Equity, diversity and inclusion (EDI) in the healthcare field are crucial in meeting the healthcare needs of a progressively diverse society. In fact, a diverse healthcare workforce enables culturally sensitive care, promotes health equity and enhances the understanding of various needs and patients’ viewpoints, potentially resulting in more effective patient treatment and improved patient outcomes. Despite this, information on the effectiveness of policies or programmes promoting EDI in health institutions is scarce. The objective of this systematic review is to assess the effects and outcomes of EDI programmes in healthcare institutions.

We will conduct Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic review of studies on EDI programmes and describe their effects and outcomes in healthcare institutions. We will search PubMed, Scopus, Web of Science, CINAHL and PsycINFO databases. Selected studies will include randomised control trials (RCTs), non-RCTs and cross-sectional studies published either in English or French. Quality appraisal of studies and a narrative synthesis of extracted data will be conducted as well as a meta-analysis if possible. The quality of evidence in this review will be assessed by the Grades of Recommendation, Assessment, Development and Evaluation.

We anticipate that this systematic review will reveal information on the effect of EDI programmes and their outcomes in healthcare institutions. We expect this information will provide insights that will lead to improvements in designing EDI policies and programmes in healthcare institutions.

No ethical clearance is required for this study as no primary data will be collected. The final manuscript will be submitted to a journal for publication. In addition to this, the results of the study will also be disseminated through conference presentations to inform the research and clinical practice.

This protocol has been registered with the International Prospective Register of Systematic Reviews; registration number CRD42024502781.

To compare differences in recruitment and attrition between placebo control randomised trials of surgery, and trials of the same surgical interventions and conditions that used non-operative (non-placebo) controls.

Meta-epidemiological study.

Randomised controlled trials were identified from an electronic search of MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials from their inception date to 21 November 2018.

Placebo control trials evaluating efficacy of any surgical intervention and non-operative control trials of the same surgical intervention were included in this study. 25 730 records were retrieved from our systemic search, identifying 61 placebo control and 38 non-operative control trials for inclusion in analysis.

Primary outcome measures were recruitment and attrition. These were assessed in terms of recruitment rate (number of participants enrolled, as a proportion of those eligible) and overall attrition rate (composite of dropout, loss to follow-up and cross-overs, expressed as proportion of total sample size). Secondary outcome measures included participant cross-over rate, dropout and loss to follow-up.

Unadjusted pooled recruitment and attrition rates were similar between placebo and non-operative control trials. Study characteristics were not significantly different apart from time to primary timepoint which was shorter in studies with placebo controls (365 vs 274 days, p=0.006). After adjusting for covariates (follow-up duration and number of timepoints), the attrition rate of placebo control trials was almost twice as high compared with non-operative controlled-trials (incident rate ratio (IRR) (95% CI) 1.8 (1.1 to 3.0), p=0.032). The incorporation of one additional follow-up timepoint (regardless of follow-up duration) was associated with reduced attrition in placebo control surgical trials (IRR (95% CI) 0.64 (0.52 to 0.79), p

Placebo control trials of surgery have similar recruitment issues but higher attrition compared with non-operative (non-placebo) control trials. Study design should incorporate strategies such as increased timepoints for given follow-up duration to mitigate losses to follow-up and dropout.

CRD42019117364.

Hip osteoarthritis (OA) is a major cause of pain and disability worldwide. Lack of effective therapies may reflect poor knowledge on its aetiology and risk factors, and result in the management of end-stage hip OA with costly joint replacement. The Worldwide Collaboration on OsteoArthritis prediCtion for the Hip (World COACH) consortium was established to pool and harmonise individual participant data from prospective cohort studies. The consortium aims to better understand determinants and risk factors for the development and progression of hip OA, to optimise and automate methods for (imaging) analysis, and to develop a personalised prediction model for hip OA.

World COACH aimed to include participants of prospective cohort studies with ≥200 participants, that have hip imaging data available from at least 2 time points at least 4 years apart. All individual participant data, including clinical data, imaging (data), biochemical markers, questionnaires and genetic data, were collected and pooled into a single, individual-level database.

