Table 1.
Randomized controlled trials of motivational interviewing for weight loss in primary care among adults
| Study | Baseline sample characteristics |
Treatment length, Min of treatment, F/U‡‡ |
Training, Fidelity |
Provider | Groups: treatment retention |
MI kg change per hour, MI 5% WL |
Summary of significant relevant findings between MI and comparison |
|---|---|---|---|---|---|---|---|
| Armit et al. 2009 (25) |
n = 136 Age: 58 BMI: NI Women: 60% Men: 40% % Minority: NI |
3 months 60–75 min F/U: 3 months |
Training: No Fidelity: No |
Exercise specialists | 1. UC+ Pedometer+ MI: 100% 2. UC+ Pedometer: 100% 3. UC: 100% |
0 kg h−1 5% WL: NI |
Weight: NS Physical activity: NS* Diet: NI Other: Blood pressure: NS* Post-exercise HR: NS* |
| Barnes et al. 2014 (26) |
n = 89 Age: 47.9 BMI: 35.3 Women: 76.4% Men: 23.6% % Minority: 34.8% |
3 months 140 min F/U: 3 months |
Training: Yes Fidelity: Yes |
Medical assistants | 1. MI: 93.3% 2. Nutrition: 90% 3. UC: 96.7% |
−0.64 kg h−1 5% WL: 25% |
Weight: NS* Physical activity: NI Diet: NI Other: Blood pressure: NS* Triglycerides: NS* HbA1C: NS Eating disorder: NS* |
| Bennett et al. 2010 (27) |
n = 101 Age: 54.4 BMI: 34.6 Women: 47.5% Men: 52.5% % Minority: 50.5% |
3 months 80 min F/U: No |
Training: No Fidelity: No |
Registered dietician | 1. MI: 98.0% 2. UC: 94% |
−1.71 kg h−1 5% WL: 25.6% |
Weight: Sig BMI: Sig Waist circumference: NS Physical activity: NI Diet: NI Other: Blood pressure: NS* |
| Bennett et al. 2012 (28) |
n = 365 Age: 54.5 BMI: 36.99–37.03 Women: 68.5% Men: 31.5% % Minority: 96.8% |
24 months 270–360 min F/U: No |
Training: No Fidelity: No |
Community health educators |
1. MI: 82.2%, 70.6% of telephone counselling calls 2. UC: 89.7% |
−0.26 kg h−1 5% WL: 20% |
Weight: Sig Physical activity: NI Diet: NI Other: Blood pressure: NS* |
| Christian et al. 2008 (29) |
n = 310 Age: 53.0–53.4 BMI: 34.8–35.4 Women: 65–68% Men: 32–35% % Minority: Hispanic/Latino 50% |
12 months 100 min F/U: No |
Training: Yes Fidelity: No |
Physicians | 1. MI: 91.0% 2. UC: 85.2% |
−0.05 kg h−1 5% WL: 21% |
Weight: NS 5% WL at 12 months: Sig Waist circumference: NS* Physical activity: Sig Moderate level: NS* Diet: NS* Other: Blood pressure: NS* Total cholesterol: Sig LDL: Sig HDL: NS* HbA1C: NS* |
| Cochrane et al. **2012 (30) |
n = 601 Age: 63.3–63.9 BMI: 27.5–28.7 Women: 9.9–13.6% Men: 86.4–90.1% % Minority: 3–4.2% |
12 months 360 min F/U: No |
Training: No Fidelity: No |
Lifestyle coach | 1. MI + NHS Health check: 84.7% 2. UC + NHS Health check: 83.8% |
−0.12 kg h−1 5% WL: NI |
Weight: NS BMI: NS Physical Activity: NS* Diet: NI Other: Blood pressure: NS Cholesterol: NS CVD risk: NS* |
| Drevenhorn et al. 2012 (31) |
n = 213 Age: NI BMI: 30.9–31.4 Women: NI Men: NI % Minority: NI |
24 months Min: NI F/U: No |
Training: Yes Fidelity: Yes |
Nurses | 1. MI: 96.1% 2. UC: 94.8% |
Kg h−1: NI 5% WL: NI |
