Gabapentinoids and Risk for Severe Exacerbation in Chronic Obstructive Pulmonary Disease : A Population-Based Cohort Study.

BACKGROUND: North American and European health agencies recently warned of severe breathing problems associated with gabapentinoids, including in patients with chronic obstructive pulmonary disease (COPD), although supporting evidence is limited. OBJECTIVE: To assess whether gabapentinoid use is associated with severe exacerbation in patients with COPD. DESIGN: Time-conditional propensity score-matched, new-user cohort study. SETTING: Health insurance databases from the Régie de l'assurance maladie du Québec in Canada. PATIENTS: Within a base cohort of patients with COPD between 1994 and 2015, patients initiating gabapentinoid therapy with an indication (epilepsy, neuropathic pain, or other chronic pain) were matched 1:1 with nonusers on COPD duration, indication for gabapentinoids, age, sex, calendar year, and time-conditional propensity score. MEASUREMENTS: The primary outcome was severe COPD exacerbation requiring hospitalization. Hazard ratios (HRs) associated with gabapentinoid use were estimated in subcohorts according to gabapentinoid indication and in the overall cohort. RESULTS: The cohort included 356 gabapentinoid users with epilepsy, 9411 with neuropathic pain, and 3737 with other chronic pain, matched 1:1 to nonusers. Compared with nonuse, gabapentinoid use was associated with increased risk for severe COPD exacerbation across the indications of epilepsy (HR, 1.58 [95% CI, 1.08 to 2.30]), neuropathic pain (HR, 1.35 [CI, 1.24 to 1.48]), and other chronic pain (HR, 1.49 [CI, 1.27 to 1.73]) and overall (HR, 1.39 [CI, 1.29 to 1.50]). LIMITATION: Residual confounding, including from lack of smoking information. CONCLUSION: In patients with COPD, gabapentinoid use was associated with increased risk for severe exacerbation. This study supports the warnings from regulatory agencies and highlights the importance of considering this potential risk when prescribing gabapentin and pregabalin to patients with COPD. PRIMARY FUNDING SOURCE: Canadian Institutes of Health Research and Canadian Lung Association.

Trends in new prescription of gabapentinoids and of coprescription with opioids in the 4 nations of the UK, 1993-2017.

We explored potential differences in time trends of gabapentinoid prescription and of opioid coprescription between 1993 and 2017 in the 4 UK nations using the Clinical Practice Research Datalink, a UK primary care database. There were distinct trends in annual rates of new gabapentin and pregabalin prescriptions in Northern Ireland. The rate of new gabapentin prescriptions rapidly increased after 2010 and exceeded that of the other nations by 2017 (rate of 836 [95% confidence interval: 787-887] per 100 000 person-years). Additionally, the rate of new pregabalin prescriptions was higher during the entire study period, reaching a peak of 1139 (95% confidence interval: 1088-1193) per 100 000 person-years in 2010, 5-fold higher than the other nations. Findings in Northern Ireland may be partly attributable to the high burden of anxiety disorders, an indication for pregabalin. Further exploration of reasons for discrepancies in gabapentinoid prescribing between UK nations is warranted.

Concomitant Use of Selective Serotonin Reuptake Inhibitors With Oral Anticoagulants and Risk of Major Bleeding.