World COACH currently consists of 9 cohorts, with 38 021 participants aged 18–80 years at baseline. Overall, 71% of the participants were women and mean baseline age was 65.3±8.6 years. Over 34 000 participants had baseline pelvic radiographs available, and over 22 000 had an additional pelvic radiograph after 8–12 years of follow-up. Even longer radiographic follow-up (15–25 years) is available for over 6000 of these participants.

The World COACH consortium offers unique opportunities for studies on the relationship between determinants/risk factors and the development or progression of hip OA, by using harmonised data on clinical findings, imaging, biomarkers, genetics and lifestyle. This provides a unique opportunity to develop a personalised hip OA risk prediction model and to optimise methods for imaging analysis of the hip.

Radical chemoradiotherapy represents the gold standard for locally advanced cervical cancer. However, despite significant progress in improving local tumour control, distant relapse continues to impact overall survival. The development of predictive and prognostic biomarkers is consequently important to risk-stratify patients and identify populations at higher risk of poorer treatment response and survival outcomes. Exploratory study of using Magnetic resonance Prognostic Imaging markers for Radiotherapy In Cervix cancer (EMPIRIC) is a prospective exploratory cohort study, which aims to investigate the role of multiparametric functional MRI (fMRI) using diffusion-weighed imaging (DWI), dynamic contrast-enhanced (DCE) and blood oxygen level-dependent imaging (BOLD) MRI to assess treatment response and predict outcomes in patients undergoing radical chemoradiotherapy for cervical cancer.

The study aims to recruit 40 patients across a single-centre over 2 years. Patients undergo multiparametric fMRI (DWI, DCE and BOLD-MRI) at three time points: before, during and at the completion of external beam radiotherapy. Tissue and liquid biopsies are collected at diagnosis and post-treatment to identify potential biomarker correlates against fMRI. The primary outcome is to evaluate sensitivity and specificity of quantitative parameters derived from fMRI as predictors of progression-free survival at 2 years following radical chemoradiotherapy for cervical cancer. The secondary outcome is to investigate the roles of fMRI as predictors of overall survival at 2 years and tumour volume reduction across treatment. Statistical analyses using regression models and survival analyses are employed to evaluate the relationships between the derived parameters, treatment response and clinical outcomes.

The EMPIRIC study received ethical approval from the NHS Health Research Authority (HRA) on 14 February 2022 (protocol number RD2021-29). Confidentiality and data protection measures are strictly adhered to throughout the study. The findings of this study will be disseminated through peer-reviewed publications and scientific conferences, aiming to contribute to the growing body of evidence on the use of multiparametric MRI in cervical cancer management.

NCT05532930.

Potentially harmful non-steroidal anti-inflammatory drugs (NSAIDs) utilisation persists at undesirable rates worldwide. The purpose of this paper is to review the literature on interventions to de-implement potentially harmful NSAIDs in healthcare settings and to suggest directions for future research.

Scoping review.

PubMed, CINAHL, Embase, Cochrane Central and Google Scholar (1 January 2000 to 31 May 2022).

Studies reporting on the effectiveness of interventions to systematically reduce potentially harmful NSAID utilisation in healthcare settings.

Using Covidence systematic review software, we extracted study and intervention characteristics, including the effectiveness of interventions in reducing NSAID utilisation.

From 7818 articles initially identified, 68 were included in the review. Most studies took place in European countries (45.6%) or the USA (35.3%), with randomised controlled trial as the most common design (55.9%). Interventions were largely clinician-facing (76.2%) and delivered in primary care (60.2%) but were rarely (14.9%) guided by an implementation model, framework or theory. Academic detailing, clinical decision support or electronic medical record interventions, performance reports and pharmacist review were frequent approaches employed. NSAID use was most commonly classified as potentially harmful based on patients’ age (55.8%), history of gastrointestinal disorders (47.1%), or history of kidney disease (38.2%). Only 7.4% of interventions focused on over-the-counter (OTC) NSAIDs in addition to prescription. The majority of studies (76.2%) reported a reduction in the utilisation of potentially harmful NSAIDs. Few studies (5.9%) evaluated pain or quality of life following NSAIDs discontinuation.

