Uncertainties and opportunities in delivering environmentally sustainable surgery: the surgeons' view.

Surgery is a carbon-heavy activity and creates a high volume of waste. Surgical teams around the world want to deliver more environmentally sustainable surgery but are unsure what to do and how to create change. There are many interventions available, but resources and time are limited. Capital investment into healthcare and engagement of senior management are challenging. However, frontline teams can change behaviours and drive wider change. Patients have a voice here too, as they would like to ensure their surgery does not harm their local community but are concerned about the effects on them when changes are made. Environmentally sustainable surgery is at the start of its journey. Surgeons need to rapidly upskill their generic knowledge base, identify which measures they can implement locally and take part in national research programmes. Surgical teams in the NHS have the chance to create a world-leading programme that can bring change to hospitals around the world. This article provides an overview of how surgeons see the surgical team being involved in environmentally sustainable surgery.

The costs of surgical site infection after abdominal surgery in middle-income countries: Key resource use In Wound Infection (KIWI) study.

BACKGROUND: Surgical site infection (SSI) is the most common complication of abdominal surgery, with substantial costs to patients and health systems. Heterogeneity in costing methods in existing SSI studies makes multi-country comparison challenging. The objective of the study was to assess the costs of SSI across middle-income countries. METHODS: Centres from a randomized controlled trial assessing interventions to reduce SSI (FALCON, ClinicalTrials.gov, NCT03700749NCT) were sampled from two upper-middle- (India, Mexico) and two lower-middle- (Ghana, Nigeria) income countries. The Key resource use In Wound Infection (KIWI) study collected data on postoperative resource use and costs from consecutive patients undergoing abdominal surgery with an incision >5 cm (including caesarean section) that were recruited to FALCON between April and October 2020. The overall costs faced by patients with and without SSI were compared by operative field contamination (clean-contaminated vs contaminated-dirty), country and timing (inpatient vs outpatient). FINDINGS: A total of 335 patients were included in KIWI; SSI occurred in 7% of clean-contaminated cases and 27% of contaminated-dirty cases. Overall, SSI was associated with an increase in postoperative healthcare costs by 75.3% (€412 international Euros) after clean-contaminated surgery and 66.6% (€331) after contaminated-dirty surgery. The highest and lowest cost increases were in India for clean-contaminated cases (€517) and contaminated-dirty cases (€223), respectively. Overall, inpatient costs accounted for 96.4% of the total healthcare costs after clean-contaminated surgery and 92.5% after contaminated-dirty surgery. CONCLUSION: SSI was associated with substantial additional postoperative costs across a range of settings. Investment in health technologies to reduce SSI may mitigate the financial burden to patients and low-resource health systems.

COVID-19 opens the door for right iliac fossa pain treatment pathway.

INTRODUCTION: The COVID-19 pandemic has increased the risks of surgery and management of common surgical conditions has changed, with greater reliance on imaging and conservative management. The negative appendectomy rate (NAR) in the UK has previously remained high. The aim of this study was to quantify pandemic-related changes in the management of patients with suspected appendicitis, including the NAR. METHODS: A retrospective study was performed at a single high volume centre of consecutive patients aged over five years presenting to general surgery with right iliac fossa pain in two study periods: for two months before lockdown and for four months after lockdown. Pregnant patients and those with previous appendectomy, including right colonic resection, were excluded. Demographic, clinical, imaging and histological data were captured, and risk scores were calculated, stratifying patients into higher and lower risk groups. Data were analysed by age, sex and risk subgroups. RESULTS: The mean number of daily referrals with right iliac fossa pain or suspected appendicitis reduced significantly between the study periods, from 2.92 before lockdown to 2.07 after lockdown (p<0.001). Preoperative computed tomography (CT) rates increased significantly from 22.9% to 37.2% (p=0.002). The NAR did not change significantly between study periods (25.5% prior to lockdown, 11.1% following lockdown, p=0.159). Twelve (75%) out of sixteen negative appendectomies were observed in higher risk patients aged 16-45 years who did not undergo preoperative CT. The NAR in patients undergoing CT was 0%. CONCLUSIONS: Greater use of preoperative CT should be considered in risk stratified patients in order to reduce the NAR.

