Quality of life after emergency laparotomy: a systematic review.

BACKGROUND: Emergency laparotomy is a commonly performed surgical procedure that has higher post-operative morbidity and mortality than elective surgery. Previous research has identified that patients valued postoperative quality of life (QoL) more than the risk of mortality when deciding to undergo emergency surgery. Current pre-operative scoring and risk stratification systems for emergency laparotomy do not account for or provide prediction tools for post-operative QoL. This study aims to systematically review previous literature to determine post-operative QoL in patients who undergo emergency laparotomy. METHODS: A literature search was undertaken in Medline, EMBASE and the Cochrane Library to identify studies measuring post-operative QoL in patients who have had emergency laparotomy up to 29th April 2023. Mean QoL scores from the studies included were combined to calculate the average effect of emergency laparotomy on QoL. The primary outcome of the review was postoperative QoL after emergency laparotomy when compared with a comparator group. Secondary outcomes included the quality of included studies. RESULTS: Ten studies in the literature assessing the QoL of patients after emergency laparotomy were identified. Three studies showed that patients had improved QoL and seven showed worse QoL following emergency laparotomy. Length of time for QoL to return to baseline varied ranged from 3 to 12 months post-operatively. Length of hospital stay was identified as an independent risk factor for poorer QoL post-surgery. CONCLUSIONS: Outcome reporting for patients who undergo emergency laparotomy should be expanded further to include QoL. Further work is required to investigate this and elicit factors that can improve QoL post-operatively.

The Role of Artificial Intelligence in Prospective Real-Time Histological Prediction of Colorectal Lesions during Colonoscopy: A Systematic Review and Meta-Analysis.

Artificial intelligence (AI) presents a novel platform for improving disease diagnosis. However, the clinical utility of AI remains limited to discovery studies, with poor translation to clinical practice. Current data suggests that 26% of diminutive pre-malignant lesions and 3.5% of colorectal cancers are missed during colonoscopies. The primary aim of this study was to explore the role of artificial intelligence in real-time histological prediction of colorectal lesions during colonoscopy. A systematic search using MeSH headings relating to "AI", "machine learning", "computer-aided", "colonoscopy", and "colon/rectum/colorectal" identified 2290 studies. Thirteen studies reporting real-time analysis were included. A total of 2958 patients with 5908 colorectal lesions were included. A meta-analysis of six studies reporting sensitivities (95% CI) demonstrated that endoscopist diagnosis was superior to a computer-assisted detection platform, although no statistical significance was reached (p = 0.43). AI applications have shown encouraging results in differentiating neoplastic and non-neoplastic lesions using narrow-band imaging, white light imaging, and blue light imaging. Other modalities include autofluorescence imaging and elastic scattering microscopy. The current literature demonstrates that despite the promise of new endoscopic AI models, they remain inferior to expert endoscopist diagnosis. There is a need to focus developments on real-time histological predictions prior to clinical translation to demonstrate improved diagnostic capabilities and time efficiency.

Which Electronic Health Record System Should We Use? A Systematic Review.

The UK government had intended to introduce a comprehensive Electronic Health Record (EHR) system in England by 2020. These EHRs would run across primary, secondary, and social care, linking data in a single digital platform. The objectives of this systematic review were to identify studies that compare EHR in terms of direct comparison between systems and to evaluate them using System and Software Quality Requirements and Evaluation (SQuaRE) ISO/IEC 25010. A systematic review was performed by searching Embase and Ovid MEDLINE databases between 1974 and April 2021. All original studies that appraised EHR systems and their providers were included. The main outcome measures were EHR system comparison and the eight characteristics of SQuaRE: functional suitability, performance efficiency, compatibility, usability, reliability, security, maintainability, and portability. A total of 724 studies were identified using the search criteria. After a review of titles and abstracts, this was filtered down to 40 studies as per the exclusion and inclusion criteria set out in our study. Seven studies compared more than one EHR. The following number of studies looked at the various aspects of the SQuaRE, respectively - 19 studies: functional suitability, performance efficiency: 18 studies, compatibility: 12 studies, usability: 25 studies, reliability: 6 studies, security: 2 studies, maintainability: 16 studies, portability: 13 studies. Epic was the most studied EHR system and one of the most implemented systems in the US market and one of the top ten in the UK. It is difficult to assess which is the most advantageous EHR system when they are assessed by SQuaRE's 8 characteristics for software evaluation.

