This outcomes study assessed the duration of benefit of subcutaneous immunotherapy (SCIT) 0-14 years after cessation by evaluating quality of life (QOL), potential relapse of symptoms, and medication usage in adults.
Methods:
Using Current Procedural Terminology (CPT) codes, we identified potential subjects who were diagnosed with allergic rhinitis and possibly received SCIT between January 1997 and 2008. We identified 543 potential subjects and mailed 543 surveys, including directions on how to access online surveys. Subjects were asked about their nasal allergy and related medical history and requested to complete two validated, standardized Quality of Life (QOL) instruments: Allergy Outcome Survey (AOS) and Mini-Rhinoconjunctivitis Quality of Life Questionnaire (mini-RQLQ).
Results:
This study grouped patients according to their duration of follow-up after discontinuation of SCIT, ranging from 0 to 14 years, and all groups completed 2-5y of immunotherapy. Results indicated the subjects were representative of the patient population normally encountered in our clinic. There was no significant difference in AOS scores for symptoms or medication usage, although there was a trend to slightly lower scores for those who completed the survey 4-6y after finishing treatment. All groups showed total Mini-RQLQ scores between 0.78 and 1.92 (average 1.2): “Not Troubled” to “Hardly Troubled at All.”
Conclusions:
All patients had a quality of life characterized as “not troubled” or “hardly troubled at all” measured by the mini-RQLQ that was maintained from 0 years to 14 years after the cessation of SCIT. This suggests that QOL remains high, and recurrence of symptoms is negligible for up to 14 years. Symptoms and medication use, as measured by the AOS, did not change significantly from 0-14 years after completion of treatment. The symptom scores for the mini-RQLQ and AOS are congruent, including the non-significant “dip” at 4-6 years suggesting that they surveys are valid measures of the same QOL improvements.