Due to the changes in delivering medical care during the Coronavirus disease 2019 (COVID‐19) pandemic, such as the heavy reliance on telehealth, it is worth exploring if this is suitable when treating complex wounds. A literature rapid review was performed to explore the existing evidence around alternative service delivery modalities. While there are organisations that have successful telehealth systems and infrastructure, for services that do not already widely use telehealth it is difficult to implement a standardised system in the current state of emergency. The evidence reviewed demonstrates that telehealth appears to currently have a limited place in chronic wound management; therefore, standardisation on determining suitability in conjunction with evaluation of telehealth during this period is needed to shape implementation of telehealth systems in the future.
Detailed population-based data are essential to understanding the epidemiology of diabetes and its clinical course. This article describes the Funen Diabetes Database (FDDB). The purpose of the FDDB was to serve as a shared electronic medical record system for healthcare professionals treating patients with diabetes. The cohort can also be used for research.
The FDDB covers a geographical area of almost 500 000 Danish inhabitants. It currently includes 3691 patients with type 1 diabetes, 19 085 patients with type 2 diabetes, 292 patients with other types of diabetes and 5992 patients with an unknown type of diabetes. Patients have been continuously enrolled from general practitioners and endocrinology departments in the Funen area in Denmark since 2003. Patients undergo a clinical work-up at their first diabetes contact and during follow-up visits. The information collected includes type of diabetes contact, blood pressure, height, weight, lifestyle factors (smoking, exercise), laboratory records (eg, haemoglobin A1c and cholesterol levels), results from foot examinations (eg, pulse, cutaneous sensitivity and ankle brachial index), results from eye examinations (eg, degree of retinopathy assessed by retinal photo and eye examination), glucose-lowering drugs and diabetic complications.
The FDDB cohort was followed for a total of 212 234 person-years up to 2016. A cross-sectional study described the prevalence of diabetic retinopathy and its associated risk factors. The clinical outcomes of patients with type 1 diabetes, type 2 diabetes and latent autoimmune diabetes in adults have been assessed. Linkage to population-based medical registries with complete follow-up has enabled the collection of extensive continuous data on general practice contacts, diagnoses and procedures from hospital contacts, medication use and mortality.
The FDDB serves as a strong data resource that will be used in future studies of diabetes epidemiology with focus on occurrence, risk factors, treatment, complications and prognosis.
Arthroscopic partial meniscectomy (APM) after degenerative meniscus tears is one of the most frequently performed surgeries in orthopaedics. Although several randomised controlled trials (RCTs) have been published that showed no clear benefit compared with sham treatment or non-surgical treatment, the incidence of APM remains high. The common perception by most orthopaedic surgeons is that there are subgroups of patients that do need APM to improve, and they argue that each study sample of the existing trials is not representative for the day-to-day patients in the clinic. Therefore, the objective of this individual participant data meta-analysis (IPDMA) is to assess whether there are subgroups of patients with degenerative meniscus lesions who benefit from APM in comparison with non-surgical or sham treatment.
An existing systematic review will be updated to identify all RCTs worldwide that evaluated APM compared with sham treatment or non-surgical treatment in patients with knee symptoms and degenerative meniscus tears. Time and effort will be spent in contacting principal investigators of the original trials and encourage them to collaborate in this project by sharing their trial data. All individual participant data will be validated for missing data, internal data consistency, randomisation integrity and censoring patterns. After validation, all datasets will be combined and analysed using a one-staged and two-staged approach. The RCTs’ characteristics will be used for the assessment of clinical homogeneity and generalisability of the findings. The most important outcome will be the difference between APM and control groups in knee pain, function and quality of life 2 years after the intervention. Other outcomes of interest will include the difference in adverse events and mental health.
All trial data will be anonymised before it is shared with the authors. The data will be encrypted and stored on a secure server located in the Netherlands. No major ethical concerns remain. This IPDMA will provide the evidence base to update and tailor diagnostic and treatment protocols as well as (international) guidelines for patients for whom orthopaedic surgeons consider APM. The results will be submitted for publication in a peer-reviewed journal.
Parkinson’s disease is the second most common chronic neurodegenerative condition with bladder dysfunction affecting up to 71%. Symptoms affect quality of life and include urgency, frequency, hesitancy, nocturia and incontinence. Addressing urinary dysfunction is one of the top 10 priority research areas identified by the James Lind Alliance and Parkinson’s UK.