Resource requirements for reintroducing elective surgery during the COVID-19 pandemic: modelling study.

BACKGROUND: The COVID-19 response required the cancellation of all but the most urgent surgical procedures. The number of cancelled surgical procedures owing to Covid-19, and the reintroduction of surgical acivirt, was modelled. METHODS: This was a modelling study using Hospital Episode Statistics data (2014-2019). Surgical procedures were grouped into four urgency classes. Expected numbers of surgical procedures performed between 1 March 2020 and 28 February 2021 were modelled. Procedure deficit was estimated using conservative assumptions and the gradual reintroduction of elective surgery from the 1 June 2020. Costs were calculated using NHS reference costs and are reported as millions or billions of euros. Estimates are reported with 95 per cent confidence intervals. RESULTS: A total of 4 547 534 (95 per cent c.i. 3 318 195 to 6 250 771) patients with a pooled mean age of 53.5 years were expected to undergo surgery between 1 March 2020 and 28 February 2021. By 31 May 2020, 749 247 (513 564 to 1 077 448) surgical procedures had been cancelled. Assuming that elective surgery is reintroduced gradually, 2 328 193 (1 483 834 - 3 450 043) patients will be awaiting surgery by 28 February 2021. The cost of delayed procedures is €5.3 (3.1 to 8.0) billion. Safe delivery of surgery during the pandemic will require substantial extra resources costing €526.8 (449.3 to 633.9) million. CONCLUSION: As a consequence of the Covid-19 pandemic, provision of elective surgery will be delayed and associated with increased healthcare costs.

Transparency in surgical randomized clinical trials: cross-sectional observational study.

BACKGROUND: RCTs provide the scientific basis upon which treatment decisions are made. To facilitate critical review, it is important that methods and results are reported transparently. The aim of this study was to explore transparency in surgical RCTs with respect to trial registration, disclosure of funding sources, declarations of investigator conflicts and data-sharing. METHODS: This was a cross-sectional review of published surgical RCTs. Ten high-impact journals were searched systematically for RCTs published in years 2009, 2012, 2015 and 2018. Four domains of transparency were explored: trial registration, disclosure of funding, disclosure of investigator conflicts, and a statement relating to data-sharing. RESULTS: Of 611 RCTs, 475 were eligible for analysis. Some 397 RCTs (83.6 per cent) were registered on a trial database, of which 190 (47·9 per cent) had been registered prospectively. Prospective registration increased over time (26 per cent in 2009, 33·0 per cent in 2012, 54 per cent in 2015, and 72·7 per cent in 2018). Funding disclosure was present in 55·0, 65·0, 69·4 and 75·4 per cent of manuscripts respectively. Conflict of interest disclosure was present in 49·5, 89·1, 94·6 and 98·3 per cent of manuscripts across the same time periods. Data-sharing statements were present in only 15 RCTs (3·2 per cent), 11 of which were published in 2018. CONCLUSION: Trial registration, disclosure of funding and disclosure of investigator conflicts in surgical RCTs have improved markedly over the past 10 years. Disclosure of data-sharing plans is exceptionally low. This may contribute to research waste and represents a target for improvement.

