Cemented or Uncemented Hemiarthroplasty for Intracapsular Hip Fracture.

BACKGROUND: Controversy exists over the use of bone cement in hip fractures treated with hemiarthroplasty. Only limited data on quality of life after cemented as compared with modern uncemented hemiarthroplasties are available. METHODS: We conducted a multicenter, randomized, controlled trial comparing cemented with uncemented hemiarthroplasty in patients 60 years of age or older with an intracapsular hip fracture. The primary outcome was health-related quality of life measured with the use of utility scores on the EuroQol Group 5-Dimension (EQ-5D) questionnaire at 4 months after randomization (range of scores, -0.594 to 1, with higher scores indicating better quality of life; range for minimal clinically important difference, 0.050 to 0.075). RESULTS: A total of 610 patients were assigned to undergo cemented hemiarthroplasty and 615 to undergo modern uncemented hemiarthroplasty; follow-up data were available for 71.6% of the patients at 4 months. The mean EQ-5D utility score was 0.371 in patients assigned to the cemented group and 0.315 in those assigned to the uncemented group (adjusted difference, 0.055; 95% confidence interval [CI], 0.009 to 0.101; P = 0.02). The between-group difference at 1 month was similar to that at 4 months, but the difference at 12 months was smaller than that at 4 months. Mortality at 12 months was 23.9% in the cemented group and 27.8% in the uncemented group (odds ratio for death, 0.80; 95% CI, 0.62 to 1.05). Periprosthetic fractures occurred in 0.5% and 2.1% of the patients in the respective groups (odds ratio [uncemented vs. cemented], 4.37; 95% CI, 1.19 to 24.00). The incidences of other complications were similar in the two groups. CONCLUSIONS: Among patients 60 years of age or older with an intracapsular hip fracture, cemented hemiarthroplasty resulted in a modestly but significantly better quality of life and a lower risk of periprosthetic fracture than uncemented hemiarthroplasty. (Funded by the National Institute for Health Research; WHiTE 5 ISRCTN number, ISRCTN18393176.).

Subacromial balloon spacer for irreparable rotator cuff tears of the shoulder (START:REACTS): a group-sequential, double-blind, multicentre randomised controlled trial.

BACKGROUND: New surgical procedures can expose patients to harm and should be carefully evaluated before widespread use. The InSpace balloon (Stryker, USA) is an innovative surgical device used to treat people with rotator cuff tears that cannot be repaired. We aimed to determine the effectiveness of the InSpace balloon for people with irreparable rotator cuff tears. METHODS: We conducted a double-blind, group-sequential, adaptive randomised controlled trial in 24 hospitals in the UK, comparing arthroscopic debridement of the subacromial space with biceps tenotomy (debridement only group) with the same procedure but including insertion of the InSpace balloon (debridement with device group). Participants had an irreparable rotator cuff tear, which had not resolved with conservative treatment, and they had symptoms warranting surgery. Eligibility was confirmed intraoperatively before randomly assigning (1:1) participants to a treatment group using a remote computer system. Participants and assessors were masked to group assignment. Masking was achieved by using identical incisions for both procedures, blinding the operation note, and a consistent rehabilitation programme was offered regardless of group allocation. The primary outcome was the Oxford Shoulder Score at 12 months. Pre-trial simulations using data from early and late timepoints informed stopping boundaries for two interim analyses. The primary analysis was on a modified intention-to-treat basis, adjusted for the planned interim analysis. The trial was registered with ISRCTN, ISRCTN17825590. FINDINGS: Between June 1, 2018, and July 30, 2020, we assessed 385 people for eligibility, of which 317 were eligible. 249 (79%) people consented for inclusion in the study. 117 participants were randomly allocated to a treatment group, 61 participants to the debridement only group and 56 to the debridement with device group. A predefined stopping boundary was met at the first interim analysis and recruitment stopped with 117 participants randomised. 43% of participants were female, 57% were male. We obtained primary outcome data for 114 (97%) participants. The mean Oxford Shoulder Score at 12 months was 34·3 (SD 11·1) in the debridement only group and 30·3 (10·9) in the debridement with device group (mean difference adjusted for adaptive design -4·2 [95% CI -8·2 to -0·26];p=0·037) favouring control. There was no difference in adverse events between the two groups. INTERPRETATION: In an efficient, adaptive trial design, our results favoured the debridement only group. We do not recommend the InSpace balloon for the treatment of irreparable rotator cuff tears. FUNDING: Efficacy and Mechanism Evaluation Programme, a Medical Research Council and National Institute for Health and Care Research partnership.