Importance: Selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed antidepressants associated with a small increased risk of major bleeding. However, the risk of bleeding associated with the concomitant use of SSRIs and oral anticoagulants (OACs) has not been well characterized. Objectives: To assess whether concomitant use of SSRIs with OACs is associated with an increased risk of major bleeding compared with OAC use alone, describe how the risk varies with duration of use, and identify key clinical characteristics modifying this risk. Design, Setting, and Participants: A population-based, nested case-control study was conducted among patients with atrial fibrillation initiating OACs between January 2, 1998, and March 29, 2021. Patients were from approximately 2000 general practices in the UK contributing to the Clinical Practice Research Datalink. With the use of risk-set sampling, for each case of major bleeding during follow-up, up to 30 controls were selected from risk sets defined by the case and matched on age, sex, cohort entry date, and follow-up duration. Exposures: Concomitant use of SSRIs and OACs (direct OACs and vitamin K antagonists [VKAs]) compared with OAC use alone. Main Outcomes and Measures: The main outcome was incidence rate ratios (IRRs) of hospitalization for bleeding or death due to bleeding. Results: There were 42 190 patients with major bleeding (mean [SD] age, 74.2 [9.3] years; 59.8% men) matched to 1 156 641 controls (mean [SD] age, 74.2 [9.3] years; 59.8% men). Concomitant use of SSRIs and OACs was associated with an increased risk of major bleeding compared with OACs alone (IRR, 1.33; 95% CI, 1.24-1.42). The risk peaked during the initial months of treatment (first 30 days of use: IRR, 1.74; 95% CI, 1.37-2.22) and persisted for up to 6 months. The risk did not vary with age, sex, history of bleeding, chronic kidney disease, and potency of SSRIs. An association was present both with concomitant use of SSRIs and direct OACs compared with direct OAC use alone (IRR, 1.25; 95% CI, 1.12-1.40) and concomitant use of SSRIs and VKAs compared with VKA use alone (IRR, 1.36; 95% CI, 1.25-1.47). Conclusions and Relevance: This study suggests that among patients with atrial fibrillation, concomitant use of SSRIs and OACs was associated with an increased risk of major bleeding compared with OAC use alone, requiring close monitoring and management of risk factors for bleeding, particularly in the first few months of use.

Concomitant Use of Selective Serotonin Reuptake Inhibitors and Oral Anticoagulants and Risk of Major Bleeding: A Systematic Review and Meta-analysis.

BACKGROUND: Selective serotonin reuptake inhibitors (SSRIs), the most prescribed antidepressants, are associated with a modestly increased risk of major bleeding. However, in patients treated with both SSRIs and oral anticoagulants (OACs), the risk of major bleeding may be substantial. OBJECTIVE: To assess the risk of major bleeding associated with concomitant use of SSRIs and OACs, compared with OAC use alone. METHODS: We searched MEDLINE, Embase, PsycINFO, and the Cochrane Central Register of Controlled Trials (from inception to December 1, 2021) for clinical trials and observational studies assessing the association between concomitant use of SSRIs and OACs and the risk of major bleeding. Given sufficient homogeneity of studies, we conducted a random-effects meta-analysis to estimate a pooled hazard ratio (HR) of major bleeding associated with concomitant use of SSRIs and OACs, compared with OAC use alone. RESULTS: The review comprised 14 studies, including 7 cohort and 7 nested case-control studies. Following assessment of clinical and methodological heterogeneity, eight studies with a total of 98,070 patients were eligible for the meta-analysis. The pooled HR of major bleeding associated with concomitant use of SSRIs and OACs was 1.35 (95% confidence interval [CI]: 1.14-1.58). In secondary analyses, the pooled HR for concomitant use of SSRIs and direct OACs was 1.47 (95% CI: 1.03-2.10). CONCLUSION: Concomitant use of SSRIs and OACs was associated with an increased risk of major bleeding. Overall, our findings suggest that physicians may need to tailor treatment according to individual patient risk factors for bleeding when prescribing SSRIs to patients using OACs.

Oral Anticoagulants and the Risk of Dementia in Patients With Nonvalvular Atrial Fibrillation: A Population-Based Cohort Study.