A call for governments to pause Twitter censorship: using Twitter data as social-spatial sensors of COVID-19/SARS-CoV-2 research diffusion.

In this study we determined whether Twitter data can be used as social-spatial sensors to show how research on COVID-19/SARS-CoV-2 diffuses through the population to reach the people that are affected by the disease. We performed a cross-sectional bibliometric analysis between 23rd March and 14th April 2020. Three sources of data were used: (1) deaths per number of population for COVID-19/SARS-CoV-2 retrieved from John Hopkins University and Worldometer, (2) publications related to COVID-19/SARS-CoV-2 retrieved from World Health Organisation COVID-19 database, and (3) tweets of these publications retrieved from Altmetric.com and Twitter. In the analysis, the number of publications used was 1761, and number of tweets used was 751,068. Mapping of worldwide data illustrated that high Twitter activity was related to high numbers of COVID-19/SARS-CoV-2 deaths, with tweets inversely weighted with number of publications. Regression models of worldwide data showed a positive correlation between the national deaths per number of population and tweets when holding number of publications constant (coefficient 0.0285, S.E. 0.0003, p < 0.001). Twitter can play a crucial role in the rapid research response during the COVID-19/SARS-CoV-2 pandemic, especially to spread research with prompt public scrutiny. Governments are urged to pause censorship of social media platforms to support the scientific community's fight against COVID-19/SARS-CoV-2.

Are disruptive innovations recognised in the healthcare literature? A systematic review.

The study aims to conduct a systematic review to characterise the spread and use of the concept of 'disruptive innovation' within the healthcare sector. We aim to categorise references to the concept over time, across geographical regions and across prespecified healthcare domains. From this, we further aim to critique and challenge the sector-specific use of the concept. PubMed, Medline, Embase, Global Health, PsycINFO, Maternity and Infant Care, and Health Management Information Consortium were searched from inception to August 2019 for references pertaining to disruptive innovations within the healthcare industry. The heterogeneity of the articles precluded a meta-analysis, and neither quality scoring of articles nor risk of bias analyses were required. 245 articles that detailed perceived disruptive innovations within the health sector were identified. The disruptive innovations were categorised into seven domains: basic science (19.2%), device (12.2%), diagnostics (4.9%), digital health (21.6%), education (5.3%), processes (17.6%) and technique (19.2%). The term has been used with increasing frequency annually and is predominantly cited in North American (78.4%) and European (15.2%) articles. The five most cited disruptive innovations in healthcare are 'omics' technologies, mobile health applications, telemedicine, health informatics and retail clinics. The concept 'disruptive innovation' has diffused into the healthcare industry. However, its use remains inconsistent and the recognition of disruption is obscured by other types of innovation. The current definition does not accommodate for prospective scouting of disruptive innovations, a likely hindrance to policy makers. Redefining disruptive innovation within the healthcare sector is therefore crucial for prospectively identifying cost-effective innovations.

Are papers addressing certain diseases perceived where these diseases are prevalent? The proposal to use Twitter data as social-spatial sensors.

We propose to use Twitter data as social-spatial sensors. This study deals with the question whether research papers on certain diseases are perceived by people in regions (worldwide) that are especially concerned by these diseases. Since (some) Twitter data contain location information, it is possible to spatially map the activity of Twitter users referring to certain papers (e.g., dealing with tuberculosis). The resulting maps reveal whether heavy activity on Twitter is correlated with large numbers of people having certain diseases. In this study, we focus on tuberculosis, human immunodeficiency virus (HIV), and malaria, since the World Health Organization ranks these diseases as the top three causes of death worldwide by a single infectious agent. The results of the social-spatial Twitter maps (and additionally performed regression models) reveal the usefulness of the proposed sensor approach. One receives an impression of how research papers on the diseases have been perceived by people in regions that are especially concerned by these diseases. Our study demonstrates a promising approach for using Twitter data for research evaluation purposes beyond simple counting of tweets.

Surgical Innovation in the Era of Global Surgery: A Network Analysis.

