Bisphosphonates in Glucocorticoid-Treated Patients With Duchenne Muscular Dystrophy: A Systematic Review and Grading of the Evidence

BACKGROUND AND OBJECTIVES

Bisphosphonates are routinely used to treat osteoporosis in patients with Duchenne muscular dystrophy (DMD), a rare, severely debilitating neuromuscular disease. We sought to synthesize and grade benefits and harms evidence of bisphosphonates in glucocorticoid-treated patients with DMD.

METHODS

In this systematic review (PROSPERO identifier: CRD42020157606), we searched MEDLINE, CINAHL, Embase, PsycINFO, Web of Science, and CENTRAL for articles published from inception up to and including March 31, 2023, reporting results in any language from any study type. Quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations framework.

RESULTS

We identified 19 publications involving 1,010 children and adults from 12 countries across all inhabited continents except South America. We found high-quality evidence that bisphosphonates significantly increase the areal lumbar spine bone mineral density (BMD) Z score in glucocorticoid-treated patients with DMD. The greatest improvements were recorded in controlled settings among patients treated with intravenous zoledronate. Evidence of benefits to fracture risks was inconclusive and/or of low quality, primarily due to lack of controlled data and small samples. Bisphosphonates were generally well-tolerated, although adverse events related to the first infusion (i.e., "acute phase reaction") were frequently reported.

DISCUSSION

There is high-quality evidence supporting the use of bisphosphonates to increase the areal lumbar spine BMD Z score in patients with DMD and glucocorticoid-induced osteoporosis. Our synthesis and grading affirm current recommendations put forward in the 2018 DMD Clinical Care Considerations and should be helpful in raising awareness about anticipated benefits of bisphosphonates, prevailing unmet needs, and potential safety issues in their use.

Self-Reported Health-Related Quality of Life of Children with Spinal Muscular Atrophy: Preliminary Insights from a Nationwide Patient Registry in Germany

BACKGROUND

Spinal muscular atrophy (SMA) is a rare, severely debilitating neuromuscular disease characterized by a wide spectrum of progressive muscular atrophy and weakness.

OBJECTIVES

The objective of this pilot study was to estimate self-assessed health-related quality of life (HRQoL) of children with SMA.

METHODS

Children with SMA were recruited via the German national TREAT-NMD SMA patient registry and asked to self-complete the following rating-scales: KIDSCREEN-27, KINDL, the PedsQL 3.0 Neuromuscular Module (PedsQL 3.0 NMM), EQ-5D-5L, and the Health Utilities Index (HUI). Estimates were stratified by current best motor function of the lower limb and trunk (i.e., non-sitter, sitter, and walker) and SMA type (i.e., type I, II, and III).

RESULTS

In total, 17 children with SMA (mean age: 9.88 years, SD: 4.33 years, range: 5-16 years; 59% female) participated in the study. Across examined strata, the mean KIDSCREEN-27 total score was estimated at between 48.24 and 83.81; the mean KINDL total score at between 60.42 and 76.73; the mean PedsQL 3.0 NMM total score at between 58.00 and 83.83; the mean EQ-5D-5L utility at between 0.31 and 0.99; and the mean HUI-derived utility at between -0.02 and 0.96.

CONCLUSIONS

The results from this pilot study show that German children with SMA, despite significant physical disability, have surprisingly good HRQoL as assessed using KIDSCREEN-27. Yet, many reside in health states associated with low utility. The disease burden was generally higher among non-sitters compared with walkers, and SMA type I compared with type III, but more research is needed to further delineate this variability. Our preliminary findings contribute to the understanding of HRQoL in pediatric patients with SMA and should be helpful to inform the design of future studies of this patient population.

Factors Associated with Respiratory Health and Function in Duchenne Muscular Dystrophy: A Systematic Review and Evidence Grading

BACKGROUND

Despite advances in the medical management of the disease, respiratory involvement remains a significant source of morbidity and mortality in children and adults with Duchenne muscular dystrophy (DMD).

OBJECTIVE

The objective of this systematic literature review was to synthesize and grade published evidence of factors associated with respiratory health and function in DMD.

METHODS

We searched MEDLINE, Embase, and the Cochrane Library for records of studies published from January 1, 2000 (to ensure relevance to current care practices), up until and including December 31, 2022, reporting evidence of prognostic indicators and predictors of disease progression in DMD. The quality of evidence (i.e., very low to high) was assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework.

RESULTS

The bibliographic search strategy resulted in the inclusion of 29 articles. In total, evidence of 10 factors associated with respiratory health and function in patients with DMD was identified: glucocorticoid exposure (high- to very low-quality evidence), DMD mutations (low-quality evidence), DMD genetic modifiers (low-quality evidence), other pharmacological interventions (i.e., ataluren, eteplirsen, idebenone, and tamoxifen) (moderate- to very low-quality evidence), body mass index and weight (low-quality evidence), and functional ability (low-quality evidence).

CONCLUSIONS

In conclusion, we identified a total of 10 factors associated with respiratory health in function in DMD, encompassing both pharmacological therapies, genetic mutations and modifiers, and patient clinical characteristics. Yet, more research is needed to further delineate sources of respiratory heterogeneity, in particular the genotype-phenotype association and the impact of novel DMD therapies in a real-world setting. Our synthesis and grading should be helpful to inform clinical practice and future research of this heavily burdened patient population.

Predictors of Loss of Ambulation in Duchenne Muscular Dystrophy: A Systematic Review and Meta-Analysis

Objective

The objective of this study was to describe predictors of loss of ambulation in Duchenne muscular dystrophy (DMD).

Methods

This systematic review and meta-analysis included searches of MEDLINE ALL, Embase, and the Cochrane Database of Systematic Reviews from January 1, 2000, to December 31, 2022, for predictors of loss of ambulation in DMD. Search terms included "Duchenne muscular dystrophy" as a Medical Subject Heading or free text term, in combination with variations of the term "predictor". Risk of bias was assessed using the Newcastle-Ottawa Scale. We performed meta-analysis pooling of hazard ratios of the effects of glucocorticoids (vs. no glucocorticoid therapy) by fitting a common-effect inverse-variance model.

Results

The bibliographic searches resulted in the inclusion of 45 studies of children and adults with DMD from 17 countries across Europe, Asia, and North America. Glucocorticoid therapy was associated with delayed loss of ambulation (overall meta-analysis HR deflazacort/prednisone/prednisolone: 0.44 [95% CI: 0.40-0.48]) (n = 25 studies). Earlier onset of first signs or symptoms, earlier loss of developmental milestones, lower baseline 6MWT (i.e.,<350 vs. ≥350 metres and <330 vs. ≥330 metres), and lower baseline NSAA were associated with earlier loss of ambulation (n = 5 studies). Deletion of exons 3-7, proximal mutations (upstream intron 44), single exon 45 deletions, and mutations amenable of skipping exon 8, exon 44, and exon 53, were associated with prolonged ambulation; distal mutations (intron 44 and downstream), deletion of exons 49-50, and mutations amenable of skipping exon 45, and exon 51 were associated with earlier loss of ambulation (n = 13 studies). Specific single-nucleotide polymorphisms in CD40 gene rs1883832, LTBP4 gene rs10880, SPP1 gene rs2835709 and rs11730582, and TCTEX1D1 gene rs1060575 (n = 7 studies), as well as race/ethnicity and level of family/patient deprivation (n = 3 studies), were associated with loss of ambulation. Treatment with ataluren (n = 2 studies) and eteplirsen (n = 3 studies) were associated with prolonged ambulation. Magnetic resonance biomarkers (MRI and MRS) were identified as significant predictors of loss of ambulation (n = 6 studies). In total, 33% of studies exhibited some risk of bias.

