Discover the most talked about and latest scientific content & concepts.

Concept: Number needed to harm


Successful coexistence between large carnivores and humans is conditional upon effective mitigation of the impact of these species on humans, such as through livestock depredation. It is therefore essential for conservation practitioners, carnivore managing authorities, or livestock owners to know the effectiveness of interventions intended to reduce livestock predation by large carnivores. We reviewed the scientific literature (1990-2016), searching for evidence of the effectiveness of interventions. We found experimental and quasi-experimental studies were rare within the field, and only 21 studies applied a case-control study design (3.7% of reviewed publications). We used a relative risk ratio to evaluate the studied interventions: changing livestock type, keeping livestock in enclosures, guarding or livestock guarding dogs, predator removal, using shock collars on carnivores, sterilizing carnivores, and using visual or auditory deterrents to frighten carnivores. Although there was a general lack of scientific evidence of the effectiveness of any of these interventions, some interventions reduced the risk of depredation whereas other interventions did not result in reduced depredation. We urge managers and stakeholders to move towards an evidence-based large carnivore management practice and researchers to conduct studies of intervention effectiveness with a randomized case-control design combined with systematic reviewing to evaluate the evidence.

Concepts: Number needed to harm, Science, Epidemiology, Study design, Case-control study, Relative risk, Cohort study, Predation


Extravasation of medications during peripheral intravenous (PIV) therapy can result in harm to pediatric patients. These medications have physical and/or biologic factors that cause tissue damage. To assist in clinical decisions when using these infusates, an evidence-based table of medications stratified by their relative risk of causing harm if extravasated was developed. Local data and experience, a systematic review of the pediatric literature, and measured pH and osmolality of common pediatric preparations of PIV infusates were used to create a 3-tiered table of PIV infusates categorized by relative risk of causing harm if extravasated.

Concepts: Evidence-based medicine, Extravasation, Relative risk, Medical statistics, Result, Number needed to harm, Causality, Medicine


Policies that allow directly citing motorists for seat belt non-use (primary enforcement) have been shown to reduce motor vehicle crash deaths relative to secondary enforcement, but the evidence base is dated and does not account for recent improvements in vehicle designs and road safety. The purpose of this study was to test whether recent upgrades to primary enforcement still reduce motor vehicle crash deaths.

Concepts: Seat belt legislation, Number needed to harm, Automobile


OBJECTIVES: We assessed the evidence relating preterm delivery (PTD), low birth weight, small for gestational age (SGA), pre-eclampsia and gestational hypertension to five occupational exposures (working hours, shift work, lifting, standing and physical workload). We conducted a systematic search in Medline and Embase (1966 to 2011), updating a previous search with a further 6 years of observations. METHODS: As before, combinations of keywords and medical subject headings were used. Each relevant paper was assessed for completeness of reporting and potential for important bias or confounding, and its effect estimates abstracted. Where similar definitions of exposure and outcome existed we calculated pooled estimates of relative risk (RR) in meta-analysis. RESULTS: Analysis was based on 86 reports (32 cohort investigations, 57 with usable data on PTD, 54 on birth weight and 11 on pre-eclampsia/gestational hypertension); 33 reports were new to this review. For PTD, findings across a substantial evidence base were generally consistent, effectively ruling out large effects (eg, RR>1.2). Larger and higher quality studies were less positive, while meta-estimates of risk were smaller than in previous analyses and best estimates pointed to modest or null effects (RR 1.04 to 1.18). For SGA, the position was similar but meta-estimates were even closer to the null (eight of nine RRs≤1.07). For pre-eclampsia/gestational hypertension the evidence base remains insufficient. CONCLUSIONS: The balance of evidence is against large effects for the associations investigated. As the evidence base has grown, estimates of risk in relation to these outcomes have become smaller.

Concepts: Publication bias, Evidence-based medicine, Number needed to harm, Systematic review, Meta-analysis, Hypertension, Childbirth, Obstetrics


There is rising awareness that we need multidisciplinary approaches integrating psychological treatments for schizophrenia, but a comprehensive evidence based on their relative efficacy is lacking. We will conduct a network meta-analysis (NMA), integrating direct and indirect comparisons from randomised controlled trials (RCTs) to rank psychological treatments for schizophrenia according to their efficacy, acceptability and tolerability.

Concepts: Number needed to harm, Avicenna, Meta-analysis, The Canon of Medicine, Evidence-based medicine, Systematic review, Publication bias, Randomized controlled trial


Studies evidenced that reduction in cardiovascular disease (CVD) mortality in diabetic patients can be attributed to improvements in major CVD risk factors and evidence-based treatments. Furthermore, studies showed that the relative risk of CVD mortality associated with diabetes compared with non-diabetes is stronger in women than in men. Hence, we aimed to examine trends in CVD risk factors and intervention measures by sex and diabetic status.