BACKGROUND AND OBJECTIVES: Nonvalvular atrial fibrillation (NVAF) is associated with an increased risk of dementia. Oral anticoagulants (OACs) are essential for stroke prevention in NVAF, and studies have shown a possible protective effect on dementia. However, findings have been inconsistent and hampered by methodological limitations. Thus, we assessed whether the use of OACs is associated with a decreased incidence of dementia in patients with NVAF. In addition, we explored the impact of the cumulative duration of OAC use on the incidence of dementia. METHODS: Using the UK Clinical Practice Research Datalink, we formed a cohort of all patients aged 50 years or older with an incident diagnosis of NVAF between 1988 and 2017 and no prior OAC use, with a follow-up until 2019. Patients were considered unexposed until 6 months after their first OAC prescription for latency considerations and exposed thereafter until the end of follow-up. We used time-dependent Cox regression models to estimate hazard ratios (HRs), adjusted for 54 covariates, with 95% CIs for dementia associated with OAC use, compared with nonuse. We also assessed whether the risk varied with the cumulative duration of OAC use, compared with nonuse, by comparing prespecified exposure categories defined in a time-varying manner and by modeling the HR using a restricted cubic spline. RESULTS: The cohort included 142,227 patients with NVAF, with 8,023 cases of dementia over 662,667 person-years of follow-up (incidence rate 12.1, 95% CI 11.9-12.4 per 1,000 person-years). OAC use was associated with a decreased risk of dementia (HR 0.88, 95% CI 0.84-0.92) compared with nonuse. A restricted cubic spline also indicated a decreased risk of dementia, reaching a low at approximately 1.5 years of cumulative OAC use and stabilizing thereafter. Moreover, OAC use decreased the risk in patients aged 75 years and older (HR 0.84, 95% CI 0.80-0.89), but not in younger patients (HR 0.99, 95% CI 0.90-1.10). DISCUSSION: In patients with incident NVAF, OACs were associated with a decreased risk of dementia, particularly in elderly individuals. This warrants consideration when weighing the risks and benefits of anticoagulation in this population. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that in patients with NVAF, OAC use (vs nonuse) is associated with a decreased risk of dementia.

Exploring human factors in the operating room: scoping review of training offerings for healthcare professionals.

BACKGROUND: Human factors (HF) integration can improve patient safety in the operating room (OR), but the depth of current knowledge remains unknown. This study aimed to explore the content of HF training for the operative environment. METHODS: We searched six bibliographic databases for studies describing HF interventions for the OR. Skills taught were classified using the Chartered Institute of Ergonomics and Human Factors (CIEHF) framework, consisting of 67 knowledge areas belonging to five categories: psychology; people and systems; methods and tools; anatomy and physiology; and work environment. RESULTS: Of 1851 results, 28 studies were included, representing 27 unique interventions. HF training was mostly delivered to interdisciplinary groups (n = 19; 70 per cent) of surgeons (n = 16; 59 per cent), nurses (n = 15; 56 per cent), and postgraduate surgical trainees (n = 11; 41 per cent). Interactive methods (multimedia, simulation) were used for teaching in all studies. Of the CIEHF knowledge areas, all 27 interventions taught 'behaviours and attitudes' (psychology) and 'team work' (people and systems). Other skills included 'communication' (n = 25; 93 per cent), 'situation awareness' (n = 23; 85 per cent), and 'leadership' (n = 20; 74 per cent). Anatomy and physiology were taught by one intervention, while none taught knowledge areas under work environment. CONCLUSION: Expanding HF education requires a broader inclusion of the entirety of sociotechnical factors such as contributions of the work environment, technology, and broader organizational culture on OR safety to a wider range of stakeholders.

Long-Term Risk of Major Bleeding after Discontinuing Anticoagulation for Unprovoked Venous Thromboembolism: A Systematic Review and Meta-analysis.

