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Statistics in Medicine Dec 2023In randomized trials, comparability of the treatment groups is ensured through allocation of treatments using a mechanism that involves some random element, thus...
In randomized trials, comparability of the treatment groups is ensured through allocation of treatments using a mechanism that involves some random element, thus controlling for confounding of the treatment effect. Completely random allocation ensures comparability between the treatment groups for all known and unknown prognostic factors. For a specific trial, however, imbalances in prognostic factors among the treatment groups may occur. Although accidental bias can be avoided in the presence of such imbalances by stratifying the analysis, most trialists, regulatory agencies, and other stakeholders prefer a balanced distribution of prognostic factors across the treatment groups. Some procedures attempt to achieve balance in baseline covariates, by stratifying the allocation for these covariates, or by dynamically adapting the allocation using covariate information during the trial (covariate-adaptive procedures). In this Tutorial, the performance of minimization, a popular covariate-adaptive procedure, is compared with two other commonly used procedures, completely random allocation and stratified blocked designs. Using individual patient data of 2 clinical trials (in advanced ovarian cancer and age-related macular degeneration), the procedures are compared in terms of operating characteristics (using asymptotic and randomization tests), predictability of treatment allocation, and achieved balance. Fifty actual trials of various sizes that applied minimization for treatment allocation are used to investigate the achieved balance. Implementation issues of minimization are described. Minimization procedures are useful in all trials but especially when (1) many major prognostic factors are known, (2) many centers of different sizes accrue patients, or (3) the trial sample size is moderate.
Topics: Humans; Bias; Randomized Controlled Trials as Topic; Research Design; Sample Size
PubMed: 37867447
DOI: 10.1002/sim.9916 -
Respirology (Carlton, Vic.) Nov 2014Over the past decade, several non-surgical and minimally invasive bronchoscopic lung volume reduction (BLVR) techniques have been developed to treat patients with severe... (Review)
Review
Over the past decade, several non-surgical and minimally invasive bronchoscopic lung volume reduction (BLVR) techniques have been developed to treat patients with severe chronic obstructive pulmonary disease (COPD). BLVR can be significantly efficacious, suitable for a broad cohort of patients, and associated with a solid safety profile at a reasonable expense. The introduction of BLVR is also expected to accelerate the further development of interventional pulmonology worldwide. Recently, results from clinical studies on BLVR techniques have been published, providing valuable information about the procedure's indications, contraindications, patient-selection criterion and outcomes. BLVR utilizing one-way endobronchial valves is gaining momentum as an accepted treatment in regular medical practice because of the identification of best responders. Patients with a heterogeneous emphysema distribution and without inter-lobar collateral ventilation show encouraging results. Furthermore, for patients with collateral ventilation, who are not considered candidates for valve treatment, and for patients with homogeneous emphysema, the introduction of lung volume reduction coil treatment is a promising solution. Moreover, with the development of newer treatment modalities, that is, biochemical sealant and thermal water vapor, the potential to treat emphysema irrespective of collateral flow, may be further increased. Nevertheless, patient selection for BLVR treatment will be crucial for the procedure's success and should be performed using a multidisciplinary team approach. Consequently, BLVR needs to be concentrated in high-volume centres that will offer better quality and experience with treatment challenges and adverse events. This review gives a general overview of BLVR from an expert and scientific perspective.
Topics: Bronchoscopy; Humans; Outcome Assessment, Health Care; Patient Selection; Pneumonectomy; Prognosis; Pulmonary Disease, Chronic Obstructive
PubMed: 25124070
DOI: 10.1111/resp.12362 -
BMC Medical Research Methodology Jul 2022Meta-analysis is a central method for quality evidence generation. In particular, meta-analysis is gaining speedy momentum in the growing world of quantitative... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Meta-analysis is a central method for quality evidence generation. In particular, meta-analysis is gaining speedy momentum in the growing world of quantitative information. There are several software applications to process and output expected results. Open-source software applications generating such results are receiving more attention. This paper uses Python's capabilities to provide applicable instruction to perform a meta-analysis.
