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Trial registered on ANZCTR


Registration number
ACTRN12615001226594
Ethics application status
Approved
Date submitted
5/11/2015
Date registered
9/11/2015
Date last updated
27/11/2018
Date data sharing statement initially provided
27/11/2018
Date results information initially provided
27/11/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Using discreet choice experiments to elicit patient perception of acceptable risk in total knee arthroplasty: study protocol for a randomised controlled trial
Scientific title
Maximum Acceptable Risk of Complication in Total Knee Arthroplasty (MARKA) Study: using discreet choice experiments to elicit patient and surgeon perception of acceptable risk in total knee arthroplasty
Secondary ID [1] 287756 0
None
Universal Trial Number (UTN)
Trial acronym
MARKA Study
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Osteoarthritis 296628 0
Total Knee Arthroplasty 296629 0
Patient Expectations 296632 0
Condition category
Condition code
Musculoskeletal 296867 296867 0 0
Osteoarthritis
Surgery 296931 296931 0 0
Other surgery

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Patients in the intervention arm will complete a survey containing a risk-benefit preference decision aiding tool: a discrete choice experiment (DCE) survey. The DCE tool includes items about post-operative pain, stiffness, quality of life, complications and adverse events (health states) following knee replacement surgery. These items are organised into a number of scenarios and then organised into pairs, and patients are asked to choose between a number of these pairs of choices. The remainder of the survey includes items about how much improvement in symptoms patients expect following knee surgery, the level of control over things in your life, and attitude towards taking risks, and the physical and emotional experiences associated with knee pain.
Participants are required to complete the survey prior to total knee replacement (TKR) during their routine pre-admission appointment at St Vincent's Hospital, Melbourne. The survey will take approximately 30 minutes to complete. Patients will also be required to complete a brief patient expectation survey 1-week prior to scheduled TKR, which will take approximately 5-minutes to complete. Surveys can be completed electronically or paper-based hardcopy. Electronic surveys will be completed using a portable computer with administrative assistance provided from the study coordinator
Intervention code [1] 293196 0
Other interventions
Comparator / control treatment
Patients in the control arm will complete a reduced survey that does not contain the DCE activity. The survey includes items about how much improvement in symptoms patients expect following knee surgery, the level of control over things in your life, and attitude towards taking risks, and the physical and emotional experiences associated with knee pain. Participants are required to complete the survey prior to total knee replacement (TKR) during their routine pre-admission appointment at St Vincent's Hospital, Melbourne. The survey will take approximately 25-minutes to complete. Surveys can be completed electronically or paper-based hardcopy. Electronic surveys will be completed using a portable computer with administrative assistance provided from the study coordinator
Control group
Active

