title: Measuring quality of sedation in adult mechanically ventilated critically ill patients. the Vancouver Interaction and Calmness Scale. Sedation Focus Group.
abstract: There are no reliable, valid, and responsive scales to measure the quality of sedation in adult critically ill patients. Our objective was to develop a summated rating scale with these properties and to define the minimal clinically important difference (MCID). We developed and tested the scale in an 18-bed medical-surgical intensive care unit (ICU) (12-bed acute and 6-bed subacute unit). Following identification of relevant domains and item derivation, 116 observations were made on 38 patients; psychometric properties and interrater reliability were assessed to allow item reduction. The final scale consisted of two five-item subscales quantifying calmness and interaction along a continuum from 5 to 30 points. Interrater reliability was 0.89 and 0.90; internal consistency was 0. 95 for both subscales. To test construct validity, MCID, and responsiveness 302 observations were made on 54 patients. Construct validity: calmness score vs. need for further intervention to make the patient calm (R = -0.82, P < 0.001); interaction score discriminated between acute vs. subacute units, mean scores 15.28 +/- 8.26 vs. 23.54 +/- 7.42, mean difference 8.27 (95% CI - 10.32 to -6.22); MCID - 2.2 and 2.5 for the calmness and interaction subscales; Guyatt's responsiveness statistics - 1.4 and 2.3. The Vancouver Interaction and Calmness Scale (VICS) is reliable, valid, and responsive.
authors.affiliation: Clinical Service Unit: Pharmaceutical Sciences, Vancouver General Hospital, 855 W 12th Avenue, Vancouver, British Columbia, Canada V5Z 1M9. jdelemos@vanhosp.bc.ca
authors.forename: J
authors.initials: J
authors.lastname: de Lemos
authors.forename: M
authors.initials: M
authors.lastname: Tweeddale
authors.forename: D
authors.initials: D
authors.lastname: Chittock
mesh_terms: D000328:Adult; D000368:Aged; D016292:Procedural Sedation; D016638:Critical Illness; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D015203:Reproducibility of Results; D012121:Respiration, Artificial