Conclusion

Our synthesis of predictors of loss of ambulation in DMD contributes to the understanding the natural history of disease and informs the design of new trials of novel therapies targeting this heavily burdened patient population.

Health-related quality of life of children with spinal muscular atrophy in Sweden: A prospective cohort study in the era of disease-modifying therapy

The objective of this study was to estimate change over time in health-related quality of life (HRQoL) of children with spinal muscular atrophy (SMA) in Sweden. Children with SMA were identified via the National Patient Register by the National Board of Health and Welfare in Sweden. Patient HRQoL was caregiver proxy-assessed using the Pediatric Quality of Life Inventory 4.0 Generic Core Scales at baseline, as well as at 6, 12, and 18 months of follow-up. Results were stratified by SMA type. Mothers and fathers to 27 children with SMA (mean patient age: 9.17 years; 59% female) participated in the study. All patients received disease-modifying therapy. At baseline, across SMA types, the mean total score was estimated at between 52.68 and 59.19, Physical Functioning score at between 26.39 and 40.34, Emotional Functioning score at between 66.82 and 68.57, Social Functioning score at between 55.00 and 70.45, and School Functioning score at between 70.45 and 78.33. The mean annual total score change was estimated at -2.03 for SMA type I, 4.11 for SMA type II, and 1.12 for SMA type III. In conclusion, we show that SMA has a detrimental impact on HRQoL that extends above and beyond somatic disability. Children with SMA type II experienced a dramatic increase in HRQoL over time, predominantly related to improvement in physical and social functioning. Our data helps quantify the patient burden of disease and adds to the rapidly expanding body of evidence of the effectiveness of recently approved disease-modifying therapies for SMA.

Lifetime impact of achondroplasia study in Europe (LIAISE): findings from a multinational observational study

BACKGROUND

Achondroplasia, caused by a pathogenic variant in the fibroblast growth factor receptor 3 gene, is the most common skeletal dysplasia. The Lifetime Impact of Achondroplasia Study in Europe (LIAISE; NCT03449368) aimed to quantify the burden of achondroplasia among individuals across a broad range of ages, including adults.

METHODS

Demographic, clinical and healthcare resource use data were collected from medical records of achondroplasia patients enrolled in 13 sites across six European countries in this retrospective, observational study. Descriptive statistics or event rates per 100 person-years were calculated and compared across age groups as well as by history of limb lengthening. Patient-reported outcomes (quality of life [QoL], pain, functional independence, work productivity and activity impairments) were evaluated using questionnaires at the time of enrolment. An exploratory analysis investigated correlations between height (z-score or centimetres) and patient-reported outcomes.

RESULTS

Overall, 186 study patients were included, with a mean age of 21.7 ± 17.3 years (range 5.0-84.4). At least one complication or surgery was reported for 94.6% and 72.0% of patients, respectively, at a rate of 66.6 and 21.5 events per 100 person-years. Diverse medical and surgical complications were reported for all ages in a bimodal distribution, occurring more frequently in the youngest and oldest age groups. A total of 40 patients had previously undergone limb lengthening (capped at 20% per the study protocol). The most frequent surgery types varied by age, in line with complication profiles. Healthcare resource use was high across all age groups, especially among the youngest and oldest individuals, and did not differ substantially according to history of limb lengthening. Compared to general population values, patients reported impaired QoL particularly for physical functioning domains. In addition, patients reported difficulty carrying out daily activities independently and pain starting in childhood. Patient height correlated with multiple patient-reported outcomes.

CONCLUSIONS

The findings of this study suggest that, across an individual's lifetime, achondroplasia is associated with multisystem complications, reduced QoL and functionality, and increased pain. These results highlight the large amount of healthcare resources that individuals with achondroplasia require throughout their lifespans and provide novel insights into current achondroplasia management practices across Europe. Trial registration ClinicalTrials.gov, NCT03449368, Submitted 14 December 2017 - prospectively registered, https://clinicaltrials.gov/ct2/show/record/NCT03449368.

Caregiver Burden of Spinal Muscular Atrophy: A Systematic Review

OBJECTIVE

The objective of our study was to review, synthesize, and grade published evidence of caregiver burden of spinal muscular atrophy (SMA), a rare autosomal-recessive neuromuscular disease.

METHODS

We searched Embase and PubMed for full-text articles published from inception up until 28 February, 2022, reporting results from studies of caregiver burden (i.e., negative aspects of providing informal care) in SMA. Two investigators independently screened article titles and abstracts for eligibility, reviewed full-text versions of selected records, extracted the data, and assessed risk of bias using the Newcastle-Ottawa Scale. The evidence was synthesized to answer the following questions: (1) In which geographical settings have the caregiver burden of SMA been studied? (2) What aspects of the caregiver burden of SMA have been investigated? (3) What instruments have been used to measure the caregiver burden of SMA? (4) What is known of the caregiver burden of SMA? (5) How is the caregiver burden of SMA impacted by available disease-modifying drugs?

RESULTS

We identified 15 publications, covering samples from a total of ten countries (i.e., Australia, Canada, China, France, Germany, Romania, Spain, Turkey, the UK, and the USA), reporting estimates of caregiver burden derived using data recorded via surveys or interviews. The most common instruments used to measure caregiver burden were the Zarit Caregiver Burden Interview, the EQ-5D-5L, and the PedsQL Family Impact Model. Caregiving in SMA was found to be associated with reduced health-related quality of life, impaired family function, depression and anxiety, strain, and stress, as well as a substantial impact on work life and productivity. Evidence of the impact of disease-modifying drugs on caregiver burden in SMA was scarce.

CONCLUSIONS

Caregivers to patients with SMA were found to be subject to a significant burden, including impaired health-related quality of life, reduced work ability and productivity, and financial stress, and many devote a substantial proportion of their time to provide informal care. Yet, the current body of literature is relatively scarce and more research is needed to better understand the clinical implications of informal caregiving in SMA and the relationship between caregiver burden and SMA types, as well as the impact of new disease-modifying treatments. Our synthesis will be helpful in informing clinical and social support programs (e.g., the routine screening of depression among caregivers, as well as financial support schemes to help manage the long-term day-to-day care) directed towards families caring for patients with SMA.

Gene Therapy for Neuromuscular Diseases: Health Economic Challenges and Future Perspectives

Highly efficacious, potentially curative gene therapies holds immense clinical promise, but also present complex challenges. At the time of regulatory approval and health technology assessment (HTA), evidence of efficacy and safety of gene therapies is often uncertain. In addition, research, development, and manufacturing costs, small pools of eligible patients, and the fact that many gene therapies are administered only once means that they frequently are associated with very high “one-off” price points. Although only a limited number of products have been brought to market globally, hundreds of clinical trials of gene therapies, including several of monogenetic neuromuscular diseases, are currently ongoing. Over time, as more and more conditions become amendable to gene therapy, the number of transformative, high-cost treatments is likely to increase considerably. For these reasons, concerns have been raised regarding the suitability of current health policy systems, including HTA frameworks, in ensuring appropriate access to these therapeutic innovations while simultaneously safeguarding value for taxpayers’ money, as well as affordability and sustainability. This review provides a summary overview of current challenges and future perspectives of gene therapies for neuromuscular diseases from a health economic point of view.

