Chan, P

Harridge, S

Hart, N

Hopkinson, N

Maharaj, R

McNelly, A

Montgomery, H

Moxham, J

Puthucheary, Z

Rawal, J

UCL Discovery

Physical Activity Levels, Primary Care Costs and Quality-Adjusted Life Years (QALYs) in Survivors of Critical IllnessDaily physical activity (PA) appears commonly limited in Intensive Care Unit (ICU) survivors We assessed this using both subjective and objective methods, also recording primary care costs (PCC) and deriving Quality-Adjusted Life Years (QALYs) 18 months post-ICU discharge Because it is associated with reduced survival rates2. Over a 5 year period, elderly patients with a frailty score of 4 (roughly mid-range) have:20% lower survival rate and 10% greater chance of being placed in institutional care.   Similar loss of physiological reserve, characterising frailty in the elderly and leading to reduced physical function, may also occur in survivors of critical illnessWe sought to assess the prevalence of frailty in ICU survivors; and to investigate the relationship of frailty to subjective and objective measures of physical activity (PA)  Figure 1: Kaplan–Meier curves of survival (top) and avoidance of institutional care (bottom) for elderly patients2A. McNelly1, R. Maharaj2, J. Rawal1, P. Chan1, N. Hopkinson3, J. Moxham4, S. Harridge5, N. Hart6, H. Montgomery1, Z. Puthucheary1,71 Institute of Health and Human Performance, University College London, UK; 2 Department of Anaesthesia, King’s College Hospital NHS Foundation Trust, UK 3 NIHR Respiratory Biomedical Research Unit at Royal Brompton and Harefield NHS Foundation Trust and Imperial College London, UK4 Department of Respiratory Medicine, King’s College London, UK 5 Centre of Human and Aerospace Physiological Sciences, King’s College London, UK; 6 Lane Fox Clinical Respiratory Physiology Unit, Guy’s and St Thomas’ NHS Foundation Trust, London, UK;7 Division of Respiratory and Critical Care Medicine, University Medicine Cluster, National University Health Systems, Singapore AimsWhy is frailty important?AimsBodily painRole - physicalPhysical functionRole -emotionalMental healthVitalityGeneral healthSocial function020406080100Normal controls1ARDS survivors2MUSCLE-UK survivors1.Hopman et al. CMAJ. 2000; 163(3):265-71.2.Herridge et al. N Engl J Med. 2003; 348(8):683-93Figure 3: Median SF-36 Domain Scores Subjects were drawn from the Musculoskeletal Ultrasound Study in Critical Care: Longitudinal Evaluation (MUSCLE-UK) Study (Clinical Trials.gov Identifier: NCT01106300) Invasively ventilated for >48 hours; on ICU >7days; age > 18 yearsPA assessed during home visits at a mean of 18 months post-ICU discharge: 15/63 recruited patients had died; 41 were contacted; 30 patients provided data PatientsObjective accelerometry (SenseWear Pro, BodyMedia Inc, Pittsburgh, US)Subjective PA levels from self-reported survey, SF-36 (QualityMetric Inc, Lincoln, US) Clinical Frailty Scale (CFS, Table 1)Correlation, Hierarchical Multiple Regression, and Area Under Receiver Operating Characteristic analysis (AUROC) were performed using SPSS v21MethodsTable 1: Clinical Frailty Scale3 A measure of frailty in geriatric and critically ill patients (Score - Frailty grade)1 - Very fit2 - Well3 - Managing well4 - Vulnerable5 - Mildly frail6 - Moderately frail7 - Severely frail8 - Very Severely frail9 - Terminally illFigure 1: Methods for Functional AssessmentSubjects were drawn from the MUSCLE-UK Study1 being (i) invasively ventilated for >48 hours and (ii) on ICU >7days. At 18 months post-ICU discharge we determined:• Daily step count (Sensewear activity monitors) • Health-related quality of life (SF-36 survey)• Clinical Frailty Scale Score2 (Table 1)• QALYs; PCCs and Cost Utility Ratios (CURs)MethodsTwenty-seven patients were studied [14 female; age 55.3 years (95%CI 48.3 - 62.3); post-ICU discharge 573 days (95%CI 