A cross-sectional investigation of cognition and epileptiform discharges in juvenile absence epilepsy.

OBJECTIVES: Despite the prevalence of cognitive symptoms in the idiopathic generalized epilepsies (IGEs), cognitive dysfunction in juvenile absence epilepsy (JAE), a common yet understudied IGE subtype, remains poorly understood. This descriptive study provides a novel, comprehensive characterization of cognitive functioning in a JAE sample and examines the relationship between cognition and 24-h epileptiform discharge load. METHOD: Forty-four individuals diagnosed with JAE underwent cognitive assessment using Woodcock Johnson III Test of Cognitive Abilities with concurrent 24-h ambulatory EEG monitoring. Generalized epileptiform discharges of any length, and prolonged generalized discharges ≥3 s were quantified across wakefulness and sleep. The relationship between standardized cognitive scores and epileptiform discharges was assessed through regression models. RESULTS: Cognitive performances in overall intellectual ability, acquired comprehension-knowledge, processing speed, long-term memory storage and retrieval, and executive processes were 0.63-1.07 standard deviation (SD) units lower in the JAE group compared to the population reference mean, adjusted for educational attainment. Prolonged discharges (≥3 s) were recorded in 20 patients (47.6%) from 42 available electroencephalography (EEG) studies and were largely unreported. Duration and number of prolonged discharges were associated with reduced processing speed and long-term memory storage and retrieval. SIGNIFICANCE: Cognitive dysfunction is seen in patients with JAE across various cognitive abilities, including those representing more stable processes like general intellect. During 24-h EEG, prolonged epileptiform discharges are common yet underreported in JAE despite treatment, and they show moderate effects on cognitive abilities. If epileptiform burden is a modifiable predictor of cognitive dysfunction, therapeutic interventions should consider quantitative 24-h EEG with routine neuropsychological screening. The growing recognition of the spectrum of neuropsychological comorbidities of IGE highlights the value of multidisciplinary approaches to explore the causes and consequences of cognitive deficits in epilepsy.

Study of capsule endoscopy delivery at scale through enhanced artificial intelligence-enabled analysis (the CESCAIL study).

AIM: Lower gastrointestinal (GI) diagnostics have been facing relentless capacity constraints for many years, even before the COVID-19 era. Restrictions from the COVID pandemic have resulted in a significant backlog in lower GI diagnostics. Given recent developments in deep neural networks (DNNs) and the application of artificial intelligence (AI) in endoscopy, automating capsule video analysis is now within reach. Comparable to the efficiency and accuracy of AI applications in small bowel capsule endoscopy, AI in colon capsule analysis will also improve the efficiency of video reading and address the relentless demand on lower GI services. The aim of the CESCAIL study is to determine the feasibility, accuracy and productivity of AI-enabled analysis tools (AiSPEED) for polyp detection compared with the 'gold standard': a conventional care pathway with clinician analysis. METHOD: This multi-centre, diagnostic accuracy study aims to recruit 674 participants retrospectively and prospectively from centres conducting colon capsule endoscopy (CCE) as part of their standard care pathway. After the study participants have undergone CCE, the colon capsule videos will be uploaded onto two different pathways: AI-enabled video analysis and the gold standard conventional clinician analysis pathway. The reports generated from both pathways will be compared for accuracy (sensitivity and specificity). The reading time can only be compared in the prospective cohort. In addition to validating the AI tool, this study will also provide observational data concerning its use to assess the pathway execution in real-world performance. RESULTS: The study is currently recruiting participants at multiple centres within the United Kingdom and is at the stage of collecting data. CONCLUSION: This standard diagnostic accuracy study carries no additional risk to patients as it does not affect the standard care pathway, and hence patient care remains unaffected.

Structural-functional connectivity bandwidth of the human brain.

