Table 3.
Outcomes comparison between control and intervention groups
| Outcomes | All 12 parishes | 10 parishes in which the experiment started at the same time (sensitive analysis)a | ||||||
|---|---|---|---|---|---|---|---|---|
| Control (6 parishes) | Intervention (6 parishes) | Difference (intervention minus control) | p b | Control (5 parishes) | Intervention (5 parishes) | Difference (intervention minus control) | p b | |
| % | % | % | % | % | % | |||
| Main outcomes | ||||||||
| Difference in proportion of soda selection (Week 1 − baseline)c | 4.5% | −3.7% | −8.2% | .03 | 5.2% | −5.4% | −10.6% | .01 |
| Proportion of soda selection at Week 1 after baseline | 63.8% | 56.3% | −7.5% | .26 | 62.7% | 56.3% | −6.4% | .46 |
| Secondary outcomes | ||||||||
| Difference in proportion of soda selection (Week 3 − baseline)c | 8.9% | 2.7% | −6.2% | .15 | 10.8% | 2.1% | −8.7% | .05 |
| Proportion of soda selection at Week 3 after baseline | 68.2% | 62.7% | −5.6% | .26 | 68.4% | 63.8% | −4.6% | .46 |
| Self-reported outcomes | ||||||||
| Difference in soda purchase for personal consumption (in liters)d | −0.7 | −0.7 | 0.1 | .75 | −0.8 | −0.8 | 0.0 | .92 |
| Difference in soda purchase for familiar consumption (in liters)d | −2.6 | −2.2 | 0.5 | .63 | −2.8 | −2.5 | 0.3 | .92 |
aSensitivity analysis including only those dyads that participated in the experiment simultaneously.
bWilcoxon rank-sum test. Bold estimates are significant (p < .05).
cDifferences correspond to difference-in-difference approaches, that is, [observation at week × minus baseline in the intervention group] minus [observation at week × minus baseline in the control group].
dPurchasing behaviors were asked immediately after the Week 3 mass service and represent the difference between the self-reported median values (in liters) of soda purchased during the last week compared to a usual week in the previous month.