Statistics in publishing:the (mis)use of the p-value (part 1)

In hand surgery research, most studies, whether observational studies or randomized controlled trials (RCT), are aimed at finding out whether there is an effect (association or difference) of a certain determinant on a specific outcome. This is usually determined using null-hypothesis significance test- ing (NHST), in which a p-value <0.05 is considered as evidence that the findings are significant. Although this method is widely used, it has been criticized since its inception. The critique has been mainly focused on the misuse of NHST, but also more con- ceptually on the method itself. In part 1 of this two-part article, we discuss some examples of how the p-value can be misused, using a simulated data- set partly based on real data from an RCT (Broekstra et al., 2022). In part 2, we will discuss the conceptual criticism and offer some guidance on alternatives. In this example study, women with a distal radial fracture were randomized either to an intervention (cast þ rehabilitation programme) or control (cast only) group in a 1:1 ratio. The intervention was aimed at restoring hand function, which was mea- sured using the Patient-Rated Wrist Evaluation (PRWE), a validated patient-reported outcome meas- ure for determining hand function in patients with wrist problems, with a score ranging between 0 (no problems) and 100 (severe problem

Validation of the ArthroS virtual reality simulator for arthroscopic skills

Virtual reality simulator training has become important for acquiring arthroscopic skills. A new simulator for knee arthroscopy ArthroS™ has been developed. The purpose of this study was to demonstrate face and construct validity, executed according to a protocol used previously to validate arthroscopic simulators. Twenty-seven participants were divided into three groups having different levels of arthroscopic experience. Participants answered questions regarding general information and the outer appearance of the simulator for face validity. Construct validity was assessed with one standardized navigation task. Face validity, educational value and user friendliness were further determined by giving participants three exercises and by asking them to fill out the questionnaire. Construct validity was demonstrated between experts and beginners. Median task times were not significantly different for all repetitions between novices and intermediates, and between intermediates and experts. Median face validity was 8.3 for the outer appearance, 6.5 for the intra-articular joint and 4.7 for surgical instruments. Educational value and user friendliness were perceived as nonsatisfactory, especially because of the lack of tactile feedback. The ArthroS™ demonstrated construct validity between novices and experts, but did not demonstrate full face validity. Future improvements should be mainly focused on the development of tactile feedback. It is necessary that a newly presented simulator is validated to prove it actually contributes to proficiency of skill

Validation of the PASSPORT V2 training environment for arthroscopic skills

Virtual reality simulators used in the education of orthopaedic residents often lack realistic haptic feedback. To solve this, the (Practice Arthroscopic Surgical Skills for Perfect Operative Real-life Treatment) PASSPORT simulator was developed, which was subjected to fundamental changes: improved realism and user interface. The purpose was to demonstrate its face and construct validity. Thirty-one participants were divided into three groups having different levels of arthroscopic experience. Participants answered questions regarding general information and the outer appearance of the simulator for face validity. Construct validity was assessed with one standardized navigation task, which was timed. Face validity, educational value and user-friendliness were determined with two representative exercises and by asking participants to fill out the questionnaire. A value of 7 or greater was considered sufficient. Construct validity was demonstrated between experts and novices. Median task time for the fifth trial was 55 s (range 17-139 s) for the novices, 33 s (range 17-59 s) for the intermediates, and 26 s (range 14-52 s) for the experts. Median task times of three trials were not significantly different between the novices and intermediates, and none of the trials between intermediates and experts. Face validity, educational value and user-friendliness were perceived as sufficient (median >7). The presence of realistic tactile feedback was considered the biggest asset of the simulator. Proper preparation for arthroscopic operations will increase the quality of real-life surgery and patients' safety. The PASSPORT simulator can assist in achieving this, as it showed construct and face validity, and its physical nature offered adequate haptic feedback during training. This indicates that PASSPORT has potential to evolve as a valuable training modalit

How valid are commercially available medical simulators?

