Does Motivational Interviewing Improve Behavioral Weight Loss Outcomes for Obesity?

Obesity Clinical Trial

— BWLP+MI  

Official title:

Adding Motivational Interviewing to a Behavioral Weight Loss Treatment for Obesity: A Randomized Controlled Trial

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02649634
• Other study ID #: CFREB#5297
• Status: Completed
• Phase: N/A
• First received: January 5, 2016
• Last updated: January 5, 2016
• Start date: September 2007
• Est. completion date: January 2010

Study information

• Verified date: January 2016
• Source: University of Calgary
• Contact: n/a
• Is FDA regulated: No
• Health authority: Canada: Ethics Review Committee
• Study type: Interventional

Clinical Trial Summary

The purpose of this study is to determine whether adding motivational interviewing (MI) to a behavioural weight loss program (BWLP) results in improved weight loss in adults with overweight and obesity.

Description:

Although behavioural weight loss programs (BWLP) are typically the first line of treatment for overweight and obesity, they are plagued by high attrition rates and poor adherence. Studies evaluating the benefit of adding motivational interviewing (MI) to BWLPs have yielded mixed findings. The main purpose of this randomized controlled trial was to assess the efficacy of adding MI to a BWLP on weight loss and adherence outcomes among 135 overweight and obese individuals who were enrolling in a 12-week BWLP.

This study used a randomized, controlled, longitudinal, between-subjects design to investigate the effects of a two-session MI intervention on weight loss in obese participants who enrolled in a behavioural weight loss program. Patients received either two 45-60 minute MI interventions or two 45-60 minute attention control interviews. The control group interview consisted of questions ascertaining weight history, diet history, dietary awareness and physical activity. Questions for the control group focused primarily on assessment of past behaviour whereas questions for the MI group focused on enhancing motivation by exploring and resolving ambivalence. Weight was measured at baseline, end of the BWLP, 1 month following BWLP completion, and 6 months following BWLP completion. Program adherence (measured as number of BWLP sessions attended out of 24) was assessed a the main secondary dependent measure. Importance, readiness, and confidence for weight change were also assessed throughout the study, along with several other secondary outcome measures.

Research personnel informed all BWLP participants about the study at the initial BWLP group intake assessments, which occurred just prior to the commencement of the formal BWLP. Individuals who expressed interest in participating were contacted by phone by a research assistant and screened for eligibility. If eligible, an appointment was made for the first MI/control session which was scheduled within the first two weeks of the BWLP. Participants were asked to complete the change rating questionnaires prior to this interview (i.e., importance, readiness, and confidence for change ratings), and randomization occurred immediately prior to this interview. After the first interview, participants were contacted during the 10th week of the BWLP to schedule a second MI/control session, which occurred approximately during the 12th week of the program. Immediately following each interview, all participants filled out the change rating questionnaires. Participants were all contacted several weeks following program completion to schedule the one-month follow-up assessment. Finally, all participants were contacted approximately five months following program completion in order to schedule the six-month follow-up assessment.

Sessions were tape recorded for all participants for quality assurance purposes. A subset of tapes were used to assess for treatment integrity.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 135
• Est. completion date: January 2010
• Est. primary completion date: January 2010
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Overweight to obese (BMI greater than or equal to 25 kilograms per meter squared).

Exclusion Criteria:

• Pregnancy (or intention of becoming pregnant within 9 months)

• Health issues that would preclude participation in physical activity

• Concurrent involvement in another weight loss program.