Timing of Clinical Interventions in Patients With Duchenne Muscular Dystrophy: A Systematic Review and Grading of Evidence

Background: Clinical medical management guidelines of Duchenne muscular dystrophy (DMD) emphasize prevention and early identification and treatment. Objective: The objective of our study was to review, synthesize, and grade published evidence of the impact of the timing of clinical interventions in DMD. Methods: We searched PubMed, Embase, and the Cochrane Library for records published from inception up until November 19, 2021, reporting evidence of the impact of the timing of clinical interventions in DMD. We assessed the quality of evidence using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework. Results: We included 12 publications encompassing 1,623 patients with DMD from seven countries (Australia, France, Germany, Italy, Japan, the United Kingdom, and the United States of America). Six (50%) studies reported evidence of an impact of the timing of initiation of glucocorticoids on loss of ambulation, cardiomyopathy, fractures, forced vital capacity, and height and BMI; four (33%) of cardiac medication (i.e., angiotensin-converting enzyme inhibitors, β-blockers, and eplerenone) on left ventricular size and function and survival; one (8%) of lower limb surgery on motor quotient and loss of ambulation; and one (8%) of ataluren on lower extremity and motor function. The overall quality of the body of evidence was low. Conclusion: While there is a clinical rationale for anticipatory diagnostic and therapeutic strategies, evidence of the impact of the timing of initiation of treatments in patients with DMD is still emerging. Further research of this topic is warranted to inform treatment guidelines in this indication.

Prognostic indicators of disease progression in Duchenne muscular dystrophy: A literature review and evidence synthesis

BACKGROUND

Duchenne muscular dystrophy (DMD) is a rare, severely debilitating, and fatal neuromuscular disease characterized by progressive muscle degeneration. Like in many orphan diseases, randomized controlled trials are uncommon in DMD, resulting in the need to indirectly compare treatment effects, for example by pooling individual patient-level data from multiple sources. However, to derive reliable estimates, it is necessary to ensure that the samples considered are comparable with respect to factors significantly affecting the clinical progression of the disease. To help inform such analyses, the objective of this study was to review and synthesise published evidence of prognostic indicators of disease progression in DMD. We searched MEDLINE (via Ovid), Embase (via Ovid) and the Cochrane Library (via Wiley) for records published from inception up until April 23 2021, reporting evidence of prognostic indicators of disease progression in DMD. Risk of bias was established with the grading system of the Centre for Evidence-Based Medicine (CEBM).

RESULTS

Our search included 135 studies involving 25,610 patients from 18 countries across six continents (Africa, Asia, Australia, Europe, North America and South America). We identified a total of 23 prognostic indicators of disease progression in DMD, namely age at diagnosis, age at onset of symptoms, ataluren treatment, ATL1102, BMI, cardiac medication, DMD genetic modifiers, DMD mutation type, drisapersen, edasalonexent, eteplirsen, glucocorticoid exposure, height, idebenone, lower limb surgery, orthoses, oxandrolone, spinal surgery, TAS-205, vamorolone, vitlolarsen, ventilation support, and weight. Of these, cardiac medication, DMD genetic modifiers, DMD mutation type, and glucocorticoid exposure were designated core prognostic indicators, each supported by a high level of evidence and significantly affecting a wide range of clinical outcomes.

CONCLUSION

This study provides a current summary of prognostic indicators of disease progression in DMD, which will help inform the design of comparative analyses and future data collection initiatives in this patient population.

Assessment of face validity of a disease model of nonsense mutation Duchenne muscular dystrophy: a multi-national Delphi panel study

OBJECTIVE

The objective of this study was to assess the face validity of a disease model evaluating the cost-effectiveness of ataluren for the treatment of nonsense mutation Duchenne muscular dystrophy (nmDMD).

METHODS

This was a Delphi panel study comprising of physicians with first-hand experience of ataluren for the treatment of nmDMD. Consensus was sought for previously unvalidated model data, including patient health status and quality of life measured using the Health Utility Index (HUI), mortality, informal caregiving, and the expected benefit of early ataluren treatment across four states: (1) ambulatory, (2) non-ambulatory, not yet requiring ventilation support, (3) non-ambulatory, night-time ventilation support, and (4) non-ambulatory, full-time ventilation support.

RESULTS

Nine experts from five countries participated in the Delphi panel. Consensus was obtained for all questions after three panel rounds (except for two HUI-questions concerning hand function [dexterity]). Consensus HUI-derived utilities for state (1) were 1.0000 for ataluren on top of best supportive care (BSC) and 0.7337 for BSC alone. Corresponding estimates for state (2) were 0.3179 and 0.2672, for state (3) 0.1643 and 0.0913, and for state (4) -0.0732 and -0.1163. Consensus mortality rates for states (1), (2), and (3) were 4%, 13%, and 33%, and life expectancy in state (4) was agreed to be 3 years. Panelists further agreed that two informal caregivers typically provide day-to-day care/support to patients with nmDMD, and that starting treatment with ataluren at 2 versus 5 years of age would be expected to delay loss of ambulation by an additional 2 years, and initiation of night-time and full-time ventilation support by an additional 3 years, respectively.

LIMITATIONS

The main limitation concerns the size of the Delphi panel, govern primarily by the rarity of the disease.

CONCLUSION

This study confirms the face validity of key clinical parameters and assumptions underlying the ataluren cost-effectiveness model.

Rasch Analysis of the Pediatric Quality of Life Inventory 4.0 Generic Core Scales Administered to Patients With Duchenne Muscular Dystrophy

OBJECTIVES

The objective of this study was to examine the psychometric properties of the Pediatric Quality of Life Inventory 4.0 Generic Core Scales (PedsQL 4.0 GCS) in Duchenne muscular dystrophy (DMD), a rare, severely debilitating, and ultimately fatal neuromuscular disease.

METHODS

Patients with DMD were recruited from 20 centers across 9 countries as part of the Cooperative International Neuromuscular Research Group Duchenne Natural History Study (NCT00468832). The psychometric properties of the PedsQL 4.0 GCS were examined using Rasch analysis.

RESULTS

In total, 329 patients with DMD (mean age 9 years, range 3-18 years, 75% ambulatory) completed the PedsQL 4.0 GCS. The most difficult instrument items, expressing the greatest loss in health-related quality of life, were those associated with emotional well-being (eg, being teased by other children, feeling sad, and not making friends), as opposed to somatic disability (eg, lifting heavy objects, participating in sports, and running). The mean item and person fit residuals were estimated at 0.301 (SD: 1.385) and -0.255 (1.504), respectively. In total, 87% (20 of 23) of items displayed disordered thresholds, and many exhibited nontrivial dependency. The overall item-trait interaction χ² value was 178 (115 degrees of freedom, P<.001). Our analysis also revealed significant issues with differential item functioning, and by investigating residual principal component loadings, the PedsQL 4.0 GCS total score was found to be multidimensional.

CONCLUSIONS

The PedsQL 4.0 GCS records information clinically relevant to patients with DMD, but the total scale score may not be fit for purpose as a measure health-related quality of life in this disease population.

