Most published meta-regression analyses based on aggregate data suffer from methodological pitfalls: a meta-epidemiological study.

BACKGROUND Due to clinical and methodological diversity, clinical studies included in meta-analyses often differ in ways that lead to differences in treatment effects across studies. Meta-regression analysis is generally recommended to explore associations between study-level characteristics and treatment effect, however, three key pitfalls of meta-regression may lead to invalid conclusions. Our aims were to determine the frequency of these three pitfalls of meta-regression analyses, examine characteristics associated with the occurrence of these pitfalls, and explore changes between 2002 and 2012. METHODS A meta-epidemiological study of studies including aggregate data meta-regression analysis in the years 2002 and 2012. We assessed the prevalence of meta-regression analyses with at least 1 of 3 pitfalls: ecological fallacy, overfitting, and inappropriate methods to regress treatment effects against the risk of the analysed outcome. We used logistic regression to investigate study characteristics associated with pitfalls and examined differences between 2002 and 2012. RESULTS Our search yielded 580 studies with meta-analyses, of which 81 included meta-regression analyses with aggregated data. 57 meta-regression analyses were found to contain at least one pitfall (70%): 53 were susceptible to ecological fallacy (65%), 14 had a risk of overfitting (17%), and 5 inappropriately regressed treatment effects against the risk of the analysed outcome (6%). We found no difference in the prevalence of meta-regression analyses with methodological pitfalls between 2002 and 2012, nor any study-level characteristic that was clearly associated with the occurrence of any of the pitfalls. CONCLUSION The majority of meta-regression analyses based on aggregate data contain methodological pitfalls that may result in misleading findings

Prognostic factors for the occurrence of post-operative shoulder stiffness after arthroscopic rotator cuff repair: a systematic review

Post-operative shoulder stiffness (POSS) is one of the most frequent complications after arthroscopic rotator cuff repair (ARCR). Factors specifying clinical prediction models for the occurrence of POSS should rely on the literature and expert assessment. Our objective was to map prognostic factors for the occurrence of POSS in patients after an ARCR.; Longitudinal studies of ARCR reporting prognostic factors for the occurrence of POSS with an endpoint of at least 6 months were included. We systematically searched Embase, Medline, and Scopus for articles published between January 1, 2014 and February 12, 2020 and screened cited and citing literature of eligible records and identified reviews. The risk of bias of included studies and the quality of evidence were assessed using the Quality in Prognosis Studies tool and an adapted Grading of Recommendations, Assessment, Development and Evaluations framework. A database was implemented to report the results of individual studies. The review was registered on PROSPERO (CRD42020199257).; Seven cohort studies including 23 257 patients were included after screening 5013 records. POSS prevalence ranged from 0.51 to 8.75% with an endpoint ranging from 6 to 24 months. Due to scarcity of data, no meta-analysis could be performed. Overall risk of bias and quality of evidence was deemed high and low or very low, respectively. Twenty-two potential prognostic factors were identified. Increased age and male sex emerged as protective factors against POSS. Additional factors were reported but do require further analyses to determine their prognostic value.; Available evidence pointed to male sex and increased age as probable protective factors against POSS after ARCR. To establish a reliable pre-specified set of factors for clinical prediction models, our review results require complementation with an expert's opinion

Load-induced glenohumeral translation after rotator cuff tears : protocol for an in vivo study

Background: Rotator cuff tears are a common shoulder injury, but they sometimes remain undiagnosed, as symptoms can be limited. Altered shoulder biomechanics can lead to secondary damage and degeneration. In biomechanical analyses, the shoulder (ie, the glenohumeral joint) is normally idealized as a ball-and-socket joint, even though a translation is often observed clinically. To date, no conclusive changes in glenohumeral translation have been reported in patients with rotator cuff tears, and it is unknown how an additional handheld weight that is comparable to those used during daily activities will affect glenohumeral translations in patients with rotator cuff tears. Objective: This study aims to assess the load-induced glenohumeral translation (liTr) in patients with rotator cuff tears and its association with the load-induced changes in muscle activation (liMA). Methods: Patients and asymptomatic controls will be recruited. Participants will fill out health questionnaires and perform 30° arm abduction and adduction trials, during which they will hold different handheld weights of a maximum of 4 kg while motion capture and electromyographic data are collected. In addition, fluoroscopic images of the shoulders will be taken for the same movements. Isometric shoulder muscle strength for abduction and rotation will be assessed with a dynamometer. Finally, shoulder magnetic resonance images will be acquired to assess muscle status and injury presence. The dose-response relationship between additional weight, liTr, and liMA will be evaluated. Results: Recruitment and data collection began in May 2021, and they will last until the recruitment target is achieved. Data collection is expected to be completed by the end of 2022. As of November 2022, data processing and analysis are in progress, and the first results are expected to be submitted for publication in 2023. Conclusions: This study will aid our understanding of biological variations in liTr, the influence of disease pathology on liTr, the potential compensation of rotator cuff tears by muscle activation and size, and the association between liTr and patient outcomes. The outcomes will be relevant for diagnosis, treatment, and rehabilitation planning in patients with rotator cuff tears

