Health care utilization and costs for children and adults with duchenne muscular dystrophy

Methods used to account for caregivers' sex and gender within studies examining the financial burden of caregivers of children and adolescents : Results from a scoping review

Background

Interest in the financial burden of informal caregivers has been growing. Unfortunately, it remains unclear which method(s) should be used when quantifying this burden.

Purpose

We conducted a scoping review aimed at identifying which methods have been used to conduct such work and quantified their performance. We were also interested in examining how sex and gender considerations were considered within selected studies.

Data Sources

Using a standardized approach, we identified studies published between 2012 and 2022 that aimed to document the financial burden of caregivers to child and adolescent patients. Our search strategy was applied to the MEDLINE, Embase, CINHAL, and Academic Search Premier databases.

Study Selection

Manuscript selection was performed by pairs of reviewers.

Data Extraction

Data extraction was performed by one reviewer with a second reviewer performing quality control. Results were reported using a narrative approach.

Data Synthesis

We identified 9801 unique citations, of which 200 were included in our review. Selected studies covered various disease area (eg, infection/parasitic diseases [n = 31, 16%]) and included quantitative (n = 180, 90%), qualitative (n = 4, 2%) and mixed study designs (n = 16, 8%). Most studies (n = 182, 91%) used questionnaires/surveys, either alone or in combination with other methods, to assess caregivers' financial burden. Less than half (n = 93, 47%) of studies reported on caregivers' sex and none reported on their gender.

Conclusion

We conducted an unrestricted review of published studies examining caregiver's financial burden which allowed us to identify general methodological trends observed in this literature. We believe this work may help improve future studies focusing on this important issue.

Are We Capturing the Socioeconomic Burden of Rare Genetic Disease? A Scoping Review of Economic Evaluations and Cost-of-Illness Studies

BACKGROUND AND OBJECTIVES

Rare diseases have a significant impact on patients, families, the health system, and society. Measuring the socioeconomic burden is crucial to valuing interventions for rare diseases. Healthcare system costs are significant, but so are costs to other government sectors, patients, families, and society. To understand the breadth of costs captured in rare disease studies, we examined the cost categories and elements of socioeconomic burden captured in published studies.

METHODS

A scoping review was conducted using five electronic databases to identify English language economic evaluations and cost-of-illness studies of interventions for rare diseases (2011-21). We mapped costs using a previously developed evidence-informed framework of socioeconomic burden costs for rare disease.

RESULTS

Of 4890 studies identified, 48 economic evaluations and 22 cost-of-illness studies were included. While 18/22 cost-of-illness studies utilized a societal perspective, only 7/48 economic evaluations incorporated societal costs. Most reported cost categories related to medical costs, with medication and hospitalizations being the most common elements for both study designs. Costs borne by patients, families, and society were reported less among economic evaluations than cost-of-illness studies. These included: productivity (10% vs 77%), travel/accommodation (6% vs 68%), government benefits (4% vs 18%), and family impacts (0% vs 50%).

CONCLUSIONS

Contrary to cost-of-illness analyses, most of the included economic evaluations did not account for the hidden burden of rare diseases, that is, costs borne by patients, families, and societies. Including these types of costs in future studies would provide a more comprehensive picture of the burden of disease, providing empirical data to inform how we value and make decisions regarding rare disease interventions, health policy, and resource allocation.

Newborn Screening for the Diagnosis and Treatment of Duchenne Muscular Dystrophy

A pilot newborn screening (NBS) program for Duchenne muscular dystrophy (DMD) study proposes to assess the feasibility of the screening procedure, temporal course of the various steps of screening, and the public acceptability of the program. This is particularly vital to ascertain as DMD is considered a 'non-treatable' disease and thus does not fit the traditional criteria for newborn screening. However, modern perspectives of NBS for DMD are changing and point to possible net benefits for children and their families undertaking NBS for DMD. The aim of this workshop was to establish pathways for the successful implementation and evaluation of a pilot NBS for DMD program in Australia. Consensus was reached as to the rationale for, potential benefits, risks, barriers and facilitators of screening, alongside the establishment of screening protocols and clinical referral pathways.

Estimating Societal Cost of Illness and Patients' Quality of Life of Duchenne Muscular Dystrophy in Egypt

OBJECTIVES

Duchenne muscular dystrophy (DMD) is a rare neuromuscular disease that causes substantial economic burden. This study aims to measure the DMD cost from societal perspective and the quality of life (QOL) of the Egyptian patients.

