Epidemiology, disease burden and costs of Duchenne muscular dystrophy in Germany: an observational, retrospective health claims data analysis

Abstract

Background: Duchenne muscular dystrophy (DMD) is a rare genetic disorder that primarily affects males. Beginning in childhood, patients experience ambulatory loss, heart failure and need ventilation. Disease management has improved, however, DMD remains debilitating, and has no cure. The rarity of the disease makes research difficult, and German prevalence data are lacking. Cost and resource utilization estimations are based on small sample sizes or self-reported data, limiting generalizability and adds the potential for recall bias. With a retrospective study on a healthcare claims database, we adapted algorithms to identify DMD patients and categorized them by disease stages 1-4 (early ambulatory, late ambulatory, early non-ambulatory, late non-ambulatory) with increasing disease progression. We analyzed annual prevalence, burden of disease, healthcare resource utilization and direct medical care costs, by time under observation (patient year).

Results: From 2016 to 2021, we identified 134 patients for which we could determine a disease stage and determined an extrapolated prevalence of DMD in Germany between 14.85 (95%CI 12.17, 17.95) and 18.91 (95%CI 15.70, 22.61) per 100,000 males under 40 years of age. Most patients we identified met DMD stage 4 group criteria (47.01%), followed by stage 3 (37.31%), stage 2 (33.58%) and only 4.48% in stage 1. The average age increased with progressing disease, from 4.27 years in stage 1, to 11.43, 18.86 and 23.21 in stage groups 2, 3 and 4, respectively. In the stage 2 group, diagnosis codes reflecting mobility support and orthopedic surgical interventions (15.56% of the group) were documented. In the stage 3 group, decubitus prevention was documented, increasing to around half of patients in the stage 4 group. Total direct mean healthcare costs per patient year increased substantially with disease severity group, from €2,180.73 (SD 16,258.90) in stage 1; €13,599.83 (SD 33,756.07) in stage 2; €14,472.08 (SD 27,245.78) in stage 3 and finally €41,888.70 (SD 117,718.13) in stage 4. Especially in stage groups 3 and 4, medical aids accounted for about half of total costs.

Conclusions: We present an algorithm on which further research can be based, and provide a current picture of epidemiology, burden of disease and healthcare utilization and direct costs of DMD in Germany.

Keywords: Algorithm; Costs; Disease stages; Duchenne muscular dystrophy; Epidemiology; Germany; Healthcare resource utilization; Prevalence; Real-world data.

Fig. 1

Flow diagram of inclusion criteria/algorithm to identify DMD patients (n, %) at each step Abbreviations: n: number of patients

Fig. 2

Box plot of age by DMD disease stage criteria, longitudinally collected across 2017–2021 (n = 134) Abbreviations: DMD: Duchenne muscular dystrophy

Fig. 3

DMD prevalence and proportion (%) of patients by disease stage allocation/year (2016–2021) in Germany *Note: per 100,000 male patients < 40 years of age, with 95% confidence intervals. In 2016, there was not yet enough observation time to determine patients’ DMD disease stage, therefore information is only available from 2017 onwards

Fig. 4

Mean direct healthcare costs (€) by sector and disease stage allocation, per patient year (2017–2021)