We investigated whether a price increase on regular (sugary) soft drinks and an educational intervention would reduce their sales. Methods. We implemented a 5-phase intervention at the Brigham and Women's Hospital cafeteria in Boston, Massachusetts. After posting existing prices of regular and diet soft drinks and water during baseline, we imposed several interventions in series: a price increase of 35% on regular soft drinks, a reversion to baseline prices (washout), an educational campaign, and a combination price and educational period. We collected data from a comparison site, Beth Israel Deaconess Hospital, also in Boston, for the final 3 phases. Results. Sales of regular soft drinks declined by 26% during the price increase phase. This reduction in sales persisted throughout the study period, with an additional decline of 18% during the combination phase compared with the washout period. Education had no independent effect on sales. Analysis of the comparison site showed no change in regular soft drink sales during the study period. Conclusions. A price increase may be an effective policy mechanism to decrease sales of regular soda. Further multisite studies in varied populations are warranted to confirm these results.
Block, Jason P., Amitabh Chandra, Katherine D. McManus, and Walter C. Willett. "Point-of-Purchase Price and Education Intervention to Reduce Consumption of Sugary Soft Drinks." American Journal of Public Health 100.8 (August 2010): 1427-1433.