Introduction GERD is a common and bothersome ailment that can lead to more severe gastrointestinal disease. Treatment discontinuation is a metric that provides an insight into treatment satisfaction and treatment efficacy. Various alginate products are available to alleviate the symptoms of GERD, and Gaviscon formulations represent the most commonly used product. The purpose of this study was to characterise the epidemiology and treatment switching patterns between Gaviscon formulations and other alginate products indicated for GERD.

Methods Data for this study were derived from a 10% sample of the UK population in the Clinical Practice Research Datalink (CPRD). Eligible subjects had a first diagnosis of GERD in 2009, allowing for 5 year follow-up period. Survival analysis methods were used to analyse switching patterns within alginate groups comparing alginate versus Gaviscon. Potential clinical indicators of people likely to switch were identified using a classification and regression tree (CART), and significant covariates then used as co-variables for a Cox regression model.

Results Following exclusions, 22,625 patients were identified for analysis. The average age at time of diagnosis of these patients was 52 years, with 57.1% females. 69.6% of patients were current alcohol drinkers compared to the three other alcohol groups, never drunk (14.9%), previous drinkers (3.1%) and missing (12.5%). The Kaplan-Meier plot (figure) illustrates that the time to a first switch within alginates was quicker for patients that experience a switch from a generic alginate to Gaviscon compared to Gaviscon to a generic alginate. The proportion of patients that had not switched at the end of treatment years were as follows: year 1: 0.97 vs 0.91, year 2: 0.94 vs 0.85, year 3: 0.92 vs 0.82, year 4:0.91 vs 0.77 and year 5:0.88 vs 0.75. CART modelling elucidated three co-variables associated with switching treatment: first prescription of generic alginate or Gaviscon, gender, and alcohol status. In the Cox model there was a corresponding difference in these metrics: alginate to Gaviscon versus Gaviscon to alginate (aHR = 1.77, 95% CI 1.38–2.28).

Conclusion There was an association between the type of alginate prescribed for GERD treatment and the likelihood of switching. Patients were more likely to switch from alginate to Gaviscon compared with the reverse. The data showed that those patients taking Gaviscon from first prescription were less likely to switch to an alternative alginate treatment. Possible explanations for this include potential differences in efficacy, or differences in organoleptic properties.

Disclosure of Interest D. Williams Conflict with: This work was funded by Reckitt Benckiser, C. Currie: None Declared, P. Okhuoya: None Declared, J. Wilkinson: None Declared, E. Berni: None Declared