ANTECEDENTES: Los ensayos clínicos aleatorizados y controlados (randomized controlled trials, RCT) proporcionan la base científica para la toma de decisiones terapéuticas. Es importante que los métodos y los resultados se presenten de forma transparente para facilitar la revisión crítica. El objetivo de este estudio fue investigar la transparencia en los RCTs del ámbito quirúrgico según su registro, declaraciones de las fuentes de financiación del estudio y conflicto de interés de los investigadores, así como información referente a compartir los datos. MÉTODOS: Revisión transversal de RCTs quirúrgicos publicados. Se realizó una búsqueda sistemática de los RCTs publicados en 10 revistas de alto impacto en los años 2009, 2012, 2015 y 2018. Se exploraron cuatro dominios de transparencia: el registro de los ensayos, la declaración de los fondos utilizados, la declaración de los conflictos de los investigadores y la información referente a la forma de compartir los datos. RESULTADOS: De 611 RCTs, se incluyeron en el análisis 475. Un total de 397 (83,6%) estudios se registraron en una base de datos de ensayos clínicos, de forma prospectiva en 190 (47,9%). El registro prospectivo aumentó a lo largo del tiempo (26,0% en 2009, 33,0% en 2012, 53,5% en 2015 y 72,7% en 2018). Se mencionaban las fuentes de financiación en el 55%, 65%, 69,4% y 75,4% de los manuscritos, respectivamente. La declaración de conflictos de interés estuvo presente en el 49,5%, 89,1%, 94,6% y 98,3% de los manuscritos en esos mismos períodos de tiempo. Las declaraciones relativas a compartir los datos de la investigación constaban en solo 15 (3,2%) RCTs, 11 de los cuales fueron publicados en el 2018. CONCLUSIÓN: En los últimos 10 años ha mejorado de forma notable el registro de los ensayos y las declaraciones de las fuentes de financiación y conflicto de interés en los RCTs quirúrgicos. La declaración referente a compartir los datos es excepcionalmente baja, lo que puede contribuir al desperdicio de la investigación y constituye un objetivo de mejora.

Evaluation of appendicitis risk prediction models in adults with suspected appendicitis.

BACKGROUND: Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. METHODS: A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16-45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). RESULTS: Some 5345 patients across 154 UK hospitals were identified, of which two-thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut-off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut-off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). CONCLUSION: Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision-making by identifying adults in the UK at low risk of appendicitis were identified.

ANTECEDENTES: La apendicitis es la urgencia quirúrgica de cirugía general más frecuente en todo el mundo, pero su diagnóstico sigue siendo un desafío. El objetivo de este estudio fue determinar si los modelos de predicción de riesgo existentes pueden identificar de manera fiable a los pacientes del Reino Unido que se presentan en el hospital con dolor agudo en la fosa ilíaca derecha (right iliac fossa, RIF) con bajo riesgo de apendicitis. MÉTODOS: Se realizó una búsqueda sistemática para identificar todos los modelos existentes de predicción de riesgo de apendicitis. Los modelos se validaron utilizando los datos del Reino Unido de un estudio International prospectivo de cohortes que incluía pacientes consecutivos de 16 a 45 años que se presentaron en el hospital con dolor agudo en RIF entre marzo y junio de 2017. El criterio de valoración principal fue la mejor especificidad que era posible alcanzar con el modelo (proporción de pacientes que no tenían apendicitis correctamente clasificados como de bajo riesgo) manteniendo una tasa de fracaso < 5% (proporción de pacientes identificados como de bajo riesgo que realmente tuvieron apendicitis). RESULTADOS: Se identificaron 5.345 pacientes en 154 hospitales del Reino Unido, de los cuales dos tercios (67,6%, 3.613/5.345) eran mujeres. Las mujeres tenían más del doble de probabilidades de someterse a una apendicectomía con un apéndice histológicamente normal (28,2%; 272/964) en comparación con los varones (12,1%; 120/993, riesgo relativo 2,33 (i.c. del 95% 1,92-2,84), P < 0,001)). Entre los 15 modelos de predicción de riesgo validados, el sistema de puntuación de apendicitis en adultos (Adult Appendicitis Score) fue el que obtuvo la mejor predicción (punto de corte ≤ 8, especificidad 63%, tasa de fracaso 3,7%). El sistema de puntuación de la respuesta inflamatoria de apendicitis (Appendicitis Inflammatory Response Score) fue el que obtuvo la mejor predicción en los varones (punto de corte ≤ 2, especificidad 25%, tasa de fracaso 2,4%). CONCLUSIÓN: Las mujeres del Reino Unido tuvieron un riesgo desproporcionado de ingreso sin intervención quirúrgica, así como porcentajes elevados de apendicectomías blancas. Se encontraron modelos de predicción de riesgos para apoyar la toma de decisiones compartida mediante la identificación de adultos del Reino Unido con bajo riesgo de apendicitis.

Mesh versus suture repair of primary inguinal hernia in Ghana.

