Sex- and age-specific background incidence rates for various medical events in the German population aged ≥ 50 years using a nationwide monitoring system of claims data.

INTRODUCTION: Background incidence rates (BI) of diseases are crucial for interpreting medical events that occur in a temporal association with an intervention, such as vaccination. In 2018, a new adjuvanted herpes zoster (HZ) vaccine was introduced in Germany for use in adults aged ≥50 years. In this context, we assessed granular BI for 16 immune-related and other medical conditions in this age-group. Here, we describe the methodology applied and present exemplary results for Guillain-Barré syndrome (GBS), psoriasis and type 1 diabetes mellitus (T1DM).

METHOD: We used a data platform that contains outpatient claims data from all statutory health insured persons in Germany. We calculated sex- and age-specific incidence rates (IRs) in people aged ≥50 years in 2014-2016. To account for possible misestimation due to the use of solely outpatient data an "inpatient factor" was assessed using in- and outpatient claims data from a large German statutory health insurance company.

RESULTS: In all age-strata IRs of GBS, psoriasis and T1DM were higher in men than in women and varied between age-groups. IR per 100,000 men and women was 5-8 and 3-5 for GBS, 268-430 and 230-412 for psoriasis and 26-39 and 15-28 for T1DM, respectively. The magnitude of the inpatient factor differed between diseases, sexes and age groups.

CONCLUSIONS: The extensive data platform allows to assess sex- and age-specific IRs even for very rare conditions. IRs varied between sexes and age groups, stressing the importance of granular BI to interpret potential post-marketing, vaccine-related medical events, thereby supporting vaccine safety communication.