Weight: NS* BMI: NS* Waist circumference: NS* Waist–hip ratio: NS* Physical Activity: Sig Diet: NI Other: Blood pressure: NS* Heart rate: Sig Total cholesterol: NS* LDL: NS* HDL: Sig |
| Ely et al. 2008 (32) |
n = 107 Age: 49–50 BMI: 36–37 Women: 77% Men: 23% % Minority: 13% |
6 months 8 calls, Min: NI F/U: No |
Training: No Fidelity: No |
Master’s counsellors | 1. MI: NI 2. UC: NI Overall: 50% |
Kg h−1: NI 5% WL: NI Overall: 17.8% |
Weight: Sig Physical activity: NS Diet: NS Other: NI |
| Greaves et al. 2008 (33) |
n = 141 Age: 53.3–54.5 BMI: NI Women: 64% Men: 36% % Minority: NI |
6 months 374 min avg F/U: No |
Training: Yes Fidelity: Yes |
Ex-NHS staff health visitor, rehabilitation nurse, and postgraduates students in sports and health science |
1. MI: 94.4% 2. Standardized information pack: 100% |
−0.05 kg h−1 5% WL: 24% |
Weight: Sig %5 WL: Sig Physical activity: NS* Diet: NI Other: NI |
| Groeneveld et al. 2010 (34) |
n = 595 PA/Diet group: Age: 47.4 BMI 28.8 Women: 0% Men: 100% % Minority: NI |
6 months 195–300 min F/U: 6 months |
Training: Yes Fidelity: Yes |
Occupational physician or occupational nurse |
1. MI: 66.4% 2. UC: 100% |
−0.14 kg h−1 5% WL: 20.4% |
Weight: Sig BMI: Sig Physical activity: NI Diet: NI Other: Blood pressure: NS* HDL cholesterol: NS* Cholesterol ratio: NS* HbA1c: NS* |
| Hardcastle et al. 2008 (35) and 2013 (49) |
n = 334 Age: 50.22 BMI: 33.67–34.28 Women: 67%* Men: 33%* % Minority: NI |
6 months 20–150 min F/U: 12 months |
Training: Yes Fidelity: Yes |
Registered dietician and physical activity specialist (graduate in exercise science, specializing in exercise psychology) |
1. MI: NI 2. Standard exercise and nutrition information: NI Overall F/U: 65% |
−0.25 kg h−1 5% WL: NI |
Weight: NS by 18 months Physical activity: Sig Walking: Sig % inactive: Sig Vigorous and moderate: NS Diet: fruit/vegetable: NS* Fat: NS Other: Diastolic blood pressure: Sig Cholesterol: NS* LDL: NS HDL: NS Triglycerides: NS CHD risk: NS |
| Harris et al., **††2013 (37) |
n = 804 Age: overall NI 67% ≥ 60 BMI: NI, 75% overweight/obese Women: 49.3% Men: 50.7% % Minority: 0.5% aboriginal/Torres Strait Islander, 4.4% non-English |
6 months Min: NI F/U: NI |
Training: Yes Fidelity: No |
Community health nurses |
1. MI: NI 2. UC: NI |
kg h−1: NI 5% WL: NI |
Weight: NS Physical activity: NS Diet: NS Other: NI |
| Harris et al. **2012 (36) |
n = 814 Age: 40–64, Mean NI BMI: NI Women: 49.3% Men: 50.7% % Minority: NI |
12 months 540 min F/U: No |
Training: No Fidelity: No |
Physician, practice nurse |
1. MI: 95.1% 2. UC: 97.5% |
−0.01 kg h−1 5% WL: NI |
Weight: NS Physical activity: Sig Diet: Sig only at 6 months Other: Blood pressure: NS Lipids: NS CVD risk: NS |
| Heinrich et al. 2010 (38) |
n = 618 Age: 59 BMI: NI Women: 44.9% Men: 55.1% % Minority: NI |
24 months 160 min F/U: No |
Training: Yes Fidelity: Yes |
Nurses | 1. MI: NI 2. UC: NI Overall F/U: 72% |