Conduct a randomised controlled trial (RCT) targeting people with Parkinson’s disease (PwP) who have self-reported problematic lower urinary tract symptoms, investigating the effectiveness of transcutaneous tibial nerve stimulation (TTNS) compared with sham TTNS. Implement a standardised training approach and package for the correct application of TTNS. Conduct a cost-effectiveness analysis of TTNS compared with sham TTNS.
An RCT of 6 weeks with twice weekly TTNS or sham TTNS. Participants will be recruited in 12 National Health Service neurology/movement disorder services, using a web-based randomisation system, and will be shown how to apply TTNS or sham TTNS. Participants will receive a weekly telephone call from the researchers during the intervention period. The trial has two coprimary outcome measures: International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form and the International Prostate Symptom Score. Secondary outcomes include a 3-day bladder diary, quality of life, acceptability and fidelity and health economic evaluation. Outcomes will be measured at 0, 6 and 12 weeks.
A sample size of 208 randomised in equal numbers to the two arms will provide 90% power to detect a clinically important difference of 2.52 points on the Internatioanl Consultation on Incontinence Questionnaire - Short Form (ICIQ-SF) and of 3 points in the International Prostate Symptom Score total score at 12 weeks at 5% significance level, based on an SD of 4.7 in each arm and 20% attrition at 6 weeks. Analysis will be by intention to treat and pre defined in a statistical analysis plan
East of Scotland Research Ethics Service (EoSRES), 18/ES00042, obtained on 10 May 2018. The trial will allow us to determine effectiveness, safety, cost and acceptability of TTNS for bladder dysfunction in PWP. Results will be published in open access journals; lay reports will be posted to all participants and presented at conferences.
To demonstrate how data-driven variability methods can be used to identify changes in disease recording in two English electronic health records databases between 2001 and 2015.
Repeated cross-sectional analysis that applied data-driven temporal variability methods to assess month-by-month changes in routinely collected medical data. A measure of difference between months was calculated based on joint distributions of age, gender, socioeconomic status and recorded cardiovascular diseases. Distances between months were used to identify temporal trends in data recording.
400 English primary care practices from the Clinical Practice Research Datalink (CPRD GOLD) and 451 hospital providers from the Hospital Episode Statistics (HES).
The proportion of patients (CPRD GOLD) and hospital admissions (HES) with a recorded cardiovascular disease (CPRD GOLD: coronary heart disease, heart failure, peripheral arterial disease, stroke; HES: International Classification of Disease codes I20-I69/G45).
Both databases showed gradual changes in cardiovascular disease recording between 2001 and 2008. The recorded prevalence of included cardiovascular diseases in CPRD GOLD increased by 47%–62%, which partially reversed after 2008. For hospital records in HES, there was a relative decrease in angina pectoris (–34.4%) and unspecified stroke (–42.3%) over the same time period, with a concomitant increase in chronic coronary heart disease (+14.3%). Multiple abrupt changes in the use of myocardial infarction codes in hospital were found in March/April 2010, 2012 and 2014, possibly linked to updates of clinical coding guidelines.
Identified temporal variability could be related to potentially non-medical causes such as updated coding guidelines. These artificial changes may introduce temporal correlation among diagnoses inferred from routine data, violating the assumptions of frequently used statistical methods. Temporal variability measures provide an objective and robust technique to identify, and subsequently account for, those changes in electronic health records studies without any prior knowledge of the data collection process.
End-stage kidney disease (ESKD) is a major public health problem affecting more than 2 million people worldwide. It is one of the most severe chronic non-communicable diseases. Haemodialysis (HD) is the most common therapeutic option but is also associated with a risk of cardiovascular events, hospitalisation and suboptimal quality of life. Over the past decades, haemodiafiltration (HDF) has become available. Although high-dose HDF has shown some promising survival advantage compared to conventional HD, the evidence remains controversial. A Cochrane systematic review found, in low-quality trials, with various convective forms of dialysis, a reduction in cardiovascular, but not all-cause mortality and the effects on non-fatal cardiovascular events and hospitalisation were uncertain. In contrast, an individual patient data analysis suggested that high-dose HDF reduced both all-cause and cardiovascular mortality compared to HD. In view of these discrepant results, a definitive trial is required to determine whether high-dose HDF is preferable to high-flux HD. The comparison of high-dose HDF with high-flux HD (CONVINCE) study will assess the benefits and harms of high-dose HDF versus a conventional high-flux HD in adults with ESKD.