Outcomes
Primary outcome [1] 296524 0
A primary outcome will be changes in patient-reported knee pain between baseline and 1-year post TKR. Pain will be measured on the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index (Bellamy et al., 1998). The WOMAC consists of 24 items, with knee pain measured using a 5-item subscale. The pain subscale will be transformed to a score ranging from 0 to 100, with a higher score indicating greater pain.
Timepoint [1] 296524 0
Baseline before total knee replacement surgery and 1-year post surgery
Primary outcome [2] 296566 0
A primary outcome will be changes in patient-reported knee stiffness between baseline and 1-year post TKR. Knee stiffness will be measured on the WOMAC (Bellamy et al. 1998) using the two-item stiffness subscale. The stiffness subscale will be transformed to a score ranging from 0 to 100, with a higher score indicating greater stiffness.
Timepoint [2] 296566 0
Baseline before total knee replacement and 1-year post surgery
Primary outcome [3] 296567 0
A primary outcome will be changes in patient-reported knee function between baseline and 1-year post TKR. Knee function will be measured on the WOMAC (Bellamy et al. 1998) using the 17-item function subscale. The function subscale will be transformed to a score ranging from 0 to 100, with a higher score indicating greater stiffness.
Timepoint [3] 296567 0
Baseline before total knee replacement and 1-year post surgery
Secondary outcome [1] 318668 0
Psychological well-being: derived from the 12-item Short Form Health Survey mental component score
Timepoint [1] 318668 0
Baseline before total knee replacement surgery and 1-year post surgery
Secondary outcome [2] 318669 0
Recovery expectations following TKA: measured using the 19-item Hospital for Special Surgery: Knee Surgery Expectations Survey
Timepoint [2] 318669 0
Patients will complete this at baseline before total knee replacement surgery and before completing the DCE survey (or control survey); 1-week prior to scheduled TKR; and 12 months after surgery. In addition, orthopaedic surgeons will complete the same recovery expectations survey (Hospital for Special Surgery: Knee Surgery Expectations Survey) for patients consented for TKA immediately following the consult after consenting the patient.. This will allow for a matched surgeon/patient comparison of expectations for recovering following TKA.
Secondary outcome [3] 318670 0
Personality: measured using the Big Five Personality Inventory, a 15-item questionnaire
Timepoint [3] 318670 0
Baseline before total knee replacement surgery to allow for subgroup analyses of post-operative outcomes.
Secondary outcome [4] 318671 0
Control: measured using the Locus of Control, a 7-item questionnaire
Timepoint [4] 318671 0
Baseline before total knee replacement surgery to allow for subgroup analyses of post-operative outcomes.
Secondary outcome [5] 318672 0
Risk Attitudes: measured using the British Household Panel Survey
Timepoint [5] 318672 0
Baseline before total knee replacement surgery to allow for subgroup analyses of post-operative outcomes.
Secondary outcome [6] 318673 0
Fear avoidance beliefs: measured using the 5-item Fear Avoidance Beliefs Questionnaire
Timepoint [6] 318673 0
Baseline before total knee replacement surgery to allow for subgroup analyses of post-operative outcomes.
Secondary outcome [7] 318674 0
Catastrophizing: measured using the 13-item Pain Catastrophizing Scale
Timepoint [7] 318674 0
Baseline before total knee replacement surgery to allow for subgroup analyses of post-operative outcomes.
Secondary outcome [8] 318675 0
Optimism: measured using the 10-item Life Orientation Test-Revised questionnaire
Timepoint [8] 318675 0
Baseline before total knee replacement surgery to allow for subgroup analyses of post-operative outcomes.

Eligibility
Key inclusion criteria
(i) Patients on the surgical waiting list for primary TKA for end stage OA at St Vincent's Hospital, Melbourne; (ii) orthopaedic surgeons/registrars who consult at the orthopaedic clinics at St Vincent's Hospital, Melbourne.
Minimum age
18 Years
Maximum age
85 Years
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
(i) Patients undergoing revision surgery or surgery for neoplastic disease; (ii) Inability to provide informed consent due to mental incompetence (e.g., intellectual disability, dementia) (iii) active drug or alcohol use disorder which in the opinion of the investigators makes the patient unsuitable for participation in the trial (iv) limited English language fluency.

