Introduction: Allergen immunotherapy is a long-term treatment that has been associated with patient adherence issues. The aim of the study was to increase the knowledge on compliance of patients allergic to house dust mites, receiving sublingual immunotherapy (SLIT).
Methods: A retrospective observational study was performed in 53 Spanish allergy units. We enrolled patients undergoing the SLIT treatment for house dust mites including a scheduled control visit 12 months after initiating the therapy. We conducted a comprehensive assessment of compliance using three methods. In the first step, an allergist evaluated the patients according to the results of an interview and the existing medical records. The subjects taking more than 80% of the overall prescription were defined as compliant. The remaining noncompliant patients were divided into groups taking less than 25%, 25-50%, and 50-80% of the prescribed SLIT. In the second stage, we conducted the Morisky-Green test. Finally, the noncompliant patients were asked to fill a self-report assessment form. Data were stratified into age groups. The potential factors affecting compliance were also investigated.
Results: Overall, 380 subjects participated in the study. The compliance rate was 79.7%, and the treatment discontinuation rate was 22.5%, while 66.8% of patients were adherent (both compliant and continuing with the treatment). The results showed that children were the most compliant and adolescents the least compliant (86.6% and 60.9%, respectively). The main reason for noncompliance was "forgetting some doses" in 31.0% of the children, 48.0% of the adolescents, and 53.2% of the adults. Compliance was associated with the following factors: age, number of annual control visits, and reduction in symptomatic medication.
Conclusion: Our results showed that two out of three patients with house dust mite-induced allergic rhinitis adhered to the SLIT treatment. Multidisciplinary and integral solutions are needed to improve the compliance, with special attention paid to adolescents.
Funding: Stallergenes Greer Spain.
Keywords: Adherence; Allergen immunotherapy; Allergy; Pulmonary; Respiratory; Sublingual immunotherapy; Treatment interruption.