BACKGROUND: The human brain is a complex network that seamlessly manifests behaviour and cognition. This network comprises neurons that directly, or indirectly mediate communication between brain regions. Here, we show how multilayer/multiplex network analysis provides a suitable framework to uncover the throughput of structural connectivity (SC) to mediate information transfer-giving rise to functional connectivity (FC). METHOD: We implemented a novel method to reconcile SC and FC using diffusion and resting-state functional MRI connectivity data from 484 subjects (272 females, 212 males; age = 29.15 ± 3.47) from the Human Connectome Project. First, we counted the number of direct and indirect structural paths that mediate FC. FC nodes with indirect SC paths were then weighted according to their least restrictive SC path. We refer to this as SC-FC Bandwidth. We then mapped paths with the highest SC-FC Bandwidth across 7 canonical resting-state networks. FINDINGS: We found that most pairs of FC nodes were connected by SC paths of length two and three (SC paths of length >5 were virtually non-existent). Direct SC-FC connections accounted for only 10% of all SC-FC connections. The majority of FC nodes without a direct SC path were mediated by a proportion of two (44%) or three SC path lengths (39%). Only a small proportion of FC nodes were mediated by SC path lengths of four (5%). We found high-bandwidth direct SC-FC connections show dense intra- and sparse inter-network connectivity, with a bilateral, anteroposterior distribution. High bandwidth SC-FC triangles have a right superomedial distribution within the somatomotor network. High-bandwidth SC-FC quads have a superoposterior distribution within the default mode network. CONCLUSION: Our method allows the measurement of indirect SC-FC using undirected, weighted graphs derived from multimodal MRI data in order to map the location and throughput of SC to mediate FC. An extension of this work may be to explore how SC-FC Bandwidth changes over time, relates to cognition/behavior, and if this measure reflects a marker of neurological injury or psychiatric disorders.

A systematic review of resting-state functional connectivity in obesity: Refining current neurobiological frameworks and methodological considerations moving forward.

Obesity is the second most common cause of preventable morbidity worldwide. Resting-state functional magnetic resonance imaging (fMRI) has been used extensively to characterise altered communication between brain regions in individuals with obesity, though findings from this research have not yet been systematically evaluated within the context of prominent neurobiological frameworks. This systematic review aggregated resting-state fMRI findings in individuals with obesity and evaluated the contribution of these findings to current neurobiological models. Findings were considered in relation to a triadic model of problematic eating, outlining disrupted communication between reward, inhibitory, and homeostatic systems. We identified a pattern of consistently increased orbitofrontal and decreased insula cortex resting-state functional connectivity in individuals with obesity in comparison to healthy weight controls. BOLD signal amplitude was also increased in people with obesity across studies, predominantly confined to subcortical regions, including the hippocampus, amygdala, and putamen. We posit that altered orbitofrontal cortex connectivity may be indicative of a shift in the valuation of food-based rewards and that dysfunctional insula connectivity likely contributes to altered homeostatic signal processing. Homeostatic violation signals in obesity may be maintained despite satiety, thereby 'hijacking' the executive system and promoting further food intake. Moving forward, we provide a roadmap for more reliable resting-state and task-based functional connectivity experiments, which must be reconciled within a common framework if we are to uncover the interplay between psychological and biological factors within current theoretical frameworks.

Functional connectivity during feedback learning in smokers.

BACKGROUND: Although it has been traditionally assumed that dysregulation of psychological processes in smokers results from activity within specific brain regions, an emerging view regards such dysregulation as attributable to aberrant communication between distinct brain regions. These processes can be measured during appropriate task paradigms such as the learning from errors task. This study aims to elucidate interactions between brain regions underlying the process of learning from errors, punishment and sensitivity to reward in dependent smokers. METHODS: Functional MRI data from 23 age-matched dependent smokers (8 females, mean age = 25.48, SD = 4.46) and 23 controls (13 females, mean age = 24.83, SD = 5.99) were analysed during a feedback-based associative learning task. Functional connectivity between the dorsal anterior cingulate cortex, nucleus accumbens and reward/sensorimotor areas was investigated during a feedback learning task. RESULTS: Behaviourally, smokers exhibited lower error correction rates and were less sensitive to punishment magnitude. Smokers showed increased functional connectivity between dorsal anterior cingulate cortex/nucleus accumbens seed regions and numerous reward-related target regions including the putamen, anterior cingulate and orbitofrontal cortex. CONCLUSIONS: Reduced learning from errors and widespread aberrant functional connectivity contribute to the emerging functional characterisation of dependent smokers and may bear significant implications when considering the efficacy of smoking interventions.

The incidence and prevalence of inflammatory bowel disease in UK primary care: a retrospective cohort study of the IQVIA Medical Research Database.

