Do radiological research articles apply the term "pilot study" correctly? Systematic review

AIM: To determine what proportion of radiological studies used the term "pilot" correctly. MATERIAL AND METHODS: Indexed studies describing themselves as a "pilot" in their title were identified from four indexed radiological journals. The aim was to identify 20 consecutive, eligible studies from each journal, as this sample size was deemed sufficient to be representative as to how this methodological description was employed by authors of radiological articles. Data were extracted relating to study design and data presented. The review was reported according to PRISMA guidelines. RESULTS: The search string used identified 658 records across the four targeted journals. Ultimately, 78 reviews describing 5,572 patients were selected for systematic review. Median sample size was just 20 patients. No individual study qualified as a genuine pilot study when assessed against the a priori criteria. In reality, the large majority (66 studies, 84.6%) were framed as studies of diagnostic test accuracy. A significant proportion (21 studies, 26.9%) was retrospective, and the overwhelming majority were conducted in single centres (76 centres, 94.7%). Most (55 studies, 70.5%) stated no rationale for their sample size, and no study presented a formal power calculation. CONCLUSION: Radiological "pilot" studies are mostly underpowered studies of diagnostic test accuracy. In order to have scientific credibility, authors, reviewers, and editors of radiological journals are encouraged to familiarise themselves with different methodological study designs and their precise implications

Solitary rectal ulcer syndrome (SRUS): observational case series findings on MR defecography

Objective: Radiological findings in solitary rectal ulcer syndrome (SRUS) are well described for evacuation proctography (EP) but sparse for magnetic resonance defecography (MRD). In order to rectify this, we describe the spectrum of MRD findings in patients with histologically proven SRUS. / Materials and methods: MRD from twenty-eight patients (18 female; 10 males) with histologically confirmed SRUS were identified. MRD employed a 1.5-T magnet and a standardized technique with the rectal lumen filled with gel and imaged sagittally in the supine position, before, during, and after attempted rectal evacuation. A single radiologist observer with 5 years’ experience in pelvic floor imaging made the anatomical and functional measurements. / Results: Sixteen patients (10 female) demonstrated internal rectal intussusception and 3 patients (11%) demonstrated complete external rectal prolapse. Anterior rectoceles were noted in 12 female patients (43%). Associated anterior and middle compartment weakness (evidenced by excessive descent) was observed in 18 patients (64%). Cystocele was found in 14 patients (50%) and uterine prolapse was noted in 7 patients (25%). Enterocoeles were detected in 5 patients (18%) and peritoneocoele in 5 patients (18%). None had sigmoidocoele. Sixteen patients (57%) demonstrated delayed voiding and 13 patients (46%) incomplete voiding, suggesting defecatory dyssynergia. / Conclusion: MRD can identify and grade both rectal intussusception and dyssynergia in SRUS, and also depict associated anterior and/or middle compartment descent. Distinction between structural and functional findings has important therapeutic implications. Key Points: MRD can identify and grade both rectal intussusception and dyssynergia in patients with SRUS. MRD is an acceptable substitute to evacuation proctography in assessing anorectal dysfunctions when attempting to avoid ionizing radiation. SRUS influences the pelvic floor globally. MRD depicts associated anterior and/or middle compartment prolapse

How to avoid describing your radiological research study incorrectly

This review identifies and examines terms used to describe a radiological research “study” or “trial”. A taxonomy of clinical research descriptions is explained with reference to medical imaging examples. Because many descriptive terms have precise methodological implications, it is important that these terms are understood by readers and used correctly by researchers, so that the reader is not misled

Making useful clinical guidelines: the ESGAR perspective

Clinical guidelines are important and influential; they can improve processes involved in patient care, thereby also improving patient outcomes. They are both commonly downloaded from journal websites and highly cited, helping clinical decision making and service commissioning. Yet, the quality of such guidelines is highly variable; a review of 279 guidelines published between 1985 and 1997 found that overall adherence to high-quality methodological standards was less than 50%. Just as Altman has argued that the misuse of statistics is unethical for primary research, it is equally inappropriate for guideline documents to recommend specific practices unless developed robustly and transparently. To do otherwise risks erroneous care, and, ultimately, patient harm. Readers of guidelines (clinicians, patients and policy-makers) require reassurance that these authoritative documents have identified, appraised and considered the available evidence, or draw attention to weaknesses in the literature if appropriate

A systematic methodological review of non-randomised interventional studies of elective ventral hernia repair: clear definitions and a standardised minimum dataset are needed