Many varied interventions to de-implement potentially harmful NSAIDs have been applied in healthcare settings worldwide. Based on these findings and identified knowledge gaps, further efforts to comprehensively evaluate the effectiveness of interventions and the combination of intervention characteristics associated with effective de-implementation are needed. In addition, future work should be guided by de-implementation theory, focus on OTC NSAIDs and incorporate patient-focused strategies and outcomes, including the evaluation of unintended consequences of the intervention.

Emergency medical services (EMSs) personnel are at high risk for developing work-related musculoskeletal disorders (WMSDs). However, no studies have yet investigated the prevalence and effect of these disorders on the Jordanian EMS personnel. Therefore, this study aimed to determine the prevalence of WMSDs among Jordanian EMS personnel and its associated factors.

This study used a cross-sectional design. Participants were asked to complete a self-administrated and validated questionnaire to measure the WMSDs, including a demographic survey and the Nordic Musculoskeletal Questionnaire. Descriptive and multivariable regression analyses were used.

The Jordanian Civil Defence stations in the main cities of Jordan.

The sample consisted of 435 EMS workers which were obtained across the country of Jordan. A total of 79.0% of the participants were male, with a mean age of 27.9 (±4.3 SD) years.

The pain in the lower back (308, 70.8%) and neck (252, 57.9%) were the most reported in the last 12 months. Furthermore, about half of the participants reported having pain in their upper back (234, 53.8%), knee (227, 52.2%) and shoulder (226, 52.0%) pain in the last 12 months. Overall, WMSDs in at least one body part were significantly associated with age, experience, being a male, increased body mass index and lower educational level.

There is a high prevalence of musculoskeletal complaints among EMS personnel. Multiple variables may be incorporated into a national prevention campaign and professional development programme to educate EMS personnel on avoiding WMSDs.

Fetal alcohol spectrum disorder (FASD) is a neurodevelopmental disorder caused by alcohol exposure during pregnancy. FASD is associated with neurodevelopmental deviations, and 50%–94% of children with FASD meet the Diagnostic and Statistical Manual of Mental Disorders-fifth edition diagnostic criteria for attention deficit hyperactivity disorder (ADHD). There is a paucity of evidence around medication efficacy for ADHD symptoms in children with FASD. This series of N-of-1 trials aims to provide pilot data on the feasibility of conducting N-of-1 trials in children with FASD and ADHD.

A pilot N-of-1 randomised trial design with 20 cycles of stimulant and placebo (four cycles of 2-week duration) for each child will be conducted (n=20) in Melbourne, Australia.

Feasibility and tolerability will be assessed using recruitment and retention rates, protocol adherence, adverse events and parent ratings of side effects. Each child’s treatment effect will be determined by analysing teacher ADHD ratings across stimulant and placebo conditions (Wilcoxon rank). N-of-1 data will be aggregated to provide an estimate of the cohort treatment effect as well as individual-level treatment effects. We will assess the sample size and number of cycles required for a future trial. Potential mediating factors will be explored to identify variables that might be associated with treatment response variability.

The study was approved by the Hospital and Health Service Human Research Ethics Committee (HREC/74678/MonH-2021-269029), Monash (protocol V6, 25 June 2023).

Individual outcome data will be summarised and provided to participating carers and practitioners to enhance care. Group-level findings will be presented at a local workshop to engage stakeholders. Findings will be presented at national and international conferences and published in peer-reviewed journals. All results will be reported so that they can be used to inform prior information for future trials.

NCT04968522.

Improving sustainable transportation options will help cities tackle growing challenges related to population health, congestion, climate change and inequity. Interventions supporting active transportation face many practical and political hurdles. Implementation science aims to understand how interventions or policies arise, how they can be translated to new contexts or scales and who benefits. Sustainable transportation interventions are complex, and existing implementation science frameworks may not be suitable. To apply and adapt implementation science for healthy cities, we have launched our mixed-methods research programme, CapaCITY/É. We aim to understand how, why and for whom sustainable transportation interventions are successful and when they are not.