BACKGROUND: The long-term risk of major bleeding after discontinuing anticoagulant therapy for a first unprovoked venous thromboembolism (VTE) is uncertain. OBJECTIVES: To determine the incidence of major bleeding up to 5 years after discontinuing anticoagulation for a first unprovoked VTE. METHODS: We searched MEDLINE, EMBASE, and Cochrane CENTRAL (from inception to January 2021) to identify relevant randomized controlled trials (RCTs) and prospective cohort studies reporting major bleeding after discontinuing anticoagulation in patients with a first unprovoked or weakly provoked VTE who had completed (IMAGE_)3 months of initial treatment. Unpublished data on major bleeding events and person-years were obtained from authors of included studies to calculate study-level incidence rates. Random-effects meta-analysis was used to pool results across studies. RESULTS: Of 1,123 records identified by the search, 20 studies (17 RCTs) and 8,740 patients were included in the analysis. During 13,011 person-years of follow-up after discontinuing anticoagulation, the pooled incidence of major bleeding (n = 41) and fatal bleeding (n = 7) per 100 person-years was 0.35 (95% confidence interval [CI]: 0.20-0.54) and 0.09 (95% CI: 0.05-0.15). The 5-year cumulative incidence of major bleeding was of 1.0% (95% CI: 0.4-2.4%). The case-fatality rate of major bleeding after discontinuing anticoagulation was 19.9% (95% CI: 10.6-31.1%). CONCLUSION: The risk of major bleeding once anticoagulants are discontinued in patients with a first unprovoked VTE is not zero. Estimates from this study can help clinicians counsel patients about the incremental risk of major bleeding with extended anticoagulation to guide decision making about treatment duration for unprovoked VTE.

Exploring human factors in the operating room: a protocol for a scoping review of training offerings for healthcare professionals.

INTRODUCTION: Applying human factors principles in surgical care has potential benefits for patient safety and care delivery. Although different theoretical frameworks of human factors exist, how providers are being trained in human factors and how human factors are being understood in vivo in the operating room (OR) remain unknown. The aim of this scoping review is to evaluate the application of human factors for the OR environment as described by education and training offerings for healthcare professionals. METHODS AND ANALYSIS: This scoping review will follow the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews guidelines. MEDLINE, Embase, PsycINFO, CINAHL, Health and Psychosocial Instruments and ERIC databases were searched on August 2020 from inception to identify relevant studies that describe the content, application and impact of human factors training for healthcare professionals or trainees who work in or interface with the OR environment. Titles, abstracts and full texts will be independently screened by two authors for eligible studies. Any disagreements will be resolved by discussion or by a third author when disagreement persists. Study information and training characteristics, such as the training tool used and type of learners and teachers, will be charted and summarised, and key themes in human factors training will be identified. Each training offering will be classified under the appropriate knowledge area(s) of human factors described by the Chartered Institute of Ergonomics & Human Factors (CIEHF). Themes that are not captured by the CIEHF framework will be independently recorded by two authors and included based on group discussion and consensus. ETHICS AND DISSEMINATION: Research ethics board approval is not required for this scoping review. The findings of this study will be disseminated at local and national conferences and will be published in a peer-reviewed journal.

Core Outcome Sets for Medium-Chain Acyl-CoA Dehydrogenase Deficiency and Phenylketonuria.

BACKGROUND: Evidence to guide treatment of pediatric medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency and phenylketonuria (PKU) is fragmented because of large variability in outcome selection and measurement. Our goal was to develop core outcome sets (COSs) for these diseases to facilitate meaningful future evidence generation and enhance the capacity to compare and synthesize findings across studies. METHODS: Parents and/or caregivers, health professionals, and health policy advisors completed a Delphi survey and participated in a consensus workshop to select core outcomes from candidate lists of outcomes for MCAD deficiency and PKU. Delphi participants rated the importance of outcomes on a nine-point scale (1-3: not important, 4-6: important but not critical, 7-9: critical). Candidate outcomes were progressively narrowed down over 3 survey rounds. At the workshop, participants evaluated the remaining candidate outcomes using an adapted nominal technique, open discussion, and voting. After the workshop, we finalized the COSs and recommended measurement instruments for each outcome. RESULTS: There were 85, 61, and 53 participants across 3 Delphi rounds, respectively. The candidate core outcome lists were narrowed down to 20 outcomes per disease to be discussed at the consensus workshop. Voting by 18 workshop participants led to COSs composed of 8 and 9 outcomes for MCAD deficiency and PKU, respectively, with measurement recommendations. CONCLUSIONS: These are the first known pediatric COSs for MCAD deficiency and PKU. Adoption in future studies will help to ensure best use of limited research resources to ultimately improve care for children with these rare diseases.