METHODS

We conducted interviews with caregivers of patients with DMD. The questionnaire included demographics, healthcare resource use, and nonmedical and indirect costs. Total disease burden was estimated with a bottom-up approach. QOL was measured with a disease-specific tool. Costs and utilities were stratified by the disease stage.

RESULTS

Caregivers of 97 patients with DMD were interviewed. The mean annual per-patient cost of $17 485 (SD ± 9240) was estimated resulting in a total burden of $138 217 043 in Egypt. Nonmedical costs made up the largest category representing 54% followed by medical then indirect costs. Informal care made the greatest contribution of nonmedical costs whereas physiotherapy was the largest medical subcategory. Nonmedical costs were highest in stage 3 and lowest at early stages whereas medical costs were almost steady among all stages with differences in individual subcategories. Of all medical costs, 95% were out of pocket. The mean utility score was 0.43 (± 0.31), which decreases with disease progression.

CONCLUSION

Our study quantified the huge economic burden of DMD on the society and how it differs in different stages. Almost the whole burden is paid by households resulting in catastrophic expenditures, which leads to reduced compliance and quality of care. QOL is also severely compromised. Our findings can inform future healthcare policies and economic evaluation of new DMD therapies.

The Relationship between Obesity and Clinical Outcomes in Young People with Duchenne Muscular Dystrophy

Background: Duchenne muscular dystrophy (DMD) is a severe X-linked neuromuscular disorder. Young people with DMD have high rates of obesity. There is emerging evidence that a higher BMI may negatively affect clinical outcomes in DMD. This study aimed to explore the relationship between obesity and clinical outcomes in DMD. Methods: This was a retrospective clinical audit of young people (two–21 years) with DMD. Height and weight were collected to calculate BMI z-scores to classify obesity, overweight and no overweight or obesity (reference category). Cox proportional hazards models determined the impact of obesity at five to nine years on clinical milestones including time to: loss of ambulation, timed function test cut-offs, obstructive sleep apnoea (OSA) diagnosis and first fracture. Results: 158 young people with DMD were included; most (89.9%) were steroid-treated. Mean follow-up was 8.7 ± 4.7 years. Obesity prevalence increased from age five (16.7%) to 11 years (50.6%). Boys with obesity at nine years sustained a fracture earlier (hazard ratio, HR: 2.050; 95% CI: 1.038–4.046). Boys with obesity at six to nine years were diagnosed with OSA earlier (e.g., obesity nine years HR: 2.883; 95% CI: 1.481–5.612). Obesity at eight years was associated with a 10 m walk/run in 7–10 s occurring at an older age (HR: 0.428; 95% CI: 0.207–0.887), but did not impact other physical function milestones. Conclusions: Although 50% of boys with DMD developed early obesity, the impact of obesity on physical function remains unclear. Obesity puts boys with DMD at risk of OSA and fractures at a younger age. Early weight management interventions are therefore important.

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.

Health Care Use of Cardiac Specialty Care in Children With Muscular Dystrophy in the United States

Background

Duchenne and Becker muscular dystrophy are progressive disorders associated with cardiac mortality. Guidelines recommend routine surveillance; we assess cardiac resource use and identify gaps in care delivery.

Methods and Results

Male patients, aged 1 to 18 years, with Duchenne and Becker muscular dystrophy between January 2013 and December 2017 were identified in the IBM MarketScan Research Database. The cohort was divided into <10 and 10 to 18 years of age. The primary outcome was rate of annual health care resource per person year. Resource use was assessed for place of service, cardiac testing, and medications. Adjusted incidence rate ratios (IRRs) were estimated using a Poisson regression model. Medication use was measured by proportion of days covered. There were 1386 patients with a median follow‐up time of 3.0 years (interquartile range, 1.9–4.7 years). Patients in the 10 to 18 years group had only 0.40 (95% CI, 0.35–0.45) cardiology visits per person year and 0.66 (95% CI, 0.62–0.70) echocardiography/magnetic resonance imaging per person year. Older patients had higher rates of inpatient admissions (IRR, 1.46; 95% CI, 1.03–2.09), outpatient cardiology visits (IRR, 2.0; 95% CI, 1.66–2.40), cardiac imaging (IRR, 1.59; 95% CI, 1.40–1.80), and Holter monitoring (IRR, 3.33; 95% CI, 2.35–4.73). A proportion of days covered >80% for angiotensin‐converting enzyme inhibitors/angiotensin receptor blockers was observed in 13.6% (419/3083) of total person years among patients in the 10 to 18 years group.

