Adherence to Polyethylene Glycol Treatment in Children with Functional Constipation Is Associated with Parental Illness Perceptions, Satisfaction with Treatment, and Perceived Treatment Convenience

Objectives: To assess treatment adherence in children with functional constipation and to evaluate the association with parental beliefs about medication, illness perceptions, treatment satisfaction, and satisfaction with information about medication. Study design: A cross-sectional survey was administered among parents of children with functional constipation treated with polyethylene glycol. Adherence was measured via the Medication Adherence Report Scale (MARS-5, score 5-25), with greater scores indicating better adherence (scores ≥23 were defined as adherent). Beliefs about medication, illness perceptions, satisfaction with treatment, and satisfaction with information about treatment were measured with the Beliefs about Medication Questionnaire, the Brief Illness Perception Questionnaire, the Treatment Satisfaction Questionnaire for Medication (TSQM), and the Satisfaction with Information about Medication Questionnaire. Associations between the questionnaire scores and adherence (MARS-5 score as a continuous variable) were analyzed with regression analyses. Results: In total, 43 of 115 included children (37%) were adherent (MARS-5 ≥23). Spearman rank correlation test revealed a statistically significant correlation between TSQM-convenience, TSQM-satisfaction, Brief Illness Perception Questionnaire question 8 (emotions), and the MARS-5 score (rs 0.342, P =.000; rs 0.258, P =.006; rs –0.192, P =.044), which suggests that parental perceived treatment convenience, satisfaction with treatment, and illness perceptions may affect adherence in children with functional constipation. In the hierarchical multivariate regression model, 22% of the variability of the MARS-5 score could be explained by the selected predictors. The TSQM-convenience score contributed the most to the model (β: 0.384, P =.000). Conclusions: Parents reported low adherence rates in their children with functional constipation. Treatment inconvenience, dissatisfaction with treatment, and the emotional impact of functional constipation may negatively influence treatment adherence.