Characteristics and outcomes of 627 044 COVID-19 patients living with and without obesity in the United States, Spain, and the United Kingdom.

BACKGROUND: A detailed characterization of patients with COVID-19 living with obesity has not yet been undertaken. We aimed to describe and compare the demographics, medical conditions, and outcomes of COVID-19 patients living with obesity (PLWO) to those of patients living without obesity. METHODS: We conducted a cohort study based on outpatient/inpatient care and claims data from January to June 2020 from Spain, the UK, and the US. We used six databases standardized to the OMOP common data model. We defined two non-mutually exclusive cohorts of patients diagnosed and/or hospitalized with COVID-19; patients were followed from index date to 30 days or death. We report the frequency of demographics, prior medical conditions, and 30-days outcomes (hospitalization, events, and death) by obesity status. RESULTS: We included 627 044 (Spain: 122 058, UK: 2336, and US: 502 650) diagnosed and 160 013 (Spain: 18 197, US: 141 816) hospitalized patients with COVID-19. The prevalence of obesity was higher among patients hospitalized (39.9%, 95%CI: 39.8-40.0) than among those diagnosed with COVID-19 (33.1%; 95%CI: 33.0-33.2). In both cohorts, PLWO were more often female. Hospitalized PLWO were younger than patients without obesity. Overall, COVID-19 PLWO were more likely to have prior medical conditions, present with cardiovascular and respiratory events during hospitalization, or require intensive services compared to COVID-19 patients without obesity. CONCLUSION: We show that PLWO differ from patients without obesity in a wide range of medical conditions and present with more severe forms of COVID-19, with higher hospitalization rates and intensive services requirements. These findings can help guiding preventive strategies of COVID-19 infection and complications and generating hypotheses for causal inference studies.

Prognostic factors for finger interphalangeal joint osteoarthritis: a systematic review.

OBJECTIVE: Radiographic hand OA affects one in five adults. Symptomatic hand OA can result in functional impairment, pain and reduced quality of life. A prevalent form of hand OA is IP joint OA, however prognostic factors for IP joint OA remain poorly understood. This systematic review aimed to identify prognostic factors for IP joint OA, and to summarize the diagnostic criteria for IP joint OA in prognostic studies. METHODS: EMBASE, MEDLINE, Scopus and The Cochrane Library were searched from inception until 19 February 2020 (PROSPERO CRD42019116782). Eligible studies described diagnostic criteria defining IP joint OA, and assessed potential prognostic factors for IP joint OA. Risk of bias was assessed using a modified Quality in Prognosis Studies (QUIPS) tool and a best evidence synthesis was used. RESULTS: Eighteen studies were included (risk of bias: eight high, three moderate, seven low). All defined OA radiographically, and three studies incorporated clinical symptoms into their definition of OA. Forty-nine potential prognostic factors were assessed. Eight were prognostic: older age in women, female gender (both moderate evidence); family history of Heberden's nodes, Kashin-Beck disease, older age in men, dental occupation in men, finger fracture, parity (all limited evidence). Higher BMI in women (limited evidence) was prognostic for symptomatic radiographic OA. No prognostic factors for symptomatic OA were identified. CONCLUSION: IP joint OA is most commonly defined radiographically, yet criteria were heterogeneous. Eight prognostic factors for radiographic IP joint OA and one for symptomatic radiographic IP joint OA were identified, all with limited or moderate evidence. Further studies on causality and on prognostic pathways are needed.

Low rate of subsequent surgery and serious complications following intra-articular steroid injection for base of thumb osteoarthritis: national cohort analysis.

OBJECTIVES: Intra-articular steroid injection is commonly used to treat base of thumb osteoarthritis (BTOA), despite a lack of large-scale data on safety and effectiveness. We estimate the incidence of serious complications and further procedures following BTOA injection, including the risk of post-operative serious surgical site infection for subsequent operative intervention. METHODS: Hospital Episode Statistics data linked to mortality records from 1 April 1998 to 31 March 2017 were used to identify all BTOA injections undertaken in adults in the National Health Service secondary care in England. Patients were followed up longitudinally until death or 31 March 2017. A multivariable regression with a Fine and Gray model adjusting for the competing risk of mortality in addition to age, sex and socioeconomic deprivation was used to identify factors associated with progression to further procedure. Secondary outcomes included serious complications after injection and subsequent surgical site infection. RESULTS: A total of 19 120 primary injections were performed during the 19-year period in 18 356 patients. Of these 76.5% were female; mean age 62 years (s.d. 10.6); 50.48% underwent further procedure; 22.40% underwent surgery. Median time to further intervention was 412 days (IQR 110-1945). Female sex was associated with increased risk of proceeding to surgery. Serious complication rate following injection was 0.04% (0.01-0.08) within 90 days. Of those proceeding to surgery 0.16% (0.06-0.34) presented with a wound infection within 30 days and 90 days, compared with an overall post-operative wound infection rate of 0.03% (0.02-0.05). CONCLUSIONS: Very low rates of serious complications were identified following BTOA injections performed in secondary care; only one in five patients proceeded to subsequent surgery. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov, https://www.clinicaltrials.gov, NCT03573765.

