D1.202 - Comparison of 2 different medication scores for the calculation of the Combined Symptom and Medication Score – EAACI versus paediatric medication in Germany

The CSMS according to the EAACI position paper (Pfaar et al., Allergy 2014) proposes a stepwise approach regarding rescue medication intake. However, as shown in several clinical trials, very few patients take oral glucocorticosteroids but need antihistamine eye drops to alleviate eye symptoms, which are not reflected in the weighted EAACI score (Mösges et al., Allergy 2024). Here, we present 2 different approaches (weighted/additive) to calculate the medication score and the impact on the CSMS.

This epidemiologic study was planned as a multicentre study in Germany.  Following inclusion, 479 grass pollen allergic participants documented their allergic symptoms and anti-allergic medication intake via an eDiary (CCC STUDY Diary App) for 30 days during the grass pollen season 2025. The medication score (dMS) was either calculated according to EAACI (weighted) using a stepwise scoring system (step 0: no medication, step 1: oral antihistamines, step 2: corticosteroid nasal spray) or with an additive scoring (0: no medication, 0.5: antihistamine eye drops, 1.0: oral antihistamines, 1.5: corticosteroid nasal spray, in any order).

When comparing the weighted dMS and CSMS with the additive scores, the mean/median weighted scores were higher than the additive scores. Although the differences were statistically significant, their magnitude was small and unlikely to be clinically meaningful. The correlations between both scores were very strong with Spearman’s rho of 0.983 for dMS and 0.990 for CSMS (p<0.001). Linear regression analyses also confirmed a strong correlation with beta values of 0.966 for dMS and 0.986 for CSMS. Blend-Altman analysis confirmed a good methodological agreement with a low bias value of 0.157 (SD: 0.2970) with 95% limits of agreement ranging from -0.425 to 0.739.

The study supports the robustness and reproducibility of the CSMS, showing that is an appropriate metric for assessing allergic disease severity.  Sensitivity analyses demonstrate a high level of agreement between weighted and additive CSMS and dMS calculation methods, confirming the reproducibility of the used approaches.