the cost-effectiveness of an adapted community-based aerobic walking program for individuals ...

202 Pages·2012·4.92 MB·English

THE COST-EFFECTIVENESS OF AN ADAPTED COMMUNITY-BASED AEROBIC
WALKING PROGRAM FOR INDIVIDUALS WITH MILD OR MODERATE
OSTEOARTHRITIS OF THE KNEE

GINO DE ANGELIS

Thesis submitted to the Faculty of Graduate and Postdoctoral Studies (FGPS) in partial
fulfilment of the requirements for the MSc degree in Epidemiology

Department of Epidemiology and Community Medicine
Faculty of Medicine
University of Ottawa, Ottawa, Ontario, Canada

© Gino De Angelis, Ottawa, Canada, 2012

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ABSTRACT

This thesis investigated the cost-effectiveness of a 12-month supervised aerobic walking
program with or without a behavioural intervention and an educational pamphlet, compared to an
unsupervised/self-directed educational pamphlet intervention, among individuals with moderate
osteoarthritis (OA) of the knee. Analyses included an economic evaluation to assess the cost
effectiveness of the two walking interventions from both the societal and Canadian
provincial/territorial health care payer perspectives. A value of information analysis exploring
the potential value of future research was also performed. Results revealed that the
unsupervised/self-directed intervention was the most cost-effective approach given that it cost
the least to implement and participants had higher quality-adjusted life years (QALYs). Walking,
either supervised in a community setting, or unsupervised in a setting such as the home, may be a
favourable non-pharmacological option for the management of OA of the knee. The thesis
concludes with a policy discussion relating to the funding of non-pharmacological therapies.

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ACRONYMS AND ABBREVIATIONS

ACR American College of Rheumatology
AIMS-2 Arthritis Impact Measurement Scales 2
ALF Aggregate locomotor function score
BMI Body mass index
C Self-directed walking intervention
CCS Comparative controlled study
CCT Controlled clinical trial
CEAC Cost-effectiveness acceptability curve
CSRI Client Services Receipt Inventory
CPDD Calcium pyrophosphate-deposition disease
CUA Cost-utility analysis
EQ-5D EuroQol-5 Dimension Questionnaire
ESCAPE Enabling Self-management and Coping with Arthritic Knee Pain through Exercise
EVPI Expected Value of Perfect Information
HAD Hospital Anxiety and Depression score
HRU Health resource utilization
HsW Health-sector-Wide
ICER Incremental cost-effectiveness ratio
INB Incremental net benefit
IRGL Impact of Rheumatic Diseases on General health and Lifestyle index
LHIN Local health integration networks
MAR Missing at random
MCAR Missing completely at random
MET Total metabolic equivalent
NHS National Health Service
NMB Net monetary benefit
NSAID Non-steroidal anti-inflammatory drug
OA Osteoarthritis
OARSI Osteoarthritis Research Society International
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OKS Oxford Knee Score
PA Physical activity
PACEex Program for Arthritis Control through Education and Exercise
PAR Physical activity recall
PHAC Public Health Agency of Canada
PICO Population, Intervention, Comparison, and Outcome
PTA Percutaneous transluminal angioplasty
QALY Quality-adjusted life year
QOL Quality of life
RCT Randomized controlled trial
SD Standard deviation
SE Standard error
SF-36 Short Form (36) Health Survey
SF-6D Short Form Six-Dimension utility index
SMART Senior’s Maintaining Actives Roles Together program
TAS The Arthritis Society
VAS Visual analogue scale
W Supervised walking intervention
WB Supervised walking and behavioural intervention
WTP Willingness to pay
WOMAC Western Ontario and McMaster Universities Osteoarthritis Index