Background: Most patients in Ghana undergo suture repair for primary inguinal hernia. Although there is strong evidence from high-income country settings to indicate superiority of mesh repair for inguinal hernia, the evidence to support the safety and effectiveness of mesh repair in the Ghanaian setting is limited. This study aimed to compare hernia recurrence rates following suture versus mesh repair in Ghana. Methods: Men aged 18 years or over presenting with symptomatic, reducible inguinal hernias were included. Over the first 6 months all consecutive patients were enrolled prospectively and underwent a standardized suture repair; an equal number of patients were subsequently enrolled to undergo mesh repair. The primary outcome was hernia recurrence within 3 years of the index operation. Multivariable analysis was adjusted for age and right or left side. Adjusted odds ratios (ORs) with 95 per cent confidence intervals are reported. Results: A total of 116 sutured and 116 mesh inguinal hernia repairs were performed. Three years after surgery, follow-up data were available for 206 of the 232 patients (88·8 per cent). Recurrence occurred significantly more frequently in the suture repair group (23 of 103, 22·3 per cent) than in the mesh group (7 of 103, 6·8 per cent) (P = 0·002). In multivariable analysis, suture repair was independently associated with an increased risk of recurrence (OR 4·51, 95 per cent c.i. 1·76 to 11·52; P = 0·002). Conclusion: In Ghana, mesh inguinal hernia repair was associated with reduced 3-year recurrence compared with sutured repair. Controlled dissemination across Ghana should now be assessed.

Feasibility study for a randomized clinical trial of bupivacaine, lidocaine with adrenaline, or placebo wound infiltration to reduce postoperative pain after laparoscopic cholecystectomy.

Background: Short-term pain relief can be achieved by local anaesthetic infiltration of port sites at the end of laparoscopic surgery. This study aimed to assess feasibility of performing an RCT to evaluate short-term postoperative analgesia after laparoscopic surgery in Nigeria using two local anaesthetics for port-site infiltration versus saline placebo. Methods: This was a placebo-controlled, patient- and outcome assessor-blinded, external feasibility RCT. Patients undergoing elective laparoscopic cholecystectomy for symptomatic ultrasound-proven gallstones were randomized into three groups: lidocaine with adrenaline (epinephrine), bupivacaine or saline control. The feasibility of recruitment, compliance with randomized treatment allocation, and completion of pain and nausea outcome measures were evaluated. Pain was assessed at 2, 6, 12 and 24 h after surgery using a 0-10-point numerical rating scale (NRS) and a four-point verbal rating scale. Nausea was assessed using NRS at the same time points. Clinical outcomes were assessed only in patients who received the correct randomized treatment allocation. Results: Of 79 patients screened for eligibility, 69 were consented and randomized (23 per group). Overall, compliance with randomized treatment allocation was achieved in 64 patients (93 per cent). All pain and nausea assessments were completed in these 64 patients. On the NRS, most patients had moderate to severe pain at 2 h (39 of 64, 61 per cent), which gradually reduced. Only six patients (9 per cent) had moderate to severe pain at 24 h. Conclusion: Recruitment, compliance with the randomized allocation, and completion of pain outcome measures were satisfactory. This study demonstrates the feasibility of conducting a surgical RCT in a resource-limited setting. Registration number: ISRCTN 17667918 (https://www.isrctn.com).

Systematic review of the stage of innovation of biological mesh for complex or contaminated abdominal wall closure.

BACKGROUND: Achieving stable closure of complex or contaminated abdominal wall incisions remains challenging. This study aimed to characterize the stage of innovation for biological mesh devices used during complex abdominal wall reconstruction and to evaluate the quality of current evidence. METHODS: A systematic review was performed of published and ongoing studies between January 2000 and September 2017. Eligible studies were those where a biological mesh was used to support fascial closure, either prophylactically after midline laparotomy, or for reinforcement after repair of incisional hernia with midline incision. The primary outcome measure was the IDEAL framework stage of innovation. The key secondary outcome measure was the GRADE criteria for study quality. RESULTS: Thirty-five studies including 2681 patients were included. Four studies considered mesh prophylaxis, 23 considered hernia repair, and eight reported on both. There was one published randomized trial (IDEAL stage 3), none of which was of high quality; the others were non-randomized studies (IDEAL stage 2a). A detailed description of surgical technique was provided in most studies (27 of 35); however, no study reported outcomes according to the European Hernia Society consensus statement and only two described quality control of surgical technique during the study. From 21 ongoing randomized trials and observational studies, 11 considered repair of incisional hernia and 10 considered prophylaxis (seven in elective settings). CONCLUSION: The evidence base for biological mesh is limited, and better reporting and quality control of surgical techniques are needed. Although results of ongoing trials over the next decade will improve the evidence base, further study is required in the emergency and contaminated settings.