OBJECTIVE: To present a novel network-based framework for the study of collaboration in surgery and demonstrate how this can be used in practice to help build and nurture collaborations that foster innovation. BACKGROUND: Surgical innovation is a social process that originates from complex interactions among diverse participants. This has led to the emergence of numerous surgical collaboration networks. What is still needed is a rigorous investigation of these networks and of the relative benefits of various collaboration structures for research and innovation. METHODS: Network analysis of the real-world innovation network in robotic surgery. Hierarchical mixed-effect models were estimated to assess associations between network measures, research impact and innovation, controlling for the geographical diversity of collaborators, institutional categories, and whether collaborators belonged to industry or academia. RESULTS: The network comprised of 1700 organizations and 6000 links. The ability to reach many others along few steps in the network (closeness centrality), forging a geographically diverse international profile (network entropy), and collaboration with industry were all shown to be positively associated with research impact and innovation. Closed structures (clustering coefficient), in which collaborators also collaborate with each other, were found to have a negative association with innovation (P < 0.05 for all associations). CONCLUSIONS: In the era of global surgery and increasing complexity of surgical innovation, this study highlights the importance of establishing open networks spanning geographical boundaries. Network analysis offers a valuable framework for assisting surgeons in their efforts to forge and sustain collaborations with the highest potential of maximizing innovation and patient care.

Evaluating the implications of Brexit for research collaboration and policy: a network analysis and simulation study.

OBJECTIVE: To evaluate the role of the European Union (EU) as a research collaborator in the UK's success as a global leader in healthcare research and innovation and quantify the impact that Brexit may have. DESIGN: Network and regression analysis of scientific collaboration, followed by simulation models based on alternative scenarios. SETTING: International real-world collaboration network among all countries involved in robotic surgical research and innovation. PARTICIPANTS: 772 organisations from industry and academia nested within 56 countries and connected through 2397 collaboration links. MAIN OUTCOME MEASURES: Research impact measured through citations and innovation value measured through the innovation index. RESULTS: Globally, the UK ranks third in robotic surgical innovation, and the EU constitutes its prime collaborator. Brokerage opportunities and collaborators' geographical diversity are associated with a country's research impact (c=211.320 and 244.527, respectively; p<0·01) and innovation (c=18.819 and 30.850, respectively; p<0·01). Replacing EU collaborators with US ones is the only strategy that could benefit the UK, but on the condition that US collaborators are chosen among the top-performing ones, which is likely to be very difficult and costly, at least in the short term. CONCLUSIONS: This study suggests what has long been argued, namely that the UK-EU research partnership has been mutually beneficial and that its continuation represents the best possible outcome for both negotiating parties. However, the uncertainties raised by Brexit necessitate looking beyond the EU for potential research partners. In the short term, the UK's best strategy might be to try and maintain its academic links with the EU. In the longer term, strategic relationships with research powerhouses, including the USA, China and India, are likely to be crucial for the UK to remain a global innovation leader.

Collaborative patterns, authorship practices and scientific success in biomedical research: a network analysis.

OBJECTIVE: To investigate the relationship between biomedical researchers' collaborative and authorship practices and scientific success. DESIGN: Longitudinal quantitative analysis of individual researchers' careers over a nine-year period. SETTING: A leading biomedical research institution in the United Kingdom. PARTICIPANTS: Five hundred and twenty-five biomedical researchers who were in employment on 31 December 2009. MAIN OUTCOME MEASURES: We constructed the co-authorship network in which nodes are the researchers, and links are established between any two researchers if they co-authored one or more articles. For each researcher, we recorded the position held in the co-authorship network and in the bylines of all articles published in each three-year interval and calculated the number of citations these articles accrued until January 2013. We estimated maximum likelihood negative binomial panel regression models. RESULTS: Our analysis suggests that collaboration sustained success, yet excessive co-authorship did not. Last positions in non-alphabetised bylines were beneficial for higher academic ranks but not for junior ones. A professor could witness a 20.57% increase in the expected citation count if last-listed non-alphabetically in one additional publication; yet, a lecturer suffered from a 13.04% reduction. First positions in alphabetised bylines were positively associated with performance for junior academics only. A lecturer could experience a 8.78% increase in the expected citation count if first-listed alphabetically in one additional publication. While junior researchers amplified success when brokering among otherwise disconnected collaborators, senior researchers prospered from socially cohesive networks, rich in third-party relationships. CONCLUSIONS: These results help biomedical scientists shape successful careers and research institutions develop effective assessment and recruitment policies that will ultimately sustain the quality of biomedical research and patient care.