Costs of Illness of Spinal Muscular Atrophy: A Systematic Review

OBJECTIVES

The objective of our study was to conduct a systematic literature review of estimates of costs of illness of spinal muscular atrophy (SMA).

METHODS

We searched MEDLINE (through PubMed), CINAHL, Embase, Web of Science, National Health Service Economic Evaluation Database, and the National Health Service Health Technology Assessment Database for studies published from inception up until 31 August, 2020, reporting direct medical, direct non-medical, and/or indirect costs of any phenotype of SMA. Two reviewers independently screened records for eligibility, extracted the data, and assessed studies for risk of bias using the Newcastle-Ottawa Scale. Costs were adjusted and converted to 2018 US dollars.

RESULTS

The search identified 14 studies from eight countries (Australia, France, Germany, Italy, Spain, Sweden, the UK, and the USA). The mean per-patient annual direct medical cost of illness was estimated at between $3320 (SMA type III, Italy) and $324,410 (SMA type I, USA), mean per-patient annual direct non-medical cost between $25,880 (SMA types I-III, Spain) and $136,800 (SMA type I, Sweden), and mean per-patient annual indirect cost between $9440 (SMA type I, Germany) and $74,910 (SMA type II, Australia). Most studies exhibited a risk of bias.

CONCLUSIONS

The current body of evidence of costs of illness of SMA is relatively scarce and characterized by considerable variability across geographical settings and disease phenotypes. Our review provides data pertaining to the economic impact of SMA, which is of particular relevance in light of emerging treatments and ongoing research in this field, and underscores the substantial unmet medical need in this patient population.

Economic Costs of Myasthenia Gravis: A Systematic Review

OBJECTIVES

The objective of our study was to conduct a systematic literature review of economic costs (henceforth costs) associated with myasthenia gravis (MG).

METHODS

We searched MEDLINE (through PubMed), CINAHL, Embase, PsycINFO, and Web of Science for studies reporting costs of MG published from inception up until March 18, 2020, without language restrictions. Two reviewers independently screened records for eligibility, extracted the data, and assessed included studies for risk of bias using the Newcastle-Ottawa Scale. Costs were inflated and converted to 2018 United States dollars ($).

RESULTS

The search identified 16 articles for data extraction and synthesis. Estimates of costs of MG were found for samples from eight countries spanning four continents (Europe, North America, South America, and Asia). Across studies, the mean per-patient annual direct medical cost of illness was estimated at between $760 and $28,780, and cost per hospitalization between $2550 and $164,730. The indirect cost of illness was estimated at $80 and $3550. Costs varied considerably by patient characteristics, and drivers of the direct medical cost of illness included intravenous immunoglobulin and plasma exchange, myasthenic crisis, mechanical ventilatory support, and hospitalizations.

CONCLUSIONS

We show that the current body of literature of costs of MG is sparse, limited to a few geographical settings and resource categories, mostly dated, and subject to non-trivial variability, both within and between countries. Our synthesis will help researchers and decision-makers identify gaps in the local health economic context of MG and inform future cost studies and economic evaluations in this patient population.

Activities of daily living in myotonic dystrophy type 1

OBJECTIVES

The objective of this cross-sectional, observational study was to investigate performance of activities of daily living in patients with myotonic dystrophy type 1 (DM1).

MATERIALS AND METHODS

Adults with genetically confirmed DM1 were recruited from Newcastle University (Newcastle upon Tyne, UK) and University College London Hospitals NHS Foundation Trust (London, UK). Data on activities of daily living were recorded through the DM1-ActivC (scale scores range between 0 and 100, where a higher/lower score indicates a higher/lower ability).

RESULTS

Our sample comprised 192 patients with DM1 (mean age: 46 years; 51% female). Patients reported most difficulties with running, carrying and putting down heavy objects, and standing on one leg, and least difficulties with eating soup, washing upper body, and taking a shower. Irrespective of the disease duration (mean: 20 years), most patients were able to perform basic and instrumental activities of daily living (eg personal hygiene and grooming, showering, eating, cleaning and shopping), with the exception of functional mobility/transfer tasks (eg walking uphill and running). The mean DM1-ActivC total score was estimated at 71 (95% CI: 68-74). Estimated progenitor cytosine-thymine-guanine repeat length and age explained 27% of the variance in DM1-ActivC total scores (P < .001).

CONCLUSIONS

We show that DM1 impairs performance of activities of daily living, in particular those requiring a high degree of muscle strength, stability and coordination. Yet, across the evolution of the disease, the majority of patients will still be able to independently perform most basic and instrumental activities of daily living.

Stated preferences for relapsed or refractory mantle cell lymphoma treatments in Sweden and Germany

Background: We aimed to elicit treatment preferences in relapsed/refractory mantle cell lymphoma (r/r MCL). Materials & methods: A discrete-choice experiment comprising six attributes ('overall survival', 'progression-free survival', 'fatigue', 'nausea', 'risk of serious infections' and 'treatment administration') was administered to r/r MCL patients, physicians and the general population (GP) in Sweden and Germany. Results: 18 patients, 68 physicians and 191 GP members participated. 'Overall survival' was the most important attribute, followed by 'risk of serious infection' and 'progression-free survival' among physicians and the GP. In contrast, 'treatment administration' was the second most important attribute to patients, followed by 'risk of serious infection.' Conclusion: Preferences for characteristics differentiating treatments of r/r MCL varies between patients, physicians and members of the GP.

Health-Related Quality of Life in Patients with Adult-Onset Myotonic Dystrophy Type 1: A Systematic Review

Background

Adult-onset myotonic dystrophy type 1 (DM1) is a chronic, multisystem disorder that leads to disability and premature death.

Objectives

The objective of our study was to conduct a systematic literature review of the health-related quality of life (HRQoL) of patients with DM1.

Methods

We searched Embase, Web of Science, and PubMed for English language full-text articles reporting results from studies of HRQoL in patients with adult-onset DM1 published between 1 January 2000 and 21 February 2018. We excluded reviews, editorials, and studies reporting results for a sample with fewer than five patients (to allow for meaningful inference).

Results

The search identified 266 unique publications. Of these, 231 were excluded following title and abstract screening and 16 after full-text review, leaving 19 articles for data synthesis. We found 15 articles measuring the HRQoL of patients with adult-onset DM1 using the 36-Item Short Form Health Survey (SF-36), six using the Individualized Neuromuscular Quality of Life Questionnaire (INQoL), and one using Cantril’s Ladder. Available evidence shows that patient HRQoL is impaired in DM1, mainly due to compromised physical health, but also reveals that substantial heterogeneity exists in estimates across studies.

Conclusions

HRQoL in adult-onset DM1 has been extensively studied using the SF-36 and the INQoL, but current estimates are inconclusive, and little is known of the impact of the disease as measured using other instruments. Our data synthesis should help characterize the patient burden of DM1 and inform future studies of HRQoL in this indication.

Electronic supplementary material

The online version of this article (10.1007/s40271-019-00357-y) contains supplementary material, which is available to authorized users.

Disease burden of myotonic dystrophy type 1

OBJECTIVE

The objective of this cross-sectional, observational study was to investigate the disease burden of myotonic dystrophy type 1 (DM1), a disabling muscle disorder.