COVID-19 in patients with autoimmune diseases: characteristics and outcomes in a multinational network of cohorts across three countries.

OBJECTIVE: Patients with autoimmune diseases were advised to shield to avoid coronavirus disease 2019 (COVID-19), but information on their prognosis is lacking. We characterized 30-day outcomes and mortality after hospitalization with COVID-19 among patients with prevalent autoimmune diseases, and compared outcomes after hospital admissions among similar patients with seasonal influenza. METHODS: A multinational network cohort study was conducted using electronic health records data from Columbia University Irving Medical Center [USA, Optum (USA), Department of Veterans Affairs (USA), Information System for Research in Primary Care-Hospitalization Linked Data (Spain) and claims data from IQVIA Open Claims (USA) and Health Insurance and Review Assessment (South Korea). All patients with prevalent autoimmune diseases, diagnosed and/or hospitalized between January and June 2020 with COVID-19, and similar patients hospitalized with influenza in 2017-18 were included. Outcomes were death and complications within 30 days of hospitalization. RESULTS: We studied 133 589 patients diagnosed and 48 418 hospitalized with COVID-19 with prevalent autoimmune diseases. Most patients were female, aged ≥50 years with previous comorbidities. The prevalence of hypertension (45.5-93.2%), chronic kidney disease (14.0-52.7%) and heart disease (29.0-83.8%) was higher in hospitalized vs diagnosed patients with COVID-19. Compared with 70 660 hospitalized with influenza, those admitted with COVID-19 had more respiratory complications including pneumonia and acute respiratory distress syndrome, and higher 30-day mortality (2.2-4.3% vs 6.32-24.6%). CONCLUSION: Compared with influenza, COVID-19 is a more severe disease, leading to more complications and higher mortality.

Risk of depression, suicide and psychosis with hydroxychloroquine treatment for rheumatoid arthritis: a multinational network cohort study.

OBJECTIVES: Concern has been raised in the rheumatology community regarding recent regulatory warnings that HCQ used in the coronavirus disease 2019 pandemic could cause acute psychiatric events. We aimed to study whether there is risk of incident depression, suicidal ideation or psychosis associated with HCQ as used for RA. METHODS: We performed a new-user cohort study using claims and electronic medical records from 10 sources and 3 countries (Germany, UK and USA). RA patients ≥18 years of age and initiating HCQ were compared with those initiating SSZ (active comparator) and followed up in the short (30 days) and long term (on treatment). Study outcomes included depression, suicide/suicidal ideation and hospitalization for psychosis. Propensity score stratification and calibration using negative control outcomes were used to address confounding. Cox models were fitted to estimate database-specific calibrated hazard ratios (HRs), with estimates pooled where I2 <40%. RESULTS: A total of 918 144 and 290 383 users of HCQ and SSZ, respectively, were included. No consistent risk of psychiatric events was observed with short-term HCQ (compared with SSZ) use, with meta-analytic HRs of 0.96 (95% CI 0.79, 1.16) for depression, 0.94 (95% CI 0.49, 1.77) for suicide/suicidal ideation and 1.03 (95% CI 0.66, 1.60) for psychosis. No consistent long-term risk was seen, with meta-analytic HRs of 0.94 (95% CI 0.71, 1.26) for depression, 0.77 (95% CI 0.56, 1.07) for suicide/suicidal ideation and 0.99 (95% CI 0.72, 1.35) for psychosis. CONCLUSION: HCQ as used to treat RA does not appear to increase the risk of depression, suicide/suicidal ideation or psychosis compared with SSZ. No effects were seen in the short or long term. Use at a higher dose or for different indications needs further investigation. TRIAL REGISTRATION: Registered with EU PAS (reference no. EUPAS34497; http://www.encepp.eu/encepp/viewResource.htm? id=34498). The full study protocol and analysis source code can be found at https://github.com/ohdsi-studies/Covid19EstimationHydroxychloroquine2.