METHODS
We used the PythonMeta package with several modifications to perform the meta-analysis on an open-access dataset from Cochrane. The analyses were complemented by employing Python's zEpid package capable of creating forest plots. Also, we developed Python scripts for contour-enhanced funnel plots to assess funnel plots asymmetry. Finally, we ran the analyses in R and STATA to check the cross-validity of the results.
RESULTS
A stepwise instruction on installing the software and packages and performing meta-analysis was provided. We shared the Python codes for meta-analysts to follow and generate the standard outputs. Our results were similar to those yielded by R and STATA.
CONCLUSION
We successfully produced standard meta-analytic outputs using Python. This programming language has several flexibilities to improve the meta-analysis results even further.
Topics: Humans; Programming Languages; Publications; Research Design; Software
PubMed: 35820854
DOI: 10.1186/s12874-022-01673-y -
Stroke Sep 2019Background and Purpose- Radial artery catheterization is an alternate route of access that has started to gain more widespread use for neuroendovascular procedures, and...
Background and Purpose- Radial artery catheterization is an alternate route of access that has started to gain more widespread use for neuroendovascular procedures, and there have been few studies that describe its safety and efficacy. We present our institution's experience in performing neuroendovascular interventions via a transradial approach, with excellent clinical outcomes and patient satisfaction measures. Methods- We conducted a retrospective analysis and identified 223 patients who underwent 233 consecutive neuroendovascular interventions via radial artery access at our institution. The incidence of perioperative and postprocedural complications was investigated. We identified a subset of 98 patients who have undergone both transradial and transfemoral cerebral angiograms and compared clinical outcomes and patient satisfaction measures between the 2 groups. Results- The overall incidence of complications was low across all procedures performed via transradial access. Peri-procedurally, only 2 patients had symptomatic radial artery spasm, and there were no instances of iatrogenic complications (vessel dissection, stroke, and hemorrhage). In 10 cases (4.3%), the intended procedure could not be completed via a transradial approach, and, thus, femoral artery access had to be pursued instead. Ten patients complained of minor postprocedural complications, although none required therapeutic intervention. The mean procedure time was shorter for diagnostic angiograms performed via transradial versus transfemoral access (18.8±15.8 versus 39.5±31.1 minutes; P=0.025). Patients overall reported shorter recovery times with transradial access, and the majority of patients (94%) would elect to have subsequent procedures performed via this route. Conclusions- Radial artery catheterization is a safe and durable alternative to perform a wide range of neuroendovascular procedures, with a low rate of complications. On the whole, patients prefer transradial compared with transfemoral access.
Topics: Cardiac Catheterization; Cerebral Angiography; Female; Hemorrhage; Humans; Middle Aged; Radial Artery; Retrospective Studies; Stroke; Treatment Outcome
PubMed: 31311466
DOI: 10.1161/STROKEAHA.119.025811 -
Research Synthesis Methods May 2023We developed metadta, a flexible, robust, and user-friendly statistical procedure that fuses established and innovative statistical methods for meta-analysis,... (Meta-Analysis)
Meta-Analysis Review
We developed metadta, a flexible, robust, and user-friendly statistical procedure that fuses established and innovative statistical methods for meta-analysis, meta-regression, and network meta-analysis of diagnostic test accuracy studies in Stata. Using data from published meta-analyses, we validate metadta by comparing and contrasting its features and output to popular procedures dedicated to the meta-analysis of diagnostic test accuracy studies; (midas [Stata], metandi [Stata], metaDTA [web application], mada [R], and MetaDAS [SAS]). We also demonstrate how to perform network meta-analysis with metadta, for which no alternative procedure is dedicated to network meta-analysis of diagnostic test accuracy data in the frequentist framework. metadta generated consistent estimates in simple and complex diagnostic test accuracy data sets. We expect its availability to stimulate better statistical practice in the evidence synthesis of diagnostic test accuracy studies.