This international, prospective, open label, randomised controlled trial aims to recruit 1800 ESKD adults treated with HD in nine European countries. Patients will be randomised 1:1 to high-dose HDF versus continuation of conventional high-flux HD. The primary outcome will be all-cause mortality at 3 years’ follow-up. Secondary outcomes will include cause-specific mortality, cardiovascular events, all-cause and infection-related hospitalisations, patient-reported outcomes (eg, health-related quality of life) and cost-effectiveness.
The CONVINCE study will address the question of benefits and harms of high-dose HDF compared to high-flux HD for kidney replacement therapy in patients with ESKD with a focus on survival, patient perspectives and cost-effectiveness.
Netherlands National Trial Register (NTR 7138).
To measure the paediatric user and prescription prevalence in inpatient and ambulatory settings in South Korea, Hong Kong, Taiwan, Japan and Australia by age and gender. A further objective was to list the most commonly used drugs per drug class, per country.
Hospital inpatient and insurance paediatric healthcare data from the following databases were used to conduct this descriptive drug utilisation study: (i) the South Korean Ajou University School of Medicine database; (ii) the Hong Kong Clinical Data Analysis and Reporting System; (iii) the Japan Medical Data Center; (iv) Taiwan’s National Health Insurance Research Database and (v) the Australian Pharmaceutical Benefits Scheme. Country-specific data were transformed into the Observational Medical Outcomes Partnership Common Data Model.
Children (≤18 years) with at least 1 day of observation in any of the respective databases from January 2009 until December 2013 were included.
For each drug class, we assessed the per-protocol overall user and prescription prevalence rates (per 1000 persons) per country and setting.
Our study population comprised 1 574 524 children (52.9% male). The highest proportion of dispensings was recorded in the youngest age category (
Country-specific paediatric drug utilisation patterns were described, ranked and compared between four East Asian countries and Australia. The widespread use of mucolytics in East Asia warrants further investigation.
To explore the intentions of nurses to respond to requests for legal assisted‐dying.
As more Western nations legalize assisted‐dying, requests for access will increase across clinical domains. Understanding the intentions of nurses to respond to such requests is important for the construction of relevant policy and practice guidelines.
A total of 45 Australian nurses from aged, palliative, intensive, or cancer care settings surveyed in November 2018.
Q‐methodology studying nurses’ evaluations of 49 possible responses to a request for a hastened death. Data consisted of rank‐ordered statements analysed by factor analysis with varimax rotation.
Four distinct types of intentions to respond to requests for assisted‐dying: a) refer and support; b) object to or deflect the request; c) engage and explore the request; or d) assess needs and provide information.
The findings underscore the complexity of intentionality in assisted‐dying nursing practice and differences from other forms of end‐of‐life care, particularly regarding patient advocacy and conscientious objection. This study enables further research to explore determinants of these intentions. It can also assist the development of professional guidance by linking policy and clinical intentions.
Identified a basic range of nurses’ intentions to respond to requests for assisted‐dying, as there was no evidence at present. Developed a fourfold typology of intentions to respond with most nurses intending to engage in practices that support the requestor and sometimes the request itself. A minority would object to discussing the request. The relatively low level of advocacy within the intended responses selected also is distinctly different from other end‐of‐life care research findings. This research could assist nursing associations in jurisdictions transitioning to legal assisted‐dying to develop guidance ways nurses can frame their responses to requests.
To explore practitioner perspectives on the facilitators, barriers and outcomes associated with interdisciplinary rounding practices (IDR).
Interdisciplinary rounding practices is frequently used intervention to promote collaboration and patient‐centred care in hospital units. Previous research supports that having IDR in place can lead to greater perceptions of collaboration and practitioner satisfaction; however, the practice does not always lead to better outcomes for patients. For IDR to be successful, unit leadership needs a greater understanding of facilitators and barriers as perceived by team members. At both the individual and organisational levels, there is limited understanding on what influences the success of IDR. This study seeks to explore factors influencing interdisciplinary rounding and perceived outcomes by team members.
A quasi‐qualitative design was used to address the aim of this study. Four open‐ended questions were emailed to practitioners across fifteen units in two academic health centres. All units identified as having IDR in place.