Temporal Trends and Geographical Variation in Dupuytren Disease Surgery in England: A Population-Based Cohort Study.

BACKGROUND: Dupuytren disease (DD) is a common fibroproliferative disease of the palmar fascia. The mainstay of DD treatment in England is surgery with either percutaneous needle fasciotomy, limited fasciectomy, or dermofasciectomy. This study aimed to investigate the temporal trends and geographical variation of primary DD surgery in England. METHODS: A longitudinal population-based cohort study was perfomed using the Hospital Episode Statistics database from April 1, 2007, to March 31, 2017. Directly standarized rates were estimated over time (between financial years 2007-2008 and 2016-2017) and by geographic region (by clinical commissioning groups [CCGs]; financial years 2010-2011, 2013-2014, and 2016-2017). The Office for National Statistics midyear population estimates were used as the reference population. MAIN FINDINGS: Primary DD surgery was undertaken at a steadily increasing rate from financial year 2007 to 2008, to 2016 to 2017 in England. There was a striking 3.6-fold variation in the rates of primary DD surgery among National Health Service CCGs in England place of residence. CONCLUSIONS: This significant variation in DD surgical treatment in England suggests a need for the development of standardized surgical practice across all CCGs and National Health Service hospitals, promoting equality of access to cost-effective health care.

Risk factors for the progression of finger interphalangeal joint osteoarthritis: a systematic review.

Progressive hand interphalangeal joint (IPJ) osteoarthritis is associated with pain, reduced function and impaired quality of life. However, the evidence surrounding risk factors for IPJ osteoarthritis progression is unclear. Identifying risk factors for IPJ osteoarthritis progression may inform preventative strategies and early interventions to improve long-term outcomes for individuals at risk of IPJ osteoarthritis progression. The objectives of the study were to describe methods used to measure the progression of IPJ osteoarthritis and identify risk factors for IPJ osteoarthritis progression. MEDLINE, EMBASE, Scopus, and The Cochrane Library were searched from inception to 19th February 2020 (PROSPERO CRD42019121034). Eligible studies assessed potential risk factor/s associated with IPJ osteoarthritis progression. Risk of bias was assessed using a modified QUIPS Tool, and a best evidence synthesis was performed. Of eight eligible studies, all measured osteoarthritis progression radiographically, and none considered symptoms. Eighteen potential risk factors were assessed. Diabetes (adjusted mean difference between 2.06 and 7.78), and larger finger epiphyseal index in males (regression coefficient ß = 0.202) and females (ß = 0.325) were identified as risk factors (limited evidence). Older age in men and women showed mixed results; 13 variables were not risk factors (all limited evidence). Patients with diabetes and larger finger epiphyseal index might be at higher risk of radiographic IPJ osteoarthritis progression, though evidence is limited and studies are biased. Studies assessing symptomatic IPJ osteoarthritis progression are lacking.

The Adolescent Champion Model: Primary Care Becomes Adolescent-Centered via Targeted Quality Improvement.

OBJECTIVE: To evaluate the effects of implementing the Adolescent Champion model, a novel quality improvement program targeted at helping primary care sites become more adolescent-centered. STUDY DESIGN: Nine primary care sites from pediatrics, family medicine, and medicine-pediatrics implemented the Adolescent Champion model. Each site identified a multidisciplinary champion team to undergo training on adolescent-centered care, deliver prepackaged trainings to other staff and providers, make youth-friendly site changes, implement a standardized flow to confidentially screen for risky behaviors, and complete a quality improvement project regarding confidentiality practices. Adolescent patients, staff, and providers were surveyed at baseline, year-end, and 1-year follow-up to assess changes. RESULTS: Adolescent patients' experiences with both their provider and the site overall significantly improved (P values from <.0001 to .004, N = 474 baseline, 386 year-end). Staff perceived an improvement in clinic practices relating to adolescents and in their ability to make institutional and personal change (P < .0001, N = 121 baseline, 109 year-end). The majority of changes were sustained 1-year postintervention. Frequently noted site improvements included: (1) initiating a method to gather feedback from adolescent patients; (2) adding trainings on confidentiality, cultural humility, and using a nonjudgmental approach; (3) updating immunizations at every visit; and (4) training providers in long acting reversible contraception via implant training. CONCLUSIONS: Implementing the Adolescent Champion model successfully helped primary care sites become more adolescent-centered. Further studies are needed to evaluate the effects of this model on patient outcomes.

