Disease Progression Stages and Burden in Patients with Duchenne Muscular Dystrophy Using Administrative Claims Supplemented by Electronic Medical Records

INTRODUCTION

This study aims to identify stages of Duchenne muscular dystrophy (DMD) and assess the disease burden by progression stage using real-world administrative claims supplemented by relevant electronic medical record (EMR) data.

METHODS

Claims and EMR data from the Decision Resources Group's Real World Data Repository (2011-2020) were used to identify patients with DMD by diagnosis code and to stratify them into four disease stages by diagnosis and procedure markers reflective of DMD progression. Clinical and medical history data from the Cooperative International Neuromuscular Research Group (CINRG) were used to validate the developed claims-based staging algorithm. The distribution and drivers by disease stage, as well as disease burden, were examined.

RESULTS

A total of 938 (94%) of patients with DMD identified in claims/EMR data had sufficient information for stage classification. Patients were classified by stage based on patient characteristics and the presence or absence of progression markers such as genetic testing, wheelchair usage, scoliosis treatment, or ventilation assistance. Average ages at stages 1-4 are 7, 13, 18, and 23 years, respectively. Using natural history data, the claims-based staging algorithm was validated with high sensitivity and specificity rates. Both healthcare resource utilization and medical charges increased by stage. For example, the average annualized total charges were $17,688 (stage 1), $36,868 (stage 2), $72,801 (stage 3), and $167,285 (stage 4).

CONCLUSIONS

Large-scale claims data supplemented by EMR data can be used to characterize DMD progression and evaluate disease burden which may inform the design of future real-world studies about DMD.

Duchenne expert physician perspectives on Duchenne newborn screening and early Duchenne care

Duchenne muscular dystrophy (DMD) is a progressive, fatal neuromuscular disorder typically diagnosed between 4 and 5 years of age. DMD currently has five FDA approved therapies, which has led to increased interest in newborn screening (NBS) for DMD. Our objective was to explore the perspectives and predicted practices of physicians (primarily neurologists) who will likely be responsible for the follow-up of infants identified with DMD through NBS. A short survey was developed and distributed to physicians who are responsible for providing care for patients with Duchenne at Certified Duchenne Care Centers across the USA. Twenty-seven physicians responded to statements about benefit and readiness for dystrophinopathy NBS, which care recommendations they would make at initial infant visits, and when they would recommend initiating approved therapies. Most DMD physicians indicated they see benefit in NBS (82%) and believe the DMD care community is ready for NBS in dystrophinopathies (74%). The majority of physicians would recommend multiple interventions, including genetic counseling, maternal carrier testing, referral to early intervention services, screening siblings, discussion of clinical trials, exon skipping therapies, and assessment of social and language development at initial visits. The majority of physicians also indicated they would recommend initiating approved therapies much earlier than the typical age of diagnosis.

[Surface dose reduction achieved by means of a lead glass filter in case of teletherapy with Co 60 radiation (author's transl)]

The surface dose of irradiated patients can be reduced by the insertion of a lead glass filter with a thickness of 4 mm at the ray emergence point of a Co 60 gammatron. The lead glass which is made stable against color alterations by radiation, will absorb the secondary electrons produced by the gamma radiation at the collimator and shutter system of the gammatron. The filter allows to reduce the surface dose in a tissue depth of 0,05 to 0,1 mm by a maximum rate of 16% according to the size of the irradiation field. Measurements were taken with a soft radiation chamber in several tissue depths within and outside the field using three different filtering methods (without any filter, 1 mm plexiglas, 4 mm lead glass). There are essential advantages for teletherapy of deep tumors by the use of a lead glass filter, so that the insertion of such a filter is recommended for all Co 60 units.

[Tangential pendulum irradiation of the thoracic wall with co-60 during radiation therapy of surgically treated cancers of the breast: comparison of measurement and computation methods for irradiation planning (author's transl)]

The irradiation technique for tangential pendulum 60-Co-irradiation of the thoracic wall is described, and the possibility of a homogeneous irradiation of the thoracic region of interest by means of individual irradiation planning together with a careful, but practicable, technique of positioning and adjustment is shown. The radiation load to the lung can be kept on a moderate level. Phantom measurements with thermoluminescence probes, films and an ionization chamber have been performed for three typical forms of the thorax. Dose distributions thus obtained show a satisfying accordance with calculated values of the dose, the deviations amounting to 3 to 8%. The EDP program applied, COMRAD, thus permits computation of individual pendulum isodoses with sufficient accuracy in practice, and therefore, may be used regularly.

[Stomatological identification after air disasters]

The paper describes experiences of stomatological identification after two air disasters and shows potentialities and limits of an odontologic(al) comparison. The application of a 16-bit-computer is pointed out as the essential improvement of the work.

[Measurement of the distance of the rectal mucosa from a gynecologic afterloading applicator based on the drop in performance of a cobalt-60-source]

PURPOSE

Assessment of the distance from a gynecological afterloading applicator to the rectum mucosa.

METHODS

The appropriate afterloading applicator for HDR-Ir-therapy is used for that purpose. A Co-60-source (370 MBq) with a guiding wire is positioned at the tip of the applicator and then withdrawn in steps of 1 cm. For each of these points the maximum dose at the rectum mucosa is measured with an ionisation chamber. From a reference curve it is then possible to determine the distance from the rectum mucosa to the applicator and to mark it in the calculated isodose plan. The actual daily dose to the rectum mucosa is planned not to exceed 3.0 Gy in the maximum.

RESULTS

Up to now the measurements were performed in 91 patients. The minimal distances of the rectum mucosa from the applicator were found to range from 5 to 18 mm with an average value of 14 mm.

CONCLUSIONS

The comparison of the measurement with the readings of the rectum probe during each session showed, that the method is suitable to avoid an overdose at the rectum mucosa.

[Irradiation planning in conservative treatment of cancer of the breast (author's transl)]

Investigations of homogeneous irradiation of the breast with opposed wedge filter fields are presented. Isodose plans calculated with the help of computer programs were compared with measurements of isodose distributions (LiF rods in polystyrol phantoms), and the possibility of optimizing the irradiation method by means of computed plans was examined. Differences between the calculated and the measured values maximally amounted to 10% (programs SIDOS U2 and COMRAD). The calculations correctly describe the place of dose maxima, the homogeneity of the irradiation and tendency to isodose shift caused by variation of the shape of the breast, of the angle of incidence of radiation and of the angles of the wedges. The results are demonstrated using isodose lines in the mediolateral and in the craniocaudal plane of the breast.