Describe the management of myotonic dystrophy (DM) patients compared with matched controls (MCs) in the five years post-diagnosis.
DM types 1 and 2 are rare, dominantly inherited, multisystem diseases that cause progressive muscle weakness and myotonia, along with variable cardiopulmonary, gastrointestinal, and neurological manifestations. Long-term data on patients with DM are limited.
We used PharMetrics deidentified US claims (Jan-2010—Mar-2021) to identify patients with DM (≥2 DM claims ≥30 days apart; index date=first diagnosis date) and non-DM controls (matched 3:1 on index month, age, region, gender, plan, and payer types). Subjects had five years of data following their index date. Costs were adjusted to 2020 dollars. Comorbid conditions classified by Agency for Healthcare Research and Quality (AHRQ) specific categories and prescription (Rx) products by Anatomical Therapeutic Classes (ATC). Reported findings significant for p<0.0001. Results We identified 892 DM-patients and 2,676 MCs. In the 5 years post-diagnosis, across care locations, DM patients had annual mean costs $21,728(SD $50,684) vs $6,221($13,347) for MCs, services 93.40(118.53) vs 42.61(52.68), and days of care 35.77(39.31) vs 16.76(18.90). Annually, DM-patients filled more Rxs 21.8(25.63) vs 13.5(20.42), costing $3,277($11,078) vs $1,450($4,904), on more days 15.14(15.91) vs 9.22(12.00). Over 5 years, DM patients used 14.85(11.57) vs 10.72(10.05) unique Rx from 30.73(25.08) vs 21.93(21.24) ATC4 classes. DM patients averaged 45.12(32.21) vs. 24.93(21.69) unique (ICD-9/-10) diagnoses within 24.08(12.44) vs. 14.63(10.22) AHRQ categories. Per-member-per-year comorbid conditions higher for prevalence(>20%), costs(>$62) and services(>0.2) included other nervous system disorders, cardiac dysrhythmias, other gastrointestinal disorders, and cataracts.
Healthcare utilization was significantly higher in DM patients 5 years post-diagnosis versus controls. Utilization likely reflects multi-specialty care in managing DM. There is no cure or approved therapy for DM. The data reflect the burden on DM patients and their families and provide insight into management that may reduce morbidity and mortality.