A new acute scaphoid fracture assessment method: a reliability study of the 'long axis' measurement.

BACKGROUND: The aim of this study was to assess the inter observer and intra observer reliability of acute scaphoid fracture classification methods including a novel 'long axis' measurement, a simple method which we have developed with the aim of improving agreement when describing acute fractures. METHODS: We identified sixty patients with acute scaphoid fractures at two centres who had been investigated with both plain radiographs and a CT (Computed Tomography) scan within 4 weeks of injury. The fractures were assessed by three observers at each centre using three commonly used classification systems and the 'long axis' method. RESULTS: Inter observer reliability: based on X-rays the 'long axis' measurement demonstrated substantial agreement (Intraclass Correlation Coefficient (ICC) =0.76) and was significantly more reliable than the Mayo (p < 0.01), the most reliable of the established classification systems with moderate levels of agreement (kappa = 0.56). Intra observer reliability: the long axis measurement demonstrated almost perfect agreement whether based on X-ray (ICC = 0.905) or CT (ICC = 0.900). CONCLUSIONS: This study describes a novel pragmatic 'long axis' method for the assessment of acute scaphoid fractures which demonstrates substantial inter and intra observer reliability. The 'long axis' measurement has clear potential benefits over traditional classification systems which should be explored in future clinical research.

Closure of the radial forearm donor site using a local hatchet flap: analysis of 45 consecutive cases.

BACKGROUND: The radial forearm free flap (RFFF) is widely used in reconstructive surgery. Traditional donor-site closure by grafting may be associated with significant aesthetic and functional morbidity. We report our experience with primary closure using a local hatchet flap. METHODS: In all, 45 consecutive patients who underwent RFFF reconstruction in the head and neck during an 8-year period were retrospectively assessed with regards to their donor-site morbidity. RESULTS: The mean age of the patients was 54, with 23 being female. The mean RFFF area harvested was 37.7 cm; mean width, 7.6 cm (5.5-11 cm); and mean length, 4.7 cm (3.5-6.5 cm). All patients had their donor site closed primarily utilizing a local hatchet flap. At the time of follow-up, there were 33 surviving patients, of which 31 patients were available for assessment. CONCLUSIONS: We recommend this technique of primary closure of the RFFF donor site: it is well tolerated by the patient, with good cosmesis and is associated with no discernable functional morbidity.

Preventable hand injuries: A national audit.

Little is known of the scale of avoidable injuries presenting to medical services on a national level in the UK. This study aimed to assess the type and incidence of preventable wrist and hand injuries (as defined by the core research team) at a national level in the UK. 28 UK hospitals undertook a service evaluation of all hand trauma cases presenting to their units over a 2 week period in early 2021 identifying demographical and aetiological information about injuries sustained. 1909 patients were included (184 children) with a median age of 40 (IQR 25-59) years. The commonest five types of injury were fractures of the wrist; single phalangeal or metacarpal fractures; fingertip injuries; and infection, with the most common mechanisms being mechanical falls and manual labour. This is the first extensive survey of preventable hand injuries in the UK, identifying a need for further work into prevention to reduce healthcare burden and cost. 50% of injuries presenting to hand surgeons are preventable, with the most common injuries being single fractures of the wrist, phalanx and metacarpal. Few preventable injuries were related to alcohol or narcotic intoxication. Further research is needed to identify how to initiate injury prevention measures for hand injuries, particularly focussed towards hand fracture prevention.

Statistics for the hand surgeon. Part 2: avoiding common pitfalls.

In this second of a two-part article, we describe some of the common statistical pitfalls encountered in hand surgery research. These include dichotomania, the 'Table 2 fallacy', p-hacking, regression to the mean, overfitting and unaccounted data clustering. We explain the impact of these pitfalls on hand surgery research and describe techniques to avoid them. The aim of this two-part article was to provide a starting point for hand surgeons to refer to when conducting or analysing research and provide resources and references for interested readers to explore.

Statistics for the hand surgeon. Part 1: principles and application to hand surgery research.

