BACKGROUND AND AIMS Lupus nephritis (LN) is the most common severe manifestation of systemic lupus erythematosus (SLE) and can lead to end-stage renal disease and death. However, there are limited data to contextualize the burden of LN in Germany, with no published studies using national claims data. This cross-sectional study aimed to estimate the annual prevalence of SLE and LN from 2011–17 using claims data from the Betriebskrankenkassen (BKK) German Sickness Fund Database. METHOD For each study year (2011–17), three patient populations were identified using International Classification of Diseases, Tenth Revision, German Modification (ICD-10-GM) codes: (1) Patients with SLE (≥1 SLE inpatient claim or ≥1 outpatient claim with a confirmatory claim in a separate quarter within ± 3 years); (2) Patients with LN, sensitive definition (based on the presence of SLE [as above] with ≥ 1 nephritis claim within ± 1 year from the initial SLE claim) and (3) Patients with LN, specific definition (based on the presence of SLE [as above] with ≥ 2 nephritis claims in separate quarters within ± 1 year from the initial SLE claim). For each year, the annual prevalence of SLE and LN/100 000 was estimated by dividing the number of patients identified in each population by the number of individuals insured in the database in that year. The proportion of SLE patients with LN was also estimated. To estimate the total number of patients with SLE and LN in Germany by age and sex standardization, the German statutory health insurance (SHI) system (covering 87% of the German population) was used to extrapolate from the prevalence calculated in the BKK database. RESULTS Approximately 5 million patients were insured in the BKK database between 2011–17; the ratio of insured males to females was ∼1:1 throughout the study period. The annual prevalence of SLE and LN/100 000 increased from 2011 (SLE, 37.68; LN sensitive, 12.79; LN specific, 9.99) to 2017 (SLE, 54.74; LN sensitive, 19.06; LN specific, 15.16) (Fig. 1). In 2017, the ratio of males to females/100 000 patients was ∼1:5.5 for the SLE cohort, 1:4.5 for the LN-sensitive cohort and 1:4.4 for the LN-specific cohort. The proportion of SLE patients with LN remained consistent across the study period, ranging from 26.51% (specific definition) and 33.96% (sensitive definition) in 2011 to 27.69% and 34.82%, respectively, in 2017. When extrapolating the prevalence estimates to the wider German SHI system, the estimated number of SLE patients was >41 000 in 2017, with the total LN patient population ranging from 11 515 (specific definition) to 14 483 (sensitive definition) (Fig. 2). CONCLUSION The prevalence of LN increased between 2011 and 2017 among patients insured in the BKK database and is estimated to impact >11 000 patients in the wider German SHI system. Limitations include an absence of renal biopsy information and the inability to distinguish patients with active nephritis from those with historical or inactive LN based on clinical parameters. Nonetheless, these data highlight the prevalence of LN among patients with SLE and the need for effective screening and disease management to improve patient outcomes. Further work to understand the treatment and economic burden of LN among patients with SLE in Germany is ongoing.

Background While numerous publications have estimated the prevalence of diagnosed hypertrophic cardiomyopathy (HCM), none have quantified the real-world proportion of obstructive and non-obstructive HCM using nationally representative data sources in any European countries. Purpose To estimate the prevalence of diagnosed HCM and its subtypes in the UK and Germany. Methods Patients with HCM were identified in the UK from 01 Apr 2009 to 30 Oct 2020 and Germany from 2011 to 2019. UK patients with HCM were identified using electronic health records from the Clinical Practice Research Datalink (CPRD) primary care data linked with Hospital Episode Statistics (HES) secondary care data using ICD-10 (I42.1, I42.2), Read, Medcode, SNOMED, and OPCS codes. German patients with HCM were identified using a nationally representative administrative claims data pool (WIG2 Benchmark database) from several German Statutory Health Insurance (SHI)-insurances using ICD-10 and OPS codes. Obstructive HCM was identified as any obstructive HCM diagnosis, any HCM diagnosis with septal reduction therapy, and any HCM diagnosis and left ventricular outflow tract obstruction (LVOTO; not in German claims data). Non-obstructive HCM was any non-obstructive or unspecified HCM diagnosis without evidence of any obstructive HCM. Annual prevalence was calculated for each year in the respective study periods and average annual prevalence across the study period. Results The average annual prevalence rate of HCM was 4.15/10,000 in the UK and 8.61/10,000 in Germany, while the average annual prevalence rate of obstructive HCM was 2.84/10,000 in the UK and 4.18/10,000 in Germany (Table). The proportion of HCM that was obstructive HCM was 68% in the UK and 49% in Germany. The prevalence rates of diagnosed HCM and obstructive HCM tended to increase over time (Figure). Conclusion The prevalence of HCM, obstructive HCM and the proportion of HCM that is obstructive varied between the UK and Germany. The prevalence of HCM was generally consistent with previously published estimates. Although there are limitations with coding in administrative data, it is important to differentiate obstructive HCM from non-obstructive HCM given their unique treatments and disease progression and management, especially since at least 49–68% of HCM is obstructive. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): Bristol Myers-Squibb