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Obesity
• Overweight
• Weight Loss

Intervention

Behavioral:
• Motivational Interviewing
The semi-structured MI protocol was a 45-minute intervention based on general MI principles and guidelines, MI strategies specific to health care practice, and MI principles for obesity treatment. The MI protocol included the following components: (1) eliciting concerns about weight; (2) exploring ambivalence; (3) assessing importance and confidence for change; (4) writing a decisional balance; (5) bolstering self-efficacy; (6) looking towards the future; and (8) eliciting ideas for possible changes participant could make to work towards weight loss. Although there was slight variation, the protocol for both MI sessions consisted of similar components.
• Attention Control
The attention control interview was a semi-structured interview ascertaining information relevant to health history, weight history, diet history, dietary and physical activity habits. The majority of questions for the control interviews were drawn from the Behavioural Weight Loss Program intake application. It was designed to be structurally equivalent to the MI session in terms of length of session, timing of sessions, and treatment modality. The goal of the attention-control interview was to provide a pseudo-intervention that controlled for factors common to attending treatment (e.g., attending treatment sessions, having personal contact with a therapist, discussing weight-related issues).

Locations

Country	Name	City	State
n/a

Sponsors (1)

Lead Sponsor	Collaborator
University of Calgary

References & Publications (10)

Armstrong MJ, Mottershead TA, Ronksley PE, Sigal RJ, Campbell TS, Hemmelgarn BR. Motivational interviewing to improve weight loss in overweight and/or obese patients: a systematic review and meta-analysis of randomized controlled trials. Obes Rev. 2011 Sep;12(9):709-23. doi: 10.1111/j.1467-789X.2011.00892.x. Epub 2011 Jun 21. Review. — View Citation

Clark MM, Abrams DB, Niaura RS, Eaton CA, Rossi JS. Self-efficacy in weight management. J Consult Clin Psychol. 1991 Oct;59(5):739-44. — View Citation

DiLillo V, Siegfried NJ, West DS. Incorporating motivational interviewing into behavioral obesity treatment. Cognitive and Behavioral Practice 10(2): 120-130, 2003.

DiMarco ID, Klein DA, Clark VL, Wilson GT. The use of motivational interviewing techniques to enhance the efficacy of guided self-help behavioral weight loss treatment. Eat Behav. 2009 Apr;10(2):134-6. doi: 10.1016/j.eatbeh.2009.02.001. Epub 2009 Feb 15. — View Citation

Fairburn CG, Beglin SJ. Assessment of eating disorders: interview or self-report questionnaire? Int J Eat Disord. 1994 Dec;16(4):363-70. — View Citation

Hemmelgarn BR, McAlister FA, Grover S, Myers MG, McKay DW, Bolli P, Abbott C, Schiffrin EL, Honos G, Burgess E, Mann K, Wilson T, Penner B, Tremblay G, Milot A, Chockalingam A, Touyz RM, Tobe SW; Canadian Hypertension Education Program. The 2006 Canadian Hypertension Education Program recommendations for the management of hypertension: Part I--Blood pressure measurement, diagnosis and assessment of risk. Can J Cardiol. 2006 May 15;22(7):573-81. — View Citation

Kristal AR, Shattuck AL, Henry HJ. Patterns of dietary behavior associated with selecting diets low in fat: reliability and validity of a behavioral approach to dietary assessment. J Am Diet Assoc. 1990 Feb;90(2):214-20. — View Citation

Paffenbarger RS Jr, Wing AL, Hyde RT. Physical activity as an index of heart attack risk in college alumni. Am J Epidemiol. 1978 Sep;108(3):161-75. — View Citation

Webber KH, Gabriele JM, Tate DF, Dignan MB. The effect of a motivational intervention on weight loss is moderated by level of baseline controlled motivation. Int J Behav Nutr Phys Act. 2010 Jan 22;7:4. doi: 10.1186/1479-5868-7-4. — View Citation