METHODS

Adults with DM1 were recruited as part of the PhenoDM1 study from Newcastle University (Newcastle upon Tyne, UK). Disease burden data were recorded through the Individualized Neuromuscular Quality of Life (INQoL) questionnaire. Results were examined by sex and clinical variables [e.g. the six-minute walk test (6MWT), the Mini Mental State Examination, and estimated progenitor and modal allele CTG repeat length].

RESULTS

Our sample consisted of 60 patients with DM1 (mean age: 45 years; 45% female). Muscle weakness and fatigue constituted the two most common disease manifestations, reported by 93% and 90% of patients, respectively, followed by muscle locking (73%). Most patients (> 55%) reported feeling anxious/worried, depressed, frustrated, and/or having low confidence/self-esteem, 23% and 33% indicated substantial impairment of daily and leisure activities, respectively, and 47% did not work as a consequence of the disease. Estimated progenitor CTG length corrected by age correlated surprisingly well with INQoL scores. Differences by sex were generally minor.

CONCLUSION

We show that DM1 is associated with a substantial disease burden resulting in impairment across many different domains of patients' lives, emphasizing the need for a holistic approach to medical management. Our results also show that the INQoL records relevant information about patients with DM1, but that further investigation of the psychometric properties of the scale is needed for meaningful interpretation of instrument scores.

A mini-review and implementation model for using ataluren to treat nonsense mutation Duchenne muscular dystrophy

AIM

Ataluren has been approved for treating nonsense mutation Duchenne muscular dystrophy (nmDMD), and there are currently discussions concerning drug access and applications beyond the development programme. This study provides an overview of nmDMD and ataluren, stipulates clinical rules for treatment initiation and discontinuation and proposes a model for the implementation of orphan drugs in clinical practice in Sweden.

METHODS

This was a targeted mini-review of the literature from 1995 to 2018, which included cohort studies, guidelines, randomised clinical trials, clinical commentaries and reviews. The review covered the pathophysiology, epidemiology and burden of nmDMD and the clinical programme for ataluren.

RESULTS

Based on the current evidence, and our experiences, we recommend that patients with nmDMD should be given ataluren as soon as possible after diagnosis and this treatment should continue until they reach a forced vital capacity of <30%, and, or, a score of at least six on the Brooke upper extremity scale. We propose an implementation model that comprises a coordinating specialist physician and a national expert committee responsible for providing clinical intelligence to ensure appropriate use.

CONCLUSION

Our clinical recommendations and proposed implementation model will inform the optimum medical management of nmDMD in Sweden and help ensure timely, equal access to ataluren and similar orphan drugs.

Standardized Questionnaire for the Measurement, Valuation, and Estimation of Costs of Informal Care Based on the Opportunity Cost and Proxy Good Method

Costs of informal care account for a significant component of total societal costs for many chronic and disabling illnesses. Yet, costs associated with the provision of informal care is seldom included in economic evaluations of new health technologies, increasing the risk of suboptimal decisions on the allocation of resources from the perspective of society. Our objective was to propose a standardized questionnaire for the measurement, valuation, and estimation of caregiver indirect (productivity) and informal care costs as separate mutually exclusive subsets of total costs in cost-of-illness studies and as an input to economic evaluations from the societal perspective. We developed a questionnaire for data collection and step-by-step analysis procedures for resource valuation and cost estimation. Data concerning absenteeism from work and time devoted to informal care were recorded using the recall method. Indirect (productivity) and paid informal care costs were valued and estimated according to the human-capital approach as the loss of production. Unpaid informal care costs were valued and estimated as the loss of leisure time quantified using the opportunity cost and proxy good method. The new questionnaire, titled the Caregiver Indirect and Informal Care Cost Assessment Questionnaire, contains 13 questions regarding caregiver current and previous work status, productivity, and the provision of informal care (stratified by time devoted to household activities, personal care, practical support, and emotional support). The proposed questionnaire should be helpful to inform the design, implementation, and execution of future cost-of-illness studies and economic evaluations from the perspective of society.

The Position of Neuromuscular Patients in Shared Decision Making. Report from the 235th ENMC Workshop: Milan, Italy, January 19-20, 2018

In the era of patient-centered medicine, shared decision-making (SDM) - in which healthcare professionals and patients exchange information and preferences and jointly reach a decision - has emerged as the gold standard model for the provision of formal healthcare. Indeed, in many geographical settings, patients are frequently invited to participate in choices concerning the design and delivery of their medical management. From a clinical perspective, benefits of this type of patient involvement encompass, for example, enhanced treatment satisfaction, improved medical compliance, better health outcomes, and maintained or promoted quality of life. Yet, although the theory and enactment of SDM in healthcare are well-described in the literature [1-3], comparatively less attention has been devoted to contextualizing questions relating to if, when, and how to include patients in decisions within medical research. In this context, patient involvement would be expected to be potentially relevant for and applicable to a wide range of activities and processes, from the identification of research priorities and development of grant applications, to the design of patient information and consent procedures, formulation of interventions, identification and recruitment of study sample populations, feasibility of a clinical trial, identification, selection, and specification of endpoints and outcomes in clinical trials and observational studies, data collection and analysis, and dissemination of results. To this end, 45 clinicians, healthcare professionals, researchers, patients, caregivers, and representatives from regulatory authorities and pharmaceutical companies from 15 different countries met to discuss the level of involvement of patients with neuromuscular diseases, specifically in the following settings of medical research for neuromuscular diseases: i) registries and biobanks; ii) clinical trials; and iii) regulatory processes. In this report, we present summaries of the talks that were given during the workshop, as well as discussion outcomes from the three topic areas listed above.

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.

Personal Income Before and After Diagnosis of Multiple Sclerosis

BACKGROUND

Multiple sclerosis (MS) is associated with serious morbidity and labor force absenteeism, but little is known of the long-term impact of the disease on personal income.

OBJECTIVES

To assess long-term consequences of MS on personal salary and disposable income.

METHODS

Patients with MS in Sweden were identified in a nationwide, disease-specific register and matched with general population controls. We assessed mean annual personal gross salary and disposable income each year before and after index (i.e., the MS diagnosis date) using data from national registers.

RESULTS

The final sample consisted of 5,472 patients and 54,195 controls (mean age 39 years; 70% females). There was no significant difference in gross salary between patients and controls in any year within the pre-index period. In contrast, on average during follow-up post diagnosis, patients with MS had €5,130 less gross salary per year compared with controls, ranging from a loss of €2,430 the first year to €9,010 after 11 years. Within 10 years after index, 45% of patients had at least one record of zero gross salary, compared with 32% for controls. Mean annual disposable income was comparable between patients and controls across follow-up, with significant differences only at years 9 and 10 post-index.

CONCLUSIONS

We show that many patients with MS in Sweden lose their ability to support for themselves financially but still have a relatively high disposable income because of social transfers. Our findings underscore the detrimental impact of MS on affected patients and the considerable economic burden of disease to society.

Psychometric analysis of the pediatric quality of life inventory 3.0 neuromuscular module administered to patients with duchenne muscular dystrophy: A rasch analysis

INTRODUCTION

Our objective in this study was to assess the psychometric properties of the English (UK and USA) version of the Pediatric Quality of Life Inventory 3.0 Neuromuscular Module (PedsQL NMM) administered to patients with Duchenne muscular dystrophy (DMD).