BACKGROUND: Our knowledge of the incidence and prevalence of inflammatory bowel disease (IBD) is uncertain. Recent studies reported an increase in prevalence. However, they excluded a high proportion of ambiguous cases from general practice. Estimates are needed to inform health care providers who plan the provision of services for IBD patients. We aimed to estimate the IBD incidence and prevalence in UK general practice. METHODS: We undertook a retrospective cohort study of routine electronic health records from the IQVIA Medical Research Database covering 14 million patients. Adult patients from 2006 to 2016 were included. IBD was defined as an IBD related Read code or record of IBD specific medication. Annual incidence and 12-month period prevalence were calculated. RESULTS: The prevalence of IBD increased between 2006 and 2016 from 106.2 (95% CI 105.2-107.3) to 142.1 (95% CI 140.7-143.5) IBD cases per 10,000 patients which is a 33.8% increase. Incidence varied across the years. The incidence across the full study period was 69.5 (95% CI 68.6-70.4) per 100,000 person years. CONCLUSIONS: In this large study we found higher estimates of IBD incidence and prevalence than previously reported. Estimates are highly dependent on definitions of disease and previously may have been underestimated.

Vocational rehabilitation via social firms: a qualitative investigation of the views and experiences of employees with mental health problems, social firm managers and clinicians.

BACKGROUND: Employment within social firms in the UK is under-developed and under-researched, but a potentially beneficial route to vocational rehabilitation for people with mental health problems. This study explores the views and experiences of employees with mental ill-health, managers of social firms and mental health clinicians, in order to understand the potential value of social firms for the vocational rehabilitation, employment and well-being of people with mental health problems. METHODS: Semi-structured interviews were conducted with 23 employees with mental health problems in 11 social firms in England. A focus group and individual interviews were conducted with 12 managers of social firms. Two focus groups were held with 16 mental health clinicians. Data were analysed using thematic analysis. RESULTS: Most employees expressed very positive views about working in a social firm. In responses from both employees and social firm managers, an overarching theme regarding the supportive ethos of social firms encompassed several related features: openness about mental health issues; peer, team and management support; flexibility; and support to progress and develop skills over time. Managers identified benefits of employing people with mental health problems who were sufficiently recovered. Knowledge of social firms within clinician focus groups was very limited, although clinicians thought they could be a welcome additional vocational resource. CONCLUSIONS: High levels of job satisfaction among social firm employees may be explained by the supportive ethos of these working environments. Social firms have potential to be a helpful addition to the range of vocational pathways available for people with mental ill-health. Further mixed methods investigations of experiences and outcomes in order to understand who engages with and benefits from this form of vocational rehabilitation would be valuable in informing decisions about scaling up the model.

Meniscal tears are more common than previously identified, however, less than a quarter of people with a tear undergo arthroscopy.

PURPOSE: The management of meniscal tears is a widely researched and evolving field. Previous studies reporting the incidence of meniscal tears are outdated and not representative of current practice. The aim of this study was to report the current incidence of MRI confirmed meniscal tears in patients with a symptomatic knee and the current intervention rate in a large NHS trust. METHODS: Radiology reports from 13,358 consecutive magnetic resonance imaging scans between 2015 and 2017, performed at a large UK hospital serving a population of 470,000, were assessed to identify patients with meniscal tears. The hospital database was interrogated to explore the subsequent treatment undertaken by the patient. A linear regression model was used to identify if any factors predicted subsequent arthroscopy. RESULTS: 1737 patients with isolated meniscal tears were identified in patients undergoing an MRI for knee pain, suggesting a rate of 222 MRI confirmed tears per 100,000 of the population aged 18 to 55 years old. 47% attended outpatient appointments and 22% underwent arthroscopy. Root tears [odds ratio (95% CI) 2.24 (1.0, 4.49); p = 0.049] and bucket handle tears were significantly associated with subsequent surgery, with no difference between the other types of tears. The presence of chondral changes did not significantly affect the rate of surgery [0.81 (0.60, 1.08); n.s]. CONCLUSION: Meniscal tears were found to be more common than previously described. However, less than half present to secondary care and only 22% undergo arthroscopy. These findings should inform future study design and recruitment strategies. In agreement with previous literature, bucket handle tears and root tears were significant predictors of subsequent surgery. LEVEL OF EVIDENCE: III.

Effect of Platelet-Rich Plasma Injection vs Sham Injection on Tendon Dysfunction in Patients With Chronic Midportion Achilles Tendinopathy: A Randomized Clinical Trial.