BACKGROUND: Ventral hernias (VHs) often recur after surgical repair and subsequent attempts at repair are especially challenging. Rigorous research to reduce recurrence is required but such studies must be well-designed and report representative and comprehensive outcomes. // OBJECTIVE: We aimed to assesses methodological quality of non-randomised interventional studies of VH repair by systematic review. // METHODS: We searched the indexed literature for non-randomised studies of interventions for VH repair, January 1995 to December 2017 inclusive. Each prospective study was coupled with a corresponding retrospective study using pre-specified criteria to provide matched, comparable groups. We applied a bespoke methodological tool for hernia trials by combining relevant items from existing published tools. Study introduction and rationale, design, participant inclusion criteria, reported outcomes, and statistical methods were assessed. // RESULTS: Fifty studies (17,608 patients) were identified: 25 prospective and 25 retrospective. Overall, prospective studies scored marginally higher than retrospective studies for methodological quality, median score 17 (IQR: 14-18) versus 15 (IQR 12-18), respectively. For the sub-categories investigated, prospective studies achieved higher median scores for their, 'introduction', 'study design' and 'participants'. Surprisingly, no study stated that a protocol had been written in advance. Only 18 (36%) studies defined a primary outcome, and only 2 studies (4%) described a power calculation. No study referenced a standardised definition for VH recurrence and detection methods for recurrence varied widely. Methodological quality did not improve with publication year or increasing journal impact factor. // CONCLUSION: Currently, non-randomised interventional studies of VH repair are methodologically poor. Clear outcome definitions and a standardised minimum dataset are needed

A systematic methodological review of reported perioperative variables, postoperative outcomes and hernia recurrence from randomised controlled trials of elective ventral hernia repair: clear definitions and standardised datasets are needed

BACKGROUND: This systematic review assesses the perioperative variables and post-operative outcomes reported by randomised controlled trials (RCTs) of VH repair. This review focuses particularly on definitions of hernia recurrence and techniques used for detection. OBJECTIVE: Our aim is to identify and quantify the inconsistencies in perioperative variable and postoperative outcome reporting, so as to justify future development of clear definitions of hernia recurrence and a standardised dataset of such variables. METHODS: The PubMed database was searched for elective VH repair RCTs reported January 1995 to March 2016 inclusive. Three independent reviewers performed article screening, and two reviewers independently extracted data. Hernia recurrence, recurrence rate, timing and definitions of recurrence, and techniques used to detect recurrence were extracted. We also assessed reported post-operative complications, standardised operative outcomes, patient reported outcomes, pre-operative CT scan hernia dimensions, intra-operative variables, patient co-morbidity, and hernia morphology. RESULTS: 31 RCTs (3367 patients) were identified. Only 6 (19.3%) defined hernia recurrence and methods to detect recurrence were inconsistent. Sixty-four different clinical outcomes were reported across the RCTs, with wound infection (30 trials, 96.7%), hernia recurrence (30, 96.7%), seroma (29, 93.5%), length of hospital stay (22, 71%) and haematoma (21, 67.7%) reported most frequently. Fourteen (45%), 11 (35%) and 0 trials reported CT measurements of hernia defect area, width and loss of domain, respectively. No trial graded hernias using generally accepted scales. CONCLUSION: VH RCTs report peri- and post-operative variables inconsistently, and with poor definitions. A standardised minimum dataset, including definitions of recurrence, is required

Post-imaging colorectal cancer or interval cancer rates after computed tomographic colonography: A systematic review and meta-analysis

Background: CT colonography (CTC) is highly sensitive for colorectal cancer, but “interval” or postimaging colorectal cancer (PICRC) rates (diagnosis of cancer after initial negative CTC) are unknown, as are their underlying causes. Methods: We conducted a systematic review and meta-analysis of post-CTC PICRC rates and causes by searching MEDLINE, EMBASE and the Cochrane Register. We included randomised, cohort, cross-sectional or case-control studies published Jan 1994-Feb 2017, using CTC performed according to international consensus standards with aim of detecting cancer or polyps, and reporting PICRC rates or sufficient data to allow their calculation. Two independent reviewers extracted data from the study reports. We used random-effects meta-analysis to estimate pooled PICRC rates, expressed using (a) total number of cancers and (b) total number of CTC scans as denominators, and (c) per 1000 person-years. Primary study authors provided details of retrospective CTC image review and causes for each PICRC. The study is registered (PROSPERO:CRD42016046838). Findings: 2977 articles were screened and 12 analysed. These reported 19,867 patients (18-96 years; of 11,590 with sex data available, 6532 (56·4%) female) from March 2002-May 2015. At mean 34 months’ follow-up (range: 3 to 128·4 months), CTC detected 643 cancers and 29 PICRCs were diagnosed. The pooled PICRC rate was 4·42 PICRCs/100 cancers detected; 95%CI 3·03-6·42, corresponding to 1·61 PICRCs/1000 CTCs (95%CI 1·11-2·33) or 0·64 PICRCs/1000 person-years (95%CI 0·44-0·92). Heterogeneity was low (I2 =0%). Over half (17/28, 61%) of PICRCs were due to perceptual error and visible in retrospect. Interpretation: The 3-year PICRC rate post-CTC is 4·4%, or 0·64 per 1000 person-years, towards the lower end of range reported for colonoscopy. Most arise from perceptual errors. Radiologist training and quality assurance may help reduce PICRC rates. Funding: St Mark’s Hospital Foundation and the UCL/UCLH Biomedical Research Centre

