Altering the Availability of Healthier vs. Less Healthy Items in Vending Machines

Healthy Diet Clinical Trial

Official title:

Impact of the Availability of Healthier vs. Less Healthy Foods and Beverages on Purchasing From Hospital Vending Machines

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03252158
• Other study ID #: PRE.2017.029
• Status: Completed
• Phase: N/A
• Start date: August 17, 2017
• Est. completion date: March 28, 2018

Study information

• Verified date: May 2018
• Source: University of Cambridge
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Background: While there is some evidence that increasing the range of healthier foods and drinks and/or decreasing the range of less healthy options may increase healthier choices, more work is needed to establish the reproducibility of any effect. The current study aims to investigate the impact of altering the availability of healthier and less healthy foods and cold beverages in hospital vending machines.

Methods: An adapted multiple treatment reversal design will be used, in which all standard vending machines serving snack foods and/or cold beverages in one hospital in England change the number of slots containing (i) less healthy items and (ii) healthier items over eight 4-week periods. Changes will take place in a two-step process whereby decreases are implemented in a separate study period prior to increases in the contrasting food group. Following a 4-week baseline period, all vending machines will be standardised to have 75% healthier drinks and/or 25% healthier snacks (study period 1). Vending machines (n=9) will be randomly allocated to the order in which they: (1) decrease less healthy foods and increase healthier foods or (2) decrease healthier foods and increase less healthy foods (study periods 2&3 and 5&6). After each decrease-increase pair, machines will return to the standardised 75% healthier drinks and 25% healthier snacks (study periods 4 and 7). Sales data will be obtained via records of machine restocking.

Planned Analysis: The impact of the availability intervention will be assessed in separate linear mixed models for cold drinks and snacks, examining the impact on total energy (kcal) purchased, per restocking interval, with random effects for vending machine.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 10
• Est. completion date: March 28, 2018
• Est. primary completion date: March 28, 2018
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: N/A and older

Eligibility

Inclusion Criteria:

• All vending machines at one UK hospital selling standard-fare (i.e. not healthier alternatives) cold beverages and snack foods

Exclusion Criteria:

• Healthier alternative vending machines; vending machines selling hot drinks or meals

Related Conditions & MeSH terms

• Healthy Diet

Intervention

Behavioral:
• Availability of healthier vs. less healthy foods
Altering the number of slots containing (a) healthier and (b) less healthy foods or beverages in hospital vending machines. Changes follow a 2-step process whereby decreases are implemented in a separate study period prior to increases in the contrasting group. Following a 4-week baseline period, all vending machines will be standardised to have 75% healthier drinks and/or 25% healthier snacks (study period 1). Vending machines will be randomly allocated to the order in which they: (1) decrease less healthy foods and increase healthier foods or (2) decrease healthier foods and increase less healthy foods (study periods 2&3 and 5&6). After each decrease-increase pair, machines will return to the standardised 75% healthier drinks / 25% healthier snacks (study periods 4 and 7).

Locations

Country	Name	City	State
United Kingdom	University of Cambridge	Cambridge	Cambridgeshire

Sponsors (2)

Lead Sponsor	Collaborator
University of Cambridge	Oxford University Hospitals NHS Foundations Trust

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Energy purchased	Energy purchased (kcal) per restocking interval from intervention (standard-fare) vending machines	Restocking interval (between 2-4 days; restocking occurs on set weekdays for each machine, to match usual restocking)
Secondary	Number of items sold	Number of items sold per restocking interval from intervention (standard-fare) vending machines	Restocking interval (between 2-4 days; restocking occurs on set weekdays for each machine, to match usual restocking)
Secondary	Energy purchased (healthier alternative machines)	Energy purchased (kcal) per restocking interval from non-intervention (healthier-fare) vending machines	Restocking interval (between 2-4 days; restocking occurs on set weekdays for each machine, to match usual restocking)
Secondary	Number of items sold (healthier alternative machines)	Number of items sold per restocking interval from non-intervention (healthier-fare) vending machines	Restocking interval (between 2-4 days; restocking occurs on set weekdays for each machine, to match usual restocking)