Importance: Platelet-rich plasma injections are used as a treatment for chronic midportion Achilles tendinopathy, but evidence for this treatment is limited. Objective: In adults with midportion Achilles tendinopathy, to assess the effects of a single platelet-rich plasma injection, compared with sham injection, on the outcome of the Victorian Institute of Sport Assessment-Achilles (VISA-A) score (a single composite measure of Achilles tendinopathy severity). Design, Setting, and Participants: A participant-blinded, multicenter randomized clinical trial that included 240 people from 24 sites assigned to either a platelet-rich plasma injection or a sham injection between April 2016 and February 2020. Final follow-up was July 2020. Participants were older than 18 years with midportion Achilles tendon pain for more than 3 months as confirmed by ultrasound, magnetic resonance imaging, or both. Interventions: A single intratendinous platelet-rich plasma injection (n = 121) or a single sham injection (insertion of a subcutaneous dry needle not entering the tendon) (n = 119). Main Outcomes and Measures: The primary outcome was the VISA-A score, measured 6 months after treatment allocation. The VISA-A score contains 8 questions that cover 3 domains of pain, function, and activity, analyzed as a composite score (range, 0 [worst symptoms] to 100 [no symptoms]; minimal clinically important difference in score, 12 points). The primary analysis was adjusted for laterality, age, sex, and baseline VISA-A score. Results: Among 240 patients assigned to a platelet-rich plasma or sham injection (mean age, 52 years; 138 [58%] women), 221 (92%) completed the trial. At 6-month follow-up, mean VISA-A score values in the plasma-rich plasma group vs the sham injection group were 54.4 vs 53.4 (adjusted mean difference, -2.7 [95% CI, -8.8 to 3.3]). The most common adverse events compared between patients in the platelet-rich plasma group vs the sham group were injection site discomfort (97 vs 73 patients), swelling (56 vs 52 patients) and bruising (48 vs 49 patients). Conclusions and Relevance: Among patients with chronic midportion Achilles tendinopathy, treatment with a single injection of intratendinous platelet-rich plasma, compared with insertion of a subcutaneous dry needle, did not reduce Achilles tendon dysfunction at 6 months. These findings do not support the use of this treatment for chronic midportion Achilles tendinopathy. Trial Registration: isrctn.org Identifier: ISRCTN13254422.

Adaptive seamless clinical trials using early outcomes for treatment or subgroup selection: Methods, simulation model and their implementation in R.

Adaptive seamless designs combine confirmatory testing, a domain of phase III trials, with features such as treatment or subgroup selection, typically associated with phase II trials. They promise to increase the efficiency of development programmes of new drugs, for example, in terms of sample size and/or development time. It is well acknowledged that adaptive designs are more involved from a logistical perspective and require more upfront planning, often in the form of extensive simulation studies, than conventional approaches. Here, we present a framework for adaptive treatment and subgroup selection using the same notation, which links the somewhat disparate literature on treatment selection on one side and on subgroup selection on the other. Furthermore, we introduce a flexible and efficient simulation model that serves both designs. As primary endpoints often take a long time to observe, interim analyses are frequently informed by early outcomes. Therefore, all methods presented accommodate interim analyses informed by either the primary outcome or an early outcome. The R package asd, previously developed to simulate designs with treatment selection, was extended to include subgroup selection (so-called adaptive enrichment designs). Here, we describe the functionality of the R package asd and use it to present some worked-up examples motivated by clinical trials in chronic obstructive pulmonary disease and oncology. The examples both illustrate various features of the R package and provide insights into the operating characteristics of adaptive seamless studies.

Understanding local ethnic inequalities in childhood BMI through cross-sectional analysis of routinely collected local data.