METHODS

Patients with DMD from the UK and the US completed the PedsQL NMM online. The psychometric properties of the instrument were examined using Rasch analysis.

RESULTS

A total of 278 patients completed the PedsQL NMM. Model misfit was identified for 6 of 25 items (item fit residual: mean 0.162, standard deviation [SD] 2.333), 22 of 25 items displayed disordered thresholds, and item dependency was high. The mean person fit residual was estimated at -0.183 (SD 1.475). The Person Separation Index and Cronbach's α were estimated at 0.904 and 0.915, respectively.

DISCUSSION

The English version of the PedsQL NMM may not be a valid measure of health-related quality of life in patients with DMD. Muscle Nerve 58: 367-373, 2018.

Economic Evaluation in Duchenne Muscular Dystrophy: Model Frameworks for Cost-Effectiveness Analysis

BACKGROUND

Several treatments are on the horizon for Duchenne muscular dystrophy (DMD), a terminal orphan disease. In many jurisdictions, decisions regarding pricing and reimbursement of these health technologies comprise evidence of value for money.

OBJECTIVE

The objective of this study was to develop a cost-effectiveness model based on the Duchenne muscular dystrophy Functional Ability Self-Assessment Tool (DMDSAT), a new rating scale created specifically to measure disease progression in clinical practice and trials and model DMD in economic evaluations, and compare it with two alternative model structures.

METHODS

We constructed three Markov cohort state-transition models to evaluate the cost-effectiveness of a hypothetical intervention for DMD versus standard of care in a UK setting. Model I was based on the DMDSAT, model II on stages of disease as defined in the DMD clinical care guidelines and model III on patients' ventilation status. The conceptual model structures were formulated in collaboration with three DMD experts.

RESULTS

All three models were judged to have good validity with regards to the appropriateness of the choice of modelling technique, conceptual representation of the disease, model input data and model outcomes. Across frameworks, lifetime direct medical costs with standard of care ranged between £217,510 and £284,640, total costs between £624,240 and £713,840, and total number of quality-adjusted life-years between 5.96 and 7.17.

CONCLUSIONS

We present a first version of a model for the economic evaluation of treatments for DMD based on the DMDSAT, as well as two alternative frameworks encompassing conventional staging of disease progression. Our findings should be helpful to inform health technology assessments and health economic programmes of future treatments for DMD.

Sick leave and disability pension before and after diagnosis of multiple sclerosis

Background:

Multiple sclerosis (MS) is associated with considerable morbidity and serious disability, but little is known of the long-term impact of the disease on work ability.

Objectives:

To assess sick leave (short-term absence) and disability pension (long-term absence) before and after diagnosis of MS.

Methods:

Patients with MS in Sweden were identified in a nationwide disease-specific register and matched with general population controls. Sick leave and disability pension were measured before and after index (i.e. the MS diagnosis date).

Results:

The final sample comprised 6092 patients and 60,345 controls (mean age 39 years; 70% female). The mean annual prevalence of sick leave ranged from 12% the first year after index to 23% after 11 years among patients and from 13% to 13% among controls. Corresponding estimates for disability pension were 12% and 55% for patients and 7% and 9% for controls. Significant differences in sick leave were observed up to 15 years before index and 3 years for disability pension.

Conclusion:

Patients with MS in Sweden have elevated levels of sick leave and disability pension up to 15 years before disease diagnosis. Our results highlight the burden of disease on affected patients and society and underscore the substantial unmet medical need.

Health-related quality of life in patients with Duchenne muscular dystrophy: a multinational, cross-sectional study

AIM

To estimate health-related quality of life (HRQOL) in patients with Duchenne muscular dystrophy (DMD).

METHOD

HRQOL was assessed using the Health Utilities Index Questionnaire (HUI) and the Pediatric Quality of Life Inventory (PedsQL) neuromuscular module version 3.0 online. Results were stratified by disease stage (early/late ambulatory/non-ambulatory) and caregivers' perceptions of patients' health and mental status.

RESULTS

A total of 770 patient-caregiver pairs (173 German, 122 Italian, 191 UK, and 284 USA) participated. Most caregivers (>84%) perceived their patients as happy/somewhat happy and in excellent/very good/good health, irrespective of current ambulatory class. In contrast, mean patient utility (reflecting public preferences: 0, dead; 1, perfect health) deteriorated with disease course, from 0.75 in early ambulatory males to 0.15 in the most severely affected patients. Mean patient PedsQL scores (0-100, higher score indicating better HRQOL) decreased from 80 to 57 across ambulatory classes.

INTERPRETATION

HRQOL in DMD, measured through public preferences, is substantially impaired in relation to the general population and significantly associated with disease progression. Still, most patients are perceived as happy and in good health by their caregivers, indicating that influential domains of HRQOL remain intact through the disease progression. Our findings emphasize the challenges in measuring HRQOL in a rare, progressive childhood condition such as DMD.

Quantifying the burden of caregiving in Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a rare pediatric neuromuscular disease associated with progressive muscle degeneration and extensive care needs. Our objective was to estimate the caregiver burden associated with DMD. We made cross-sectional assessments of caregiver health-related quality of life (HRQL) and burden using the EuroQol EQ-5D, a Visual Analogue Scale (VAS), the SF-12 Health Survey, and the Zarit Caregiver Burden Interview (ZBI) administered online. Results were stratified by disease stage (early/late ambulatory/non-ambulatory) and caregivers’ rating of patients’ health and mental status. In total, caregivers to 770 patients participated. Mean EQ-5D utility ranged between 0.85 (95 % CI 0.82–0.88) and 0.77 (0.74–0.80) across ambulatory classes and 0.88 (0.85–0.90) and 0.57 (0.39–0.74) across caregivers’ rating of patients’ health and mental status. Mean VAS score was 0.74 (0.73–0.75), mean SF-12 Mental Health Component Summary score 44 (43–45), and mean ZBI score 29 (28–30). Anxiety and depression, recorded in up to 70 % of caregivers depending on patients’ health and mental status, was significantly associated with annual household cost burden (>$5000 vs. <$1000, odds ratio 1.76, 95 % CI 1.18–2.63) and hours of leisure time devoted to informal care per week (25–50 vs. <25 h 2.01, 1.37–2.94; >50 vs. <25 h 3.35, 2.32–4.83) (p < 0.007). We show that caring for a person with DMD can be associated with a substantial burden and impaired HRQL. Our findings suggest that caregivers to patients with DMD should be screened for depression and emphasize the need for a holistic approach to family mental health in the context of chronic childhood disease.

Residual effect after oral bisphosphonate treatment and healthy adherer effects--the Swedish Adherence Register Analysis (SARA)

Little is known of the effect of alendronate and risedronate on osteoporotic fractures after discontinuation of therapy. We found that time on treatment was significantly inversely associated with the incidence of hospitalized fractures during posttreatment follow-up. Our results will inform health economic analysis of osteoporosis interventions.

INTRODUCTION

Real-world persistence to treatment of osteoporosis is well-understood, but little is known of the posttreatment residual effect on fractures. The objective of this study was to investigate the residual effect of alendronate and risedronate on fractures and assess whether a healthy adherer effect confounds the association between persistence and residual anti-fracture effect.