Mentoring perception, scientific collaboration and research performance: is there a 'gender gap' in academic medicine? An Academic Health Science Centre perspective.

OBJECTIVES: The 'gender gap' in academic medicine remains significant and predominantly favours males. This study investigates gender disparities in research performance in an Academic Health Science Centre, while considering factors such as mentoring and scientific collaboration. MATERIALS AND METHODS: Professorial registry-based electronic survey (n=215) using bibliometric data, a mentoring perception survey and social network analysis. Survey outcomes were aggregated with measures of research performance (publications, citations and h-index) and measures of scientific collaboration (authorship position, centrality and social capital). Univariate and multivariate regression models were constructed to evaluate inter-relationships and identify gender differences. RESULTS: One hundred and four professors responded (48% response rate). Males had a significantly higher number of previous publications than females (mean 131.07 (111.13) vs 79.60 (66.52), p=0.049). The distribution of mentoring survey scores between males and females was similar for the quality and frequency of shared core, mentor-specific and mentee-specific skills. In multivariate analysis including gender as a variable, the quality of managing the relationship, frequency of providing corrective feedback and frequency of building trust had a statistically significant positive influence on number of publications (all p<0.05). CONCLUSIONS: This is the first study in healthcare research to investigate the relationship between mentoring perception, scientific collaboration and research performance in the context of gender. It presents a series of initiatives that proved effective in marginalising the gender gap. These include the Athena Scientific Women's Academic Network charter, new recruitment and advertisement strategies, setting up a 'Research and Family Life' forum, establishing mentoring circles for women and projecting female role models.

Leadership behaviours and healthcare research performance: prospective correlational study.

OBJECTIVES: The aims of the study were to determine whether differences in leadership self-perception/behaviour in healthcare researchers may influence research performance and to evaluate whether certain leadership characteristics are associated with enhanced leadership efficiency in terms of motivation, effectiveness and satisfaction. DESIGN AND PARTICIPANTS: All Faculty of Medicine Professors at Imperial College London (n=215) were sent the Multifactor Leadership Questionnaire (MLQ) Self form as a means of evaluating self-perception of leadership behaviours. MAIN OUTCOME MEASURES: For each professor, we extracted objective research performance measures (total number of publications, total number of citations and h index) from 1 January 2007 to 31 December 2009. The MLQ measured three leadership outcomes, which included motivation, effectiveness and satisfaction. Regression analysis was used to determine associations. RESULTS: A total number of 90 responses were received, which equated to a 42% response rate. There were no significant correlations between transformational, transactional or passive/avoidant leadership behaviours and any of the research performance measures. The five transformational leadership behaviours (ie, idealised attributes (IA), idealised behaviours (IB), inspirational motivation (IM), intellectual stimulation (IS), individual consideration (IC)) were highly significant predictors of leadership outcomes, extra effort (all B>0.404, SE=0.093-0.146, p<0.001), effectiveness (IA, IM, IS, IC B>0.359, SE=0.093-0.146, p<0.001; IB B=0.233, SE=0.103, p=0.026) and satisfaction (IA, IM, IS, IC B>0.483, SE=0.086-0.139, p<0.001; IB B=0.296, SE=0.101, p=0.004). Similarly, contingent reward was a significant predictor of extra effort (B=0.400, SE=0.123, p=0.002), effectiveness (B=0.353, SE=0.113, p=0.002) and satisfaction (B=0.326, SE=0.114, p=0.005). CONCLUSIONS: This study demonstrates that transformational leadership and contingent reward positively influence leadership efficiency in healthcare researchers. Although we did not show an association between leadership behaviours and research performance metrics, further studies using contextual performance measures at team and organisational levels are required.

Mentoring perception and academic performance: an Academic Health Science Centre survey.

