Trial Outcomes & Findings for Price Changes and Hypothetical Food Purchases in Adult Grocery Shoppers (NCT NCT01619787)
NCT ID: NCT01619787
Last Updated: 2017-01-10
Results Overview
Change in total calories as a result of taxes of 12.5% and 25%.
Recruitment status
COMPLETED
Target enrollment
217 participants
Primary outcome timeframe
Study Completion
Results posted on
2017-01-10
Participant Flow
Recruitment in the Western New York Area targeted primary household grocery shoppers through the local community during 2011-2013.
Interested eligible participants were screened and offered to start the study.
Participant milestones
| Measure |
Online Grocery
All participants completed a baseline session where behavioral measures of delay discounting, relative reinforcing value and relative reinforcing efficacy were measured. Participants then completed five shopping sessions under various price conditions. Age and Body Mass Index were measured at the end of the six session study.
|
|---|---|
|
Overall Study
STARTED
|
217
|
|
Overall Study
COMPLETED
|
212
|
|
Overall Study
NOT COMPLETED
|
5
|
Reasons for withdrawal
| Measure |
Online Grocery
All participants completed a baseline session where behavioral measures of delay discounting, relative reinforcing value and relative reinforcing efficacy were measured. Participants then completed five shopping sessions under various price conditions. Age and Body Mass Index were measured at the end of the six session study.
|
|---|---|
|
Overall Study
Lost to Follow-up
|
5
|
Baseline Characteristics
Price Changes and Hypothetical Food Purchases in Adult Grocery Shoppers
Baseline characteristics by cohort
| Measure |
Lean Participants
n=102 Participants
Participants whose baseline BMI is less than 25.
All participants completed a baseline session where behavioral measures of delay discounting, relative reinforcing value and relative reinforcing efficacy were measured. Participants then completed five shopping sessions under various price conditions. Age and Body Mass Index were measured at the end of the six session study; therefore, 5 participants were lost to follow up and no age or body mass index are reported for these participants.
|
Overweight/Obese Participants
n=110 Participants
Participants whose baseline BMI is greater than or equal to 25.
All participants completed a baseline session where behavioral measures of delay discounting, relative reinforcing value and relative reinforcing efficacy were measured. Participants then completed five shopping sessions under various price conditions. Age and Body Mass Index were measured at the end of the six session study; therefore, 5 participants were lost to follow up and no age or body mass index are reported for these participants.
|
Total
n=212 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
|
43.0 years
STANDARD_DEVIATION 7.5 • n=99 Participants
|
42.5 years
STANDARD_DEVIATION 7.4 • n=107 Participants
|
42.7 years
STANDARD_DEVIATION 7.4 • n=206 Participants
|
|
Gender
Female
|
99 Participants
n=99 Participants
|
105 Participants
n=107 Participants
|
204 Participants
n=206 Participants
|
|
Gender
Male
|
3 Participants
n=99 Participants
|
5 Participants
n=107 Participants
|
8 Participants
n=206 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
2 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
2 Participants
n=206 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
100 Participants
n=99 Participants
|
110 Participants
n=107 Participants
|
210 Participants
n=206 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=99 Participants
|
1 Participants
n=107 Participants
|
1 Participants
n=206 Participants
|
|
Race (NIH/OMB)
Asian
|
5 Participants
n=99 Participants
|
3 Participants
n=107 Participants
|
8 Participants
n=206 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
0 Participants
n=206 Participants
|
|
Race (NIH/OMB)
Black or African American
|
14 Participants
n=99 Participants
|
22 Participants
n=107 Participants
|
36 Participants
n=206 Participants
|
|
Race (NIH/OMB)
White
|
79 Participants
n=99 Participants
|
83 Participants
n=107 Participants
|
162 Participants
n=206 Participants
|
|
Race (NIH/OMB)
More than one race
|
1 Participants
n=99 Participants
|
0 Participants
n=107 Participants
|
1 Participants
n=206 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
3 Participants
n=99 Participants
|
1 Participants
n=107 Participants
|
4 Participants
n=206 Participants
|
|
Body Mass Index
|
32.6 kg/m^2
STANDARD_DEVIATION 6.6 • n=99 Participants
|
22.2 kg/m^2
STANDARD_DEVIATION 2.0 • n=107 Participants
|
27.6 kg/m^2
STANDARD_DEVIATION 7.2 • n=206 Participants
|
|
Relative Reinforcing Value High Energy Dense Foods (RRV HED)
|
13.8 Highest Response schedule completed
STANDARD_DEVIATION 50.4 • n=99 Participants
|
15.9 Highest Response schedule completed
STANDARD_DEVIATION 25.1 • n=107 Participants
|
14.7 Highest Response schedule completed
STANDARD_DEVIATION 38.8 • n=206 Participants
|
|
Relative Reinforcing Value Low Energy Dense Foods (RRV LED)
|
26.0 Highest response schedule completed
STANDARD_DEVIATION 34.7 • n=99 Participants
|
23.9 Highest response schedule completed
STANDARD_DEVIATION 30.4 • n=107 Participants
|
25.2 Highest response schedule completed
STANDARD_DEVIATION 32.9 • n=206 Participants
|
|
Delay Discounting $10 reward (DD 10)
|
0.7 indifference proportion*delay proportion
STANDARD_DEVIATION 0.3 • n=99 Participants
|
0.6 indifference proportion*delay proportion
STANDARD_DEVIATION 0.3 • n=107 Participants
|
0.6 indifference proportion*delay proportion
STANDARD_DEVIATION 0.3 • n=206 Participants
|
|
Delay Discounting $100 reward (DD 100)
|
0.7 indifference proportion*delay proportion
STANDARD_DEVIATION 0.2 • n=99 Participants
|
0.7 indifference proportion*delay proportion
STANDARD_DEVIATION 0.3 • n=107 Participants
|
0.7 indifference proportion*delay proportion
STANDARD_DEVIATION 0.3 • n=206 Participants
|
PRIMARY outcome
Timeframe: Study CompletionPopulation: Data is reported for 199 participants. Out of 217 participants who started the study, 5 participants were lost to follow up, 1 participant shopped in the same store twice, 2 participants had conditions that would affect shopping, 2 participants did not report minority status and 8 male participants were excluded due to the small sample number.