METHODS

A treatment-naïve cohort from the Swedish Prescribed Drug Register was identified through prescriptions for alendronate or risedronate between 2005 and 2009. Persistence was estimated, and patients were stratified by time on treatment (<1 month, 1-6 months, 7-12 months, and >12 months). Survival analysis was used to study hospitalized fractures and mortality up to 18 months after treatment discontinuation.

RESULTS

The crude incidence proportion of fractures the first 6 months after treatment discontinuation ranged from 2.26% (<1 month of treatment) to 1.16% (>12 months). The corresponding estimates for month 7 to 12 after discontinuation was 3.18 to 1.96%, and for month 13 to 18 after discontinuation 2.69 to 1.95%. Adjusted regression results showed that patients persisting with therapy for >12 months had 60% lower fracture risk the first six months after treatment discontinuation (RR 0.40, p = 0.001). Patient characteristics, including prevalent fractures and co-morbidities, and posttreatment mortality were comparable across persistence durations, and we found no evidence of a healthy adherer effect.

CONCLUSIONS

Time on bisphosphonate treatment was significantly inversely associated with the incidence of hospitalized fractures during posttreatment follow-up. We found no evidence of a healthy adherer effect confounding the relationship between treatment persistence and fracture risk.

Compliance to Care Guidelines for Duchenne Muscular Dystrophy

BACKGROUND

International care guidelines for Duchenne muscular dystrophy (DMD) were published in 2010, but compliance in clinical practice is unknown.

OBJECTIVE

The objective of our study was to compare real-world DMD care in Germany, Italy, the UK, and the US with the clinical recommendations.

METHODS

DMD patients from Germany, Italy, the UK, and the US were identified through Translational Research in Europe - Assessment & Treatment of Neuromuscular Diseases (TREAT-NMD) registries and invited with a caregiver to complete a questionnaire with questions regarding DMD-related healthcare. Estimates of care were stratified by disease stage (early/late ambulatory/non-ambulatory) and compared against the care guidelines.

RESULTS

A total of 770 patients (173 German, 122 Italian, 191 UK, and 284 US) completed the questionnaire. Poor compliance to guidelines of routine follow-up by neuromuscular, cardiac, and respiratory specialists, physiotherapy, and access to medical devices and aids were observed in all countries. Less than 27% (209 of 770) of patients met all absolute recommendations, ranging from 9% (11 of 122) in Italy to 37% (70 of 191) in the UK, and from 49% (76 of 155) in the early ambulatory class to 16% (33 of 205) in the late non-ambulatory class.

CONCLUSIONS

We show that the medical management of DMD varies substantially between Germany, Italy, the UK, and the US. Experience of real-world DMD care appears to be in poor agreement with the DMD clinical guidelines and increased compliance is urgently needed to improve treatment outcomes and enable patients to lead fulfilling, independent lives into adulthood.

The burden of Duchenne muscular dystrophy: an international, cross-sectional study

OBJECTIVE

The objective of this study was to estimate the total cost of illness and economic burden of Duchenne muscular dystrophy (DMD).

METHODS

Patients with DMD from Germany, Italy, United Kingdom, and United States were identified through Translational Research in Europe-Assessment & Treatment of Neuromuscular Diseases registries and invited to complete a questionnaire online together with a caregiver. Data on health care use, quality of life, work status, informal care, and household expenses were collected to estimate costs of DMD from the perspective of society and caregiver households.

RESULTS

A total of 770 patients (173 German, 122 Italian, 191 from the United Kingdom, and 284 from the United States) completed the questionnaire. Mean per-patient annual direct cost of illness was estimated at between $23,920 and $54,270 (2012 international dollars), 7 to 16 times higher than the mean per-capita health expenditure in these countries. Indirect and informal care costs were substantial, each constituting between 18% and 43% of total costs. The total societal burden was estimated at between $80,120 and $120,910 per patient and annum, and increased markedly with disease progression. The corresponding household burden was estimated at between $58,440 and $71,900.

CONCLUSIONS

We show that DMD is associated with a substantial economic burden. Our results underscore the many different costs accompanying a rare condition such as DMD and the considerable economic burden carried by affected families. Our description of the previously unknown economic context of a rare disease serves as important intelligence input to health policy evaluations of intervention programs and novel therapies, financial support schemes for patients and their families, and the design of future cost studies.

The comparative gastrointestinal tolerability of proprietary versus generic alendronate in patients treated for primary osteoporosis

OBJECTIVE

The objective of this study was to analyze the comparative gastrointestinal tolerability of proprietary versus generic alendronate in patients treated for primary osteoporosis.

METHODS

The study was based on all patients starting therapy with alendronate in Sweden between 2005 and 2009. The primary outcome measure was the start of treatment with a gastroprotective agent and the secondary outcome was hospitalization for gastrointestinal adverse event (GIAE). The incidence of both outcomes was measured within the first six months after the initiation of the alendronate treatment.

RESULTS

The crude incidence of gastroprotective treatment during the first six months following the start of the alendronate therapy was 5.45% (bootstrapped CI(95) 4.09%-7.19%) and 5.04% (bootstrapped CI(95) 4.74%-5.38%) for patients prescribed proprietary and generic alendronate, respectively. The crude six-month incidence of hospitalization for GIAE was 0.43% (bootstrapped CI(95) 0.14%-1.29%) and 0.71% (bootstrapped CI(95) 0.55%-0.91%) for proprietary and generic alendronate, respectively. Controlling for age, sex, and other available covariates, there was no significant difference in the risk of GIAEs between proprietary and generic alendronate.

CONCLUSIONS

No significant difference in the incidence of GIAEs was identified between patients prescribed proprietary and generic alendronate between 2005 and 2009 in Sweden. More research is needed to provide conclusive evidence of the gastrointestinal tolerability profiles of proprietary and generic alendronate.

The association between automatic generic substitution and treatment persistence with oral bisphosphonates

Automatic generic substitution of alendronate products, used to reduce drug costs, and medication persistence was studied retrospectively between 2006 and 2009. During this period the number of, and the rate of substitution between, alendronate products increased while persistence decreased. Patient preferences should be considered when designing and evaluating generic policies.

INTRODUCTION

Automatic generic substitution (AGS) was implemented in Sweden in 2002. The objective of this study was to investigate the association between AGS and persistence with alendronate treatment of primary osteoporosis in Sweden.

METHODS

An open historical cohort of women and men (n = 36,433) was identified in the Swedish Prescribed Drug Register through filled prescriptions for alendronate or risedronate between 2005 and 2009. Co-morbidity data was extracted from the National Patient Register. The association between AGS and medication persistence was investigated using non-parametric and parametric survival analysis.

RESULTS

Between 2006 and 2009, the number of alendronate products increased from 15 to 25, the proportion of prescriptions constituting a substitution increased from 10.8% to 45.2%, and the proportion of patients persisting with alendronate treatment for 12 months fell from 66.9% to 51.7%. Patients starting alendronate treatment in 2006 had lower risk of stopping treatment compared with those starting in 2007 (HR 1.34, 95% CI 1.29-1.39), 2008 (HR 1.49, 95% CI 1.43-1.55), and 2009 (HR 1.50, 95% CI 1.40-1.60). No difference was observed in persistence with proprietary risedronate during the same period. Individuals who had their alendronate product substituted at the first prescription refill had significantly higher probability of discontinuation (HR 1.25, 95% CI 1.20-1.30).