Identifying predictors of ventral hernia recurrence: systematic review and meta-analysis.

BACKGROUND: Ventra hernias are increasing in prevalence and many recur despite attempted repair. To date, much of the literature is underpowered and divergent. As a result there is limited high quality evidence to inform surgeons succinctly which perioperative variables influence postoperative recurrence. This systematic review aimed to identify predictors of ventral hernia recurrence. METHODS: PubMed was searched for studies reporting prognostic data of ventral hernia recurrence between 1 January 1995 and 1 January 2018. Extracted data described hernia type (primary/incisional), definitions of recurrence, methods used to detect recurrence, duration of follow-up, and co-morbidity. Data were extracted for all potential predictors, estimates and thresholds described. Random-effects meta-analysis was used. Bias was assessed with a modified PROBAST (Prediction model Risk Of Bias ASsessment Tool). RESULTS: Screening of 18 214 abstracts yielded 274 individual studies for inclusion. Hernia recurrence was defined in 66 studies (24.1 per cent), using 41 different unstandardized definitions. Three patient variables (female sex, age 65 years or less, and BMI greater than 25, 30, 35 or 40 kg/m2), five patient co-morbidities (smoking, diabetes, chronic obstructive pulmonary disease, ASA grade III-IV, steroid use), two hernia-related variables (incisional/primary, recurrent/primary), six intraoperative variables (biological mesh, bridged repair, open versus laparoscopic surgery, suture versus mesh repair, onlay/retrorectus, intraperitoneal/retrorectus), and six postoperative variables (any complication, surgical-site occurrence, wound infection, seroma, haematoma, wound dehiscence) were identified as significant prognostic factors for hernia recurrence. CONCLUSION: This study summarized the current evidence base for predicting ventral hernia recurrence. Results should inform best practice and future research

An evaluation of computed tomographic colonography in the English national bowel cancer screening programme

Colorectal cancer (CRC) is a common, important disease with a mortality approaching 50%. Outcomes can be improved by screening because early CRC has an excellent prognosis and there is a long, easily treatable premalignant phase. England has a national bowel cancer screening programme (BCSP) based on faecal occult blood testing (FOBt), followed by colonoscopy for those testing positive. However, not all subjects can undergo colonoscopy due to frailty or technical failure. The preferred alternative is computed tomographic colonography (CTC), an X-ray scan of the cleansed, gas-distended colon. Little is known regarding performance characteristics and other attributes of CTC in the English BCSP, the subject of this thesis. The thesis is structured as follows: Section A provides an overview of CRC screening and the BCSP, followed by a systematic review and meta-analysis of the diagnostic performance of CTC for FOBt-positive subjects. Section B describes current usage of CTC in the BCSP via a national survey of current practice and an analysis of neoplasia detection rates in comparison to colonoscopy, including sub-analyses of the effects of (a) variable FOBt positivity and (b) terminal digit preference bias. Section C evaluates patient experience via comparative analysis of national questionnaires for CTC and colonoscopy. Reasons for non-attendance for colonic testing (despite a positive FOBt result) are investigated via an interview study, and a discrete choice experiment tests the influence of extracolonic abnormalities on the acceptability of CTC (for both patients and healthcare professionals). Section D evaluates methods to improve diagnostic accuracy, using eye-tracking to investigate why radiologists miss polyps, and the effect of increased viewing speeds. The different spectrum of disease encountered in a screening population is explored via comparison of the CTC appearances of screen-detected and symptomatic colorectal cancers. Section E concludes and summarises the thesis, and makes recommendations for future research