West DS, DiLillo V, Bursac Z, Gore SA, Greene PG. Motivational interviewing improves weight loss in women with type 2 diabetes. Diabetes Care. 2007 May;30(5):1081-7. Epub 2007 Mar 2. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in weight at end of behavioural weight loss program	Weight was measured to the nearest 0.1 kg using a balance beam scale	Change from baseline in weight at the end of the behavioural weight loss program - up to 24 weeks	No
Secondary	Change in weight at 1 month follow up	a digital scale (Tanita BWB-800S), which assessed weight to the nearest 0.1 kg, was used for the 1 month follow-up assessment	Change from baseline in weight 1 month after the end of the behavioural weight loss program	No
Secondary	Change in weight at 6 month follow up	a digital scale (Tanita BWB-800S), which assessed weight to the nearest 0.1 kg, was used for the 6 month follow-up assessment	Change from baseline in weight 6 months after the end of the behavioural weight loss program	No
Secondary	Adherence	The number of behavioural weight loss programs that were attended out of 24	Assessed once at the end of the behavioural weight loss program - 24 weeks	No
Secondary	Change ratings after the first motivational interviewing or attention control interview	Self-report ratings of: readiness, importance, and confidence for change, on 11-point visual analogue scales.	Change ratings measured immediately after the first MI or attention control interview	No
Secondary	Change ratings after the second motivational interviewing or attention control interview	Self-report ratings of: readiness, importance, and confidence for change, on 11-point visual analogue scales.	Change ratings measured immediately after the second MI or attention control interview	No
Secondary	Change in BMI at end of behavioural weight loss program	Weight was measured to the nearest 0.1 kg using a balance beam scale, height was measured to the nearest 0.1 cm using a stadiometer at the beginning of the behavioural weight loss program. BMI was calculated as weight in Kilograms divided by height in meters squared.	Change from baseline in BMI at the end of the behavioural weight loss program - up to 24 weeks	No
Secondary	Change in BMI at 6 month follow up	A digital scale (Tanita BWB-800S), which assessed weight to the nearest 0.1 kg, was used to assess weight for the 6 month follow up assessment, and the height measured at the beginning of the behavioural weight loss program was used to calculate BMI. BMI was calculated as weight in Kilograms divided by height in meter squared.	Change from baseline in BMI 6 months after the end of the behavioural weight loss program	No
Secondary	Change in physical activity at end of the behavioural weight loss program	Physical activity was measured by the Paffenbarger questionnaire (PPAQ; Paffenbarger, Wing, & Hyde, 1978). This self-report questionnaire assesses amount of activity performed during a typical week, and consists of three components: (1) stair climbing, (2) walking, and (3) sports and recreation. Participants were asked to report the frequency and duration of physical activity in the past week.	Change from baseline in physical activity as measured by the PPAQ, at the end of the behavioural weight loss program - up to 24 weeks	No
Secondary	Change in physical activity at 1 month follow up	Physical activity was measured by the Paffenbarger questionnaire (PPAQ; Paffenbarger, Wing, & Hyde, 1978). This self-report questionnaire assesses amount of activity performed during a typical week, and consists of three components: (1) stair climbing, (2) walking, and (3) sports and recreation. Participants were asked to report the frequency and duration of physical activity in the past week.	Change from baseline in physical activity as measured by the PPAQ, 1 month after the end of the behavioural weight loss program	No
Secondary	Change in physical activity at 6 month follow up	Physical activity was measured by the Paffenbarger questionnaire (PPAQ; Paffenbarger, Wing, & Hyde, 1978). This self-report questionnaire assesses amount of activity performed during a typical week, and consists of three components: (1) stair climbing, (2) walking, and (3) sports and recreation. Participants were asked to report the frequency and duration of physical activity in the past week.	Change from baseline in physical activity as measured by the PPAQ, 6 months after the end of the behavioural weight loss program	No
Secondary	Change in dietary behaviour at end of the behavioural weight loss program	Dietary behaviour was measured by the Fat-related Dietary Habits Questionnaire (DHQ; Kristal, Shattuck, & Henry, 1990). This self-report questionnaire assesses dietary behaviours and high-fat eating patterns and consists of an overall summary score and five subscale scores assessing different dimensions of fat-related dietary habits.	Change from baseline in dietary behaviour as measured by the DHQ, at the end of the behavioural weight loss program - up to 24 weeks	No
