The minimally important difference in the Rhinoconjunctivitis Total Symptom Score in grass-pollen-induced allergic rhinoconjunctivitis

• DOI: 10.1111/all.12518
• Publication Date: 2014-08-25T04:58:56Z
• Authors: P. Devillier; O. Chassany; E. Vicaut; O. de Beaumont; B. Robin; J. F. Dreyfus; P. J. Bousquet
• Keywords: Adult; Male; Adolescent; Comorbidity; Allergens; Middle Aged; Severity of Illness Index; 3. Good health; Young Adult; 03 medical and health sciences; 0302 clinical medicine; ROC Curve; Child, Preschool; Surveys and Questionnaires; Quality of Life; Humans; Pollen; Female; Prospective Studies; Child; Aged; Conjunctivitis, Allergic; Rhinitis

Background The minimally important difference (MID) has been defined as the smallest improvement considered worthwhile by a patient. MID not estimated for Rhinoconjunctivitis Total Symptom Score (RTSS). Methods In prospective multicentre study, patients consulting grass-pollen-induced allergic rhinitis (AR) recorded 15-point global rating of change scale (GRCS) score and Quality Life Questionnaire (RQLQ) on weekly basis individual symptom scores comprising RTSS daily over two consecutive weeks. in was determined with anchor-based methods (using GRCS RQLQ) distribution-based method [based RTSS' standard deviation (SD)]. Results study population comprised 806 (253 children, 250 adolescents 303 adults). During first week mean ± SD RTSSs these age groups were 6.5 3.3, 6.8 3.4 7.0 3.4, respectively. For an 2 points or 0.5 RQLQ score, regression analysis yielded MIDs 1.24 0.17 1.12 0.14 1.33 1.20 0.13 1.13 0.89 0.12 adults, When applying methods, ranged from 1.09 to (based 0.33 SDs first-week RTSS) 1.22 1.40 between second weeks). Conclusion consistently 1.1–1.3 (and could conceivably be rounded 1) AR.