PURPOSE: To determine the association between professors' self-perception of mentoring skills and their academic performance. DESIGN: Two hundred and fifteen professors from Imperial College London, the first Academic Health Science Centre (AHSC) in the UK, were surveyed. The instrument adopted was the Mentorship Skills Self-Assessment Survey. Statement scores were aggregated to provide a score for each shared core, mentor-specific and mentee-specific skill. Univariate and multivariate regression analyses were used to evaluate their relationship with quantitative measures of academic performance (publications, citations and h-index). RESULTS: There were 104 professors that responded (response rate 48%). There were no statistically significant negative correlations between any mentoring statement and any performance measure. In contrast, several mentoring survey items were positively correlated with academic performance. The total survey score for frequency of application of mentoring skills had a statistically significant positive association with number of publications (B=0.012, SE=0.004, p=0.006), as did the frequency of acquiring mentors with number of citations (B=1.572, SE=0.702, p=0.030). Building trust and managing risks had a statistically significant positive association with h-index (B=0.941, SE=0.460, p=0.047 and B=0.613, SE=0.287, p=0.038, respectively). CONCLUSIONS: This study supports the view that mentoring is associated with high academic performance. Importantly, it suggests that frequent use of mentoring skills and quality of mentoring have positive effects on academic performance. Formal mentoring programmes should be considered a fundamental part of all AHSCs' configuration.

Quality of life after intervention on the thoracic aorta.

Surgery on the thoracic aorta is challenging and historically associated with significant mortality and morbidity. In recent times, there has been increased emphasis on the importance of health-related quality of life (HRQOL) measures. It is seen as a development beyond isolated markers of outcome such as operative mortality and is particularly applicable to aortic surgery given the number of asymptomatic patients operated on (for prognostic grounds), and rapidly advancing endovascular technologies which require proper assessment. This systematic review provides an outline of all available literature detailing HRQOL in patients receiving intervention (both open and endovascular) on the thoracic aorta. In total, 30 studies were identified encompassing 4746 patients undergoing a variety of procedures from aortic root replacement to thoracoabdominal aortic aneurysm repair. While there were deficiencies in the underlying literature such as lack of baseline HRQOL assessment, the majority of the studies confirm that HRQOL after major aortic surgery (including on the elderly and in emergency situations) is acceptable and compares well to matched general populations. Strategies for improving the HRQOL in aortic surgery are summarized and include the need for surgeons to plan cerebral protection methods more carefully and to develop operative strategies to avoid reoperation or reintervention, as this is associated with deterioration of long-term HRQOL. Randomized studies measuring baseline and follow-up HRQOL at specific set points are needed. Innovative research methods could be employed in future studies with the aim of correlating HRQOL with imaging or physiological/inflammation biomarkers, or other end points such as aortic stiffness or wall shear stress to characterize disease progression and prognosis.

Aortic Stiffness Is Related to the Ischemic Brain Injury Biomarker N-Methyl-D-aspartate Receptor Antibody Levels in Aortic Valve Replacement.

Background. Aortic stiffness changes the flow pattern of circulating blood causing microvascular damage to different end-organ tissues, such as brain cells. The relationship between aortic stiffness measured by pulse wave velocity (PWV) and serum ischemic brain injury biomarker N-methyl-D-aspartate receptor antibody (NR2Ab) levels in aortic valve replacement has not been assessed. Methods. Patients undergoing aortic valve replacement (AVR) for aortic stenosis (AS) had their PWV and NR2Ab serum levels measured preoperatively. We analyzed PWV and NR2Ab in two ways: (1) as continuous variables using the actual value and (2) as dichotomous variables (PWV-norm and PWV-high groups) and (NR2Ab-low and NR2Ab-high groups). Results. Fifty-six patients (71 ± 8.4 years) were included in this study. The NR2Ab level (ng/mL) was significantly higher in the PWV-high group (n = 21) than in PWV-norm group (n = 35; median 1.8 ± 1.2 versus 1.2 ± 0.7, resp., P = 0.003). NR2Ab level was positively associated with PWV and negatively associated with male gender. Multiple regression revealed PWV independently related to NR2Ab level, and PWV cut-off was associated with a 7.23 times increase in the likelihood of having high NR2Ab (>1.8 ng/mL). Conclusion. Higher PWV in patients with surgical aortic stenosis is associated with higher levels of the ischemic brain biomarker NR2Ab.

What factors influence British medical students' career intentions?