Kg h−1: NI 5% WL: NI |
Weight: NS Physical activity: NS Diet: fruit/vegetable: NS Fat intake: NS Other: Blood pressure: NS Total cholesterol: NS LDL: NS HDL: NS Triglycerides: NS HbA1c: NS |
| Martin et al. **2006 (50) and 2008 (39) |
n = 137 Age: 40.7–43.0 Women: 100% Men: 0% % Minority: 100% |
6 months 90 min F/U: 3, 6, and 12 months |
Training: Yes Fidelity: No |
Physician | 1. MI: 71% 2. UC: 88% |
−0.96 kg h−1 5% WL: 12.5% |
Weight: Sig 5% WL: NS Physical activity: NI Diet: NI Other: NI |
| McDoniel et al. 2010a (40) |
n = 74 Age: 46.6 BMI: 36.4 Women: 58% Men: 42% % Minority: 19–22% |
6 months 120 min F/U: No |
Training: No Fidelity: No |
Master’s-level exercise physiologist |
1. MI + energy Plan based on REE†: NI 2. MI + Standard Diet: NI Overall: 75.7% |
kg h−1: 2.15 5% WL: ≈6% |
*Both groups MI Weight: NS* Physical activity: NI Diet: eating behaviour: NS* Dietary restraint: NS* Uncontrolled eating: NS* Other: Metabolic: NS |
| McDoniel, et al. 2010b (41) |
n = 111 Age: 45.5 BMI: 37.0 Women: 62% Men: 38% % Minority: 19.9–23.2% |
3 months Min: NI F/U: No |
Training: No Fidelity: No |
Master’s level exercise physiologist |
1. MI + Nutrition Program based on RMR‡: 70.9% 2. MI + Standard Nutrition Plan: 73.2% |
kg h−1: NI 5% WL: ≈9% |
*Both groups MI Weight: NS* Physical activity: NI Diet: NI Other: Blood pressure: NS* |
| Nanchahal et al. 2012 (42) |
n = 381 Age: 48.8 BMI: 33.5 Women: 72.2% Men: 27.8% % Minority: 27.4% |
12 months 420 min F/U: No |
Training: Yes Fidelity: No |
Trained non-specialists |
1. MI: 96.3% 2. UC: NI |
−0.39 kg h−1 5% WL: 32.7% |
Weight: NS* BMI: NS* Waist circumference: NS* % Body fat: NS* 5% WL: Sig Physical activity: NI Diet: NI Other: Blood pressure: NS* Heart rate: Sig |
| Penn et al. 2009 (43) |
n = 102 Age: 57 BMI: 34 Women: 58.8% Men: 41.2% % Minority: NI |
60 months 540 min F/U: No |
Training: No Fidelity: No |
Dietician and physiotherapist |
1. MI: 41.2% 2. UC: 41.2% at 60 months |
−0.46 kg h−1 at 12 months 5% WL: NI |
Weight: Sig at 12 months only Physical activity: NS Diet: NS Other: Cumulative diabetes incidence: NS* |
| Vermunt et al. **2011 (44) and 2012 (51) |
n = 925 Age: 57.9–59.5 BMI: 28.5–29 Women: 55.9–61.2% Men: 38.8–44.1% % Minority: NI |
30 months 580 min F/U: No |
Training: Yes Fidelity: No |
Nurse and physician |
1. MI: 85.4% 2. UC: 86.8% |
−0.09 kg h−1 5% WL: NI |
Weight: NS* BMI: NS* Waist circumference: NS Physical activity: NS Diet: energy intake: NS* Total saturated fat: NS Total dietary fibre: Sig Other: Fasting plasma glucose: NS* 2-h plasma glucose: NS Diabetes incidence: NS |
| Whittemore et al. **2009 (45) |
n = 58 Age: 48.2–43.2 BMI: 37.4–40.0 Women: 92% Men: 8% % Minority: 55% |
6 months 240 min F/U: No |
Training: Yes Fidelity: No |
Nurse practitioners | 1. MI: 77.4% 2. UC: 100% |
−0.11 kg h−1§ 5% WL: 25% |
Weight: % WL: NS* Physical activity: NS* Diet: NS* Other: HDL: NS* LDL: NS Glucose: NS |