Erratum to: Antimicrobials: a global alliance for optimizing their rational use in intra-abdominal infections (AGORA).

[This corrects the article DOI: 10.1186/s13017-016-0089-y.].

Cross-sectional observational study of the availability of evidence supporting novel implantable devices used in gastrointestinal surgery.

BACKGROUND: Evidence supporting the implementation of novel surgical devices is unstandardized, despite recommendations for assessing novel innovations. This study aimed to determine the proportion of novel implantable devices used in gastrointestinal surgery that are supported by evidence from RCTs. METHODS: A list of novel implantable devices placed intra-abdominally during gastrointestinal surgery was produced. Systematic searches were performed for all devices via PubMed and clinical trial registries. The primary outcome measure was the availability of at least one published RCT for each device. Published RCTs were appraised using the Cochrane tool for assessing risk of bias. RESULTS: A total of 116 eligible devices were identified (implantable mesh 42, topical haemostatics 22, antiadhesion barriers 10, gastric bands 8, suture and staple-line reinforcement 7, artificial sphincters 5, other 22). One hundred and twenty-eight published RCTs were found for 33 of 116 devices (28·4 per cent). Most were assessed as having a high risk of bias, with only 12 of 116 devices (10·3 per cent) supported by a published RCT considered to be low risk. A further 95 ongoing and 23 unpublished RCTs were identified for 42 of 116 devices (36·2 per cent), but many (64 of 116, 55·2 per cent) had no evidence from published, ongoing or unpublished RCTs. The highest stage of innovation according to the IDEAL Framework was stage 1 for 11 devices, stage 2a for 23 devices, stage 2b for one device and stage 3 for 33 devices. The remaining 48 devices had no relevant clinical evidence. CONCLUSION: Only one in ten novel implantable devices available for use in gastrointestinal surgical practice is supported by high-quality RCT evidence.

Longitudinal analysis of reporting and quality of systematic reviews in high-impact surgical journals.

BACKGROUND: The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) Statement aims to optimize the reporting of systematic reviews. The performance of the PRISMA Statement in improving the reporting and quality of surgical systematic reviews remains unclear. METHODS: Systematic reviews published in five high-impact surgical journals between 2007 and 2015 were identified from online archives. Manuscripts blinded to journal, publication year and authorship were assessed according to 27 reporting criteria described by the PRISMA Statement and scored using a validated quality appraisal tool (AMSTAR, Assessing the Methodological Quality of Systematic Reviews). Comparisons were made between studies published before (2007-2009) and after (2011-2015) its introduction. The relationship between reporting and study quality was measured using Spearman's rank test. RESULTS: Of 281 eligible manuscripts, 80 were published before the PRISMA Statement and 201 afterwards. Most manuscripts (208) included a meta-analysis, with the remainder comprising a systematic review only. There was no meaningful change in median compliance with the PRISMA Statement (19 (i.q.r. 16-21) of 27 items before versus 19 (17-22) of 27 after introduction of PRISMA) despite achieving statistical significance (P = 0·042). Better reporting compliance was associated with higher methodological quality (rs = 0·70, P < 0·001). CONCLUSION: The PRISMA Statement has had minimal impact on the reporting of surgical systematic reviews. Better compliance was associated with higher-quality methodology.

Academic requirements for Certificate of Completion of Training in surgical training: Consensus recommendations from the Association of Surgeons in Training/National Research Collaborative Consensus Group.