Across nine Canadian municipalities and the State of Victoria (Australia), our research will focus on two types of sustainable transportation interventions: all ages and abilities bicycle networks and motor vehicle speed management interventions. We will (1) document the implementation process and outcomes of both types of sustainable transportation interventions; (2) examine equity, health and mobility impacts of these interventions; (3) advance implementation science by developing a novel sustainable transportation implementation science framework and (4) develop tools for scaling up and scaling out sustainable transportation interventions. Training activities will develop interdisciplinary scholars and practitioners able to work at the nexus of academia and sustainable cities.

This study received approval from the Simon Fraser University Office of Ethics Research (H22-03469). A Knowledge Mobilization Hub will coordinate dissemination of findings via a website; presentations to academic, community organisations and practitioner audiences; and through peer-reviewed articles.

Diagnostic testing is an important tool to combat the COVID-19 pandemic, yet access to and uptake of testing vary widely 3 years into the pandemic. The WHO recommends the use of COVID-19 self-testing as an option to help expand testing access. We aimed to calculate the cost of providing COVID-19 self-testing across countries and distribution modalities.

We estimated economic costs from the provider perspective to calculate the total cost and the cost per self-test kit distributed for three scenarios that differed by costing period (pilot, annual), the number of tests distributed (actual, planned, scaled assuming an epidemic peak) and self-test kit costs (pilot purchase price, 50% reduction).

We used data collected between August and December 2022 in Brazil, Georgia, Malaysia, Ethiopia and the Philippines from pilot implementation studies designed to provide COVID-19 self-tests in a variety of settings—namely, workplace and healthcare facilities.

Across all five countries, 173 000 kits were distributed during pilot implementation with the cost/test distributed ranging from $2.44 to $12.78. The cost/self-test kit distributed was lowest in the scenario that assumed implementation over a longer period (year), with higher test demand (peak) and a test kit price reduction of 50% ($1.04–3.07). Across all countries and scenarios, test procurement occupied the greatest proportion of costs: 58–87% for countries with off-site self-testing (outside the workplace, for example, home) and 15–50% for countries with on-site self-testing (at the workplace). Staffing was the next key cost driver, particularly for distribution modalities that had on-site self-testing (29–35%) versus off-site self-testing (7–27%).

Our results indicate that it is likely to cost between $2.44 and $12.78 per test to distribute COVID-19 self-tests across common settings in five heterogeneous countries. Cost-effectiveness analyses using these results will allow policymakers to make informed decisions on optimally scaling up COVID-19 self-test distribution programmes across diverse settings and evolving needs.

Recent research has highlighted non-operative management (NOM) as a viable alternative for frail older adults with hip fractures in the final phase of life. This study aims to guide Dutch physicians and hospitals nationwide in a standardised implementation of shared decision-making regarding surgery or NOM in selected frail older adults with a hip fracture.

The patient population for implementation includes frail older adults aged ≥70 years with an acute proximal femoral fracture, nursing home care or a similar level of care elsewhere and at least one additional criterion (ie, malnutrition, severe mobility impairment or ASA≥4). The 2-year implementation study will be conducted in four phases. In phases 1 and 2, barriers and facilitators for implementation will be identified and an implementation protocol, educational materials and patient information will be developed. Phase 3 will involve an implementation pilot in 14 hospitals across the Netherlands. The protocol and educational material will be improved based on healthcare provider and patient experiences gathered through interviews. Phase 4 will focus on upscaling to nationwide implementation and the effect of the implementation on NOM rate will be measured using data from the Dutch Hip Fracture Audit.

The study was exempted by the local Medical Research Ethics Committee (MEC-2023-0270, 10 May 2023) and Medical Ethics Committee United (W23.083, 26 April 2023). The study’s results will be submitted to an open access international peer-reviewed journal. Its protocols, tools and results will be presented at several national and international academic conferences of relevant orthogeriatric (scientific) associations.