Study design
Purpose of the study
Educational / counselling / training
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Opaque, numbered, tamperproof envelopes containing assignment will be prepared. The surgeons involved in the consent of patients for TKA will have no role in the assignment process. Consenting surgeons will be blinded to patient allocation. In addition, outcome ascertainment will be blinded. Upon completion of the study, a biostatistician blinded to group allocation will analyse outcome data.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomisation will be performed by a computer-generated random assignment sequence prepared in advance.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Other design features
Phase
Type of endpoint(s)
Statistical methods / analysis
Statistical analysis will be by intention to treat. Categorical variables will be analysed using chi-squared tests (or Fisher’s Exact test for small samples) while for continuous variables we will employ (parametric) t-tests and (non-parametric) Mann-Whitney tests for symmetrically and asymmetrically distributed data, respectively. The significance of differences in dichotomous data will be tested using generalised estimating equations or linear mixed model. If there are chance imbalances in baseline patient characteristics hypothesised to influence the main outcomes, then statistical techniques that allow adjustment for confounding variables will be used as secondary analyses. DCE data will be analysed based on extensions to logistic regression, including multinomial logit models, mixed logit models, and generalised multinomial logit models (Fiebig et al., 2010). If there are more than 5% missing data, sensitivity analysis allowing for different assumptions, such as the best or worst possible scenario, will also be reported for the main outcomes of the study. The sample size calculation for this study was based on the following parameters: (i) alpha value = 0.05, 2-sided; (ii) power = 80%; (iii) expected rates of satisfaction at 1 year post TKA of 77% for patients using a risk-benefit preference (DCE) tool prior to surgery compared to 51% for patients undergoing standard procedural consent. The expected rates of satisfaction are derived from a recent study which reported 49% of patients whose expectations were not met reported dissatisfaction with their TKA compared 6% of patients whose expectations were met (Bourne et al., 2010). Incomplete data were reported in 17% of the patient cohort and therefore these patients were not included in the analysis. We have therefore assumed a worst case scenario that these 17% would have reported dissatisfaction despite having their expectations met. Based on these rates the sample size required in each group is 60. To allow for a 10% drop-out of patients, we will recruit 132 patients in total (66 per arm).

Recruitment
Recruitment status
Active, not recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC
Recruitment hospital [1] 4568 0
St Vincent's Hospital (Melbourne) Ltd - Fitzroy
Recruitment postcode(s) [1] 12182 0
3065 - Fitzroy

Funding & Sponsors
Funding source category [1] 292335 0
Government body
Name [1] 292335 0
NHMRC
Address [1] 292335 0
16 Marcus Clarke Street
Canberra City
ACT 2600
Country [1] 292335 0
Australia
Primary sponsor type
Individual
Name
Dr Michelle Dowsey
Address
St Vincent's Public Hospital
Level 2, Clinical Sciences Building
29 Regent Street
Fitzroy 3065 Victoria
Country
Australia
Secondary sponsor category [1] 291015 0
None
Name [1] 291015 0
Address [1] 291015 0
Country [1] 291015 0
Other collaborator category [1] 279294 0
Individual
Name [1] 279294 0
Prof Peter Choong
Address [1] 279294 0
St Vincent's Public Hospital
Level 2, Clinical Sciences Building
29 Regent Street
Fitzroy 3065 Victoria
Country [1] 279294 0
Australia
Other collaborator category [2] 279295 0
Individual
Name [2] 279295 0
Prof Anthony Scott
Address [2] 279295 0
Melbourne Institute of Applied Economic and Social Research
Level 5, Faculty of Business and Economics Building, 111 Barry Street, The University of Melbourne. Melbourne, VIC, 3010
Country [2] 279295 0
Australia
Other collaborator category [3] 279296 0
Individual
Name [3] 279296 0
A/Prof Vijaya Sundararajan
Address [3] 279296 0
Level 5, 161 Barry Street
The University of Melbourne
Parkville 3010 VIC Australia
Country [3] 279296 0
Australia
Other collaborator category [4] 279297 0
Individual
Name [4] 279297 0
Dr Mandana Nikpour
Address [4] 279297 0
St Vincent's Hospital
Level 6 55 Victoria Parade
Fitzroy VIC 3065
Country [4] 279297 0
Australia
Other collaborator category [5] 279298 0
Individual
Name [5] 279298 0
Dr Jinhu Li
Address [5] 279298 0
The University of Melbourne
Melbourne Institute of Applied Economic and Social Research
Level 5, FBE building, 111 Barry Street, Carlton, VIC 3053
Country [5] 279298 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 293800 0
St Vincent's Hospital Research Ethics Committee
Ethics committee address [1] 293800 0
41 Victoria Parade, Fitzroy VIC 3065
Ethics committee country [1] 293800 0
Australia
Date submitted for ethics approval [1] 293800 0
30/10/2015
Approval date [1] 293800 0
26/11/2015
Ethics approval number [1] 293800 0
LRR 177/15

