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Trial registered on ANZCTR


Registration number
ACTRN12611000509965
Ethics application status
Approved
Date submitted
16/05/2011
Date registered
16/05/2011
Date last updated
25/03/2014
Type of registration
Retrospectively registered

Titles & IDs
Public title
Cognitive behaviour therapy and motivational enhancement therapy for obese individuals and their support partners.
Scientific title
The effectiveness of motivational therapy and cognitive behaviour therapy for obese patients and support partners on weight loss and maintenance: A randomised controlled trial.
Secondary ID [1] 262177 0
Nil known
Universal Trial Number (UTN)
U1111-1118-3196
Trial acronym
None
Linked study record

Health condition
Health condition(s) or problem(s) studied:
obesity 261212 0
Condition category
Condition code
Diet and Nutrition 259363 259363 0 0
Obesity

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Patients and Support Partners:
Obese patients will attend 90-minute group sessions conducted by a clinical psychologist. The one-year period of intervention will be comprised of 8 weekly, 16 fortnightly, and 2 monthly sessions. The intervention will entail a combination of cognitive behaviour therapy (CBT) and motivational enhancement therapy (MET) that has been manualised. In the CBT component, patients will be provided with information regarding the dietary and physical activity requirements for weight loss and maintenance, and will be taught a range of behavioural and cognitive strategies to assist with weight control (e.g., self monitoring, stimulus control, goal setting, challenging negative self-talk, pleasant activity scheduling, problem-solving, relaxation training, and relapse prevention strategies). The MET component seeks to enhance patients’ intrinsic motivation to control their weight through targeting decisional balance (so that the advantages/pros of weight control come to outweigh the disadvantages/cons) and self efficacy (so that patients are confident that they can effectively control their weight over time). MET components include education regarding the nature of behavioural change (e.g., the stages of precontemplation, contemplation, preparation, action, and maintenance), examining each patient’s pros and cons of weight control (e.g., exploring valued goals and how the patient’s current weight undermines the attainment of these goals), developing alternative means of fulfilling the needs met through overeating or being overweight (e.g., learning stress management strategies if overeating is a means of coping with stress), and building confidence that change is possible (e.g., identifying each patient’s strengths and available supports).

The program for the Support Partners of obese patients will be based on programs instructing support partners in motivational strategies for patients with substance dependence and eating disorders. Support Partners will attend 90-minute group sessions conducted by a clinical psychologist. The one-year period of intervention will be comprised of 10 sessions. These groups will be run separately to those for the patients. Similar to the CBT+MET intervention for patients, Support Partners will be provided with information regarding the nature of behavioural change, assisted to examine the patient’s pros and cons of weight control, encouraged to generate alternative methods the patient can use for fulfilling the needs met through overeating or being overweight and developing a plan to introduce these methods to the patient, assisted to understand strategies for increasing the patient’s confidence that change is possible, and encouraged to adopt a communication style that is consistent with MET (e.g., being empathic and avoiding arguing or attempting to control the patient).
Intervention code [1] 258078 0
Behaviour
Comparator / control treatment
Patients alone:
Obese patients will attend 90-minute group sessions conducted by a clinical psychologist. The one-year period of intervention will be comprised of 8 weekly, 16 fortnightly, and 2 monthly sessions. The intervention will entail a combination of cognitive behaviour therapy (CBT) and motivational enhancement therapy (MET) that has been manualised. In the CBT component, patients will be provided with information regarding the dietary and physical activity requirements for weight loss and maintenance, and will be taught a range of behavioural and cognitive strategies to assist with weight control (e.g., self monitoring, stimulus control, goal setting, challenging negative self-talk, pleasant activity scheduling, problem-solving, relaxation training, and relapse prevention strategies). The MET component seeks to enhance patients’ intrinsic motivation to control their weight through targeting decisional balance (so that the advantages/pros of weight control come to outweigh the disadvantages/cons) and self efficacy (so that patients are confident that they can effectively control their weight over time). MET components include education regarding the nature of behavioural change (e.g., the stages of precontemplation, contemplation, preparation, action, and maintenance), examining each patient’s pros and cons of weight control (e.g., exploring valued goals and how the patient’s current weight undermines the attainment of these goals), developing alternative means of fulfilling the needs met through overeating or being overweight (e.g., learning stress management strategies if overeating is a means of coping with stress), and building confidence that change is possible (e.g., identifying each patient’s strengths and available supports).
Control group
Active

