Widening gap in age at muscular dystrophy-associated death between blacks and whites, 1986-2005

Racial and Ethnic Equity in Neuromuscular Care-Time for Our Action to Live Up to Potential

This Viewpoint discusses the need to improve the quality of care in neuromuscular disease for all individuals, no matter their race and ethnicity.

Selected clinical and demographic factors and all-cause mortality among individuals with Duchenne muscular dystrophy in the Muscular Dystrophy Surveillance, Tracking, and Research Network

Population-based estimates of survival among individuals with Duchenne muscular dystrophy (DMD) living in the United States are lacking. It is also unclear whether the association between glucocorticoid use and all-cause mortality persists in the context of other common treatments (cardiac medication, cough-assist, bilevel positive airway pressure, and scoliosis surgery) observed to delay mortality. Among 526 individuals identified by the Muscular Dystrophy Surveillance, Tracking, and Research Network, the estimated median survival time from birth was 23.7 years. Current glucocorticoid users had a lower hazard of mortality than non-users. Individuals who ever had scoliosis surgery had a lower hazard of mortality than individuals who did not have scoliosis surgery. Individuals who ever used cough assist had a lower hazard of mortality than individuals who never used cough assist. Non-Hispanic Black individuals had a higher hazard of mortality than non-Hispanic White individuals. No differences in hazards of mortality were observed between ever versus never use of cardiac medication and ever versus never use of bilevel positive airway pressure. The glucocorticoid observation is consistent with the 2018 Care Considerations statement that glucocorticoid use continues in the non-ambulatory phase. Our observations may inform the clinical care of individuals living with DMD.

A population-based study of mortality due to muscular dystrophies across a 36-year period in Spain

Muscular dystrophies (MD) are a group of rare hereditary degenerative diseases. Our aim was to analyze the mortality pattern in Spain from 1981 to 2016 to assess the temporal trend and discern possible geographic differences using population-based data. Annual deaths related to MD were obtained from the National Statistics Institute with codes 359.1 of the ICD-9 (1981–1998) and G71.0 of the ICD-10 (1999–2016). Age-adjusted mortality rates were calculated and changes in mortality trends were identified. The standardized mortality ratios (SMR) and their respective 95% confidence intervals were calculated by district for 1999–2016. Smoothed SMRs and posterior probability were also assessed and then mapped to look for patterns or geographic distribution. All rates were expressed per 1,000,000 inhabitants. A total of 2,512 deaths (73.8% men) were identified. The age-adjusted mortality rates varied from 0.63 (95% CI 0.40–0.95) in 1981 to 1.51 (95% CI 1.17–1.93) in 2016. MD mortality showed a significant increase of 8.81% per year (95% CI 5.0–12.7) from 1981 to 1990, remaining stable afterwards. Areas with risk of death higher than expected for Spain as a whole were identified, not showing a specific regional pattern. In conclusion, the rising trend in MD mortality might be attributable to advanced improvements in diagnostic techniques leading to a rise in prevalence. Further research on the districts with the highest mortality would be necessary.

Characterizing Enrollment in Observational Studies of Duchenne Muscular Dystrophy by Race and Ethnicity

Observational research benefits from inclusion of diverse cohorts. To characterize racial and ethnic diversity in observational and natural history research studies of Duchenne muscular dystrophy (DMD), highly cited and influential observational studies were identified. Fourteen United States-based articles were included. All studies cited >70% White participants with the majority having few racial minority participants. Enrollment of Black/African American individuals was particularly limited (<5% in all but one study), and Hispanic/Latino participants ranged from 3.3- 26.5% of cohorts. These results suggest a need for effective strategies to recruit, enroll, and retain racially and ethnically diverse populations into observational research in DMD.

Summary of Selected Healthcare Encounters among a Selection of Patients with Myotonic Muscular Dystrophy

OBJECTIVE

Research has not examined the use of health care by patients with myotonic muscular dystrophy (MMD), but it would provide insights into this population, which is prone to comorbidities and high service needs. This study is an analysis of this understudied subgroup, using a unique linked dataset to examine the characteristics and healthcare utilization patterns for people with MMD.

METHODS

This analysis used 3 South Carolina datasets (2009-2014). The subjects included individuals with at least 1 encounter with an International Classification of Diseases, Ninth Revision, Clinical Modification code of 359.21. The variables included sex, race, visit type, payer, and diagnoses. The analyses examined characteristics and number of encounters.

RESULTS

The subjects were predominately female, white, and 45 to 64 years old. A total of 44.6% of the study population had at least 1 inpatient visit, whereas 64.2% had at least 1 emergency department visit. A majority of the subjects had at least 1 office visit (55.0%), and most (85.3%) did not have a home health encounter.

