Development of a Scoring System to Determine Proportional Appropriateness of Continuous Deep Sedation: A Concept-of-Proof Study.

Abstract

Context: Some patients require continuous deep sedation (CDS) for refractory symptoms despite intensive palliative care. The principle of proportionality is proposed on the basis of clinical decisions, but no validated tools to assist such decision making are available. Aim: To develop a scoring system to determine whether CDS is proportionally appropriate. Subjects and Methods: A secondary analysis of a nationwide questionnaire survey of Japanese palliative care specialists was performed. Physicians were asked to rate the degree that they believed CDS to be appropriate in a total of 27 scenarios based on a combination of 3 factors with 3 levels: (1) the estimated survival (days, weeks, and months), (2) the patient s wish (clear and consistent, somewhat unclear and/or inconsistent, and unclear or inconsistent), and (3) confidence in refractoriness of the symptom (definite, probable, and unsure). Based on logistic regression analyses, a scoring system with two formulas (the proportionality score to determine that continuous deep sedation is appropriate [ProScoreCDS-appropriate] and proportionality score to determine that continuous deep sedation is inappropriate [ProScoreCDS-inappropriate]) to predict specialists decision that CDS is appropriate or inappropriate was developed. The accuracy of the formulas was investigated. Results: Among 695 palliative care specialists, 469 returned the questionnaire (response rate, 69%) and 440 were analyzed. Logistic regression analyses identified that all three factors were significantly associated with physicians decisions about the appropriateness of performing CDS. Using weighted value, the total score ranged from 3 to 67 for ProScoreCDS-appropriate, and 3 to 27 for ProScoreCDS-inappropriate. The area under the curve (AUC) values of ProScoreCDS-appropriate and ProScoreCDS-inappropriate were 0.88 (95% confidence interval [CI], 0.87-0.89) and 0.81 (95% CI, 0.81-0.82), respectively. Using cutoff points of 41 and 14, sensitivity and specificity were 68.6% and 88.9% for ProScoreCDS-appropriate and 67.7% and 76.0% for ProScoreCDS-inappropriate, respectively. Conclusion: A scoring system to determine whether CDS is proportionally appropriate can be constructed, and a further study to develop a clinical tool is promising.