論文が11編，アウトカム指標に変化が認められなかった論文が1編だった．

【考察】わが国における摂食嚥下訓練に関する論文が複数特定された．採択された論文の介入内容は多岐にわたったが，多くが摂食嚥下機能/改善に寄与する報告であった．今後，言語聴覚士が日々の臨床で実施している摂食嚥下訓練の有効性をエビデンスレベルの高い研究で実証し，その成果を蓄積していくことが望まれる．

　Purpose：A systematic review was performed to compile the evidence on the efficacy of swallowing training conducted by speech-language-hearing therapists in Japan.

　Method：The research question (RQ) was, “What outcomes do interventions for dysphagia by speech-language-hearing therapists bring in terms of improving/enhancing swallowing functions in Japan?” The primary search terms were “deglutition disorders,” “treatment,” “intervention,” and “training.” The study designs included randomized controlled trials (RCT), non-randomized controlled trials (non-RCT), cohort studies, and case-control studies. The selected literature was evaluated in relation to the RQ. The risk of bias was also assessed.

　Results：In the first screening, 297 English and 238 Japanese articles were examined, from these, 6 English and 27 Japanese articles were passed to the second screening. Ultimately, 6 English and 6 Japanese articles were selected for review. The study designs included 4 RCTs, 6 non-RCTs, and 2 case-control studies. The interventions were classified into intervention method/system, facilitation with stimulation, and specific training. Out of the 12 studies, 11 reported significant improvements or enhancements in swallowing function for each type of intervention, while 1 study found no changes in the outcome measures.

　Discussion：Several studies related to swallowing training in Japan were identified. Although the selected literature covered a wide range of interventions, most of them reported improvements or enhancements in swallowing function. In the future, it is desirable to conduct high-quality research to demonstrate the effectiveness of swallowing rehabilitation training, which many speech-language-hearing therapists carry out in daily clinical practice, and to compile the findings.