Secondary	Change in dietary behaviour at 1 month follow up	Dietary behaviour was measured by the Fat-related Dietary Habits Questionnaire (DHQ; Kristal, Shattuck, & Henry, 1990). This self-report questionnaire assesses dietary behaviours and high-fat eating patterns and consists of an overall summary score and five subscale scores assessing different dimensions of fat-related dietary habits.	Change from baseline in dietary behaviour as measured by the DHQ, 1 month after the end of the behavioural weight loss program	No
Secondary	Change in dietary behaviour at 6 month follow up	Dietary behaviour was measured by the Fat-related Dietary Habits Questionnaire (DHQ; Kristal, Shattuck, & Henry, 1990). This self-report questionnaire assesses dietary behaviours and high-fat eating patterns and consists of an overall summary score and five subscale scores assessing different dimensions of fat-related dietary habits.	Change from baseline in dietary behaviour as measured by the DHQ, 6 months after the end of the behavioural weight loss program	No
Secondary	Change in blood pressure at end of the behavioural weight loss program	A measure of systolic and diastolic blood pressure was taken in a standardized manner according to the Canadian Hypertension Education Program Guidelines (Hemmelgarn et al., 2006). Three different readings of blood pressure were taken at each time point (baseline and end of behavioural weight loss program), and the average of the three readings was taken as the measure of blood pressure for each time point.	Change from baseline in blood pressure at the end of the behavioural weight loss program - up to 24 weeks	No
Secondary	Change in blood pressure at 6 month follow up	A measure of systolic and diastolic blood pressure was taken in a standardized manner according to the Canadian Hypertension Education Program Guidelines (Hemmelgarn et al., 2006). Three different readings of blood pressure were taken at each time point (baseline and 6 month follow up), and the average of the three readings was taken as the measure of blood pressure for each time point.	Change from baseline in blood pressure 6 months after the end of the behavioural weight loss program	No
Secondary	Change in eating disorder symptomology at end of the behavioural weight loss program	Eating disorder symptomology was measured using the Eating Disorder Examination-Questionnaire (EDE-Q; Fairburn & Beglin, 1994). This self-report questionnaire assesses the presence and degree of specific psychopathology associated with eating disorders over the previous 28 days.	Change from baseline in eating disorder symptomology as measured by the EDE-Q, at the end of the behavioural weight loss program - up to 24 weeks	No
Secondary	Change in eating disorder symptomology at 1 month follow up	Eating disorder symptomology was measured using the Eating Disorder Examination-Questionnaire (EDE-Q; Fairburn & Beglin, 1994). This self-report questionnaire assesses the presence and degree of specific psychopathology associated with eating disorders over the previous 28 days.	Change from baseline in eating disorder symptomology as measured by the EDE-Q, 1 month after the end of the behavioural weight loss program	No
Secondary	Change in eating disorder symptomology at 6 month follow up	Eating disorder symptomology was measured using the Eating Disorder Examination-Questionnaire (EDE-Q; Fairburn & Beglin, 1994). This self-report questionnaire assesses the presence and degree of specific psychopathology associated with eating disorders over the previous 28 days.	Change from baseline in eating disorder symptomology as measured by the EDE-Q, 6 months after the end of the behavioural weight loss program	No
Secondary	Change in self-efficacy related to eating patterns at end of the behavioural weight loss program	Self-efficacy related to eating patterns was measured by the Weight Efficacy Life-Style Questionnaire (WEL; Clark, Abrams, Niaura, Eaton, & Rossi, 1991). This self-report questionnaire yields five subscale scores, which rate self-efficacy for controlling eating in different situations/dimensions: negative emotions, availability, social pressure, physical discomfort, and positive activities.	Change from baseline in self-efficacy related to eating patterns as measured by the WEL, at the end of the behavioural weight loss program - up to 24 weeks	No
Secondary	Change in self-efficacy for engaging in physical activity at end of the behavioural weight loss program	Self-efficacy for engaging in physical activity was measured by ratings of confidence that one could exercise on a 5-point Likert scale for six barriers to exercise (e.g., bad weather, stress, availability of equipment).	Change from baseline in self-efficacy for engaging in physical activity, at the end of the behavioural weight loss program - up to 24 weeks	No