NCT06079905 .

Physical restraint (PR) is prescribed in patients receiving invasive mechanical ventilation in the intensive care unit (ICU) to avoid unplanned removal of medical devices. However, it is associated with an increased risk of delirium. We hypothesise that a restrictive use of PR, as compared with a systematic use, could reduce the duration of delirium in ICU patients receiving invasive mechanical ventilation.

The Restrictive use of Restraints and Delirium Duration in ICU (R2D2-ICU) study is a national multicentric, parallel-group, randomised (1:1) open-label, controlled, superiority trial, which will be conducted in 10 ICUs. A total of 422 adult patients requiring invasive mechanical ventilation for an expected duration of at least 48 hours and eligible for prescription of PR will be randomly allocated within 6 hours from intubation to either the restrictive PR use group or the systematic PR use group, until day 14, ICU discharge or death, whichever comes first. In both groups, PR will consist of the use of wrist straps. The primary endpoint will be delirium or coma-free days, defined as the number of days spent alive in the ICU without coma or delirium within the first 14 days after randomisation. Delirium will be assessed using the Confusion Assessment Method-ICU twice daily. Key secondary endpoints will encompass agitation episodes, opioid, propofol, benzodiazepine and antipsychotic drug exposure during the 14-day intervention period, along with a core outcome set of measures evaluated 90 days postrandomisation.

The R2D2-ICU study has been approved by the Comité de Protection des Personnes (CPP) ILE DE FRANCE III—PARIS (CPP19.09.06.37521) on June 10th, 2019). Participant recruitment started on 25 January 2021. Results will be published in international peer-reviewed medical journals and presented at conferences.

NCT04273360.

Pre-eclampsia (PE) affects about 5% of Chinese pregnant women and is a major cause of maternal and perinatal morbidity and mortality. The first trimester screening model developed by the Fetal Medicine Foundation, which uses the Bayes theorem to combine maternal characteristics and medical history together with measurements of biomarkers, has been proven to be effective and has superior screening performance to that of the traditional risk factor-based approach for the prediction of PE. Prophylactic use of low-dose aspirin in women at risk for PE has resulted in a lower incidence of preterm-PE. However, there is no consensus on the preferred aspirin dosage for the prevention of preterm-PE. Evidence has also suggested that metformin has the potential benefit in preventing PE in pregnant women who are at high risk of the disorder.

We present a protocol (V.2.0, date 17 March 2022) for the AVERT trial, which is a multicentre, double-blinded, 3-arm randomised controlled trial (RCT) that uses an effective PE screening programme to explore the optimal dosage of aspirin and the role of metformin for the prevention of PE among high-risk pregnant women in China. We intend to recruit 66 000 singleton pregnancies without treatment of low-dose aspirin and metformin at 11–13 weeks’ gestation and all eligible women attending for their first trimester routine scan will be invited to undergo screening for preterm-PE by the combination of maternal factors, mean arterial pressure and placental growth factor. Women found to be at high risk of developing preterm-PE will be invited to take part in the RCT. This study will compare the incidence of preterm-PE with delivery at

Ethical approval for the study was obtained from the Joint Chinese University of Hong Kong–New Territories East Cluster Clinical Research Ethics Committee (CREC Ref. No. 2021.406) in Hong Kong and the Ethics Committee of each participating hospital in Mainland China. The study is registered at ClinicalTrials.gov. The results of the AVERT trial will be disseminated at international academic conferences and published in high-impact factor journals.

NCT05580523.

In over 50 years since the genetic counseling (GC) profession began, a systematic study of GC communication skills and patient-reported outcomes in actual sessions across multiple clinical specialties has never been conducted. To optimize GC quality and improve efficiency of care, the field must first be able to comprehensively measure GC skills and determine which skills are most critical to achieving positive patient experiences and outcomes. This study aims to characterise GC communication skills using a novel and pragmatic measure and link variations in communication skills to patient-reported outcomes, across clinical specialties and with patients from diverse backgrounds in the USA. Our community-engagement and provider-engagement approach is crucial to develop recommendations for quality, culturally informed GC care, which are greatly needed to improve GC practice.