Hand surgeons have the potential to improve patient care, both with their own research and by using evidenced-based practice. In this first part of a two-part article, we describe key steps for the analysis of clinical data using quantitative methodology. We aim to describe the principles of medical statistics and their relevance and use in hand surgery, with contemporaneous examples. Hand surgeons seek expertise and guidance in the clinical domain to improve their practice and patient care. Part of this process involves the critical analysis and appraisal of the research of others.

The association of bariatric surgery and Dupuytren's disease: a propensity score-matched cohort study.

We aimed to assess the association between bariatric surgery and incident Dupuytren's disease (DD) using propensity score-matched cohort studies among Swedish nationwide healthcare registries. Patients aged 30-79 years who underwent bariatric surgery 2006-2019 were matched on their propensity scores, up to two obese bariatric surgery-free (unexposed) patients. We applied Cox proportional hazard regression to calculate hazard ratios (HR) with 95% confidence intervals (CI) for the risk of DD overall, in subgroups of age, sex, bariatric surgery type and duration of follow-up. Among 34,959 bariatric surgery patients and 54,769 propensity score-matched obese patients, the risk of DD was increased in bariatric surgery patients compared with obese unexposed patients (HR 1.30, 95% CI 1.02-1.65), among women (HR 1.36; 1.00-1.84); those undergoing gastric bypass (HR 1.33; 1.04-1.71) and those with >5 years follow-up (HR 1.63; 1.14-2.34). Our results suggest that substantial weight loss is associated with an increased risk of DD in an obese population.Level of evidence: III.

A Virtual Fracture Clinic Pathway for Managing Suspected Paediatric Scaphoid Fractures.

INTRODUCTION: The mismanagement of an occult scaphoid fracture is a significant concern in patients presenting with anatomical snuffbox tenderness and no radiographic signs of injury. AIM: This study investigated whether a virtual fracture clinic (VFC) could improve care efficiency and expedite management decisions surrounding suspected pediatric scaphoid fractures. METHOD: Data was reviewed for patients referred via the VFC for suspected scaphoid fractures at a local trauma unit over 19 months. Patients received an "appointment" in VFC. Based on their notes and imaging, patients were referred to an outpatient clinic for repeat radiographs within two weeks (if initial radiographs demonstrated no fracture). Patients with unremarkable second x-rays were contacted and informed to mobilize and return if the pain persisted at four weeks. RESULTS: The pathway received 175 referrals; 114 male, 61 female, mean age 14 years, range 9-17) with 42 scaphoid fractures diagnosed, 35 (83.3%) on first x-ray, and 7 (16.7%) occult fractures. The pathway managed all patients as intended; 71 patients were seen face-to-face in the clinic due to age or pathology picked up on the first x-ray, and 104 required repeat radiographs. Following the second radiograph, 78 patients were discharged directly. Twenty-six patients required further review in a face-to-face clinic after their second radiograph. CONCLUSION: VFC appears to be a safe and efficient method of managing patients with suspected scaphoid fractures on short-term follow-up analysis. This cohort presents no 'missed' injuries and therefore appears safe compared to conventional treatment pathways.

Serious adverse event rates and reoperation after arthroscopic shoulder surgery: population based cohort study.

