Table 3.
Grocery, Restaurant and Targeted Food Purchases (Average Dollars per Week) by Experimental Condition (n = 252)(Mean, Standard Error, and 95% Confidence Interval)
| Total mean (SE) |
Incentive mean (SE) 95% CIa |
Restriction mean (SE) 95% CI |
Incentive Plus Restriction mean (SE) 95% CI |
Control mean (SE) 95% CI |
p | |
|---|---|---|---|---|---|---|
| N | 252 | 66 | 60 | 63 | 63 | |
| Dollars spent (average per week) | ||||||
| Groceries | ||||||
| Baseline | 68.5 (3.4) | 72.7 (6.7) 59.5, 85.8 |
66.1 (7.0) 52.4, 79.9 |
64.9 (6.8) 51.5, 78.3 |
70.1 (6.8) 56.6, 83.5 |
|
| Follow up | 101.8 (2.8) | 104.2 (5.5) 93.4, 115.0 |
94.6 (5.8) 83.2, 105.9 |
102.6 (5.6) 91.5, 113.7 |
105.3 (5.6) 94.2, 116.4 |
|
| Changeb | 33.3 (2.4) | 31.5 (4.7) 22.2, 40.9 |
28.5 (5.0) 18.7, 38.3 |
37.7 (4.8) 28.2, 47.3 |
35.2 (4.8) 25.7, 44.8 |
.56 |
| Restaurant | ||||||
| Baseline | 25.1 (1.7) | 29.6 (3.4) 22.9, 36.3 |
23.7 (3.6) 16.7, 30.8 |
24.7 (3.5) 17.8, 31.6 |
22.0 (3.5) 15.2, 28.9 |
|
| Follow up | 18.6 (1.5) | 23.2 (2.9) 17.5, 28.9 |
13.9 (3.0) 7.9, 19.9 |
19.3 (3.0) 13.4, 25.1 |
17.6 (3.0) 11.7, 23.4 |
|
| Change | −6.5 (1.1) | −6.4 (2.2) −10.8, −2.1 |
−9.8 (2.3) −14.4, −5.3 |
−5.4 (2.3) −9.9, −0.98 |
−4.5 (2.3) −8.9, −0.03 |
.38 |
| Fruit | ||||||
| Baseline | 4.0 (0.3) | 3.6 (0.6) 2.5, 4.8 |
4.3 (0.6) 3.1, 5.6 |
3.7 (0.6) 2.5, 4.9 |
4.2 (0.6) 3.0, 5.4 |
|
| Follow up | 7.0 (0.4) | 7.0 (0.8) 5.4, 8.6 |
6.0 (0.9) 4.3, 7.7 |
8.5 (0.9) 6.8, 10.1 |
6.4 (0.9) 4.7, 8.0 |
|
| Changec | 3.0 (0.3) | 3.3 (0.6) 2.1, 4.6 |
1.7 (0.7) 0.34, 3.0 |
4.8 (0.7) 3.5, 6.0 |
2.1 (0.7) 0.86, 3.4 |
.01 |
| Vegetables | ||||||
| Baseline | 4.2 (0.3) | 3.9 (0.6) 2.6, 5.1 |
4.6 (0.7) 3.3, 5.9 |
3.7 (0.7) 2.4, 5.0 |
4.5 (0.7) 3.3, 5.8 |
|
| Follow up | 7.1 (0.4) | 6.7 (0.7) 5.4, 8.1 |
6.9 (0.7) 5.4, 8.3 |
7.7 (0.7) 6.3, 9.1 |
6.9 (0.7) 5.5, 8.4 |
|
| Change | 2.9 (0.3) | 2.9 (0.5) 1.9, 3.9 |
2.3 (0.6) 1.2, 3.4 |
4.0 (0.5) 2.9, 5.1 |
2.4 (0.5) 1.3, 3.5 |
.10 |
| Sugar Sweetened Beverages | ||||||
| Baseline | 3.4 (0.3) | 3.9 (0.5) 2.9, 5.0 |
3.7 (0.6) 2.6, 4.8 |
3.1 (0.5) 2.0 4.2 |
3.0 (0.5) 1.9, 4.1 |
|
| Follow up | 3.3 (0.2) | 4.2 (0.4) 3.3, 5,0 |
2.3 (0.4) 1.4, 3.2 |
2.3 (0.4) 1.5, 3.2 |
4.5 (0.4) 3.6, 5.3 |
|
| Changed | −0.1 (0.2) | 0.2 (0.4) −0.55, 1.03 |
−1.4 (0.4) −2.2, −0.59 |
−0.8 (0.4) −1.6, 0.01 |
1.5 (0.4) 0.69, 2.3 |
.0001 |
| Sweet Baked Goods | ||||||
| Baseline | 2.4 (0.2) | 2.8 (0.4) 2.0, 3.6 |
2.3 (0.4) 1.5, 3.1 |
2.0 (0.4) 1.2, 2.8 |
2.5 (0.4) 1.7, 3.3 |
|
| Follow up | 2.6 (0.2) | 3.6 (0.3) 3.9, 4.2 |
1.6 (0.3) 0.89, 2.2 |
1.9 (0.3) 1.2, 2.5 |
3.3 (0.3) 2.7, 4.0 |
|
| Changee | 0.2 (0.2) | 0.8 (0.3) 0.10, 1.5 |
−0.7 (0.4) −1.4, 0.01 |
−0.1 (0.4) −0.78, 0.61 |
0.8 (0.4) 0.13, 1.5 |
.01 |
| Candy | ||||||
| Baseline | 1.4 (0.1) | 1.5 (0.2) 1.0, 2.0 |
1.3 (0.3) 0.78, 1.8 |
1.2 (0.3) 0.69, 1.7 |
1.7 (0.3) 1.3, 2.2 |
|
| Follow up | 1.5 (0.1) | 1.7 (0.2) 1.3, 2.2 |
1.0 (0.3) 0.52, 1.5 |
1.3 (0.2) 0.78, 1.7 |
2.1 (0.2) 1.6, 2.6 |
|
| Change | 0.1 (0.1) | 0.2 (0.2) −0.24, 0.72 |
−0.3 (0.3) −0.76, 0.23 |
0.1 (0.3) −0.41, 0.57 |
0.3 (0.3) −0.16, 0.81 |
.36 |
a95% Confidence Interval
bChange = follow up - baseline. Baseline is the weekly average for weeks 1–4. Follow up is the weekly average for weeks 5–16. Values are unadjusted
cDifference in change is significantly different (p < .05) between the Incentives Plus Restriction and the Control groups; and between the Restriction and the Incentives Plus Restriction groups
dDifference in change is significantly different (p < .05) between the Incentives and the Control groups; the Restrictions and the Control groups; the Incentives Plus Restrictions and the Control group; and the Incentives and the Restrictions groups
eDifference in change is significantly different (p < .05) between the Incentives and the Restrictions groups; and between the Restrictions and the Control groups