AIM: The aim of this study was to identify factors that influence career choice in UK medical students. METHODS: Students at seven institutions were invited to rate how important various factors were on influencing their career choices and how interested they were in pursuing different specialties. The influence of interpersonal relationship networks on career choice was also evaluated. RESULTS: 641 responses were collected. 44% (283) were male, 16% (105) were graduates and 41% (263) were final-year students. For Dermatology (p = 0.009), Paediatrics (p = 0.000), Radiology (p = 0.000), Emergency Medicine (p = 0.018) and Cardiothoracic Surgery (p = 0.000), there was a clear correlation between completing a clinical attachment and an interest in pursuing the specialty. Perceived characteristics of the speciality, individually and in clusters were considered important by specific subgroups of students, such as those interested in surgery. These students considered prestige (p = 0.0003), role models (p = 0.014), financial rewards after training (p = 0.0196) and technical challenge (p = 0.0011) as important factors. Demographics such as sex and age played a significant role in career choice. Interpersonal relationship networks do not have a significant influence on career intentions. CONCLUSIONS: This study shows that the career intentions of British medical students are influenced by their undergraduate experience and by the weight they place on different specialty-related factors.

Guidelines in cardiac clinical practice: evaluation of their methodological quality using the AGREE II instrument.

Although clinical guidelines have an influential role in healthcare practice, their development process and the evidence they cite has been subject to criticism. This study evaluates the quality of guidelines in cardiac clinical practice by examining how they adhere to validated methodological standards in guideline development. A structured review of cardiac clinical practice guidelines published in seven cardiovascular journals between January 2001 and May 2011 was performed. The AGREE II assessment tool was used by two researchers to evaluate guideline quality. A total of 101 guidelines were identified. Assessment of guidelines using AGREE II found methodological quality to be highly variable (median score, 58.70%; range, 45.34-76.40%). 'Scope and purpose' (median score, 86.1%) and 'clarity of development' (median score, 83.3 %) were the two domains within AGREE II that received the highest scores. Applicability (median score, 20.80%; range, 4.20-54.20%) and editorial independence (median score, 33.30%; range, 0-62.50%) had the lowest scores. There is considerable variability in the quality of cardiac clinical practice guidelines and this has not improved over the last 10 years. Incorporating validated guideline assessment tools, such as AGREE II, may improve the quality of guidelines.

Fast-track laparoscopic bariatric surgery: a systematic review.

This study aimed to systematically evaluate the evidence-based literature on fast-track laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic adjustable gastric banding (LAGB) to determine the feasibility and safety of fast-track laparoscopic bariatric surgery. A literature search of PubMed, EMBASE and Cochrane Library using the MeSH terms "bariatric surgery", "ambulatory surgical procedures" and related terms as keywords was performed. The study included articles that reported on intended next-day discharge for LRYGB and same-day discharge for LAGB. Data were extracted on study design and size, patient demographics, patient-selection criteria, patient preparation, perioperative management, operative details, clinical outcomes, and follow-up. The review included 13 studies classified as level 3b or 4 evidence. There were seven studies that investigated LAGB, five studies investigated LRYGB and one study detailed outcomes from both LRYGB and LAGB. Next-day discharge rate ranged from 81 to 100 % for LRYGB. Same-day discharge rate ranged from 76 to 98 % for LAGB. In LRYGB and LAGB complication, re-admission and mortality rates (≤10.5, ≤7.5, ≤0.1 %, respectively) were comparable with the conventional perioperative care. From our results, the fast-track management of patients undergoing LRYGB and LAGB is feasible. With careful patient selection and preparation within high-volume centres, and application of care pathways including close outpatient follow-up, outcomes for fast-track bariatric procedures can compare favourably with those reported in the literature for standard management, but with decreased cost. However, further studies from independent researchers are required to determine the safety of a generalised adoption of this approach outside of dedicated bariatric units, and to formally demonstrate the cost-benefit of fast-track bariatric surgery.

Enhancing the h index for the objective assessment of healthcare researcher performance and impact.