Outcomes
Primary outcome [1] 262176 0
The primary outcome is the amount of weight loss at post-treatment and the one-year follow-up. Weight will be measured at each visit using an electronic scale with a 200 kg capacity.
Timepoint [1] 262176 0
Post-treatment and one-year follow-up.
Secondary outcome [1] 276319 0
Measurements of abdominal adiposity will include waist circumference, hip circumference, and waist-to-hip ratio.
Timepoint [1] 276319 0
Post-treatment and one-year follow-up.
Secondary outcome [2] 276320 0
Blood pressure will be measured using a standard sphygmomanometer with large cuff.
Timepoint [2] 276320 0
Post-treatment and one-year follow-up.
Secondary outcome [3] 276321 0
Serum metabolic parameters will be assessed in the fasting state including glucose metabolism (blood glucose) and lipid profile (HDL-cholesterol, LDL-cholesterol, total cholesterol, and triglycerides). A fasting serum sample will be taken for the measurement of insulin (HbA1c if known diabetes). Assessment of renal function (creatinine, eGFR, and urinary microalbumin), liver function tests, and hsCRP will also be undertaken.
Timepoint [3] 276321 0
Post-treatment and one-year follow-up.
Secondary outcome [4] 276322 0
A six minute supervised walk test will be performed (after checking with the patient regarding any heart conditions) to assess exercise capacity.
Timepoint [4] 276322 0
Post-treatment and one-year follow-up.
Secondary outcome [5] 276323 0
The National Diet and Nutrition Survey is a four-day diary developed by the Medical Research Council Collaborative Centre for Human Nutrition Research which will be administered to index the amount and type of food and drink consumed.
Timepoint [5] 276323 0
Post-treatment and one-year follow-up.
Secondary outcome [6] 276324 0
The International Physical Activity Questionnaire-long version will be administered to assess five domains of physical activity over the preceding 7 days.
Timepoint [6] 276324 0
Post-treatment and one-year follow-up.
Secondary outcome [7] 276325 0
The Impact of Weight on Quality of Life Questionnaire-Lite is a 31-item self-report questionnaire which assesses the perceived effect of being overweight on five domains of quality of life: Work, Public Distress, Sexual Life, Physical Function, and Self Esteem.
Timepoint [7] 276325 0
Post-treatment and one-year follow-up.
Secondary outcome [8] 276326 0
The Binge Eating Scale is a 16-item self-report questionnaire designed to assess impulsive eating tendencies. The Body Esteem Scale is a 23-item self-report questionnaire that assesses general satisfaction with one's appearance, weight satisfaction, and a sense of others' evaluations about one's appearance.
Timepoint [8] 276326 0
Post-treatment and one-year follow-up.
Secondary outcome [9] 276327 0
The Depression Anxiety and Stress Scales are comprised of 21 items that assess depression, anxiety, and stress over the past week. The standard format will be altered to assess mood disturbance in the previous 4-week period.
Timepoint [9] 276327 0
Post-treatment and one-year follow-up.
Secondary outcome [10] 276328 0
The Rosenberg Self Esteem Scale is a 10-item self-report questionnaire that assesses one's overall evaluation of oneself as a person.
Timepoint [10] 276328 0
Post-treatment and one-year follow-up.
Secondary outcome [11] 276329 0
To assess social support for weight management, two versions of the Support for Healthy Eating Habits scale will be administered - one for friends and one for family members. Similarly, two versions of the Support for Exercise Habits scale will be administered - one for friends and one for family members. The Quality of Relationships Inventory is a 25-item self-report questionnaire that assesses the level of social support, depth, and conflict that an individual perceives to exist in a specified relationship. In this study, participants will be asked to complete the questionnaire in reference to their support partner.
Timepoint [11] 276329 0
Post-treatment and one-year follow-up.

Eligibility
Key inclusion criteria
The inclusion criteria include: 18-70 years of age; a body mass index (BMI) between 30-60; and one support partner who will be available to attend sessions.
Minimum age
18 Years
Maximum age
70 Years
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
The exlusion criteria include: psychiatric conditions (i.e., current psychosis, major depressive disorder, drug or alcohol abuse/dependence, or mental retardation) or severe medical conditions (i.e., significant hepatic or renal dysfunction and significant cardiovascular disease such as heart failure) that would preclude full participation in the study; current treatment for obesity including bariatric surgery, current treatments known to affect eating or weight (e.g., medications); pregnancy; and insufficient English to understand the treatment content.

