Predictors of Adherence to Short-Course Probiotics Among Children with Gastroenteritis who are Enrolled in a Clinical Trial.

Background: To improve our understanding of adherence to discharge medications in the ED and within research trials, we sought to quantify medication adherence and identify predictors thereof in children with acute gastroenteritis (AGE).
Methods: We conducted a secondary analysis of a randomized trial of twice daily probiotic for 5 days. The population included previously healthy children aged 3-47 months with AGE. The primary outcome was patient-reported adherence to the treatment regimen, defined a priori as having received >70% of the prescribed doses. Secondary outcomes included predictors of treatment adherence and concordance between patient-reported adherence and the returned medication sachet counts.
Results: After excluding participants with missing data on adherence, 760 participants were included in this analysis: 383 in the probiotic arm (50.4%); and 377 in the placebo arm (49.6%). Self-reported adherence was similar in both groups (77.0% in probiotic versus 80.3% in placebo). There was good agreement between self-reported adherence and sachet counts (87% within limits of agreement (-2.9 to 3.5 sachets) on the Bland-Altman plots). In the multivariable regression model, covariates associated with adherence were greater number of days of diarrhea post-emergency department visit, and the study site; covariates negatively associated with adherence were age 12-23 months, severe dehydration and greater total number of vomiting and diarrhea episodes after enrolment.
Conclusions: Longer duration of diarrhea and study site were associated with higher probiotic adherence. Age 12-23 months, severe dehydration and greater number of vomiting and diarrhea episodes post enrolment negatively predicted treatment adherence.