OBJECTIVE: To provide clinicians and patients with accurate risk estimates of serious adverse events after common elective shoulder arthroscopic procedures, including reoperation within one year. DESIGN: Population based cohort study. SETTING: Hospital Episode Statistics for NHS England, including civil registration mortality data from the Office for National Statistics. PARTICIPANTS: 288 250 arthroscopic shoulder procedures performed in 261 248 patients aged ≥16 years between 1 April 2009 and 31 March 2017. Elective procedures were grouped into subacromial decompression, rotator cuff repair, acromioclavicular joint excision, glenohumeral stabilisation, and frozen shoulder release. MAIN OUTCOME MEASURES: The primary outcomes were rates of serious adverse events (mortality, pulmonary embolism, pneumonia, myocardial infarction, acute kidney injury, stroke, and urinary tract infection) requiring inpatient care within 90 days post-surgery. Secondary outcomes were specific adverse event rates at 90 days, and reoperations (including for deep infection) within one year. RESULTS: The overall rate of complications within 90 days after arthroscopic shoulder surgery (including reoperation) was low at 1.2% (95% confidence interval 1.2% to 1.3%), with one in 81 patients at risk, and varied according to type of procedure, from 0.6% (0.5% to 0.8%) for glenohumeral stabilisation to 1.7% (1.5% to 1.8%) for frozen shoulder release. After adjustment for age, comorbidities, and sex, no effect of procedure type was observed. Pneumonia was the most common adverse event (0.3%, 0.3% to 0.4%), with one in 303 patients at risk. Pulmonary embolic events were rare, at 0.1% (0.1% to 0.1%), with one in 1428 patients at risk. At one year, the overall rate for reoperation was 3.8% (3.8% to 3.9%), with one in 26 patients at risk, ranging from 2.7% (2.5% to 3.0%) for glenohumeral stabilisation to 5.7% (5.4% to 6.1%) for frozen shoulder release. The overall rate of further surgery for deep infection was low, at 0.1% (0.1% to 0.1%), with one in 1111 patients at risk, but was higher after rotator cuff repair (0.2%, 0.2% to 0.2%), with one in 526 patients at risk. Over the study period the number of arthroscopic shoulder procedures increased, except for subacromial decompression, which decreased. CONCLUSIONS: The findings of this study suggest that risks of serious adverse events associated with common shoulder arthroscopy procedures are low. Nevertheless, serious complications do occur, and include the risk of reoperation in one in 26 patients within one year. STUDY REGISTRATION: Clinical. TRIALS: gov NCT03573765.

Serious postoperative complications and reoperation after carpal tunnel decompression surgery in England: a nationwide cohort analysis.

BACKGROUND: Carpal tunnel decompression surgery to treat carpal tunnel syndrome is a common procedure, yet data on safety and effectiveness of the operation in the general population remain scarce. We aimed to estimate the incidence of reoperation and serious postoperative complications (requiring admission to hospital or further surgery) following carpal tunnel decompression in routine clinical practice and to identify the patient factors associated with these adverse outcomes. METHODS: We did a nationwide cohort analysis including all carpal tunnel decompression surgeries in patients aged 18 years or older, done in the National Health Service in England between April 1, 1998, and March 31, 2017, using the Hospital Episode Statistics dataset linked to mortality records. Patients were followed-up until death or until the end of the study (March 31, 2017). Primary outcomes were the overall incidence of carpal tunnel decompression reoperation and serious postoperative complications (surgical site infection or dehiscence, or neurovascular or tendon injury, requiring admission to hospital or further surgery) within 30 days and 90 days after surgery. Multivariable Cox regression analysis was used to identify factors influencing complications and reoperation, and the Fine and Gray method was used to adjust for the competing risk of mortality. This study is registered with ClinicalTrials.gov, NCT03573765. FINDINGS: 855 832 carpal tunnel decompression surgeries were done between April 1, 1998, and March 31, 2017 (incidence rate 1·10 per 1000 person-years [95% CI 1·02-1·17]). 29 288 procedures (3·42%) led to carpal tunnel decompression reoperation (incidence rate 3·18 per 1000 person-years [95% CI 3·12-3·23]). Of the 855 832 initial surgeries, 620 procedures (0·070% [95% CI 0·067-0·078]) led to a serious complication within 30 days after surgery, and 698 procedures (0·082% [0·076-0·088]) within 90 days. Local complications within 90 days after surgery were associated with male sex (adjusted hazard ratio 2·32 [95% CI 1·74-3·09]) and age category 18-29 years (2·25 [1·10-4·62]). Male sex (adjusted subhazard ratio 1·09 [95% CI 1·06-1·13]), old age (>80 years vs 50-59 years: 1·09 [1·03-1·15]), and greater levels of comorbidity (Charlson score ≥5 vs 0: 1·25 [1·19-1·32]) and socioeconomic deprivation (most deprived 10% vs least deprived 10%: 1·18 [1·10-1·27]) were associated with increased reoperation risk. INTERPRETATION: To our knowledge, this is the largest national study on carpal tunnel decompression to date, providing strong evidence on serious postoperative complication and reoperation rates. Carpal tunnel decompression appears to be a safe operation in most patients, with an overall serious complication rate (requiring admission to hospital or further surgery) of less than 0·1%. FUNDING: Versus Arthritis; Medical Research Council; Royal College of Surgeons of England and National Joint Registry research fellowship; University of Oxford; National Institute for Health Research; and National Institute for Health Research Biomedical Research Centre, Oxford.