A mixed methods, sequential explanatory design will be used to collect and analyze: audio-recorded GC sessions in cancer, cardiac, and prenatal/reproductive genetic indications; pre-visit and post-visit quantitative surveys capturing patient experiences and outcomes and post-visit qualitative interview data. A novel, practical checklist will measure GC communication skills. Coincidence analysis will identify patterns of GC skills that are consistent with high scores on patient-reported measures. Two-level, multilevel models will be used to evaluate how GC communication skills and other session/patient characteristics predict patient-reported outcomes. Four community advisory boards (CABs) and a genetic counselor advisory board will inform the study design and analysis.

This study has been approved by the single Institutional Review Board of the University of Minnesota. This research poses no greater than minimal risk to participants. Results from this study will be shared through national and international conferences and through community-based dissemination as guided by the study’s CABs. A lay summary will also be disseminated to all participants.

To investigate how demographic, contractual and organisational factors are related to the retention of hospital workers in the English NHS. The study will specifically examine the trends in age-retention profiles.

A double retrospective cross-cohort study using administrative data on senior and specialty doctors, nurses and midwives who were included in the 2009 and 2014 payrolls of all English NHS hospital Trusts. These individuals were tracked over time until 2019 to examine the associations between sociodemographic characteristics and the retention of hospital workers in each cohort. Logistic regressions were estimated at the individual worker level to analyse the data. Additionally, a multilevel panel regression was performed using linked payroll-survey data to investigate the association between hospital organisation characteristics and the retention of clinical staff.

Secondary acute and mental healthcare NHS hospital Trusts in England.

70 777 senior doctors (specialty and specialist doctors and hospital consultants) aged 30–70, and a total of 448 568 between nurses and midwives of any grade aged 20–70, employed by English NHS Trusts.

Employee retention, measured through binary indicators for stayers and NHS leavers, at 1-year and 5-year horizons.

Minority doctors had lower 1-year retention rates in acute care than white doctors, while minority nurses and midwives saw higher retention. Part-time roles decreased retention for doctors but improved it for nurses. Fixed-term contracts negatively impacted both groups’ retention. Trends diverged for nurses and doctors from 2009 to 2014—nurses’ retention declined while doctors’ 5-year retention slightly rose. Engagement boosted retention among clinical staff under 51 years of age in acute care. For nurses over 50, addressing their feedback was positively associated with retention.

Demographic and contractual factors appear to be stronger predictors of hospital staff retention than organisational characteristics.

Exploring clinical information-seeking behaviour (CISB) and its associated factors contributes to its theoretical advancement and offers a valuable framework for addressing physicians’ information needs. This study delved into the dimensions, interactions, strategies and determinants of CISB among physicians at the point of care.

A grounded theory study was developed based on Strauss and Corbin’s approach. Data were collected by semistructured interviews and then analysed through open, axial and selective coding.

The study was conducted at academic centres affiliated with Isfahan University of Medical Sciences.

This investigation involved recruiting 21 specialists and subspecialists from the academic centres.

The findings revealed that physicians’ CISB encompassed multiple dimensions when addressing clinical inquiries. Seven principal themes emerged from the analysis: ‘clinical information needs’, ‘clinical question characteristics’, ‘clinical information resources’, ‘information usability’, ‘factors influencing information seeking’, ‘action/interaction encountering clinical questions’ and ‘consequences of CISB’. The core category identified in this study was ‘focused attention’.

The theoretical explanation demonstrated that the CISB process was interactive and dynamic. Various stimuli, including causal, contextual and intervening conditions, guide physicians in adopting information-seeking strategies and focusing on resolving clinical challenges. However, insufficient stimuli may hinder physicians’ engagement in CISB. Understanding CISB helps managers, policy-makers, clinical librarians and information system designers optimally implement several interventions, such as suitable training methods, reviewing monitoring and evaluating information systems, improving clinical decision support systems, electronic medical records and electronic health records, as well as monitoring and evaluating these systems. Such measures facilitate focused attention on clinical issues and promote CISB among physicians.

