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Effectiveness of a motivational interviewing intervention on weight loss, physical activity and cardiovascular disease risk factors: a randomized controlled trial with a 12- month post-intervention follow-up. Gabrielle Sherer Rotation: WPNC Preceptor: Elizabeth Koustis MS RD LD. Citation.
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Effectiveness of a motivational interviewing intervention on weight loss, physical activity and cardiovascular disease risk factors: a randomized controlled trial with a 12- month post-intervention follow-up Gabrielle Sherer Rotation: WPNC Preceptor: Elizabeth Koustis MS RD LD
Citation Hardcastle SJ, Taylor AH, Bailey MP, Harley RA, Hagger MS. Effectiveness of a motivational interviewing intervention on weight loss, physical activity and cardiovascular disease risk factors: a randomized controlled trial with a 12- month post-intervention follow-up. Int J BehavNutr Phys Act. 2013; 10: 40-56.
Background • Traditional obesity interventions in the primary care setting focused on changes in diet and physical activity behaviors shown to result in clinically significant wt reduction • Drawbacks: intensive, require considerable financial and human resources, often not translated to long term results • MI intervention in studies lasting 6 mo or less shown to result in • Increased physical activity • Reduced caloric intake • Decreased BMI
Spirit of Motivational Interviewing • Collaboration • Practitioner is a supportive partner, not a persuasive expert • Evocation • Draw out pt’s personal motives for behavior change using their perceptions and values • Elicit rather than impart wisdom and knowledge • Autonomy • Responsibility, ability, and decision to make behavioral changes are in pt’s control
Motivational Interviewing • Provides components that support psychological needs • Self-determination theory • Linked with the enhancement of self-efficacy • Social cognitive theory • Linked to increasing motivational readiness to change • Transtheoretical model
Objective • Assess whether changes in weight, BMI, physical activity, and CVD risk factors within the intervention group were maintained one-year later. • Explore the effect of counseling session attendance (dose) on maintenance outcomes. • Examine the effects of motivational interviewing on outcomes for sub-groups presenting with specific CVD risk factors at baseline.
Participants and Setting • Inclusion • 18-65 yo • At least one CVD risk factor • Excess weight BMI >/=28 • HTN 150/90 mmHg • Hypercholersterolemia >/= 5.2 mmol.l-1 • Primary care health centers- UK
Design • Baseline biochemical/anthropometric assessment conducted by trained nurses • All participants received a standard information leaflet on exercise and nutrition • Consume five portions of fruit and vegetables per day • Recommended fat intake • Recommendation to be physically active for 30 min, five times a week • physiological and psychological benefits of increased physical activity • food and physical activity quiz with advice depending upon scores • Intervention group: face-to-face consultation with a physical activity specialist or registered dietician • Opportunity to meet on up to four further occasions, for 20 to 30 mins, within the following 6 mo • Not encouraged to attend a certain number of sessions • 18 months post-baseline: all participants invited to a final assessment
Intervention • Stage Matched Approach • Precontemplative, contemplative, preparation, action, maitnance • Typical strategies • Ambivalent pts: • agenda setting • exploration of the pros and cons • importance and confidence rulers • Sufficiently motivated: • strengthening commitment • negotiating a change plan
Outcome Measures • Weight, height, systolic, and diastolic blood pressure (SBP/DBP), and fasting cholesterol • Physical activity • short interview version of the International Physical Activity Questionnaire- intensity, frequency, and duration of activity in the previous 7 days • Physical activity stage of change • ‘yes’ or ‘no’ answer to five questions in a flowchart format • Fat intake • DINE food frequency questionnaire • Fruit and vegetable consumption • five-a-day Community Evaluation Tool questionnaire (FACET)
Statistical Analysis • Satisfactory randomization • 2 MANOVAs with behavioral and biomedical outcome variables as dependent variables and intervention group as an independent variables • Effects of the MI intervention on each behavioral and biomedical outcome variable • 3 (time: baseline vs. 6-month follow-up vs. 18-month follow up) × 2 (group: MI intervention vs. minimal intervention) mixed-model ANCOVAs • Bonferroni correction for multiple comparisons • Age, gender, and smoking status entered as covariates in each model • Effect of number of sessions attended on change in behavioral and outcome measures • Hierarchical linear multiple regression analyses with number of sessions, as a continuous independent variable • Effects of intervention on relevant biomedical outcome variables in groups of participants that exhibited corresponding specific risk factors at baseline • 3 (time: baseline vs. 6-month follow-up vs. 18-month follow up) × 2 (group: MI intervention vs. minimal intervention) mixed-model ANCOVA • Bonferroni correction for multiple comparisons
Results- Intervention effects MI intervention group Control group No effect on walking scores over time No changes between baseline and 6-months and a significant decrease between baseline and 18-month (p< .001, d = 0.27) Decrease in dietary fat intake between baseline and 6-month (p< .001, d = 0.43), maintained at 18 months (p< .001, d = 0.38) Increase in BMI between 6- and 18-month (p= .007, d = 0.21) No change in DBP increase in cholesterol between 6 and 18 months (p = .007, d = 0.30). • Walking- increase between baseline and 6-months (p = .006, d = 0.24) and between baseline and 18-months (p = .032, d = 0.20) -sustained change over the follow-up period • Stage of change- increase between baseline and 6-months (p<. 001, d = 0.33), returned to near baseline levels at 18 months (p <. 001, d = 0.29) • Dietary fat intake-no difference in the MI intervention group • BMI- no significant changes • DBP- drop from baseline to 6-months (p<. 001, d = 0.29) • Cholesterol- reduced between baseline and 6-months (p = .008, d = 0.23) -maintained at 18-months (p =. 015, d = 0.22)
Results- Dose • More sessions attended = greater reduction in triglycerides (β = −0.20, t= −2.54, p= .012, d = 0.28)
Results- Subgroups MI Intervention Group Control Group Increase in BMI at 18-months compared to both baseline (p = .015, d = 0.30) and 6-months (p = .037, d = 0.26) no significant changes in cholesterol levels • BMI in obese patients -decrease in BMI between baseline and 6-months (p = .010, d = 0.26) /no differences between baseline and 18-months • Cholesterol in hypercholesterolemicpatients- decrease in cholesterol levels between baseline and 6-months (p = .005, d = 0.31) and between baseline and 18-months (p = .003, d = 0.33)
Conclusions • It is possible for a MI intervention to lead to significant behavior changes and biomedical outcomes (inc walking and dec cholesterol) that can be maintained for 12 months after intervention • Changes in the outcome variables were not associated with the number of sessions attended-effects appear to be in response to a relatively low dose of MI (average attendance 2 sessions) • MI intervention can lead to a sustained decrease in BMI for patients who were obese at baseline. • Future research should seek to further examine the dose effects of number of MI sessions and also elucidate the mechanisms behind these changes
Limitations • Low participation rate (28%) • Important biomedical markers (insulin and HbA1C) not measured • Minimal practitioner training (2 four hour training, 3 videotaped sessions) • Self-reported measures of physical activity and dietary intake
Clinical Implications • Even low doses of MI can lead to some, sustained behavioral and biochemical improvements and can be a good alternative to traditional prescriptive interventions. • MI in group settings like Move?