NCT02914821

Do Taxes Reduce the Purchasing of Soda?

Terminated NA Last updated 4 October 2018

What this trial tests

NA trial testing Simulated tax via 3 cent per ounce price increase in Obesity in 50 participants. Terminated before completion.

Timeline

1 September 2016

Primary endpoint
1 January 2018

1 January 2018

Quick facts

Lead sponsor	Harvard University
Phase	NA
Status	Terminated
Study type	INTERVENTIONAL
Allocation	non randomized
Design	crossover
Masking	none
Primary purpose	other
Enrollment	50
Start date	1 September 2016
Primary completion	1 January 2018
Estimated completion	1 January 2018

Drugs / interventions tested

• Simulated tax via 3 cent per ounce price increase

Conditions studied

• Obesity — all drugs for Obesity →
• Diabetes — all drugs for Diabetes →

Sponsor

Harvard University

Who can join

Eligibility, any sex, with Obesity or Diabetes. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

The study will take place at a cafe managed by university dining services and is located in a university building adjacent to the psychology building. The cafe sells sugar-sweetened beverages and a variety of diet drinks. The campus dining services and the manager of the cafe have given investigators permission to "tax" their sugar sweetened beverages and will provide their sales data for a 12 week period.

The investigators will introduce four arms to the experiment. One arm will be baseline data where business 'as usual' will be conducted and no price increases will be implemented on SSBs. In the general tax condition the investigators will introduce a 3 cent/ounce tax on the five SSB flavors the café offers. In the Pre-K tax condition the investigators will institute a 3 cent/ounce tax but will label the tax as proceeds going to Pre-K education. This is designed after the Philadelphia tax that was recently passed where funds were earmarked to benefit childhood education. In the childhood healthy eating program condition the investigators will institute a 3 cent/ounce tax but will label the tax as proceeds going toward childhood healthy eating programs. In all tax conditions the firm will keep the proceeds, but the research team will make a donation to a Pre-K education non-profit and a childhood healthy eating non-profit of the amount generated by the tax during the study period.

Each experimental arm will run for 3 weeks total (for a total study period of 12 weeks). The conditions will alternate by week (i.e., week 1: business as usual; week 2: general tax; week 3: pre-K tax; week 4: childhood healthy eating tax; week 5: business as usual, etc). A research assistant will visit the café each week to make any necessary changes to signs that will label the drinks.

The investigators will change the signage of the drinks in the cooler during the study period. For the baseline period there will be no changes to the signs made. Currently all beverages are labeled with their name and cost (e.g., Pepsi, $1.89). In the tax conditions the investigators will change the price of the drink (3 cents/ounce) and add a line notifying consumers of the soda 'surcharge' (note "surcharge" will be used in the study because no tax was actually passed by the local government). An example of this sign would be 'Pepsi, $2.29, includes 40 cent sugary drink surcharge.' In the Pre-K tax condition an added line will say, "Pepsi, $2.29, includes a 40 cent sugar sweetened beverage surcharge. Proceeds benefit Pre-K education." In the childhood healthy eating programs condition the text will say, "Pepsi, $2.29, includes a 40 cent sugary drink surcharge. Proceeds benefit Childhood Healthy Eating programs."

Publications & conference data

1 peer-reviewed publication reference this trial (live from Europe PMC):

1. Environmental interventions to reduce the consumption of sugar-sweetened beverages and their effects on health.
   von Philipsborn P, Stratil JM, Burns J, Busert LK, et al · · 2019 · cited 177× · PMID 31194900 · DOI 10.1002/14651858.cd012292.pub2