Concepts: Blood vessel, Number needed to harm, Medical conditions related to obesity, Cardiovascular disease, Medical statistics, Myocardial infarction, The Canon of Medicine, Epidemiology


Despite research suggesting that use of forensic assessment instruments of competency to stand trial (CST) can improve the integrity of forensic conceptualizations (Rogers & Johansson-Love, 2009), the majority of evaluators do not use these measures in CST evaluations (Nicholson & Norwood, 2000). The purpose of this study is to bridge the gap between competency evaluations based on a conventional interview and those conducted with the aid of a standardized forensic assessment instrument. To this end, we utilized an archival sample of 704 criminal defendants (543 males, 161 females) ordered to undergo evaluations of CST. In the overall sample, as well as in 2 comparison groups comprised of individuals with psychotic disorders and mental retardation, we coded evaluee responses to 45 conventional competency questions relating to factual understanding, rational understanding, and ability to cooperate with counsel. We present accuracy rates to these questions across competent and incompetent groups in an effort to provide information that can make conventional interviews more evidence-based. Using relative risk ratios, we also sought to identify the questions most associated with evaluator opinions of incompetency. Overall, the results indicated fairly consistent trends that questions relating to rational understanding and ability to cooperate with counsel were the most associated with competence. We discuss how the relative risk ratio findings and descriptive information can be used to make conventional competency interviews more objective and empirically based by providing evaluators with a normative reference point for commonly asked competency questions. (PsycINFO Database Record

Concepts: Four stages of competence, Number needed to harm, Assessment, Evaluation, Incompetence, Competence, Relative risk


The WHO world health statistics report in 2015 shows that in Europe the overall obesity rate among adults is 21.5% in males and 24.5% in females. Obesity has important consequences for morbidity, disability and quality of life.

Concepts: Alternative medicine, Number needed to harm, Avicenna, Systematic review, Russia, Europe, Gross domestic product, Medicine


It is generally well understood that possible reasons for inconsistent responding on the Minnesota Multiphasic Personality Inventory-2 Restructured Form (MMPI-2-RF), as measured by the Variable Response Inconsistency (VRIN-r) and True Response Inconsistency (TRIN-r) scales, include reading or language limitations, cognitive impairment, and intentional random responding; however, the interpretive recommendations for the test suggest that higher scores on these scales can also result from an uncooperative test-taking approach. This study utilized a sample of 3,457 predominately non-head injury disability claimants to examine the association between inconsistent responding on the MMPI-2-RF and performance on cognitive tests as well performance validity tests (PVTs), an independent indicator of uncooperative test-taking attitude. Analysis of variance found that both VRIN-r and TRIN-r were associated with statistically lower cognitive test scores. These analyses also supported that TRIN-r was associated with poor performance on collaterally administered PVTs in a subsample of individuals with average reading levels. Illustrating the practical effects of these results, in follow-up relative risk ratio analyses, individuals with elevations on TRIN-r were at up to five times greater risk of PVT failure than those without elevations. Overall, the results of this study provide some support for the interpretation that inconsistent responding on the MMPI-2-RF is associated not only with cognitive/reading problems or limitations but also an uncooperative test-taking approach, particularly for elevated TRIN-r scores. (PsycINFO Database Record

Concepts: Minnesota Multiphasic Personality Inventory, Number needed to harm, Analysis of variance, Psychometrics, Relative risk


The purpose of this study was to determine whether the effectiveness of an anterior cruciate ligament (ACL) prevention program is impacted by the individual(s) directing the program. A number-needed-to-treat analysis compared the effectiveness of injury prevention measures when either directed by a coach or a mixed leadership group consisting of coach and healthcare providers. Eleven studies were included for analysis. Number-needed-to-treat and relative risk reduction (RRR) were calculated for each study and data sets were pooled based on the intervention leader. Quality of evidence was determined by assessing individual studies (PEDro score x¯=4.55±1.97, range=2-7), applying the Oxford Centre for Evidence-Based Medicine Levels of Evidence (CEBM=2a), and the Strength of Recommendation Taxonomy (SORT=Level B). The mixed leadership group studies' RRR=48.2% (95% confidence interval (CI)=22-65) and a number-needed-to-benefit of 120 (CI=73-303) while the coach-led group’s RRR=58.4% (CI=40-71) and a number-needed-to-benefit=133 (CI=96-217). These results demonstrate that a coach-led ACL injury prevention program approach is as effective as a mixed group leadership approach. Coach-led prevention programs can be more widely implemented; however, it is imperative to ensure adequate training is in place prior to implementation of such intervention.

Concepts: Anterior cruciate ligament reconstruction, Ligament, Number needed to harm, Cruciate ligament, Knee, Leadership, Anterior cruciate ligament injury, Anterior cruciate ligament