A directed content analysis of practitioner responses was used to identify key themes. The Standards for Reporting Qualitative Research checklist was consulted for reporting of the results.
A total of 141 practitioners responded to the open‐ended questions. Three themes emerged from the data: (a) setting the stage; (b) the work of the team; and 3) benefits to patient care.
The study provides a nuanced perspective of facilitators, barriers and potential outcomes associated with IDR. Future research is needed to gain additional perspective on the role the organisation plays in promoting a healthy workplace environment as well as providing patient‐centred care.
This study provides insight into facilitators and barriers to conducting interdisciplinary rounding practices in the inpatient setting. Results can be useful to unit leaders and staff that advocate for more collaborative and patient‐centred rounding practices.
The adaptation of guidelines is an increasingly used methodology for the efficient development of contextualised recommendations. Nevertheless, there is no specific reporting guidance. The essential Reporting Items of Practice Guidelines in Healthcare (RIGHT) statement could be useful for reporting adapted guidelines, but it does not address all the important aspects of the adaptation process. The objective of our project is to develop an extension of the RIGHT statement for the reporting of adapted guidelines (RIGHT-Ad@pt Checklist).
To develop the RIGHT-Ad@pt Checklist, we will use a multistep process that includes: (1) establishment of a Working Group; (2) generation of an initial checklist based on the RIGHT statement; (3) optimisation of the checklist (an initial assessment of adapted guidelines, semistructured interviews, a Delphi consensus survey, an external review by guideline developers and users and a final assessment of adapted guidelines); and (4) approval of the final checklist. At each step of the process, we will calculate absolute frequencies and proportions, use content analysis to summarise and draw conclusions, discuss the results, draft a report and refine the checklist.
We have obtained a waiver of approval from the Clinical Research Ethics Committee at the Hospital de la Santa Creu i Sant Pau (Barcelona, Spain). We will disseminate the RIGHT-Ad@pt Checklist by publishing into a peer-reviewed journal, presenting to relevant stakeholders and translating into different languages. We will continuously seek feedback from stakeholders, surveil new relevant evidence and, if necessary, update the checklist.
To investigate whether the introduction of a named general practitioner (GP, family physician) improved patients’ healthcare for patients aged 75 and over in England.
Random sample of 27 500 patients aged 65 to 84 in 2012 within 139 English practices from the Clinical Practice Research Datalink linked with Hospital Episode Statistics.
Prospective cohort approach, measuring patients’ GP consultations and emergency hospital admissions 2 years before/after the intervention. Patients were grouped in (i) aged over 74 and (ii) younger than 75 in both periods in order to compare who were or were not subject to the intervention. Adjusted associations between the named GP scheme, continuity of care and emergency hospital admission were examined using multilevel modelling.
National Health Service policy to introduce a named accountable GP for patients aged over 74 in April 2014.
(A) Continuity of care index-score, (B) risk of emergency hospital admissions, (C) number of emergency hospital admissions.
The intervention was associated with a decrease in continuity index-scores of –0.024 (95% CI –0.030 to –0.018, p
The introduction of the named GP scheme was not associated with improvements in either continuity of care or rates of unplanned hospitalisation.
With the increasing interest in personalised medicine, the use of subgroup analyses is likely to increase. Subgroup analyses are challenging and often misused, possibly leading to false interpretations of the effect. It remains unclear to what extent key organisations warn for such pitfalls and translate current methodological research to detect these effects into research guidelines. The aim of this scoping review is to determine and evaluate the current guidance used by organisations for exploring, confirming and interpreting subgroup effects.
We identified four types of key stakeholder organisations: industry, health technology assessment organisations (HTA), academic/non-profit research organisations and regulatory bodies. After literature search and expert consultation, we identified international and national organisations of each type. For each organisation that was identified, we searched for official research guidance documents and contacted the organisation for additional guidance.
Twenty-seven (45%) of the 60 organisations that we included had relevant research guidance documents. We observed large differences between organisation types: 18% (n=2) of the industry organisations, 64% (n=9) of the HTA organisations, 38% (n=8) of academic/non-profit research organisations and 57% (n=8) of regulatory bodies provided guidance documents. The majority of the documents (n=33, 63%) mentioned one or more challenges in subgroup analyses, such as false positive findings or ecological bias with variations across the organisation types. Statistical recommendations were less common (n=19, 37%) and often limited to a formal test of interaction.