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ACKNOWLEDGEMENTS

I would like to acknowledge my thesis supervisors, Drs. Doug Coyle and Lucie Brosseau for
their instrumental guidance and support throughout my graduate studies. I wish to express my
gratitude for all of their time and dedication which allowed me to complete this research. I credit
Dr. Coyle for introducing me to the world of health economics whose expertise and skills
significantly contributed to my experience in this program. I owe my eternal gratitude to Dr.
Brosseau for her guidance over the years through which she has offered her vast knowledge that
has provided me with direction.
I wish to thank all the co-investigators of the walking study for their contributions to this
research: Drs. George Wells, Glen Kenny, Robert Reid, Andreas Maetzel, Peter Tugwell, Maria
Huijbregts, Ms. Carolyn McCullough, and Ms. Lily Chen. A special thanks to Dr. Andreas
Maetzel for his suggestions pertaining to the search strategy used for the systematic review, to
Dr. Peter Tugwell for his advice with the health resource utilization questionnaire, and to Ms.
Jessica McEwan for her assistance conducting the literature search and systematic review. Many
thanks to the study participants and the research personnel for their much appreciated assistance.
I recognize that this research would not have been possible without the financial assistance
provided by my thesis supervisors and the University of Ottawa Faculty of Graduate and
Postdoctoral studies (Master’s Admission Scholarship), and express my gratitude.
Last but not least, I thank my family and friends for their support and encouragemnt to pursue
this Master’s degree.

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TABLE OF CONTENTS

Abstract............................................................................................................................................ii
Acronyms and Abbreviations.........................................................................................................iii
Acknowledgements..........................................................................................................................v
Table of Contents ...........................................................................................................................vi
List of Figures...............................................................................................................................viii
List of Tables.................................................................................................................................ix
List of Appendices..........................................................................................................................x

Chapter 1: Introduction & Background......................................................................................1
1.1 Introduction....................................................................................................................1
1.2 Background....................................................................................................................3

Chapter 2: Systematic Review....................................................................................................11
2.1 Objective......................................................................................................................11
2.2 Methods........................................................................................................................11
2.3 Results..........................................................................................................................14
2.4 Included Studies...........................................................................................................16
2.5 Excluded Studies..........................................................................................................32
2.6 Lessons Learnt.............................................................................................................35
2.7 Discussion....................................................................................................................37
2.8 Conclusion...................................................................................................................39

Chapter 3: Methodology..............................................................................................................40
3.1. Research Question......................................................................................................40
3.2 Details of the randomized controlled trial...................................................................40
3.3 Methodology for the Economic Evaluation.................................................................43
3.4 Primary analysis...........................................................................................................51

Chapter 4: Results........................................................................................................................59
4.1 Participant characteristics............................................................................................59
4.2 Outcomes.....................................................................................................................63
4.3 Intervention Costs........................................................................................................65
4.4 Cost-Effectiveness.......................................................................................................67
4.5 Alternate Estimates of Cost Effectiveness...................................................................75
4.6 Incremental Net Benefit Analysis................................................................................79
4.7 Sensitivity analysis results...........................................................................................86
4.8 Conclusion...................................................................................................................87
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Chapter 5:
Discussion.....................................................................................................................................90
5.1. Economic Evaluation..................................................................................................90
5.2 Evidence to support funding of physical activity programs in the management of knee
OA......................................................................................................................................94
5.3 Current situation with respect to funding of exercise programs..................................99
5.4 Overall conclusion.....................................................................................................102

References...................................................................................................................................103

Appendices..................................................................................................................................118

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LIST OF FIGURES
Chapter 2: Systematic Review
Figure 2.1: Flow chart showing the various steps of study selection...............................15
Chapter 4: Results
Figure 4.1: Study Flow Chart...........................................................................................62
Figure 4.2: Incremental Net Benefit of Walking Programs versus Self Directed Program
- Health Care Costs at 18 months......................................................................................81
Figure 4.3: Incremental Net Benefit of Walking Programs versus Self Directed Program
- Societal Costs at 18 months.............................................................................................81
Figure 4.4: CEAC Health Care Costs at 18 Months.........................................................83
Figure 4.5: CEAC Societal Costs at 18 Months...............................................................84
Figure 4.6: Expected Value of Perfect Information using Health Care Costs at 12, 15 and
18 months...........................................................................................................................85
Figure 4.7: Expected Value of Perfect Information using Societal Costs at 12, 15 and 18
months................................................................................................................................86