Topics: Software; Research Design; Network Meta-Analysis; Diagnostic Tests, Routine
PubMed: 36999350
DOI: 10.1002/jrsm.1634 -
Thoracic Surgery Clinics Nov 2019Failure to recognize a short esophagus during paraesophageal hernia repair can lead to poor functional outcomes and increased recurrence rates. Diagnosis is usually done... (Review)
Review
Failure to recognize a short esophagus during paraesophageal hernia repair can lead to poor functional outcomes and increased recurrence rates. Diagnosis is usually done intraoperatively when less than 2 to 3 cm of esophagus lie in the intraabdominal position. If aggressive esophageal mediastinal mobilization is unable to lengthen the esophagus, the surgeon should perform an esophageal lengthening procedure. A modified Collis gastroplasty is most commonly used and can be performed through a variety of transabdominal or transthoracic approaches. These procedures are safe, durable, and associated with good long-term outcomes. Patient selection and safe surgical technique are key in avoiding complications.
Topics: Esophagus; Fundoplication; Gastroplasty; Hernia, Hiatal; Herniorrhaphy; Humans; Laparoscopy; Mediastinum; Organ Size; Patient Selection
PubMed: 31564395
DOI: 10.1016/j.thorsurg.2019.07.004 -
Academic Radiology May 2018A systematic review is a comprehensive search, critical evaluation, and synthesis of all the relevant studies on a specific (clinical) topic that can be applied to the... (Review)
Review
A systematic review is a comprehensive search, critical evaluation, and synthesis of all the relevant studies on a specific (clinical) topic that can be applied to the evaluation of diagnostic and screening imaging studies. It can be a qualitative or a quantitative (meta-analysis) review of available literature. A meta-analysis uses statistical methods to combine and summarize the results of several studies. In this review, a 12-step approach to performing a systematic review (and meta-analysis) is outlined under the four domains: (1) Problem Formulation and Data Acquisition, (2) Quality Appraisal of Eligible Studies, (3) Statistical Analysis of Quantitative Data, and (4) Clinical Interpretation of the Evidence. This review is specifically geared toward the performance of a systematic review and meta-analysis of diagnostic test accuracy (imaging) studies.
Topics: Humans; Diagnostic Imaging; Meta-Analysis as Topic; Research Design; Systematic Reviews as Topic
PubMed: 29371119
DOI: 10.1016/j.acra.2017.12.007 -
Minerva Chirurgica Oct 2015Since the introduction of laparoscopic and robotic technology in surgical practice, there have been multiple reports and a few clinical trials on their use in colorectal... (Review)
Review
AIM
Since the introduction of laparoscopic and robotic technology in surgical practice, there have been multiple reports and a few clinical trials on their use in colorectal surgery. Although the application of laparoscopy to right colectomy has been increasingly adopted in many institutions around the world, there are still several open issues regarding the effective role of robotics and single incision surgery. This is a review of the relevant surgical literature evaluating the risks, benefits, and costs of minimally invasive approaches to right colectomy (RC) surgery.
METHODS
Retrospective and prospective articles spanning the past 20 years were reviewed to identify the current application of minimally invasive surgery in RC. A review of the most relevant papers comparing open vs. laparoscopic vs. robotic approaches will illustrate the role of minimally invasive surgery in current clinical practice in terms of surgical outcomes, technical advantages and oncological outcomes. We then pooled the evidence for and against the application of laparoscopy and robotics in intracorporeal vs. extracorporeal anastomosis creation, single incision and natural orifice surgery.
RESULTS
Evidence shows that compared to open surgery, laparoscopic RC provides lower postoperative morbidity, faster return to normal bowel function and a shorter length of hospital stay, with a similar oncological outcome. The application of robotics to RC procedure has proven to be safe and feasible, however the intraoperative and postoperative outcomes are similar with the laparoscopic technique and no clear advantages have been demonstrated. When adopted in a single incision technique and natural orifice surgery, robotics can help to overcome the limitations of laparoscopy, enabling the surgeon to perform scar-less surgery.