Background: Since simulators offer important advantages, they are increasingly used in medical education and medical skills training that require physical actions. A wide variety of simulators have become commercially available. It is of high importance that evidence is provided that training on these simulators can actually improve clinical performance on live patients. Therefore, the aim of this review is to determine the availability of different types of simulators and the evidence of their validation, to offer insight regarding which simulators are suitable to use in the clinical setting as a training modality. Summary: Four hundred and thirty-three commercially available simulators were found, from which 405 (94%) were physical models. One hundred and thirty validation studies evaluated 35 (8%) commercially available medical simulators for levels of validity ranging from face to predictive validity. Solely simulators that are used for surgical skills training were validated for the highest validity level (predictive validity). Twenty-four (37%) simulators that give objective feedback had been validated. Studies that tested more powerful levels of validity (concurrent and predictive validity) were methodologically stronger than studies that tested more elementary levels of validity (face, content, and construct validity). Conclusion: Ninety-three point five percent of the commercially available simulators are not known to be tested for validity. Although the importance of (a high level of) validation depends on the difficulty level of skills training and possible consequences when skills are insufficient, it is advisable for medical professionals, trainees, medical educators, and companies who manufacture medical simulators to critically judge the available medical simulators for proper validation. This way adequate, safe, and affordable medical psychomotor skills training can be achieved.Biomechanical EngineeringMechanical, Maritime and Materials Engineerin

Using Primary Care Data to Report Real-World Pancreatic Cancer Survival and Symptomatology.

Pancreatic cancer is the 10th most common cancer diagnosed; despite recent advances in many areas of oncology, survival remains poor, in part owing to late diagnosis. Whilst primary care data are used widely for epidemiology and pharmacovigilance, they are less used for observing survival. In this study we extracted a pancreatic cancer cohort from a nationally representative English primary care database of electronic health records (EHRs) and reported on their symptom and mortality data. A total of 11, 649 cases were identified within the Oxford Royal College of General Practitioners (RCGP) Clinical Informatics Digital Hub network. All-cause mortality data was recorded for 4623 (39.69%). Mean age at recording of cancer diagnosis was 71.4 years (SD 12.0 years). 1-year and 5-year survival was 22.06% and 3.27% respectively. Within a multivariate model, age had a significant impact on survival; those diagnosed under the age of 60 had the longest survival, as compared to those age 60 - 79 (HR: 1.36, 95% CI: 1.20 - 1.54, p &lt; 0.001) and 80+ (HR: 2.13, 95% CI: 1.86 - 2.44, p &lt; 0.01). Symptomatology was examined; at any time point abdominal pain was the most commonly reported symptom present in 5271 cases (45.2%), but within the 12 months preceding diagnosis jaundice was the most common feature, present in 2587 patients (22.2%). Future studies clarifying other contributing factors on survival outcomes and patterns of symptomatology are needed; primary care EHRs provide an opportunity to evaluate real-world cancer patient cohort data

Supporting Training of Expertise with Wearable Technologies: The WEKIT Reference Framework

In this chapter, we present a conceptual reference framework for designing augmented reality ap-plications for supporting training. The framework leverages the capabilities of modern augmented reality and wearable technology for capturing the expert’s performance in order to train expertise. It has been designed in the context of WEKIT project which intends to deliver a novel technological platform for industrial training. The framework identifies the state-of-art augmented reality training methods which we term as “transfer mechanism” from an extensive literature review. Transfer mechanisms exploit the educational affordances of augmented reality and wearable technology to capture the expert performance and train the novice. The framework itself is based upon Merrienboer’s 4CID model which is suitable for training complex skills. The 4CID model encapsulates major elements of apprenticeship models which is a primary method of training in industries. The framework itself complements the 4CID model with expert performance data captured with help of wearable technology which is then, exploited in the model to provide a novel training approach for efficiently and effectively master the skills required. In this chapter, we will give a brief overview of our cur-rent progress in developing this framework