Conclusions

Children 10 to 18 years of age have higher rates of cardiac resource use compared with those <10 years of age. However, rates in both age groups fall short of guidelines. Opportunities exist to identify barriers to resource use and optimize cardiac care for patients with Duchenne and Becker muscular dystrophy.

Genetic neuromuscular disorders: what is the best that we can do?

The major advances in genetic neuromuscular disorders in the last 30 years have been: (a) identification of the genetic basis for hundreds of these disorders, (b) through knowing the genes, understanding their pathobiology and (c) subsequent implementation of evidence-based treatments for some of the disorders. New genomic technologies are providing precision diagnosis, mode of inheritance and likely prognosis for more patients than ever before. Parents of children with a genetic diagnosis can then use preimplantation or prenatal diagnosis to avoid having further affected children if they wish. But is this the best we can do for genetic neuromuscular disorders? Since the 1980s, it has been argued it would be better to identify Duchenne muscular dystrophy carrier mothers, rather than diagnose their affected sons. Carrier screening for recessive disorders can identify couples with a high chance of having affected children. It allows couples reproductive choice and can prevent infant morbidity and mortality and significant distress for families. Professional bodies in many countries now recommend prospective parents should be informed about carrier screening. Implementing and funding expensive therapies increases the cost-effectiveness of carrier screening, increasing its attractiveness to governments. Best practice for genetic neuromuscular disorders should include equitable access to carrier screening.

Labor market participation and productivity costs for female caregivers of minor male children with Duchenne and Becker muscular dystrophies

INTRODUCTION/AIMS

Duchenne and Becker muscular dystrophies (DBMD) are X-linked neuromuscular disorders characterized by progressive muscle weakness, leading to decreased mobility and multisystem complications. We estimate productivity costs attributable to time spent by a parent caring for a male child under the age of 18 y with DBMD, with particular focus on female caregivers of boys with Duchenne muscular dystrophy (DMD) who have already lost ambulation.

METHODS

Primary caregivers of males with DBMD in the Muscular Dystrophy Surveillance and Research Tracking Network (MD STARnet) were surveyed during 2011-2012 on family quality of life measures, including labor market outcomes. Of 211 respondents, 96 female caregivers of boys with DBMD were matched on state, year of survey, respondent's age, child's age, and number of minor children with controls constructed from Current Population Survey extracts. Regression analysis was used to estimate labor market outcomes and productivity costs.

RESULTS

Caregivers of boys with DBMD worked 296 h less per year on average than caregivers of unaffected children, translating to a $8816 earnings loss in 2020 U.S. dollars. Caregivers of boys with DMD with ≥4 y of ambulation loss had a predicted loss in annualized earnings of $23,995, whereas caregivers of boys with DBMD of the same ages who remained ambulatory had no loss of earnings.

DISCUSSION

Female caregivers of non-ambulatory boys with DMD face additional household budget constraints through income loss. Failure to include informal care costs in economic studies could understate the societal cost-effectiveness of strategies for managing DMD that might prolong ambulation.

Cost-of-illness studies in rare diseases: a scoping review

Objective

The aim of this scoping review was to overview the cost-of-illness studies conducted in rare diseases.

Methods

We searched papers published in English in PubMed from January 2007 to December 2018. We selected cost-of-illness studies on rare diseases defined as those with prevalence lower than 5 per 10,000 cases. Studies were selected by one researcher and verified by a second researcher. Methodological characteristics were extracted to develop a narrative synthesis.

Results

We included 63 cost-of-illness studies on 42 rare diseases conducted in 25 countries, and 9 systematic reviews. Most studies (94%) adopted a prevalence-based estimation, where the predominant design was cross-sectional with a bottom-up approach. Only four studies adopted an incidence-based estimation. Most studies used questionnaires to patients or caregivers to collect resource utilisation data (67%) although an important number of studies used databases or registries as a source of data (48%). Costs of lost productivity, non-medical costs and informal care costs were included in 68%, 60% and 43% of studies, respectively.

Conclusion

This review found a paucity of cost-of-illness studies in rare diseases. However, the analysis shows that the cost-of-illness studies of rare diseases are feasible, although the main issue is the lack of primary and/or aggregated data that often prevents a reliable estimation of the economic burden.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-01815-3.