Change in total calories as a result of taxes of 12.5% and 25%.
Outcome measures
| Measure |
Online Grocery
n=199 Participants
All participants completed a baseline session where behavioral measures of delay discounting, relative reinforcing value and relative reinforcing efficacy were measured. Participants then completed five shopping sessions under various price conditions. Age and Body Mass Index were measured at the end of the six session study.
|
Lean Participants
n=97 Participants
Participants with BMI less than 25.
|
Overweight/Obese Participants
n=102 Participants
Participants with BMI greater than or equal to 25.
|
|---|---|---|---|
|
Change in Energy Purchased as a Result of Taxes.
Calories Purchased in the Tax 25 Condition
|
10180.17 Total Calories Purchased
Standard Error 304.13
|
10471.42 Total Calories Purchased
Standard Error 464.73
|
10184.04 Total Calories Purchased
Standard Error 436.78
|
|
Change in Energy Purchased as a Result of Taxes.
Calories Purchased in the Regular Condition
|
10622.09 Total Calories Purchased
Standard Error 329.04
|
10507.62 Total Calories Purchased
Standard Error 427.92
|
10311.12 Total Calories Purchased
Standard Error 456.04
|
|
Change in Energy Purchased as a Result of Taxes.
Calories Purchased in the Tax 12.5 Condition
|
10401.13 Total Calories Purchased
Standard Error 292.12
|
10512.95 Total Calories Purchased
Standard Error 523.10
|
9733.12 Total Calories Purchased
Standard Error 385.34
|
PRIMARY outcome
Timeframe: Study CompletionPopulation: Data is reported for 199 participants. Out of 217 participants who started the study, 5 participants were lost to follow up, 1 participant shopped in the same store twice, 2 participants had conditions that would affect shopping, 2 participants did not report minority status and 8 male participants were excluded due to the small sample number.
Change in total calories as a result of subsidies of 12.5% and 25%.
Outcome measures
| Measure |
Online Grocery
n=199 Participants
All participants completed a baseline session where behavioral measures of delay discounting, relative reinforcing value and relative reinforcing efficacy were measured. Participants then completed five shopping sessions under various price conditions. Age and Body Mass Index were measured at the end of the six session study.
|
Lean Participants
n=97 Participants
Participants with BMI less than 25.
|
Overweight/Obese Participants
n=102 Participants
Participants with BMI greater than or equal to 25.
|
|---|---|---|---|
|
Change in Energy Purchased as a Result of Subsidies
Calories Purchased in the Regular Condition
|
10548.69 Total Calories Purchased
Standard Error 316.69
|
10507.63 Total Calories Purchased
Standard Error 437.92
|
10311.12 Total Calories Purchased
Standard Error 456.04
|
|
Change in Energy Purchased as a Result of Subsidies
Calories Purchased in the Subsidy 25 Condition
|
10189.55 Total Calories Purchased
Standard Error 300.85
|
11036.01 Total Calories Purchased
Standard Error 519.23
|
10509.31 Total Calories Purchased
Standard Error 426.99
|
|
Change in Energy Purchased as a Result of Subsidies
Calories Purchased in the Subsidy 12.5 Condition
|
10369.12 Total Calories Purchased
Standard Error 283.95
|
10176.01 Total Calories Purchased
Standard Error 442.21
|
9704.67 Total Calories Purchased
Standard Error 405.05
|
Adverse Events
Online Grocery
Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place