| Williams et al. 2014 (46) |
n = 54 Age: 47.3 BMI: 25.1 Women: 100% Men: 0% % Minority: NI |
12 months 300 min F/U: No |
Training: No Fidelity: Yes |
Dietician and exercise physiologists |
1. MI: 78.6% 2. Self-directed intervention: 69.2% |
−0.50 kg h−1 (healthy weight pts.) −0.7 kg h−1 (overweight pts.) 5% WL: NI (reported 7% by weight category) |
Weight: Sig Overweight group: NS* Percentage of body fat: NS Percentage of lean muscle: NS Waist circumference: Sig Physical activity: NS Diet: NS Other: Diastolic blood pressure: Sig Total cholesterol: NS LDL and HDL: NS Glucose: NS |
| Woollard et al. ¶1995 (47) |
n = 166 Age: 58–59 BMI: NI Women: 44.2–50% Men: 50–55.8% % Minority: NI |
18 weeks 270 min (MI-High) 75 min (MI-Low) F/U: No |
Training: No Fidelity: No |
Nurse counsellors | 1. MI-High: NI 2. MI-Low: NI 3. UC: NI |
−0.38 kg h−1 (MI-High) −0.80 kg h−1 (MI-Low) 5% WL: NI |
Weight: Sig (MI-High) Physical activity: NI Diet: Salt: Sig (MI-Low) Other: Blood pressure: Sig (MI-High) |
| Woollard et al. ¶2003 (48) |
n = 212 Age: 59.5–61.0 BMI: Women: 50.5% Men: 49.1% % Minority: NI |
12 months 720 min (MI-High) 180 min (MI-Low) F/U: 6 months |
Training: Yes Fidelity: Yes |
Nurses | 1. MI-High: 64.9% 2. MI-Low: 71.0% 3. UC: 76.8% |
0 kg h−1 (MI-High) 0 kg h−1 (MI-Low) 5% WL: NI |
Weight: NS BMI: NS Waist–hip ratio: NS Physical activity: NI Diet: total energy intake: NS*(MI-High at 18 months) Fat: NS* Sodium: NS* Potassium and fibre: NS Other: Total cholesterol: NS* (MI-High at 18 months) LDL: NS* HDL: NS* (MI-Low at 18 months) Triglycerides: NS* Ratio of plasma n3 to n6 fatty acids: NS* |
Note: For baseline characteristics, ranges were used when means were reported by group, and not for the overall sample.
*
Percentages based on those accepting invitation to participate (n = 358), not those randomized (n = 334).
†
Resting energy expenditure.
‡
Resting metabolic rate measured by a validated hand-held device.
§
Percentage of weight loss was used for this calculation as weight loss was unavailable.
¶
MI-High, high intervention was longer in time spent with clinician compared with low intervention; summary results reported for Woollard et al. 1995 and Woollard et al. 2003 are for treatment groups compared with usual care.
**
Indicates study controlled for cluster effects in RCT.
††
Indicates unclear whether study controlled for cluster effects.
‡‡
F/U refers to a follow-up assessment following a period of treatment cessation.
BMI, body mass index; CVD, cardiovascular disease; F/U, follow-up; HDL, high-density lipoprotein; LDL, low-density lipoprotein; MI, motivational interviewing; NI, not indicated/unclear; NS, not statistically different; NS*, MI group improved but did not statistically differ from comparison group; Pts, participants; Sig, significant change in MI intervention compared to UC/Control; UC, usual care; WL, weight loss.