Cost-of-illness studies in rare diseases: a scoping review

OBJECTIVE

The aim of this scoping review was to overview the cost-of-illness studies conducted in rare diseases.

METHODS

We searched papers published in English in PubMed from January 2007 to December 2018. We selected cost-of-illness studies on rare diseases defined as those with prevalence lower than 5 per 10,000 cases. Studies were selected by one researcher and verified by a second researcher. Methodological characteristics were extracted to develop a narrative synthesis.

RESULTS

We included 63 cost-of-illness studies on 42 rare diseases conducted in 25 countries, and 9 systematic reviews. Most studies (94%) adopted a prevalence-based estimation, where the predominant design was cross-sectional with a bottom-up approach. Only four studies adopted an incidence-based estimation. Most studies used questionnaires to patients or caregivers to collect resource utilisation data (67%) although an important number of studies used databases or registries as a source of data (48%). Costs of lost productivity, non-medical costs and informal care costs were included in 68%, 60% and 43% of studies, respectively.

CONCLUSION

This review found a paucity of cost-of-illness studies in rare diseases. However, the analysis shows that the cost-of-illness studies of rare diseases are feasible, although the main issue is the lack of primary and/or aggregated data that often prevents a reliable estimation of the economic burden.

The adult multidisciplinary respiratory neuromuscular clinic

Many neuromuscular disorders (NMD) are complicated by respiratory failure. These patients are best managed in a multidisciplinary outpatient clinic to provide timely access to the various disciplines they require. The key mainstay of treatment of respiratory failure in patients with NMD is noninvasive ventilation, supported by secretion clearance, speech and language therapy, optimisation of nutrition and the maintenance of mobility. Patients with specific conditions may also require cardiology, neurology, orthopaedics, urology and psychological services. The respiratory NMD multidisciplinary team should also provide access to palliative care, and caregiver health and wellbeing should also be reviewed at clinical reviews. The future of care for the respiratory NMD patient will increasingly involve home services and telehealth and the clinic should be equipped and resourced to deliver these. Although not all health systems will be able to provide all elements of the multidisciplinary team discussed here, this review provides the “ideal” recipe for the adult multidisciplinary team and the evidence base underpinning this from which a clinic can be developed.

Care for neuromuscular-related respiratory failure is complex and is best delivered in a multidisciplinary context. The future will increasingly involve home services and telehealth, and their burden needs to be considered when establishing this service.https://bit.ly/33fNsMT

Measuring quality of life in Duchenne muscular dystrophy: a systematic review of the content and structural validity of commonly used instruments

Duchenne muscular dystrophy (DMD) is an inherited X-linked neuromuscular disorder. A number of questionnaires are available to assess quality of life in DMD, but there are concerns about their validity. This systematic review aimed to appraise critically the content and structural validity of quality of life instruments for DMD. Five databases (EMBASE, MEDLINE, CINAHL, PsycINFO, and Cochrane Library) were searched, with supplementary searches in Google Scholar. We included articles with evidence on the content and/or structural validity of quality of life instruments in DMD, and/or instrument development. Evidence was evaluated against the Consensus-based Standards for the selection of health Measurement INstruments (COSMIN) criteria. Fifty five articles featured a questionnaire assessing quality of life in DMD. Forty instruments were extracted and 26 underwent assessment. Forty-one articles contained evidence on content or structural validity (including 37 development papers). Most instruments demonstrated low quality evidence and unsatisfactory or inconsistent validity in DMD, with the majority not featuring direct validation studies in this population. Only KIDSCREEN received an adequate rating for instrument design and a satisfactory result for content validity based on its development, yet, like the majority of PROMs, the measure has not been directly validated for use in DMD. Further research is needed on the validity of quality of life instruments in DMD, including content and structural validity studies in this population.

Creation of a novel algorithm to identify patients with Becker and Duchenne muscular dystrophy within an administrative database and application of the algorithm to assess cardiovascular morbidity

BACKGROUND

Outcome analyses in large administrative databases are ideal for rare diseases such as Becker and Duchenne muscular dystrophy. Unfortunately, Becker and Duchenne do not yet have specific International Classification of Disease-9/-10 codes. We hypothesised that an algorithm could accurately identify these patients within administrative data and improve assessment of cardiovascular morbidity.