539 - 614)] Mean SF-36 Physical Component Summary score ± SD for ICU survivors (39 ± 13) was lower than that of norm population (50 ± 10)Median CFS was significantly higher in ICU survivors compared to age-matched controls: 4 [Interquartile Range (IQR) 2] versus 2 [IQR1]; p=0.002 Mean daily step count was lower than that in normal controls, and worse in those with pre-existing chronic disease than without (Figure 1)Results - Physical FunctionAt 18-months post-ICU discharge:i. Cumulative PCC (mean ± SEM) were 5-fold higher for ICU survivors than for normal controls (£1210 ± 274, £238 ± 11; p=0.003), andii.QALYs (mean ± SEM) were significantly lower (0.92 ± 0.045, 1.16 ± 0.01; p=0.000) CFS was the only independent variable to contribute significantly to variation in QALYs (r2=0.38; p=0.001).The strong correlation between loss of daily step count and CUR, was influenced by the degree of pre-morbidity (at 100-80% of normal population values) (Table 2; Figure 2)Results - Cost-Effectiveness AnalysisSubjective and objective measures show that PA and QALYs are reduced 18 months after ICU admission. This model may inform the design of future rehabilitation trials in ICU patients.ConclusionAcknowledgements:Dr McNelly was supported by the Batchworth Trust; Dr Puthucheary by a National Institute of Health Research (NIHR) doctorate fellowship.Table 1: Clinical Frailty Scale2 A measure of frailty in geriatric and critically ill patients (Score - Frailty grade)Table 2: Quality Adjusted Life Years (QALYs) and Cost Utility Ratios (CURs) in ICU survivors compared to non-ICU survivors for varying permutations of pre-morbid health. *National representative sample of 22,166 British citizens.4  QALY: Quality-adjusted life years; CUR: Cost-Utility Ratio; PCC: Primary Health Care CostsFigure 1: Daily Step Count in ICU and COPD Populations3 versus ControlsCOPD: Chronic Obstructive Pulmonary Disease; ICU: Intensive Care UnitFigure 2: Effect of Level of Pre-Morbid Health on Cost Utility Ratio and Loss of Daily Step CountRed area is the UK’s National Institute for Health and Care Excellence (NICE) cost-effectiveness threshold (£20,000-30,000). ICU: Intensive Care UnitReferences:1. Puthucheary ZA et al. Acute skeletal muscle wasting in critical illness. 2013. JAMA; 310:1591-1600.2. McDermid RC, et al. 2011. Frailty in the critically ill: a novel concept. 2011. Crit Care; 15: 301.3. Shrikrishna D, et al. Quadriceps wasting and physical inactivity in patients with COPD. 2012. Eur Respir J; 40:1115–22. 4. van den Berg B, SF-6D Population Norms. 2012. Health Econom; 21:1508-12.% Pre-Morbid Baseline Health of ICU Survivors vs. Controls*100908580QALY Difference Between ICU Survivors and Controls0.2470.1300.0720.014CUR (£) 393574651350270577Loss of Daily Step Count 31591075571 - Very fit2 - Well3 - Managing well4 - Vulnerable5 - Mildly frail6 - Moderately frail7 - Severely frail8 - Very Severely frail9 - Terminally ill800001006000040000200000Cost Utility Ratio14000120001000080006000400020000Control (n=31) ICU Survivors (n=16)(no chronic disease)ICU Survivors (n=11)(chronic disease)All COPD (n=123)p=0.008*p=0.013*p=0.001*p=0.016*p<0.001*Daily steps95 90 85 806005004003002001000Loss of steps/dayPre-morbid health of ICU survivors (% normal population)Cost utility ratioSteps per dayAt 85% pre-morbid baseline health of ICU survivors vs. controls, there was:i. A difference in QALYs of 0.072ii. A cost per QALY lost (CUR) of £13,502iii. A loss of 107 daily steps

Physical activity levels, primary care costs and quality-adjusted life years (QALYs) in survivors of critical illness

http://discovery.ucl.ac.uk/1476902/1/McNelly%20ERS%20FINAL.pdf

Physical activity levels, primary care costs and quality-adjusted life years (QALYs) in survivors of critical illness

Abstract

Similar works

Full text

Available Versions

UCL Discovery