Outcomes in pediatric studies of medium-chain acyl-coA dehydrogenase (MCAD) deficiency and phenylketonuria (PKU): a review.

BACKGROUND: Inherited metabolic diseases (IMDs) are a group of individually rare single-gene diseases. For many IMDs, there is a paucity of high-quality evidence that evaluates the effectiveness of clinical interventions. Clinical effectiveness trials of IMD interventions could be supported through the development of core outcome sets (COSs), a recommended minimum set of standardized, high-quality outcomes and associated outcome measurement instruments to be incorporated by all trials in an area of study. We began the process of establishing pediatric COSs for two IMDs, medium-chain acyl-CoA dehydrogenase (MCAD) deficiency and phenylketonuria (PKU), by reviewing published literature to describe outcomes reported by authors, identify heterogeneity in outcomes across studies, and assemble a candidate list of outcomes. METHODS: We used a comprehensive search strategy to identify primary studies and guidelines relevant to children with MCAD deficiency and PKU, extracting study characteristics and outcome information from eligible studies including outcome measurement instruments for select outcomes. Informed by an established framework and a previously published pediatric COS, outcomes were grouped into five, mutually-exclusive, a priori core areas: growth and development, life impact, pathophysiological manifestations, resource use, and death. RESULTS: For MCAD deficiency, we identified 83 outcomes from 52 articles. The most frequently represented core area was pathophysiological manifestations, with 33 outcomes reported in 29/52 articles (56%). Death was the most frequently reported outcome. One-third of outcomes were reported by a single study. The most diversely measured outcome was cognition and intelligence/IQ for which eight unique measurement instruments were reported among 14 articles. For PKU, we identified 97 outcomes from 343 articles. The most frequently represented core area was pathophysiological manifestations with 31 outcomes reported in 281/343 articles (82%). Phenylalanine concentration was the most frequently reported outcome. Sixteen percent of outcomes were reported by a single study. Similar to MCAD deficiency, the most diversely measured PKU outcome was cognition and intelligence/IQ with 39 different instruments reported among 82 articles. CONCLUSIONS: Heterogeneity of reported outcomes and outcome measurement instruments across published studies for both MCAD deficiency and PKU highlights the need for COSs for these diseases, to promote the use of meaningful outcomes and facilitate comparisons across studies.

A Scoping Review of Epidemiological, Ergonomic, and Longitudinal Cohort Studies Examining the Links between Stair and Bathroom Falls and the Built Environment.

Stair and bathroom falls contribute to injuries among older adults. This review examined which features of stairs and bathrooms have been assessed in epidemiological, ergonomic, and national aging studies on falls or their risk factors. Epidemiological and ergonomic studies were eligible if published from 2006-2017, written in English, included older persons, and reported built environment measures. The data extracted included the following: study population and design, outcome measures, and stair and bathroom features. National aging studies were eligible if English questionnaires were available, and if data were collected within the last 10 years. Sample characteristics; data collection methods; and data about falls, the environment, and assistive device use were extracted. There were 114 eligible articles assessed-38 epidemiologic and 76 ergonomic. Among epidemiological studies, 2 assessed stair falls only, 4 assessed bathroom falls only, and 32 assessed falls in both locations. Among ergonomic studies, 67 simulated stairs and 9 simulated bathrooms. Specific environmental features were described in 14 (36.8%) epidemiological studies and 73 (96%) ergonomic studies. Thirteen national aging studies were identified-four had stair data and six had bathroom data. Most epidemiologic and national aging studies did not include specific measures of stairs or bathrooms; the built environment descriptions in ergonomic studies were more detailed. More consistent and detailed environmental measures in epidemiologic and national aging studies would better inform fall prevention approaches targeting the built environment.