Summary
Brief summary
Osteoarthritis (OA) is a leading cause of disability in developed nations. Total knee arthroplasty (TKA) is the mainstay of treatment for people with end-stage knee OA, and represents one of the highest volume medical interventions globally. Despite a high overall success rate with this operation, up to 1 in 3 patients remain dissatisfied following TKA. The reasons for this dissatisfaction include ongoing pain and functional limitation, which patients view as markers of poor outcome following surgery. Research indicates that the strongest predictor of patient dissatisfaction following TKA is unmet expectations. This is known to occur when patients and surgeons have different expectations of surgery. Decision making aids have been effective in aligning patient and surgeon expectations of surgery and improve health outcomes. This study will use a discrete choice experiment (DCE) as a type of decision making aid applied to patients prior to surgery to improve patient knowledge and realistic expectations of TKA. This study will test if this leads to greater health outcome and satisfaction amongst patients following TKA.
132 people with end stage OA on the waiting list for TKA will be recruited and randomly allocated to one of 2 groups using computer-generated block randomisation. A randomised controlled trial (RCT) adhering to CONSORT guidelines will evaluate the effect of applying a DCE prior to surgery on patient expectations, health outcomes and satisfaction following TKA. Patients in the intervention arm will complete a survey containing the DCE decision aiding tool, compared to the control group who will complete a modified survey that does not contain the DCE activity. Participants in both groups will be required to complete the survey prior to surgery during their routine pre-admission appointment at SVHM. Patients will also be required to complete a brief patient expectation survey 1-week prior to scheduled TKR. In addition, orthopaedic surgeons will complete a brief expectations survey for patients consented to TKA to compare matched surgeon and patient expectations for recovery following TKA. Primary outcomes will be evaluated by a blinded examiner at 12 months post-surgery using a validated self-reported pain and physical function scale. Secondary outcomes will include a range of validated measures of health and psychological wellbeing. All analyses will be conducted on an intention to treat basis using linear regression models.
This study is the first of its kind to use this approach to elicit risk-benefit tolerance in surgery and to evaluate if guiding patients through a decision making process in the form of a DCE-based survey prior to surgery will improve patient expectations, health outcomes and satisfaction following TKA. Reducing the rate of patient dissatisfaction commonly seen in patients following TKA will help to reduce the burden associated with poor outcomes on the health system.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 61238 0
Dr Michelle Dowsey
Address 61238 0
St Vincent's Public Hospital, Level 2, Clinical Sciences Building, 29 Regent street, Fitzroy 3065, Victoria, Australia
Country 61238 0
Australia
Phone 61238 0
+61 3 9231 3955
Fax 61238 0
+61 3 9416 3610
Email 61238 0
mmdowsey@unimelb.edu.au
Contact person for public queries
Name 61239 0
Dr Michelle Dowsey
Address 61239 0
St Vincent's Public Hospital, Level 2, Clinical Sciences Building, 29 Regent street, Fitzroy 3065, Victoria, Australia
Country 61239 0
Australia
Phone 61239 0
+61 3 9231 3955
Fax 61239 0
+61 3 9416 3610
Email 61239 0
mmdowsey@unimelb.edu.au
Contact person for scientific queries
Name 61240 0
Dr Michelle Dowsey
Address 61240 0
St Vincent's Public Hospital, Level 2, Clinical Sciences Building, 29 Regent street, Fitzroy 3065, Victoria, Australia
Country 61240 0
Australia
Phone 61240 0
+61 3 9231 3955
Fax 61240 0
+61 3 9416 3610
Email 61240 0
mmdowsey@unimelb.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
What supporting documents are/will be available?
Summary results
Have study results been published in a peer-reviewed journal?
No
Other publications
Have study results been made publicly available in another format?
No
Results – basic reporting
Results – plain English summary