BACKGROUND: Local-level analysis of ethnic inequalities in health is lacking, prohibiting a comprehensive understanding of the health needs of local populations and the design of effective health services. Knowledge of ethnic disparities in child weight status is particularly limited by overlooking both the heterogeneity within ethnic groupings; and the complex ecological contexts in which obesity arises. This study aimed to establish whether there was variation in childhood BMI across ethnic groups in Coventry, and the influence of individual, school and neighbourhood contexts, using routinely collected local data. METHODS: National Child Measurement Programme data were compiled for the period 2007/8-2014/15 and combined with routinely collected local data reflecting school performance and demographics, and school and neighbourhood physical environments. Multi-level modelling using Monte Carlo Markov Chain methods was used to account for the clustering of children within schools and neighbourhoods. Ethnic group differences in BMI z-score (zBMI) were explored at 4-5 years and 10-11 years for girls and boys alongside individual, school and neighbourhood covariates. RESULTS: At age 4-5 years (n = 28,407), ethnic group differences were similar for boys and girls, with children from South Asian, White other, Chinese and 'any other' ethnic groups having a significantly lower zBMI, and Black African children having a higher zBMI, versus White British (WB) children. Patterns differed considerably at age 10-11 years (n = 25,763) with marked sex differences. Boys from White other, Bangladeshi and Black African groups had a significantly higher zBMI than WB boys. For girls, only children from Black ethnic groups showed a significantly higher zBMI. Area-level deprivation was the only important school or neighbourhood covariate, but its inclusion did not explain ethnic group differences in child zBMI. CONCLUSION: This analysis contributes to the existing literature by identifying nuanced patterns of ethnic disparities in childhood adiposity in Coventry, supporting the targeting of early obesity prevention for children from Black African groups, as well as girls from Black Caribbean and Black other ethnic backgrounds; and boys from Bangladeshi and White other ethnic backgrounds. It also demonstrates the utility of exploring routinely collected local data sets in building a comprehensive understanding of local population needs.

Decision-theoretic designs for a series of trials with correlated treatment effects using the Sarmanov multivariate beta-binomial distribution.

The motivation for the work in this article is the setting in which a number of treatments are available for evaluation in phase II clinical trials and where it may be infeasible to try them concurrently because the intended population is small. This paper introduces an extension of previous work on decision-theoretic designs for a series of phase II trials. The program encompasses a series of sequential phase II trials with interim decision making and a single two-arm phase III trial. The design is based on a hybrid approach where the final analysis of the phase III data is based on a classical frequentist hypothesis test, whereas the trials are designed using a Bayesian decision-theoretic approach in which the unknown treatment effect is assumed to follow a known prior distribution. In addition, as treatments are intended for the same population it is not unrealistic to consider treatment effects to be correlated. Thus, the prior distribution will reflect this. Data from a randomized trial of severe arthritis of the hip are used to test the application of the design. We show that the design on average requires fewer patients in phase II than when the correlation is ignored. Correspondingly, the time required to recommend an efficacious treatment for phase III is quicker.

Risk factors for metachronous adenoma in the residual colon of patients undergoing curative surgery for colorectal cancer.

PURPOSE: Adenoma detection in colorectal cancer survivors is poorly characterised with insufficient evidence to inform frequency of surveillance schedule. The aim of this study was to examine adenoma incidence and recurrence in patients who have undergone colorectal cancer resection with curative intent. Survival outcomes were compared to determine if the presence of adenomas could be used to identify patients at higher risk of local recurrence. METHODS: This is a retrospective observational cohort study at a single tertiary institution between 2006 and 2012. Five hundred fifteen consecutive patients with stage I-III colorectal cancer who had preoperative colonoscopy and curative surgery were included (median follow-up 56 months (36-75 months). RESULTS: In total, 352/515 (68%) patients underwent postoperative surveillance colonoscopy in the first 5 years after resection. Male gender was associated with greater risk of detecting synchronous adenoma at index colonoscopy or in the resection specimen (OR 2.35, p < 0.001). In the first 5 years after cancer surgery, synchronous adenoma, male gender and right sided primary tumour were independent predictors of metachronous lesions (OR 2.13, p = 0.009; OR 2.07, p = 0.027 and OR 2.34, p = 0.004, respectively). Presence of synchronous or metachronous adenoma had no impact upon incidence of local recurrence, overall or disease free survival. CONCLUSIONS: Patients with synchronous adenoma remain at high risk of adenoma recurrence despite undergoing colonic resection and should be considered for early endoscopic surveillance. Men and those undergoing right-sided resection have a higher risk of metachronous adenoma in the long term and may benefit from more frequent endoscopic surveillance post resection.

Blinded versus unblinded estimation of a correlation coefficient to inform interim design adaptations.

