Effectiveness of AIT in RWD Analyses reflects Efficacy in RCTs
Tables S5, S6, S7, S8 in supplementary information summarize detailed results from the RWD analyses included. Taking a closer look at e.g. the effects on progression of allergic rhinitis using grass pollen AIT (Tab. S5), it is striking that the reduction in the use of antiallergic medication in the different assessments ranges from 18.8% to 75% compared to the non-AIT group. But comparing the results would be misleading since the assessments differed substantially concerning e.g. in-/exclusion criteria, matching process, evaluated antiallergic medication or calculation/statistical methods, even when performed in the same prescription database and nearly the same analysis periods. Therefore, the results from different assessments do not indicate that effectiveness is higher for any allergen (e.g. pollen vs. house dust mites) or allergen preparation (e.g. SLIT vs. SCIT; allergoids vs. unmodified preparations), especially since no direct comparisons between single AIT preparations or preparation groups were made within the same assessments.
In AIT RCTs, the primary endpoint is usually evaluated after one or two years of treatment whereas one key advantage of RWD is the possibility to evaluate data from longer observation periods. Despite this fact, we tried to check consistency between RCT efficacy and RWD effectiveness by using the medication scores from RCTs and the number of prescriptions in RWD analyses for preparations, which could be unambiguously identified in the RCT and RWD publications. For some preparations symptom medication (SMS) score data (47) or data on reduction of dose steps of inhaled corticosteroids (48) served as efficacy results in the RCTs in the absence of medication score data (see Table S 11 in supplementary information). The analysis proved that the efficacy shown in gold standard DBPC RCTs is rigorously confirmed in RWD over longer time periods.