Validation of the first treatment-specific questionnaire for the assessment of patient satisfaction with allergen-specific immunotherapy in allergic patients: the ESPIA questionnaire.

Background Satisfaction with treatment is a patient-reported outcome shown to be associated with the patient's health-related decisions and treatment-related behavior, thereby influencing the chances of successful treatment, and is especially relevant in long-term treatment, such as allergen-specific immunotherapy (AIT). Objective We sought to assess the psychometric properties of the Satisfaction Scale for Patients Receiving Allergen Immunotherapy (ESPIA) questionnaire so as to determine the satisfaction of patients receiving AIT treatment. Methods An observational, longitudinal, multicenter study was performed on patients with allergic rhinitis (AR) undergoing AIT treatment. Sociodemographic, clinical, and patient-centered health outcomes data were gathered at the study visits. Feasibility, reliability, validity, and sensitivity to change of the prevalidated version of the ESPIA questionnaire were assessed. Results Four hundred twenty-nine patients were included (52.2% women, 33.6 years of age, 54.5% of the cases with intermittent AR and 62.5% with moderate AR). Low levels of missing items and ceiling/floor effects were found for the overall score of the ESPIA questionnaire. The overall Cronbach α value and intraclass correlation coefficient were 0.90 and 0.92, respectively. The overall score for the ESPIA questionnaire was strongly associated with months receiving AIT, AR type and intensity, presence of conjunctivitis, self-perceived health status, effect of AR on daily life, and expectations about the AIT treatment. The pattern of correlations obtained with other patient-centered health outcomes was consistent with expectations. The ESPIA questionnaire also showed good sensitivity to change for improved health status. Conclusion The ESPIA questionnaire to assess patient satisfaction with respect to AIT treatment presented satisfactory psychometric properties for its use in clinical practice.