METHODS

Hospital discharges (n=13,189) for patients with muscular dystrophy classified by International Classification of Disease-9 code: 359.1 were identified from the Pediatric Health Information System database. An identification algorithm was created and then validated at three institutions. Multi-variable generalised linear mixed-effects models were used to estimate the associations of length of stay, hospitalisation cost, and 14-day readmission with age, encounter severity, and respiratory disease accounting for clustering within the hospital.

RESULTS

The identification algorithm improved identification of patients with Becker and Duchenne from 55% (code 359.1 alone) to 77%. On bi-variate analysis, left ventricular dysfunction and arrhythmia were associated with increased cost of hospitalisation, length of stay, and mortality (p&lt;0.001). After adjustment, Becker and Duchenne patients with left ventricular dysfunction and arrhythmia had increased length of stay with rate ratio 1.4 and 1.2 (p&lt;0.001 and p=0.004) and increased cost of hospitalization with rate ratio 1.4 and 1.4 (both p&lt;0.001).

CONCLUSIONS

Our algorithm accurately identifies patients with Becker and Duchenne and can be used for future analysis of administrative data. Our analysis demonstrates the significant effects of cardiovascular disease on length of stay and hospitalisation cost in patients with Becker and Duchenne. Better recognition of the contribution of cardiovascular disease during hospitalisation with earlier more intensive evaluation and therapy may help improve outcomes in this patient population.

Health Service Utilization and State Costs Among Adults Aging With Early-Acquired Physical Disabilities in Medicaid Managed Care

Objective: We evaluated the impact of Medicaid managed care (MMC) on health service use and state costs among adults with early-acquired physical disabilities. Method: Using claims data, we tracked utilization of the emergency department (ED), inpatient admissions, outpatient physician visits, and state expenditures on enrollees who transitioned to MMC (n = 881). The inverse propensity score weight and a difference-in-differences regression model were used to estimate the impact of MMC using their counterparts who remained in fee-for-service (n = 1,552) as the comparison group. Results: MMC reduced ED use by 3.2% points/month (p < .001). Relative to younger enrollees (age ⩽45 years), MMC reduced inpatient admissions of older enrollees (age ⩾46 years) by 3.3% points/month (p < .001), and state expenditures by US$839/month (p < .01). Discussion: MMC could reduce the hospital service use of and state spending on enrollees with early-acquired physical disabilities. This impact may vary depending on the enrollees' age.

Duchenne muscular dystrophy and caregiver burden: a systematic review

AIM

To conduct a systematic literature review of caregiver burden in Duchenne muscular dystrophy (DMD).

METHOD

We searched Embase, Web of Science, and PubMed for full-text articles reporting results from studies of caregiver burden in DMD.

RESULTS

We identified 483 unique publications. Of these, 450 were excluded after title and abstract screening, and 12 after full-text review. A total of 21 articles were included for data synthesis. Results encompassing more than 15 aspects of caregiver burden, investigated through surveys and/or interviews across 15 countries, were identified in the literature. Caregiving in DMD was frequently associated with impaired health-related quality of life, poor sleep quality, reduced family function, depression, pain, stress, sexual dysfunction, and/or lower self-esteem, as well as a considerable impact on work life and productivity.

INTERPRETATION

Providing informal care to a patient with DMD can be associated with a substantial burden. Yet, more research is needed to better understand the clinical implications of caregiving in DMD and the relationship between caregiver burden and the progression of the disease. Our data synthesis should be helpful in informing clinical and social support programmes directed to families caring for a patient with DMD.

WHAT THIS PAPER ADDS

A substantial body of evidence describes caregiver burden in Duchenne muscular dystrophy. Little is known of the family burden beyond caregivers' self-assessments.

The New Zealand Neuromuscular Disease Patient Registry; Five Years and a Thousand Patients

The New Zealand Neuromuscular Disease Patient Registry has been recruiting for five years. Its primary aim is to enable people with neuromuscular disease to participate in research including clinical trials. It has contributed data to large anonymised cohort studies and many feasibility studies, and has provided practical information and advice to researchers wanting to work with people with neuromuscular conditions. 1019 people have enrolled since the Registry's launch in August 2011 with over 70 different diagnoses. Of these; 8 patients have been involved in clinical trials, 134 in other disease-specific research and 757 have contributed anonymised data to cohort studies. As a result the Registry is now effectively facilitating almost all neuromuscular research currently taking place in New Zealand.