CONCLUSION

AGS causes increased product substitution which appears to be associated with reduced treatment persistence. Poor health outcomes and associated costs due to forgone drug exposure should be taken into account in the design and evaluation of policies implemented to encourage utilisation of generic medicines.

Adherence to treatment of primary osteoporosis and its association to fractures--the Swedish Adherence Register Analysis (SARA)

SUMMARY

Osteoporosis treatments reduce the risk of fractures. The objective of this study was to investigate adherence to treatment of osteoporosis and its association to fractures in Sweden. Adherence to treatment of osteoporosis in Sweden is poor, and time on treatment was found to be significantly associated with fracture incidence.

INTRODUCTION

The objective of this study was to estimate persistence and compliance to treatment of primary osteoporosis in Sweden. A second aim was to investigate the determinants of non-persistence and the association between adherence and fracture incidence.

METHODS

Patients were identified through filled prescriptions for alendronate, risedronate, strontium ranelate, and raloxifene between 2005 and 2009 from the Swedish Prescribed Drug Register. Persistence was investigated using survival analysis. Medication possession ratio (MPR) was used to measure compliance in persistent patients. The outcome measure in the analysis of adherence and fracture incidence was hospitalized osteoporotic fractures.

RESULTS

The final cohort consisted of 56,586 treatment-naïve patients (mean age 71, 86% women). A total of 51%, 35%, 25%, and 14% were still on treatment (switching allowed) after 1, 2, 3, and 4 years, respectively. Average MPR in persistent patients was 94.2% (CI(95) 94.2-94.3%). Compared with <1 month of therapy, treatment for 1 month to 1 year, 1 to 2 years, and 2 to 3 years was associated with a lower 3-year fracture incidence (HR 0.86, p = 0.091; HR 0.67, p < 0.001; and HR 0.59, p < 0.001, respectively). No significant relationship was identified between MPR and fracture risk.

CONCLUSIONS

Persistence to treatment of osteoporosis in Sweden is poor and approximately 50% of all treatment-naïve patients discontinue therapy within 1 year. Average refill compliance, estimated only while the patients were persistent, was found to be close to perfect. A strong association was identified between treatment persistence and fracture incidence, which calls for action to improve the current situation.

Patient preferences for characteristics differentiating ovarian stimulation treatments

BACKGROUND

Little is known concerning patient preferences for IVF treatments. The objective of this study was to elicit patient preferences for characteristics differentiating ovarian stimulation treatments.

METHODS

Women undergoing IVF were recruited from six clinics in Sweden between May 2010 and December 2010. Included patients completed a study questionnaire consisting of one contingent valuation (CV) question (with six different bids) and 16 conjoint analysis (CA) questions formulated as discrete choices between two hypothetical ovarian stimulation treatments (defined in terms of manufacturing method, method of administration, time required for administration, dose variability and hypothetical price). Patient preferences were derived using multinomial logit modelling.

RESULTS

The final study population consisted of 294 women (mean age of 35). Respondents were willing to pay €360 [95% confidence interval (CI): €340-€390] to receive FSH derived from DNA technology instead of highly purified extract from urine from post-menopausal women, €300 (95% CI: €280-€320) to administer the FSH using a prefilled injection pen instead of a conventional syringe, €30 (95% CI: €20-€40) per saved minute required for administration and €530 (95% CI: €500-€570) to reduce the dose variability from 10-20% to 1-2% (P< 0.001 for all estimates). The result from the CV was similar to the CA.

CONCLUSIONS

Women undergoing IVF place significant value on characteristics differentiating ovarian stimulation treatments. Product-specific aspects should be taken into account by decision-makers when discriminating between commercial gonadotrophins in clinical practice to align health-care decision-making with patient preferences and potentially improve the effectiveness of IVF interventions through enhanced patient satisfaction and treatment compliance. Preferences for treatment characteristics should also be considered in evaluations of ovarian stimulation products to capture their true value from a patient perspective.

Gastrointestinal tolerability and patterns of switching in patients treated for primary osteoporosis: the Swedish Adherence Register Analysis (SARA)

The objective of this study was to describe and analyze the gastrointestinal tolerability and medication switching in patients receiving treatment for primary osteoporosis in Sweden. The study was based on all patients starting therapy with alendronate, risedronate, strontium ranelate, and raloxifene in Sweden between 2005 and 2009. The primary outcome measure was start of treatment with a gastroprotective agent, and the secondary outcome was hospitalization for a gastrointestinal adverse event (GIAE). Switching was analyzed while patients were on treatment. The crude incidence of gastroprotective treatment during the first 6 months after initiation of osteoporosis therapy was 5.14%, 5.93%, 4.25%, and 2.86% for patients prescribed alendronate, risedronate, strontium ranelate, and raloxifene, respectively. Patients prescribed raloxifene had a significantly lower risk of filling a prescription for a gastroprotective agent compared with alendronate. There was no significant difference in the risk of hospitalization for GIAEs. Less than 3% switched therapy while on treatment. Patients prescribed risedronate, strontium ranelate, and raloxifene had a significantly higher risk of switching compared with patients taking alendronate. In conclusion, no significant difference in the incidence of GIAEs was found between patients prescribed alendronate, risedronate, and strontium ranelate. Individuals prescribed raloxifene had a significantly lower risk of GIAEs compared with patients prescribed alendronate. No significant difference was found in the frequency of hospitalization for GIAEs. Switching between osteoporosis medications and drug classes was uncommon. Prescribers should consider the real-world gastrointestinal safety of osteoporosis drugs when choosing between treatment options to potentially improve medication adherence and consequently effectiveness.

The societal burden of poor persistence to treatment of osteoporosis in Sweden

OBJECTIVES

Poor persistence to prescribed treatment regimens is a well-documented health problem. The issue is of particular importance in treatment of chronic diseases, such as osteoporosis. The objective of this study was to estimate the annual societal burden of real-world persistence to treatment of osteoporosis in Sweden. A second aim was to estimate the monetary net benefit of improved persistence.

METHODS

The annual societal burden was evaluated in relation to perfect persistence to a five-year treatment duration and performed using a published Markov model by Ström and colleagues. The target population was extracted from the Swedish Prescribed Drug Register and based on all treatment-naïve patients who started therapy of primary osteoporosis in Sweden during 2009. Five hypothetical interventions were investigated, with improvements in the persistent proportion of between 10% and 50%.

RESULTS

Annually, a total of 1018 fractures were estimated to be caused by non-persistence to treatment of osteoporosis in Sweden. These fractures resulted in a substantial waste of health care resources related to morbidity (€26 million annually) and a loss, in total, of 771 quality-adjusted life-years (QALYs). Using a societal willingness-to-pay for a QALY of €60000, the total annual societal burden, incorporating both monetary consequences and health effects, was estimated at €62.76 million. Given current Swedish cost-effectiveness guidelines, between approximately €225 and €1130 could be spent per patient to increase persistence, depending on the level of improvement (between 10% and 50%).

CONCLUSIONS

The total annual societal burden of current, real-world persistence was estimated at €63 million. The estimated additional fracture-related costs associated with poor persistence were larger than the current total annual expenditure on all osteoporosis medications in Sweden. Poor persistence to treatment of osteoporosis should consequently be acknowledged as an important and costly health problem, and be taken into account when evaluating osteoporosis interventions.