Kozlowski, Allan J.

Mallinson, Trudy

Pertsovskaya, Vera

Tran, Jasmine

Weaver, Jennifer A.

English

George Washington University: Health Sciences Research Commons (HSRC)

Himmelfarb Health Sciences Library, The George Washington University Health Sciences Research Commons School of Medicine and Health Sciences Student Works School of Medicine and Health Sciences 6-2022 Comparing Indices Of Responsiveness For the Coma Near-Coma Scale With and Without Pain Items Vera Pertsovskaya Jennifer A. Weaver Jasmine Tran Allan J. Kozlowski Trudy Mallinson Follow this and additional works at: https://hsrc.himmelfarb.gwu.edu/smhs_student_works  Part of the Medicine and Health Sciences Commons Comparing Indices Of Responsiveness For the Coma Near-Coma Scale With and Without Pain Items Vera Pertsovskaya,1 Jennifer A. Weaver,2 Jasmine Tran,2 Allan J. Kozlowski,3 Trudy Mallinson11 School of Medicine and Health Sciences, The George Washington University, Washington DC; 2 Department of Occupational Therapy, Colorado State University, Fort Collins, Colorado; 3 John F. Butzer Center for Research and Innovation, Grand Rapids, Michigan.Purpose: To compare indices of responsiveness for the CNC 10-item and 8-item scales. A secondary purpose is to identify proportions of improvers and non-improvers making change ≥ MCID, MDC, and cMDC.• Recovery of consciousness must be monitored using validated assessments to determine treatment effectiveness and patient response to treatment.1• Indices of responsiveness such as the distribution-based minimal clinically important difference (MCID), minimal detectable change (MDC), and conditional MDC (cMDC) indicate whether an individual or group has made a change that is greater than measurement error or a clinical standard.• Painful stimuli are common in these assessments but raise ethical concerns.• The Coma Near Coma (CNC) Scale is a short assessment (10-items)* to evaluate the neurobehavioral function (NBF) of patients with Disorders of Consciousness (DoC).2• Recent psychometric analyses indicate the assessment is unidimensional when the two pain items are removed.3• The 10 item Wright’s Person Separation Reliability is 0.89 indicating the assessment is reliable for group-level decisions.4*CNC has 11 items; the olfactory item was not administered in this study due to difficulty controlling the substance across clinical settings.INTRODUCTIONComa Near Coma Scale (CNC): • 3-point rating scale (0, 2, and 4) rescored so that a higher score indicated more neurobehavioral function:0 = no response; 1 = partially responsive state; 2 = consistent responsive state• 10-item CNC total raw score: 0 to 40; 8-item CNC total raw score: 0 to 32• Raw scores were transformed to equal-interval Rasch measures for analysesData Analysis:• Participants were evaluated twice, 12-16 days apart • Analyses conducted with (10-items) and without (8-items) pain items• Participants were classified either as improvers (CNC change > 0) or non-improvers (CNC change ≤ 0)• Indices of responsiveness (MCID, MDC, and cMDC) were calculated for all participants, improvers, and non-improversParticipants: 32 adults with severe brain injury who have been in a DoC state for at least 28 consecutive days. METHODSRESULTSTable 2: Responsiveness Indices for the CNC for Non-Improvers, Improvers, and All ParticipantsAbbr: SD=standard deviation; r=Wright’s reliability coefficient, SEM=standard error of measurement; ES=effect size; CI=confidence interval; SRM=standardized response mean.The CNC is an imprecise measure resulting in an MDC that is larger than the MCID. CNC MCID should not be used to evaluate clinical change in individual patients.Figure 1: The pair of raw scores can be matched and if the pair lands in: 1) a green cell - the patient has made an improvement beyond measurement error; 2) a red cell - the patient has made a decline beyond measurement error; 3) a gray cell - the patient has not made a change beyond measurement error; or 4) a black cell - the patient has made no change.cMDC for the 8-item CNCFigure 2: Number of Improvers and All Participants that made a change beyond measurement error using the cMDCor MDC on the 10-item and 8-item CNC.The shorter 8-item CNC detects similar number of patients making change beyond measurement error and without inflicting pain.DISCUSSION• 8-item CNC detected greater variability in this sample with less measurement error (better reliability). • Removing pain items resulted in a larger SDpooled and SRM.• Larger SDpooled resulted in larger MDC and MCIDs for both improvers and non-improvers.• This apparent contradiction of the Spearman-Brown prophecy formula5  supports previous work suggesting pain response is a concept distinct from NBF. • SRM and MCIDs were larger for the group of patients classified as improvers compared to non-improvers.• How much change in NBF is relevant depends on whether a group of patients is improving or declining.• cMDC should be used when making decisions based on changes in NBF for an individual.• cMDC is based on standard errors around specific pairs of patient measures so it is more precise than group-level standard error.• CNC may not be sensitive enough for determining group level change in NBF. • MDC for the CNC was larger than any of the MCIDs, suggesting that even large group-level change in NBF as measured by the CNC is within the range of measurement error.Clinical Relevance: Preliminary evidence supports the 8-item CNC group and patient level indices of responsiveness being as precise as the 10-item version; this suggests NBF can be tracked without administering painful stimuli.• Larger group of participants is needed to substantiate findings for responsiveness• Determine whether using the cMDC presents an added burden for practitionersFUTURE RESEARCH1. Giacino JT, Whyte J, Nakase-Richardson R, et al. Minimum Competency Recommendations for Programs That Provide Rehabilitation Services for Persons With Disorders of Consciousness: A Position Statement of the American Congress of Rehabilitation Medicine and the National Institute on Disability, Independent Living and Rehabilitation Research Traumatic Brain Injury Model Systems. Archives of physical medicine and rehabilitation. 2020;101(6):1072-1089.2. Rappaport M. The Disability Rating and Coma/Near-Coma scales in evaluating severe head injury. Neuropsychological rehabilitation. 2005;15(3-4):442-453.3. Schnakers C, Chatelle C, Vanhaudenhuyse A, et al. The Nociception Coma Scale: a new tool to assess nociception in disorders of consciousness. Pain 2010;248:215-9.4. Weaver J, Liu J, Guernon A, Bender Pape T, Mallinson T. Psychometric Properties of the Coma Near-Coma Scale for Adults in Disordered States of Consciousness: A Rasch Analysis. Archives of physical medicine and rehabilitation. 2020.5. Baumgartner TA. The applicability of the Spearman-Brown prophecy formula when applied to physical performance tests. Res Q. 1968;39(4):847-856.REFERENCESThis work was supported in part by: US Department of Defense under Grant (W81XWH-14-1-0568) and US Department of Defense under Grant JW150040.ACKNOWLEDGMENTS

Comparing Indices Of Responsiveness For the Coma Near-Coma Scale With and Without Pain Items

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Comparing Indices Of Responsiveness For the Coma Near-Coma Scale With and Without Pain Items

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