OBJECTIVE: To investigate whether the h index (a bibliometric tool which is increasingly used to assess and appraise an individual's research performance) could be improved to better measure the academic performance and citation profile for individual healthcare researchers. DESIGN: Cohort study. SETTING: Faculty of Medicine, Imperial College London, UK. PARTICIPANTS: Publication lists from 1 January 2000 until 31 December 2009 for 501 academic healthcare researchers from the Faculty of Medicine. MAIN OUTCOME MEASURES: The h index for each researcher was calculated over a nine-year period. The citation count for each researcher was differentiated into high (h(2) upper), core (h(2) centre) and low (h(2) lower) visibility areas. Segmented regression model (sRM) was used to statistically estimate number of high visibility publications (sRM value). Validity of the h index and other proposed adjuncts were analysed against academic rank and conventional bibliometric indicators. RESULTS: Construct validity was demonstrated for h index, h(2) upper, h(2) centre, h(2) lower and sRM value (all P < 0.05). Convergent validity of the h index and sRM value was shown by significant correlations with total number of publications (r = 0.89 and 0.86 respectively, P < 0.05) and total number of citations (r = 0.96 and 0.65, respectively, P < 0.05). Significant differences in h index and sRM value existed between non-physician and physician researchers (P < 0.05). CONCLUSIONS: This study supports the construct validity of the h index as a measure of healthcare researcher academic rank. It also identifies the assessment value of our developed indices of h(2) upper, h(2) centre, h(2) lower and sRM. These can be applied in combination with the h index to provide additional objective evidence to appraise the performance and impact of an academic healthcare researcher.

Measuring academic performance for healthcare researchers with the H index: which search tool should be used?

OBJECTIVES: To compare H index scores for healthcare researchers returned by Google Scholar, Web of Science and Scopus databases, and to assess whether a researcher's age, country of institutional affiliation and physician status influences calculations. SUBJECTS AND METHODS: One hundred and ninety-five Nobel laureates in Physiology and Medicine from 1901 to 2009 were considered. Year of first and last publications, total publications and citation counts, and the H index for each laureate were calculated from each database. Cronbach's alpha statistics was used to measure the reliability of H index scores between the databases. Laureate characteristic influence on the H index was analysed using linear regression. RESULTS: There was no concordance between the databases when considering the number of publications and citations count per laureate. The H index was the most reliably calculated bibliometric across the three databases (Cronbach's alpha = 0.900). All databases returned significantly higher H index scores for younger laureates (p < 0.0001). Google Scholar and Web of Science returned significantly higher H index for physician laureates (p = 0.025 and p = 0.029, respectively). Country of institutional affiliation did not influence the H index in any database. CONCLUSION: The H index appeared to be the most consistently calculated bibliometric between the databases for Nobel laureates in Physiology and Medicine. Researcher-specific characteristics constituted an important component of objective research assessment. The findings of this study call to question the choice of current and future academic performance databases.

Body mass index category as a risk factor for colorectal adenomas: a systematic review and meta-analysis.

OBJECTIVES: The association between increasing body weight and colorectal adenoma prevalence has been suggested to follow a similar pattern to excess weight and colorectal cancer, although the magnitude of this relationship has not been validated. The objective of this study was to quantify the association and dose-response relationship between body mass index (BMI) and colorectal adenoma prevalence in clinical trials. METHODS: We systematically reviewed 23 studies (168,201 participants), which compared the prevalence of colorectal adenomas according to World Health Organization BMI categories. We assessed the effects of each BMI category on colorectal adenomas where odds ratio (OR) was used as a surrogate for effect size, and applied multivariate meta-analysis as a method of sensitivity analysis to evaluate the robustness of our findings and to analyze adenoma prevalence by multiple BMI categories simultaneously to assess for a dose-response relationship. Heterogeneity and publication bias were assessed. RESULTS: Subjects with a BMI of ≥25 had a significantly higher prevalence of colorectal adenomas (OR=1.24 (95% confidence interval (CI): 1.16-1.33), P<0.01) when compared with those with BMI<25. Multivariate meta-analysis also confirmed a positive association between higher BMI categories and the prevalence of colorectal adenoma (BMI: 25-30 vs. BMI<25; OR=1.21 (95% CI: 1.07-1.38), P<0.01; BMI≥30 vs. BMI<25; OR=1.32 (95% CI: 1.18-1.48), P<0.01) and revealed a dose-response relationship. CONCLUSIONS: The positive association between obesity and colorectal adenoma prevalence demonstrates an underlying dose-response relationship according to BMI. Colorectal centers may benefit from the timely screening of obese patients for colorectal adenomas in addition to clarifying the biological role of adiposity on colorectal tumor initiation and progression.