Almost half of the organisations included in this scoping review provided guidance on subgroup effect research in their guidelines. However, there were large differences between organisations in the amount and level of detail of their guidance. Effort is required to translate and integrate research findings on subgroup analysis to practical guidelines for decision making and to reduce the differences between organisations and organisation types.
Originator pharmaceutical companies prolonging the patent of a medicine prevents rivals’ entry to the market and competition. As the entry of generic alternatives usually results in price reduction, any delay in their entry potentially deprives the National Health Service (NHS) of much-needed savings. This study estimates the potential cost savings lost to the NHS as a result of delayed entry of generic low-dose buprenorphine (LDTB) patches in England.
Two case scenarios were modelled to determine the savings from the entry of generic LDTB Butec only between February and August 2016 and the potential savings which could have been achieved if all generic LDTB patches had entered the market at the same time.
The volume of utilisation of branded and generic LDTB in UK primary care was derived from the NHS business services authority website for prescriptions dispensed between February 2015 and January 2018.
Cost savings associated with the entry of generic LDTB.
The cumulative cost savings from the introduction of Butec alone was £0.7 ($0.92) million. The model predicted that if all generic buprenorphine entered the market at the same time with Butec, they could have been achieved a £1.2 ($1.57) million saving. This means that approximately £0.5 ($0.65) million savings was lost to the NHS over the 6-month time period.
The entry of Butec was associated with cost savings. We estimated that more cost savings could have been achieved if other generic LDTB patches had entered the market at the same time to drive competition between rivals. Patent protection strategies which delayed the entry of multiple generics were responsible for the reduced cost savings to the NHS in England.
The college years are a peak period for the onset of common mental disorders. Poor mental health is associated with low academic attainment, physical, interpersonal and cognitive impairments. Universities can use online approaches to screen students for mental disorders and treat those in need. The present study aims to assess the effectiveness of a guided web-based transdiagnostic individually tailored intervention to treat students with symptoms of depression and/or anxiety.
The present study is a randomised controlled trial. Participants are Dutch college students (≥18 years) with mild to moderate depression and/or anxiety symptoms. The intervention is a guided web-based transdiagnostic individually tailored intervention that targets symptoms of depression and/or anxiety. The intervention consists of seven online sessions with a duration ranging from 4 to 7 weeks depending on individual progress. A booster session is administered 4 weeks after the completion of the seventh session. Primary outcome measures are the Patient Health Questionnaire for depression and the Generalised Anxiety Disorder 7-item scale for anxiety. These scales are administered at screening, post-treatment and follow-up assessments (6 and 12 months post-randomisation).
The Medical Ethics Committee of the Vrije Universiteit Medical Centre has approved the protocol (registration number 2016.583, A2017.362andA2018.421). Results of the trial will be published in a peer-reviewed journal.
To compare health-related quality of life and prevalence of chronic diseases in housed and homeless populations.
Cross-sectional survey with an age-matched and sex-matched housed comparison group.
Hostels, day centres and soup runs in London and Birmingham, England.
Homeless participants were either sleeping rough or living in hostels and had a history of sleeping rough. The comparison group was drawn from the Health Survey for England. The study included 1336 homeless and 13 360 housed participants.
Chronic diseases were self-reported asthma, chronic obstructive pulmonary disease (COPD), epilepsy, heart problems, stroke and diabetes. Health-related quality of life was measured using EQ-5D-3L.
Housed participants in more deprived neighbourhoods were more likely to report disease. Homeless participants were substantially more likely than housed participants in the most deprived quintile to report all diseases except diabetes (which had similar prevalence in homeless participants and the most deprived housed group). For example, the prevalence of chronic obstructive pulmonary disease was 1.1% (95% CI 0.7% to 1.6%) in the least deprived housed quintile; 2.0% (95% CI 1.5% to 2.6%) in the most deprived housed quintile; and 14.0% (95% CI 12.2% to 16.0%) in the homeless group. Social gradients were also seen for problems in each EQ-5D-3L domain in the housed population, but homeless participants had similar likelihood of reporting problems as the most deprived housed group. The exception was problems related to anxiety, which were substantially more common in homeless people than any of the housed groups.