Deteção bayesiana de outliers aditivos em processos INAR(1) com inovações binomiais negativas

Mestrado em Matemática e AplicaçõesOs processos de contagem, apesar de serem largamente usados na pr atica, continuam a ser alvo de investiga c~ao. Neste trabalho considera-se o processo de contagem autorregressivo de 1a ordem - INAR(1). O objetivo principal consiste em tratar o problema da dete c~ao de outliers aditivos em processos INAR(1), considerando uma distribui c~ao binomial negativa para o processo de inova c~oes. Aplica-se a abordagem bayesiana, atrav es da amostragem de Gibbs, para estimar a probabilidade de que uma observa c~ao seja afetada por um outlier. A metodologia proposta e ilustrada atrav es de v arios exemplos simulados e conjuntos de dados reais.Discrete-valued, or so called Integer-valued, time series is widely used in practice; but still it can be considered as a new subject for research nowadays. In this context, the variables of the process take place on nite or countable in nite sets. In this work, we study rst-order INteger-valued AutoRegressive, INAR(1), processes. The main goal, however, is to develop the statistical expressions for detecting outliers for the model, by considering the distributions of innovations as negative binomial. The Binomial thinning operator is used in process. This work considers a Bayesian approach to the problem of modeling a negative binomial integer-valued autoregressive time series contaminated with additive outliers. Furthermore, we focus on computational part of detecting the outliers of INAR(1) process where we use R software. We show how Gibbs sampling can be used to detect outlying observations in INAR(1) processes

High Incorrect Use of the Standard Error of the Mean (SEM) in Original Articles in Three Cardiovascular Journals Evaluated for 2012.

RATIONALE In biomedical journals authors sometimes use the standard error of the mean (SEM) for data description, which has been called inappropriate or incorrect. OBJECTIVE To assess the frequency of incorrect use of SEM in articles in three selected cardiovascular journals. METHODS AND RESULTS All original journal articles published in 2012 in Cardiovascular Research, Circulation: Heart Failure and Circulation Research were assessed by two assessors for inappropriate use of SEM when providing descriptive information of empirical data. We also assessed whether the authors state in the methods section that the SEM will be used for data description. Of 441 articles included in this survey, 64% (282 articles) contained at least one instance of incorrect use of the SEM, with two journals having a prevalence above 70% and "Circulation: Heart Failure" having the lowest value (27%). In 81% of articles with incorrect use of SEM, the authors had explicitly stated that they use the SEM for data description and in 89% SEM bars were also used instead of 95% confidence intervals. Basic science studies had a 7.4-fold higher level of inappropriate SEM use (74%) than clinical studies (10%). LIMITATIONS The selection of the three cardiovascular journals was based on a subjective initial impression of observing inappropriate SEM use. The observed results are not representative for all cardiovascular journals. CONCLUSION In three selected cardiovascular journals we found a high level of inappropriate SEM use and explicit methods statements to use it for data description, especially in basic science studies. To improve on this situation, these and other journals should provide clear instructions to authors on how to report descriptive information of empirical data

Minimally Invasive Extracorporeal Circulation Circuit Is Not Inferior to Off-Pump Coronary Artery Bypass Grafting: Meta-Analysis Using the Bayesian Method.

The pathophysiologic side effects of cardiopulmonary bypass have already been identified. Minimally invasive extracorporeal circulation technologies (MiECT) and off-pump coronary artery bypass graft surgery (OPCABG) aim to reduce these problems. This metaanalysis provides a comparison of MiECT and OPCABG in randomized and observational studies. A fully probabilistic, Bayesian approach of primary and secondary endpoints was conducted. MiECT does not give inferior results when compared with OPCABG. However, there is a trend to borderline significantly higher blood loss in this group in randomized controlled trials. The question whether MiECT is equivalent to OPCABG can be answered with the affirmative, but long-term follow-up data are needed to detect any advantage over time

Quality Characteristics and Clinical Relevance of In-House 3D-Printed Customized Polyetheretherketone (PEEK) Implants for Craniofacial Reconstruction

