Retailer-Led Sugar-Sweetened Beverage Price Increase Reduces Purchases in a Hospital Convenience Store in Melbourne,Australia: A Mixed Methods Evaluation

Background

Limited evidence has been gathered on the real-world impact of sugar-sweetened beverage price changes on purchasing behavior over time or in community-retail settings.

Objective

Our aim was to determine changes in beverage purchases, business outcomes, and customer and retailer satisfaction associated with a retailer-led sugar-sweetened beverage price increase in a convenience store. We hypothesized that purchases of less-healthy beverages would decrease compared to predicted sales.

Design

A convergent parallel mixed methods design complemented sales data (122 weeks pre-intervention, 17 weeks during intervention) with stakeholder interviews and customer surveys.

Participants/setting

Electronic beverage sales data were collected from a convenience store in Melbourne, Australia (August through November 2015). Convenience store staff completed semi-structured interviews (n=4) and adult customers exiting the store completed surveys (n=352).

Intervention

Beverages were classified using a state government framework. Prices of “red” beverages (eg, nondiet soft drinks, energy drinks) increased by 20%. Prices of “amber” (eg, diet soft drinks, small pure fruit juices) and “green” beverages (eg, water) were unchanged.

Main outcome measures

Changes in beverage volume, item sales, and revenue during the intervention were compared with predicted sales.

Statistical analyses

Sales data were analyzed using time series segmented regression while controlling for pre-intervention trends, autocorrelation in sales data, and seasonal fluctuations.

Results

Beverage volume sales of red (?27.6%; 95% CI ?32.2 to ?23.0) and amber (?26.7%; 95% CI ?39.3 to ?16.0) decreased, and volume of green beverages increased (+26.9%; 95% CI +14.1 to +39.7) in the 17th intervention week compared with predicted sales. Store manager and staff considered the intervention business-neutral, despite a small reduction in beverage revenue. Fifteen percent of customers noticed the price difference and 61% supported the intervention.

Conclusions

A 20% sugar-sweetened beverage price increase was associated with a reduction in their purchases and an increase in purchases of healthier alternatives. Community retail settings present a bottom-up approach to improving consumer beverage choices.