Long term risk of symptomatic recurrent venous thromboembolism after discontinuation of anticoagulant treatment for first unprovoked venous thromboembolism event: systematic review and meta-analysis.

OBJECTIVES: To determine the rate of a first recurrent venous thromboembolism (VTE) event after discontinuation of anticoagulant treatment in patients with a first episode of unprovoked VTE, and the cumulative incidence for recurrent VTE up to 10 years. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Medline, Embase, and the Cochrane Central Register of Controlled Trials (from inception to 15 March 2019). STUDY SELECTION: Randomised controlled trials and prospective cohort studies reporting symptomatic recurrent VTE after discontinuation of anticoagulant treatment in patients with a first unprovoked VTE event who had completed at least three months of treatment. DATA EXTRACTION AND SYNTHESIS: Two investigators independently screened studies, extracted data, and appraised risk of bias. Data clarifications were sought from authors of eligible studies. Recurrent VTE events and person years of follow-up after discontinuation of anticoagulant treatment were used to calculate rates for individual studies, and data were pooled using random effects meta-analysis. Sex and site of initial VTE were investigated as potential sources of between study heterogeneity. RESULTS: 18 studies involving 7515 patients were included in the analysis. The pooled rate of recurrent VTE per 100 person years after discontinuation of anticoagulant treatment was 10.3 events (95% confidence interval 8.6 to 12.1) in the first year, 6.3 (5.1 to 7.7) in the second year, 3.8 events/year (95% confidence interval 3.2 to 4.5) in years 3-5, and 3.1 events/year (1.7 to 4.9) in years 6-10. The cumulative incidence for recurrent VTE was 16% (95% confidence interval 13% to 19%) at 2 years, 25% (21% to 29%) at 5 years, and 36% (28% to 45%) at 10 years. The pooled rate of recurrent VTE per 100 person years in the first year was 11.9 events (9.6 to 14.4) for men and 8.9 events (6.8 to 11.3) for women, with a cumulative incidence for recurrent VTE of 41% (28% to 56%) and 29% (20% to 38%), respectively, at 10 years. Compared to patients with isolated pulmonary embolism, the rate of recurrent VTE was higher in patients with proximal deep vein thrombosis (rate ratio 1.4, 95% confidence interval 1.1 to 1.7) and in patients with pulmonary embolism plus deep vein thrombosis (1.5, 1.1 to 1.9). In patients with distal deep vein thrombosis, the pooled rate of recurrent VTE per 100 person years was 1.9 events (95% confidence interval 0.5 to 4.3) in the first year after anticoagulation had stopped. The case fatality rate for recurrent VTE was 4% (95% confidence interval 2% to 6%). CONCLUSIONS: In patients with a first episode of unprovoked VTE who completed at least three months of anticoagulant treatment, the risk of recurrent VTE was 10% in the first year after treatment, 16% at two years, 25% at five years, and 36% at 10 years, with 4% of recurrent VTE events resulting in death. These estimates should inform clinical practice guidelines, enhance confidence in counselling patients of their prognosis, and help guide decision making about long term management of unprovoked VTE. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42017056309.

Occult cancer detection in venous thromboembolism: the past, the present, and the future.

Unprovoked venous thromboembolism (VTE) can be the first manifestation of an undiagnosed cancer. Recently published studies have suggested that approximately 4-5% of patients with new unprovoked VTE will be diagnosed with cancer within 12 months of follow-up. Therefore, it is important for clinicians to keep a low threshold of suspicion for occult cancer in this patient population. After an unprovoked VTE diagnosis, patients should undergo a thorough medical history, physical examination, basic laboratory investigations (ie, complete blood count and liver function tests), chest X-ray, as well as age- and gender-specific cancer screening (breast, cervical, colon, and prostate). More intensive cancer screening including additional investigations (eg, computed tomography of the abdomen/pelvis) does not seem to increase the rate of occult cancer detection, decrease cancer-related morbidity, or increase survival or cost-effectiveness.