CONCLUSIONS

Investigation of the reasons for these inpatient and emergency department encounters may be helpful in identifying ways to deliver high-quality care.

Differences in Race and Ethnicity in Muscular Dystrophy Mortality Rates for Males under 40 Years of Age, 2006-2015

BACKGROUND/AIMS

Duchenne Muscular Dystrophy (DMD) has childhood onset, primarily affects males, and is usually fatal before the age of 40 years. Previous studies have indicated that this X-linked condition is more prevalent in whites than in blacks, but those were based on active surveillance, and limited to smaller populations and younger ages.

METHODS

US death data were used to calculate mortality rates by race and ethnicity, with MD as either the underlying or multiple cause of death (MCD). Poisson approximation was used for confidence intervals; chi-square was used to compare rates.

RESULTS

From 2006 to 2015, there were 3,256 deaths in males <40 years with MD as MCD, and 71% of these were aged 15-29 years. For whites, the average annual death rate was 0.43/100,000, which was significantly higher (p < 0.0001) that that of blacks (0.28), American Indian/Alaska Natives (0.20), and Asian/Pacific Islanders (0.21). The rate for non-Hispanic whites (0.46) was significantly higher (p < 0.0001) than the rates for Hispanic whites (0.31), Hispanic blacks (0.07), and non-Hispanic blacks (0.29).

CONCLUSION

Since DMD is the primary cause of deaths in young males with MD, mortality rates are a reasonable proxy for the relative difference in racial prevalence. It appears that DMD is significantly more common in white males than in males of other races.

Disparities in health care utilization by race among teenagers and young adults with muscular dystrophy

BACKGROUND

For people with muscular dystrophy (MD) health care access is crucial and utilization is expected to be high. A multidisciplinary approach is needed for optimal management of symptoms of this rare condition. Regular primary care, specialty care, therapy, and medicine use can improve quality of care and reduce need for emergency treatment and hospitalization. We analyzed health insurance and administrative data to test for racial disparities in regular care use among teenagers and young adults with MD.

METHODS

We used South Carolina Medicaid and other administrative data for individuals aged 15-24 years to determine annual health care utilization patterns for individuals with MD by race. We studied adolescents and young adults with MD because this age group represents a time when the condition is typically intensifying and the transition from pediatric to adult care is expected. We used Generalized Estimating Equation models to analyze longitudinal utilization data conditional on other factors that may lead to utilization differences.

RESULTS

Race is correlated with health care utilization among adolescents and young adults with MD. Blacks have lower overall utilization, and less primary care, therapy, and specialist care use but higher incidence of hospitalization and emergency treatment use compared with whites and also to other races. The most striking disparity was the use of outpatient services. Blacks utilized these services 50% less compared with whites and 70% less compared with others. Even in regression analysis, where we take into account individual unobserved factors and allow clustering at the individual level, these differences remained and were in most cases statistically significant.

CONCLUSIONS

Our results indicate that there are differences in health care utilization by race even when individuals have access to the same health care benefits. This means simply offering coverage to individuals with MD may not be sufficient in eliminating health disparities. Future studies will be needed to examine other possible sources of these racial disparities, such as resource awareness, health knowledge, or access barriers such as transportation.

Recipients of electric-powered indoor/outdoor wheelchairs provided by a national health service: a cross-sectional study

OBJECTIVE

To describe the characteristics across all ages of powered wheelchair users and the assistive technology prescribed by a regional specialist wheelchair service.

DESIGN

Cross-sectional study.

SETTING

Regional wheelchair service.

PARTICIPANTS

Electric-powered indoor/outdoor wheelchair (EPIOC) users (N=544) with 262 boys and men (mean age ± SD, 41.7±20.7y; range, 8-82y) and 282 girls and women (mean age ± SD, 47.2±19.7y; range, 7-92y).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Demographic, clinical/diagnostic details of EPIOC recipients, including pain, (kypho)scoliosis, and ventilators. Technical features, including specialized (adaptive) seating, tilt in space, and modified control systems. Factors were related to age groups: 1 (0-15y), 2 (16-24y), 3 (25-54y), 4 (55-74y), and 5 (≥75y).

RESULTS

Neurologic/neuromuscular conditions predominated (81%) with cerebral palsy (18.9%) and multiple sclerosis (16.4%). Conditions presenting at birth or during childhood constituted 39%. Of the participants, 99 had problematic pain, 83 had (kypho)scoliosis, and 11 used ventilators. Specialized (adaptive) seating was provided to 169 users (31%); most had cerebral palsy or muscular dystrophy. Tilt in space was used by 258 (53%) participants. Younger people were more likely to receive tilt in space than older ones. Only 92 had specialized (adaptive) seating and tilt in space (mean age ± SD, 29±17.8y; range, 8-72y). Of the participants, 52 used modified control systems.