Regulatory authorities require that the sample size of a confirmatory trial is calculated prior to the start of the trial. However, the sample size quite often depends on parameters that might not be known in advance of the study. Misspecification of these parameters can lead to under- or overestimation of the sample size. Both situations are unfavourable as the first one decreases the power and the latter one leads to a waste of resources. Hence, designs have been suggested that allow a re-assessment of the sample size in an ongoing trial. These methods usually focus on estimating the variance. However, for some methods the performance depends not only on the variance but also on the correlation between measurements. We develop and compare different methods for blinded estimation of the correlation coefficient that are less likely to introduce operational bias when the blinding is maintained. Their performance with respect to bias and standard error is compared to the unblinded estimator. We simulated two different settings: one assuming that all group means are the same and one assuming that different groups have different means. Simulation results show that the naïve (one-sample) estimator is only slightly biased and has a standard error comparable to that of the unblinded estimator. However, if the group means differ, other estimators have better performance depending on the sample size per group and the number of groups.

A comparison of electronic and manual dynamometry and goniometry in patients with fracture of the distal radius and healthy participants.

UNLABELLED: The purpose of this study was to assess the intra-rater and inter-rater reliability of electronic and manual dynamometry and goniometry in healthy volunteers, and the inter-instrument reliability in the assessment of healthy volunteers and patients recovering after a fracture of the distal radius. Grip strength, grip fatigue, pinch strength and range of motion were assessed in all participants with both the manual and electronic instruments by two physiotherapists and orthopaedic specialist trainee. The measures of dynamometry demonstrated excellent reliability (intra-class correlation coefficient >0.90), with the instruments found to be interchangeable with the exception of the grip fatigue. Variable intra-rater and inter-rater reliability was demonstrated with all planes of movement for the goniometry measures regardless of the instrument used. The results of this study support the continued use of dynamometry in the clinical setting, but raise questions regarding the use of goniometry measurements. LEVEL OF EVIDENCE: Diagnostic level III.

Measurement properties of the Disability Rating Index in patients undergoing hip replacement.

OBJECTIVE: The aim of this study was to establish and validate the measurement properties of the Disability Rating Index (DRI) in a population of adults undergoing hip replacement. METHODS: One hundred and twenty-six adults participating in a randomized controlled trial completed the Oxford Hip Score, Harris Hip Score, DRI and EuroQol Group-Five Dimensions (EQ-5D) questionnaires at four time points. The structural validity of the DRI was assessed using principal component analysis. Cronbach's α was used to determine the internal consistency and scale reliability was also assessed. Correlation between the DRI and the other functional and health-related quality of life scales was used to check criterion validity. DRI responsiveness was estimated and the interpretability of the scale was also assessed by checking for edge effects. RESULTS: Results of analyses showed that the DRI was internally consistent (Cronbach's α = 0.92), had good association with both function-specific and general health-related quality of life scores and was sensitive to change (smallest detectable change = 2.7). No evidence of edge effects was found. Furthermore, structural assessment of the DRI revealed two novel subscales representing simple tasks and difficult tasks. CONCLUSIONS: The DRI is structurally valid, responsive and concurs with functional assessment in adults undergoing hip replacement.

Flexible selection of a single treatment incorporating short-term endpoint information in a phase II/III clinical trial.

Seamless phase II/III clinical trials in which an experimental treatment is selected at an interim analysis have been the focus of much recent research interest. Many of the methods proposed are based on the group sequential approach. This paper considers designs of this type in which the treatment selection can be based on short-term endpoint information for more patients than have primary endpoint data available. We show that in such a case, the familywise type I error rate may be inflated if previously proposed group sequential methods are used and the treatment selection rule is not specified in advance. A method is proposed to avoid this inflation by considering the treatment selection that maximises the conditional error given the data available at the interim analysis. A simulation study is reported that illustrates the type I error rate inflation and compares the power of the new approach with two other methods: a combination testing approach and a group sequential method that does not use the short-term endpoint data, both of which also strongly control the type I error rate. The new method is also illustrated through application to a study in Alzheimer's disease.

A comparison of methods for treatment selection in seamless phase II/III clinical trials incorporating information on short-term endpoints.

In an adaptive seamless phase II/III clinical trial interim analysis, data are used for treatment selection, enabling resources to be focused on comparison of more effective treatment(s) with a control. In this paper, we compare two methods recently proposed to enable use of short-term endpoint data for decision-making at the interim analysis. The comparison focuses on the power and the probability of correctly identifying the most promising treatment. We show that the choice of method depends on how well short-term data predict the best treatment, which may be measured by the correlation between treatment effects on short- and long-term endpoints.