Incisional hernia (IH) is a prevalent and potentially dangerous complication of abdominal surgery, especially in high-risk groups. Mesh reinforcement of the abdominal wall has been studied as a potential intervention to prevent IHs. Randomised controlled trials (RCTs) have demonstrated that prophylactic mesh reinforcement after abdominal surgery, in general, is effective and safe. In patients with abdominal aortic aneurysm (AAA), prophylactic mesh reinforcement after open repair has not yet been recommended in official guidelines, because of relatively small sample sizes in individual trials. Furthermore, the identification of subgroups that benefit most from prophylactic mesh placement requires larger patient numbers. Our primary aim is to evaluate the efficacy and effectiveness of the use of a prophylactic mesh after open AAA surgery to prevent IH by performing an individual patient data meta-analysis (IPDMA). Secondary aims include the evaluation of postoperative complications, pain and quality of life, and the identification of potential subgroups that benefit most from prophylactic mesh reinforcement.

We will conduct a systematic review to identify RCTs that study prophylactic mesh placement after open AAA surgery. Cochrane Central Register of Controlled Trials, MEDLINE Ovid, Embase, Web of Science Core Collection and Google Scholar will be searched from the date of inception onwards. RCTs must directly compare primary sutured closure with mesh closure in adult patients who undergo open AAA surgery. Lead authors of eligible studies will be asked to share individual participant data (IPD). The risk of bias (ROB) for each included study will be assessed using the Cochrane ROB tool. An IPDMA will be performed to evaluate the efficacy, with the IH rate as the primary outcome. Any signs of heterogeneity will be evaluated by Forest plots. Time-to-event analyses are performed using Cox regression analysis to evaluate risk factors.

No new data will be collected in this study. We will adhere to institutional, national and international regulations regarding the secure and confidential sharing of IPD, addressing ethics as indicated. We will disseminate findings via international conferences, open-source publications in peer-reviewed journals and summaries posted online.

CRD42022347881.

Class II malocclusion with mandibular retrognathia is a common complication of paediatric obstructive sleep apnoea (OSA), often accompanied by transverse maxillary deficiency. In early orthodontic treatment, a twin block (TB) is a regular functional appliance for correcting this malocclusion. For paediatric OSA, the most common risk factor is adenotonsillar hypertrophy (AHT). Untreated AHT may lead to the persistence and worsening of obstructive sleep-disordered breathing traits, including habitual mouth breathing. Additionally, the clockwise mandibular rotation associated with AHT-induced pharyngeal crowding can undermine the effectiveness and stability of TB treatment. Adenotonsillectomy (T&A) is currently the first-line treatment for paediatric OSA. This proposed trial will investigate the impact of T&A surgery timing on the efficacy and stability of TB functional treatment in children with class II mandibular retrognathia and ATH.

This will be a single-centre, parallel-group, superiority randomised controlled trial with participants randomised to intervention (T&A followed by TB treatment) or control arms (TB treatment followed by T&A) in a 1:1 ratio. A total of 40 patients aged 8–14 years, diagnosed with class II mandibular retrognathia and co-existing ATH-induced OSA, and indicated for both T&A surgery and TB treatment, will be recruited at the School and Hospital of Stomatology, Wuhan University. The primary outcomes will be the changes in the apnoea-hypopnoea index and the point A-nasion-point B angle from baseline to postorthodontic treatment between the two groups. Secondary outcomes will include other dental, skeletal, upper airway and soft tissue changes, as well as subjective sleep-related and oral-related quality of life. Outcome changes within each group and between groups will be analysed.

This study is approved by the Ethics Committee of the School and Hospital of Stomatology, Wuhan University (no. 2022-D07). The research findings will be faithfully disseminated through scientific conferences or published articles.

ChiCTR2200061703 (https://www.chictr.org.cn).