Long-term risk of recurrence after discontinuing anticoagulants for a first unprovoked venous thromboembolism: protocol for a systematic review and meta-analysis.

INTRODUCTION: For patients with a first unprovoked venous thromboembolism (VTE), the optimal duration of anticoagulation is a crucial clinical dilemma which has yet to be resolved. The decision to stop anticoagulant therapy (AT) after the initial 3-6 months or to continue AT indefinitely, is primarily governed by the long-term risk of recurrence when treatment is discontinued. This risk however, is not well established, hindering decision making. METHODS AND ANALYSIS: We will conduct a systematic review and a meta-analysis of studies involving patients diagnosed with a first, symptomatic unprovoked VTE or VTE provoked by minor transient risk factors, who have completed at least 3 months of initial AT; and who were followed-up for standardised time intervals of 1, 2, 5, 10 and 20 years (±3 months) after stopping AT. We will search (from inception to January 2017) MEDLINE, Embase and the Cochrane library for randomised controlled trials and prospective observational studies. Two reviewers will conduct all screening and data collection independently. The primary outcome of the rate of recurrent VTE at the standardised time intervals will be calculated for each study from the total number of recurrent events and the corresponding number of patient-years of follow-up. We will use a random-effects model to pool study results and report a weighted estimate of the absolute rate of recurrent VTE (events per 100 patient-years) over standardised time intervals of 1, 2, 5, 10 and 20 years after discontinuing anticoagulants. ETHICS AND DISSEMINATION: Ethical approval is not applicable for this study. Findings from this study will be disseminated through peer-reviewed journal publication as well as relevant national and international conference presentations. PROSPERO REGISTRATION NUMBER: CRD42017056309.

Establishing core outcome sets for phenylketonuria (PKU) and medium-chain Acyl-CoA dehydrogenase (MCAD) deficiency in children: study protocol for systematic reviews and Delphi surveys.

BACKGROUND: Inherited metabolic diseases (IMD) are a large group of rare single-gene disorders that are typically diagnosed early in life. There are important evidence gaps related to the comparative effectiveness of therapies for IMD, which are in part due to challenges in conducting randomized controlled trials (RCTs) for rare diseases. Registry-based RCTs present a unique opportunity to address these challenges provided the registries implement standardized collection of outcomes that are important to patients and their caregivers and to clinical providers and healthcare systems. Currently there is no core outcome set (COS) for studies evaluating interventions for paediatric IMD. This protocol outlines a study that will establish COS for each of two relatively common IMD in children, phenylketonuria (PKU) and medium-chain acyl-CoA dehydrogenase (MCAD) deficiency. METHODS: This two-part study is registered with the Core Outcome Measures in Effectiveness Trials (COMET) initiative. Part 1 includes a rapid review and development of an evidence map to identify a comprehensive listing of outcomes reported in past studies of PKU and MCAD deficiency. The review follows established methods for knowledge synthesis, including a comprehensive search strategy, two stages of screening citations against inclusion/exclusion criteria by two reviewers working independently, and extraction of important data elements from eligible studies, including details of the outcomes collected and outcome measurement instruments. The review findings will inform part 2 of our study, a set of Delphi surveys to establish consensus on the highest priority outcomes for each condition. Healthcare providers, families of children with PKU or MCAD deficiency, and health system decision-makers will be invited to participate in two to three rounds of Delphi surveys. The design of the surveys will involve parents of children with IMD who are part of a family advisory forum. DISCUSSION: This protocol is a crucial step in developing the capacity to launch RCTs with meaningful outcomes that address comparative effectiveness questions in the field of paediatric IMD. Such trials will contribute high-quality evidence to inform decision-making by patients and their family members, clinicians, and policy-makers.