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LIST OF TABLES
Chapter 2: Systematic Review

Table 2.1: Drummond et al. Suggested Checklist for Assessing Economic Evaluations
for the Included Studies.....................................................................................................13
Table 2.2: Patients, Interventions, and Outcomes in the Included Studies.......................30

Chapter 3: Methodology

Table 3.1: Intervention costs.............................................................................................45
Table 3.2: Unit Costs for Ontario (2010 Canadian Dollars).............................................49
Table 3.3: Missed evaluations during the OC Transpo Bus Strike...................................53

Chapter 4: Results

Table 4.1: Participant Characteristics...............................................................................61
Table 4.2: Costs (Canadian $) and QALYs......................................................................66
Table 4.3: Cumulative Total Health care costs and QALYs at each time period...........68
Table 4.4: Cumulative Total Societal Costs and QALYs at each time period................69
Table 4.5: Multiple Regression Analysis- Mean QALY score at 18 months...................72
Table 4.6: Multiple Regression Analysis- Total Health Care Costs at 18 Months...........73
Table 4.7: Multiple Regression Analysis- Total Societal Costs at 18 Months.................74
Table 4.8: Adjusted and Unadjusted Health Care Costs and QALYs at 18 Months........75
Table 4.9: Adjusted and Unadjusted Societal Costs and QALYs at 18 Months...............75
Table 4.10: Incremental costs and QALYs by Alternative Analytical methods...............78
Table 4.11: Linear Regression Analysis of Incremental Net Benefit using Health Care
Costs with a WTP threshold of $50,000.00 at 18 months.................................................89

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LIST OF APPENDICES
Chapter 2: Systematic Review

Appendix 2.1: Search strategies for Identifying Studies Concerned with Cost-
Effectiveness of Exercise Interventions in the treatment of mild to moderate osteoarthritis
of the
knee..................................................................................................................................119
Appendix 2.2: Permission from Centre for Review and Dissemination........................120
Appendix 2.3: Centre for Review and Dissemination (University of York) Summaries of
Included Studies...............................................................................................................121
Appendix 2.4: Excluded studies....................................................................................138

Chapter 3: Methodology

Appendix 3.1: Post-Randomization Walking Interventions...........................................171
Appendix 3.2: Health Resource Utilization Questionnaire............................................172

Chapter 4: Results
Appendix 4.1: Utility Values and Costs by Time Point (Pooled Results Using Multiple
Imputation).......................................................................................................................174
Appendix 4.2: Costs (Canadian $) and QALYs (Complete Data Only).........................177
Appendix 4.3: Costs (Canadian $) and QALYs (Excluding Drop Outs)........................178
Appendix 4.4: Costs (Canadian $) and QALYs (Excluding Imputations).....................179
Appendix 4.5: Multiple Regression Analysis- Mean QALY score at 12 months.........180
Appendix 4.6: Multiple Regression Analysis- Mean QALY score at 15 months.........180
Appendix 4.7: Regression Analysis- Total Health Care Costs at 12 months.................181
Appendix 4.8: Regression Analysis- Total Health Care Costs at 15 months.................181
Appendix 4.9: Multiple Regression Analysis- Total Societal Costs at 12 months........182
Appendix 4.10: Multiple Regression Analysis- Total Societal Costs at 15 months......182
Appendix 4.11: Incremental Net Benefit of Walking Programs versus Self Directed
Program - Health Care Costs at 12 months......................................................................183
Appendix 4.12: Incremental Net Benefit of Walking Programs versus Self Directed
Program - Health Care Costs at 15 months......................................................................183
Appendix 4.13: Incremental Net Benefit of Walking Programs versus Self Directed
Program- Societal Costs at 12 months.............................................................................184
Appendix 4.14: Incremental Net Benefit of Walking Programs versus Self Directed
Program -Societal Costs at 15 months.............................................................................184
Appendix 4.15: Multiple Regression Analysis- Incremental Net Benefit with a WTP
threshold of $50,000.00, Total Health Care Costs at 18 months.....................................185
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