CONCLUSION
Laparoscopy surgery, whenever performed by adequately trained surgeons, can be safely applied to right colectomy and should be considered as the gold standard procedure. In terms of robotic surgery, to date, this technology needs more evidence from multicenter randomized clinical trials. New tools and instruments are needed to expand the field of single incision and natural orifice surgery, and make it available in current clinical practice.
Topics: Colectomy; Colonic Diseases; Evidence-Based Medicine; Humans; Laparoscopy; Meta-Analysis as Topic; Minimally Invasive Surgical Procedures; Natural Orifice Endoscopic Surgery; Randomized Controlled Trials as Topic; Risk Factors; Robotic Surgical Procedures; Time Factors; Treatment Outcome
PubMed: 26365367
DOI: No ID Found -
Journal of Robotic Surgery Aug 2023RAPN training usually takes place in-vivo and methods vary across countries/institutions. No common system exists to objectively assess trainee capacity to perform RAPN...
RAPN training usually takes place in-vivo and methods vary across countries/institutions. No common system exists to objectively assess trainee capacity to perform RAPN at predetermined performance levels prior to in-vivo practice. The identification of objective performance metrics for RAPN training is a crucial starting point to improve training and surgical outcomes. The authors sought to examine the reliability, construct and discriminative validity of objective intraoperative performance metrics which best characterize the optimal and suboptimal performance of a reference approach for training novice RAPN surgeons. Seven Novice and 9 Experienced RAPN surgeons video recorded one or two independently performed RAPN procedures in the human. The videos were anonymized and two experienced urology surgeons were trained to reliably score RAPN performance, using previously developed metrics. The assessors were blinded to the performing surgeon, hospital and surgeon group. They independently scored surgeon RAPN performance. Novice and Experienced group performance scores were compared for procedure steps completed and errors made. Each group was divided at the median for Total Errors score, and subgroup scores (i.e., Novice HiErrs and LoErrs, Experienced HiErrs and LoErrs) were compared. The mean inter-rater reliability (IRR) for scoring was 0.95 (range 0.84-1). Compared with Novices, Experienced RAPN surgeons made 69% fewer procedural Total Errors. This difference was accentuated when the LoErr Expert RAPN surgeon's performance was compared with the HiErrs Novice RAPN surgeon's performance with an observed 170% fewer Total Errors. GEARS showed poor reliability (Mean IRR = 0.44; range 0.0-0.8), for scoring RAPN surgical performance. The RAPN procedure metrics reliably distinguish Novice and Experienced surgeon performances. They further differentiated performance levels within a group with similar experiences. Reliable and valid metrics will underpin quality-assured novice RAPN surgical training.
Topics: Humans; Robotic Surgical Procedures; Robotics; Reproducibility of Results; Surgeons; Clinical Competence; Nephrectomy
PubMed: 36689078
DOI: 10.1007/s11701-023-01521-1 -
Clinics in Podiatric Medicine and... Jan 2016Whether performed as a primary procedure or used to augment and support osseous reconstruction, tendon transfers are a key skill for the foot and ankle surgeon.... (Review)
Review
Whether performed as a primary procedure or used to augment and support osseous reconstruction, tendon transfers are a key skill for the foot and ankle surgeon. Understanding the biomechanics preoperative and postoperatively is essential in performing appropriate procedures and in supporting patients through the rehabilitation process. Often the complexity of tendon transfer surgery is lost because it is deemed a soft tissue procedure and in theory should be less complex than osseous procedures. However, the dynamic nature of musculature and tendons require a deeper understanding of surgical and biomechanical concepts.
Topics: Foot; Humans; Muscle Strength; Patient Selection; Range of Motion, Articular; Tendon Transfer; Tensile Strength
PubMed: 26590719
DOI: 10.1016/j.cpm.2015.06.001