Additive manufacturing (AM) of patient-specific implants (PSIs) is gradually moving towards in-house or point-of-care (POC) manufacturing. Polyetheretherketone (PEEK) has been used in cranioplasty cases as a reliable alternative to other alloplastic materials. As only a few fused filament fabrication (FFF) printers are suitable for in-house manufacturing, the quality characteristics of the implants fabricated by FFF technology are still under investigated. This paper aimed to investigate PEEK PSIs fabricated in-house for craniofacial reconstruction, discussing the key challenges during the FFF printing process. Two exemplary cases of class III (Group 1) and class IV (Group 2) craniofacial defects were selected for the fabrication of PEEK PSIs. Taguchi’s L9 orthogonal array was selected for the following nonthermal printing process parameters, i.e., layer thickness, infill rate, number of shells, and infill pattern, and an assessment of the dimensional accuracy of the fabricated implants was made. The root mean square (RMS) values revealed higher deviations in Group 1 PSIs (0.790 mm) compared to Group 2 PSIs (0.241 mm). Horizontal lines, or the characteristic FFF stair-stepping effect, were more perceptible across the surface of Group 1 PSIs. Although Group 2 PSIs revealed no discoloration, Group 1 PSIs displayed different zones of crystallinity. These results suggest that the dimensional accuracy of PSIs were within the clinically acceptable range; however, attention must be paid towards a requirement of optimum thermal management during the printing process to fabricate implants of uniform crystallinity

Open aneurysm repair in patients with concomitant abdominal aortic aneurysm and aorto-iliac occlusive disease is associated with a high mortality and surgical complication rate

AIM OF THE STUDY: To evaluate whether the outcome after open aneurysm repair combined with aorto-femoral bypass in patients with concomitant abdominal aortic aneurysm (AAA) and aorto-iliac occlusive disease (AIOD) is inferior to open aneurysm repair for isolated AAA or aorto-femoral bypass for isolated AIOD. METHODS: We performed a retrospective analysis of 30-day mortality, 1-year mortality and surgical complications of consecutive patients undergoing elective aneurysm repair, aorto-femoral bypass or a combination of these at two vascular surgery departments from 2003 to 2013. Potential risk factors were investigated by multivariable analysis. RESULTS: Overall, 511 patients underwent open repair for isolated AAA, 104 aorto-femoral bypass for isolated AIOD and 46 open AAA repair combined with aorto-femoral bypass for concomitant AAA and AIOD. Surgical complications occurred in 17% of AAA, 23% of AIOD and 37% of combined patients (odds ratio [OR] combined vs AAA 2.76, 95% confidence interval [CI] 1.43–5.34; p = 0.003). Colon ischaemia occurred in 3.7% of AAA, 2.9% of AIOD and 13% of combined patients (incicidence rate ratio [IRR] combined vs AAA 3.27, 95% CI 1.37–7.81; p = 0.01). The 30-day mortality was 3.1% in AAA, 4.8% in AIOD, and 11% in combined patients (IRR combined vs AAA 3.17, 95% CI 1.26–7.96; p = 0.01). One-year mortality was 5.7% in AAA, 5.8% in AIOD and 15% in combined patients (IRR combined vs AAA 2.50, 95% CI 1.17–5.35; p = 0.02). CONCLUSIONS: Combined AAA repair and aorto-femoral bypass has a significantly higher 30-day mortality and postoperative complication rate than isolated AAA repair. Patients with concomitant AAA and AIOD thus represent a high-risk population, which should be considered when deciding on the indication for AAA treatment

Treatments for subacute cough in primary care : systematic review and meta-analyses of randomised clinical trials

Subacute cough following a non-specific viral infection lasting 3-8 weeks is common. However, despite many treatment options there are no systematic reviews evaluating these.; To provide a systematic overview of treatment options and outcomes evaluated in randomised clinical trials (RCTs).; Systematic review and meta-analyses assessing the overall effects of any treatment for subacute cough.; The authors systematically searched PubMed/MEDLINE and the Cochrane Central Register of Controlled Trials (last search March 2017) for RCTs in adult patients with subacute cough. The authors considered trials evaluating any outcome of any drug or non-drug treatments, apart from traditional Chinese and Asian medicines. They combined treatment effects on cough-related outcomes in random effects meta-analyses.; Six eligible RCTs including 724 patients were identified. These assessed montelukast, salbutamol plus ipratropium bromide, gelatine, fluticasone propionate, budesonide, and nociception opioid 1 receptor agonist and codeine. Five studies reported effects on various cough severity scores at various timepoints. No treatment option was associated with a clear benefit on cough recovery or other patient-relevant outcomes in any of the studies or in meta-analyses for cough outcomes at 14 days and 28 days. Reported adverse events were rather mild and reported for 14% of patients across all treatments.; Evidence on treatment options for subacute cough is weak. There is no treatment showing clear patient-relevant benefits in clinical trials