CONCLUSIONS

The diversity of EPIOC users across age and diagnostic groups is shown. Their complex interrelations with these technical features of EPIOC prescriptions are explored. Younger users were more complex because of age-related changes. This study provides outcomes of the EPIOC prescription for this heterogeneous group of very severely disabled people.

Can outcomes in Duchenne muscular dystrophy be improved by public reporting of data?

OBJECTIVE

To review current approaches for obtaining patient data in Duchenne muscular dystrophy (DMD) and consider how monitoring and comparing outcome measures across DMD clinics could facilitate standardized and improved patient care.

METHODS

We reviewed annual standardized data from cystic fibrosis (CF) clinics and DMD care guidelines and consensus statements; compared current approaches to obtain DMD patient data and outcome measures; and considered the best method for implementing public reporting of outcomes, to drive improvements in health care delivery.

RESULTS

Current methods to monitor DMD patient information (MD STARnet, DuchenneConnect, and TREAT-NMD) do not yet provide patients with comparative outcome data. The CF patient registry allows for reporting of standard outcomes across clinics and is associated with improved CF outcomes. A similar patient registry is under development for the Muscular Dystrophy Association (MDA) clinic network. Suggested metrics for quality care include molecular diagnosis, ambulatory status and age at loss of ambulation, age requiring ventilator support, and survival.

CONCLUSIONS

CF longevity has increased by almost 33% from 1986 to 2010, in part due to a CF patient registry that has been stratified by individual care centers since 1999, and publically available since 2006. Implementation of outcome reporting for MDA clinics might promote a similar benefit to patients with DMD.

Correlation of heart rate and cardiac dysfunction in Duchenne muscular dystrophy

Sinus tachycardia is common in cases of Duchenne muscular dystrophy (DMD). The authors hypothesized that an elevated heart rate would herald cardiomyopathy onset. A retrospective case-control study was performed with 55 DMD boys and 150 age-matched control boys. The variables were age, heart rate, shortening fraction, and left ventricular end-diastolic dimension. Cardiomyopathy was defined as a shortening fraction less than 28%. The DMD boys had a higher initial heart rate with no baseline echocardiographic evidence of cardiomyopathy. The control subjects showed a statistically significant age-related decline in heart rate (p = 0.001) but not the DMD boys. Cardiomyopathy developed in 17 of the 55 DMD boys over a period of 4.6 ± 1.6 years. The DMD upper and lower heart rate groups were similar in age, follow-up time, and initial shortening fraction, yet cardiomyopathy developed in 14 (42%) of 33 upper quartile boys but only 3 (14%) of 22 lower quartile DMD boys (odds ratio, 6.5 (95% confidence interval, 1.15-18.92; p < 0.05). Compared with the control subjects, the DMD boys had a higher resting heart rate and a lack of age-related heart rate decline. The DMD boys in the upper heart rate quartile were more likely to progress to cardiomyopathy than those in the lower quartiles. This study establishes heart rate elevation as a statistically significant risk factor for cardiomyopathy. Further studies may define heart rate cutoffs for early pharmacologic intervention for incipient cardiomyopathy.

Comparative effectiveness and implementation research: directions for neurology

There is an enormous unmet need for knowledge about how new insights from discovery and translational research can yield measurable, population-level improvements in health and reduction in mortality among those having or at risk for neurological disease. Once several, well-conducted randomized controlled trials establish the efficacy of a given therapy, implementation research can generate new knowledge about barriers to uptake of the therapy into widespread clinical care, and what strategies are effective in overcoming those barriers and in addressing health disparities. Comparative effectiveness research aims to elucidate the relative value (including clinical benefit, clinical harms, and/or costs) of alternative efficacious management approaches to a neurological disorder, generally through direct comparisons, and may include comparisons of methodologies for implementation. Congress has recently appropriated resources and established an institute to prioritize funding for such research. Neurologists and neuroscientists should understand the scope and objectives of comparative effectiveness and implementation research, their range of methodological approaches (formal literature syntheses, randomized trials, observational studies, modeling), and existing research resources (centers for literature synthesis, registries, practice networks) relevant to research for neurological conditions, to close the well-documented evidence-to-practice gap. Future directions include building this research resource capacity, producing scientists trained to conduct rigorous comparative effectiveness and implementation research, and embracing innovative strategies to set research priorities in these areas.