BACKGROUND: Surgical trainees are expected to demonstrate academic achievement in order to obtain their certificate of completion of training (CCT). These standards are set by the Joint Committee on Surgical Training (JCST) and specialty advisory committees (SAC). The standards are not equivalent across all surgical specialties and recognise different achievements as evidence. They do not recognise changes in models of research and focus on outcomes rather than process. The Association of Surgeons in Training (ASiT) and National Research Collaborative (NRC) set out to develop progressive, consistent and flexible evidence set for academic requirements at CCT. METHODS: A modified-Delphi approach was used. An expert group consisting of representatives from the ASiT and the NRC undertook iterative review of a document proposing changes to requirements. This was circulated amongst wider stakeholders. After ten iterations, an open meeting was held to discuss these proposals. Voting on statements was performed using a 5-point Likert Scale. Each statement was voted on twice, with ≥80% of votes in agreement meaning the statement was approved. The results of this vote were used to propose core and optional academic requirements for CCT. RESULTS: Online discussion concluded after ten rounds. At the consensus meeting, statements were voted on by 25 delegates from across surgical specialties and training-grades. The group strongly favoured acquisition of 'Good Clinical Practice' training and research methodology training as CCT requirements. The group agreed that higher degrees, publications in any author position (including collaborative authorship), recruiting patients to a study or multicentre audit and presentation at a national or international meeting could be used as evidence for the purpose of CCT. The group agreed on two essential 'core' requirements (GCP and methodology training) and two of a menu of four 'additional' requirements (publication with any authorship position, presentation, recruitment of patients to a multicentre study and completion of a higher degree), which should be completed in order to attain CCT. CONCLUSION: This approach has engaged stakeholders to produce a progressive set of academic requirements for CCT, which are applicable across surgical specialties. Flexibility in requirements whilst retaining a high standard of evidence is desirable.

Diagnosing acute appendicitis: surgery or imaging?

AIM: Investigation of suspected appendicitis varies widely across different countries, which creates variation in outcome for patients. Use of imaging drives much of this variation, with concerns over delay of imaging and radiation exposure of computed tomography being balanced against the risks of unnecessary surgery. METHOD: Two national, prospective snapshot audits (UK n = 3326 and Netherlands n = 1934) reported investigation, management and outcome of appendicectomy and can be compared to generate treatment recommendations. RESULTS: Preoperative imaging was conducted in 32.8% of UK patients in contrast to 99.5% of patients in the Netherlands. A large difference in the normal appendicectomy rate was observed (20.6% in the UK vs 3.2% in the Netherlands) and the connection between these two outcome differences cannot be neglected. CONCLUSION: This article discusses the role of imaging in the diagnostic work-up of patients who are suspected of acute appendicitis, comparing national snapshot studies as a model to do so.

A detailed analysis of outcome reporting from randomised controlled trials and meta-analyses of inguinal hernia repair.

INTRODUCTION: Evidence is needed to justify whether investment in an internationally agreed core outcome set for inguinal hernia surgery is needed. This study aimed to assess outcome reporting from randomised controlled trials (RCTs) and meta-analyses in inguinal hernia surgery. METHODS: RCTs and meta-analyses comparing surgical technique or mesh type for primary inguinal hernia repair were systematically identified. Verbatim details, type, frequency and definition of clinician-observed and -assessed outcomes were summarised. Patient-reported outcome measures (PROMs) were analysed for instrument validity and frequency of domain reporting. RESULTS: 40 RCTs (10,810 patients) and 7 meta-analyses (17,280 patients) were identified. No single PROM was reported by all studies. There were 58 different clinician-observed outcomes, with recurrence (n = 47, 100%), wound infection (n = 33, 70.2%), haematoma (n = 31, 77.5%) and seroma formation (n = 22, 46.8%) being most frequently reported. All studies measured patients' views, although only 12 (30.0%) used validated instruments. The SF36 was the most commonly used multi-dimensional valid PROM (n = 7), and a visual analogue scale assessing pain (n = 32) was the most frequently used unidimensional scale. Non-validated questionnaires assessed 25 other aspects of patients' health. Two meta-analyses defined recurrence and three chronic pain although neither ensured that included RCTs adhered to the definitions. CONCLUSIONS: Outcome reporting from RCTs concerning inguinal hernia repair is inconsistent and poorly defined, limiting meta-analyses, which themselves do not control for the differing definitions of assessed outcomes. This study justifies investment in a standardised core outcome set for inguinal hernia surgery, to improve outcome reporting and evidence synthesis.