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)
The participants will be recruited from among obese individuals in Canberra and Sydney. Some recruitment sites will include patients referred to the Metabolism and Obesity Services (MOS) at Royal Prince Alfred Hospital Sydney, local general practices, the Sydney Diabetes Prevention Project, the clinical trials database of the Institute of Obesity, Nutrition, and Exercise, University of Sydney, the public forums website of the Australian National University, and the staff intranet of the Royal Prince Alfred Hospital Sydney.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomisation of participants to interventions will follow procedures outlined in the CONSORT statement. Specifically, participants will be screened for their eligibility to participate by a Clinical Psychologist. Eligible participants will be sequentially entered into a database by the Clinical Psychologist and then a computer-generated randomisation list will be used to allocate participants to one of the two conditions. The Research Coordinator will use this computer-generated randomisation list to inform patients what condition they have been allocated to.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Completed
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)

Funding & Sponsors
Funding source category [1] 258540 0
Government body
Name [1] 258540 0
National Health & Medical Research Council (NHMRC) - Project Grant
Address [1] 258540 0
Level 1
16 Marcus Clarke Street
Canberra ACT 2601
Country [1] 258540 0
Australia
Primary sponsor type
University
Name
Australian National University
Address
The Australian National University
Canberra ACT 0200
Country
Australia
Secondary sponsor category [1] 257676 0
University
Name [1] 257676 0
University of Sydney
Address [1] 257676 0
University of Sydney NSW 2006
Country [1] 257676 0
Australia
Other collaborator category [1] 251825 0
Individual
Name [1] 251825 0
Professor Ian Caterson
Address [1] 251825 0
Institute of Obesity, Nutrition, Exercise and Eating Disorders Medical Foundation Building K25
92-94 Parramatta Road
The University of Sydney NSW 2006
Country [1] 251825 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 260509 0
ANU Human Research Ethics Committee.
Ethics committee address [1] 260509 0
ANU Human Research Ethics Committee
Research Office
Level 3 Innovations Building
Australian National University
Canberra ACT 0200
Ethics committee country [1] 260509 0
Australia
Date submitted for ethics approval [1] 260509 0
19/01/2010
Approval date [1] 260509 0
03/03/2010
Ethics approval number [1] 260509 0
2010/028

Summary
Brief summary
Aims: The primary aim of the present study is to improve the maintenance of weight loss in obese adults. To do so, it will combine the most promising approaches suggested by previous research, namely, (i) motivational enhancement therapy (MET) and (ii) instructing the support partners of obese patients in the strategies of MET. Given the prevalence of obesity, any feasible solution will need to limit the need for patients to have intensive, ongoing healthcare. By enhancing the self-motivation of patients to control their weight over time and improving the quality of social support patients have for weight control, this double-faceted approach aims to improve the maintenance of weight loss while minimising the need of patients for ongoing healthcare service utilisation.

Method: The current study entails a two-arm randomised controlled trial in which obese patients will receive a one-year cognitive-behavioural weight control intervention augmented by MET; this intervention will be implemented with and without the inclusion of support partners.
A total of 150 patients from Canberra and Sydney will participate in the study (75 in each of the two treatment conditions), yielding an estimated power of 80%. The inclusion criteria include 18-70 years of age, a body mass index between 30-60, and the availability of one support partner to attend sessions. Patients will be excluded if they have psychiatric or medical conditions that would preclude full participation in the study, are currently receiving treatment for obesity or treatments known to affect weight, or are pregnant. A comprehensive battery of medical, behavioral and psychological measures will be administered at baseline, post-treatment and at a one-year follow-up to evaluate the effectiveness of the various interventions. Treatment will consist of 26 sessions for patients and, in the conditions targeting social support, 10 sessions for support partners over a 12-month period. All treatments will be manual-based and treatment fidelity checks and quality control will be undertaken.
Trial website
N/A
Trial related presentations / publications
Rieger, E., Treasure, J., Swinbourne, J., Adam, B., Manns, C., & Caterson, I. (2014). The effectiveness of including support people in a cognitive-behavioural weight loss maintenance program for obese adults: Study rationale and design. Clinical Obesity, 4, 77-90. doi:10.1111/cob.12042
Public notes

Contacts
Principal investigator
Name 32248 0
A/Prof Elizabeth Rieger
Address 32248 0
Research School of Psychology, Australian National University, Canberra ACT 0200
Country 32248 0
Australia
Phone 32248 0
+61 2 6125 4208
Fax 32248 0
Email 32248 0
Elizabeth.Rieger@anu.edu.au
Contact person for public queries
Name 15495 0
A/Prof Elizabeth Rieger
Address 15495 0
Research School of Psychology (Building 39) The Australian National University Canberra ACT 0200
Country 15495 0
Australia
Phone 15495 0
+61 2 6125 4208
Fax 15495 0
+61 2 6125 0499
Email 15495 0
Elizabeth.Rieger@anu.edu.au
Contact person for scientific queries
Name 6423 0
A/Prof Elizabeth Rieger
Address 6423 0
Research School of Psychology (Building 39) The Australian National University Canberra ACT 0200
Country 6423 0
Australia
Phone 6423 0
+61 2 6125 4208
Fax 6423 0
+61 2 6125 3827
Email 6423 0
Elizabeth.Rieger@anu.edu.au

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary