Related Experiment Video
Updated: Jul 3, 2026

Sublingual Immunotherapy as an Alternative to Induce Protection Against Acute Respiratory Infections
Published on: August 30, 2014
Sublingual immunotherapy in youngsters: adherence in a randomized clinical trial
E Röder1, M Y Berger, H de Groot
1Section of Allergology, Department of Internal Medicine, Erasmus MC-University Medical Center Rotterdam, The Netherlands.
Insights
Adherence to sublingual immunotherapy (SLIT) medication in children with hayfever was good, with 77% using at least 80% of prescribed doses. Disease severity, age, and treatment perception influenced adherence and study completion.
Area of Science:
- Allergy and Immunology
- Pediatric Medicine
- Clinical Trials
Background:
- Effective treatment adherence is crucial, yet data on medication intake in pediatric sublingual immunotherapy (SLIT) trials are scarce.
- This study addresses the need for adherence quantification in SLIT for children with rhinoconjunctivitis.
Purpose of the Study:
- To measure adherence to study protocol and medication in children undergoing SLIT for rhinoconjunctivitis.
- To identify factors influencing adherence to SLIT in pediatric populations.
Main Methods:
- A 2-year randomized controlled trial involving 204 children (6-18 years) with hayfever, using grass pollen extract or placebo.
- Adherence to protocol was defined by study completion; medication adherence was determined by weighing remaining medication (≥80% used).
- Analysis included patient, disease, and treatment-related factors influencing adherence.
Main Results:
- 154 children completed the study; the primary reason for discontinuation was difficulty adhering to the medication schedule.
- Older children, those with greater difficulty following instructions, and those with lower treatment effect evaluations were more likely to drop out.
- Overall, 77% of participants adhered to medication intake (≥80% usage), contrasting with 99% self-reported adherence. Non-adherent participants had more severe pre-trial symptoms.
Conclusions:
- Pediatric adherence to SLIT protocols and medication was generally good, though drop-out was linked to age and treatment perception.
- Non-adherence was associated with pre-trial symptom severity; however, non-adherence did not explain the observed ineffectiveness of SLIT.
- Findings highlight the importance of addressing medication instructions and patient expectations to improve adherence in pediatric SLIT.
Background:
Adherence is essential for effective treatment. Although several trials on the efficacy of sublingual immunotherapy (SLIT) in youngsters have been published, few contain data on medication intake.
Objective:
We aimed to quantify adherence both to study protocol and medication intake as well as to identify factors that may influence adherence to SLIT in youngsters with rhinoconjunctivitis.
Methods:
Two hundred and four youngsters (6-18 years) with hayfever participated in a randomized controlled trial and used grass pollen extract or placebo for 2 years. The primary outcome of the trial was the mean daily total rhinoconjunctivitis symptom score in the second grass pollen season. Participants having completed the follow-up were considered adherent to the study protocol. Adherence to medication intake was assessed by weighing the study medication. Participants who completed the follow-up and used > or = 80% of the prescribed medication were considered adherent to medication intake. Patient-, disease- and treatment-related factors were analysed.
Results:
One hundred and fifty-four youngsters completed the study. The main reason for discontinuation was the inability to take medication according to schedule. Drop-outs were older, had more difficulty following the medication instructions and their overall evaluation of the treatment effect was lower. The number and reasons for drop-out did not differ between treatment groups. In total, 77% of the participants was adherent to medication intake. Self-reported adherence was 99%. Non-adherent participants experienced more severe symptoms before the trial. Symptom scores did not differ between adherent and non-adherent participants. In adherent as well as non-adherent participants, no difference was found between verum and placebo group with respect to symptom scores.
Conclusion:
Adherence to both study protocol and medication intake was good. Drop-out was affected by age, evaluation of the treatment effect and medication instructions. Non-adherence to medication intake was influenced by the severity of the disease before the trial. The ineffectiveness of SLIT could not be explained by non-adherence.