While differences in health between housed socioeconomic groups can be described as a ‘slope’, differences in health between housed and homeless people are better understood as a ‘cliff’.
To investigate healthcare costs associated with hyperkalaemia (HK) among patients with chronic kidney disease (CKD), heart failure (HF) or diabetes.
Before–after cohort study of patients with HK and matched patients without HK.
Population-based databases covering primary and secondary care for the entire of Northern Denmark.
Patients with a first incident record of CKD (n=78 372), HF (n=14 233) or diabetes (n=37 479) during 2005–2011. Among all patients experiencing a first HK event (potassium level >5.0 mmol/L), healthcare costs were compared during 6 months before and 6 months after the HK event. The same cost assessment was conducted 6 months before and after a matched index date in a comparison cohort of patients without HK.
Mean costs of hospital care, general practice and dispensed drugs converted to 2018 Euros.
Overall, 17 747 (23%) CKD patients, 5141 (36%) HF patients and 4183 (11%) diabetes patients with a first HK event were identified. More than 40% of all HK patients across the patient groups had subsequent HK events with successively shorter times between the events. In CKD patients, overall mean costs were 5518 higher 6 months after versus before first HK, while 441 higher in matched CKD patients without HK, yielding HK-associated costs of 5077. Corresponding costs associated with a HK event were 6018 in HF patients, and 4862 in diabetes patients.
Among CKD, HF and diabetes patients, an incident HK event was common, and a large proportion of the patients experienced recurrent HK events. Substantial increase in healthcare costs associated with a HK event was observed in the HK patients compared with non-HK patients. These results are important to better understand the potential economic impact of HK among high-risk comorbid patients in a real-wold setting and help inform decision-making for clinicians and healthcare providers.
People with multiple sclerosis (MS) are less physically active, and more sedentary than their peers despite evidence that activity helps to manage MS-related symptoms. Traditional approaches to increasing physical activity, such as exercise programmes, can be challenging for people with MS, especially those with walking disability. Focusing on decreasing prolonged sitting, and increasing light-intensity activities may be more feasible and result in more sustainable behaviour change in persons with MS. This paper describes the rationale and development of a sedentary behaviour intervention targeting persons with MS.
The feasibility and preliminary efficacy of a sedentary behaviour intervention will be tested using a prepost intervention design in 40 adults with MS. The 22-week programme includes a 15-week intervention and a 7-week follow-up. The intervention itself is divided into two stages: Sit-Less and Move-More. The Sit-Less stage is designed to encourage participants to break up prolonged sitting bouts, while the Move-More stage promotes increasing steps per day, in addition to interrupting sitting. The intervention is delivered through individual coaching sessions between an interventionist and a participant, and an accompanying newsletter based on social cognitive theory. A Fitbit is used to monitor activity throughout the programme. Process, resource and management metrics will be recorded (eg, retention, time required for communication during the trial). Sedentary and physical activities and MS-related symptoms are measured before and after the intervention and again during follow-up. Experiences with the programme are explored through an online survey and one-on-one interviews.
The Health Research Ethics Board at the University of Alberta granted permission to conduct this study. Results will be disseminated in scientific journals and conferences, and the MS Society of Alberta. Physical therapists and kinesiologists are important stakeholders and will be targeted during dissemination.
Asthma and chronic obstructive pulmonary disease (COPD) are common respiratory conditions, which result in significant morbidity worldwide. These conditions are associated with a range of non-specific symptoms, which in themselves are a target for health research. Such research is increasingly being conducted using electronic health records (EHRs), but computable phenotype definitions, in the form of code sets or code lists, are required to extract structured data from these large routine databases in a systematic and reproducible way. The aim of this protocol is to specify a systematic review to identify code sets for respiratory symptoms in EHRs research.
MEDLINE and Embase databases will be searched using terms relating to EHRs, respiratory symptoms and use of code sets. The search will cover all English-language studies in these databases between January 1990 and December 2017. Two reviewers will independently screen identified studies for inclusion, and key data will be extracted into a uniform table, facilitating cross-comparison of codes used. Disagreements between the reviewers will be adjudicated by a third reviewer. This protocol has been produced in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol guidelines.
As a review of previously published studies, no ethical approval is required. The results of this review will be submitted to a peer-reviewed journal for publication and can be used in future research into respiratory symptoms that uses electronic healthcare databases.