Riviste scientifiche

Police body cams were meant to keep us safer. Are they working?

New Scientist - Me, 18/10/2017 - 20:00
Equipping police officers with body-worn cameras was intended to defuse tense situations, but footage of brutal incidents keeps going viral

Huge Piccadilly Circus screen will target ads at certain cars

New Scientist - Me, 18/10/2017 - 20:00
A vast electronic display in London's Piccadilly Circus will use cameras to watch nearby cars and target certain models with certain ads

AlphaGo’s AI upgrade gets round the need for human input

New Scientist - Me, 18/10/2017 - 20:00
AlphaGo Zero, Google DeepMind's artificially intelligent Go player, dominates humans and other AIs by learning itself – without any human training

Gravitational waves have let us see huge neutron stars colliding

New Scientist - Me, 18/10/2017 - 19:00
We’ve taken the first pictures of neutron stars colliding 130 million light years away. The resulting gravitational waves may solve some big cosmic mysteries

Online game will spot if you have hidden cybersecurity talents

New Scientist - Me, 18/10/2017 - 18:16
A music major or law student might have native cybersecurity skills a trained IT student doesn’t – and this online game will identify you

A tech-destroying solar flare could hit Earth within 100 years

New Scientist - Me, 18/10/2017 - 12:30
If the sun spews “superflares” as often as other stars, one could take down power systems, damage the ozone layer and destroy satellites in the next century

Google and Apple yet to fix Wi-Fi hole in a billion devices

New Scientist - Me, 18/10/2017 - 12:20
The KRACK vulnerability is bad news for Android and Apple now, but long-term consequences are in store for the internet of things

Astronaut wee could show us how the plumes on Enceladus work

New Scientist - Me, 18/10/2017 - 01:07
The way spaceships vent urine and water may be a good stand-in for studying how jets of vapour escape the hidden ocean on one of Saturn’s icy moons

Benefit and harm of intensive blood pressure treatment: Derivation and validation of risk models using data from the SPRINT and ACCORD trials

PLoS Medicine - Ma, 17/10/2017 - 23:00

by Sanjay Basu, Jeremy B. Sussman, Joseph Rigdon, Lauren Steimle, Brian T. Denton, Rodney A. Hayward

Background

Intensive blood pressure (BP) treatment can avert cardiovascular disease (CVD) events but can cause some serious adverse events. We sought to develop and validate risk models for predicting absolute risk difference (increased risk or decreased risk) for CVD events and serious adverse events from intensive BP therapy. A secondary aim was to test if the statistical method of elastic net regularization would improve the estimation of risk models for predicting absolute risk difference, as compared to a traditional backwards variable selection approach.

Methods and findings

Cox models were derived from SPRINT trial data and validated on ACCORD-BP trial data to estimate risk of CVD events and serious adverse events; the models included terms for intensive BP treatment and heterogeneous response to intensive treatment. The Cox models were then used to estimate the absolute reduction in probability of CVD events (benefit) and absolute increase in probability of serious adverse events (harm) for each individual from intensive treatment. We compared the method of elastic net regularization, which uses repeated internal cross-validation to select variables and estimate coefficients in the presence of collinearity, to a traditional backwards variable selection approach. Data from 9,069 SPRINT participants with complete data on covariates were utilized for model development, and data from 4,498 ACCORD-BP participants with complete data were utilized for model validation. Participants were exposed to intensive (goal systolic pressure < 120 mm Hg) versus standard (<140 mm Hg) treatment. Two composite primary outcome measures were evaluated: (i) CVD events/deaths (myocardial infarction, acute coronary syndrome, stroke, congestive heart failure, or CVD death), and (ii) serious adverse events (hypotension, syncope, electrolyte abnormalities, bradycardia, or acute kidney injury/failure). The model for CVD chosen through elastic net regularization included interaction terms suggesting that older age, black race, higher diastolic BP, and higher lipids were associated with greater CVD risk reduction benefits from intensive treatment, while current smoking was associated with fewer benefits. The model for serious adverse events chosen through elastic net regularization suggested that male sex, current smoking, statin use, elevated creatinine, and higher lipids were associated with greater risk of serious adverse events from intensive treatment. SPRINT participants in the highest predicted benefit subgroup had a number needed to treat (NNT) of 24 to prevent 1 CVD event/death over 5 years (absolute risk reduction [ARR] = 0.042, 95% CI: 0.018, 0.066; P = 0.001), those in the middle predicted benefit subgroup had a NNT of 76 (ARR = 0.013, 95% CI: −0.0001, 0.026; P = 0.053), and those in the lowest subgroup had no significant risk reduction (ARR = 0.006, 95% CI: −0.007, 0.018; P = 0.71). Those in the highest predicted harm subgroup had a number needed to harm (NNH) of 27 to induce 1 serious adverse event (absolute risk increase [ARI] = 0.038, 95% CI: 0.014, 0.061; P = 0.002), those in the middle predicted harm subgroup had a NNH of 41 (ARI = 0.025, 95% CI: 0.012, 0.038; P < 0.001), and those in the lowest subgroup had no significant risk increase (ARI = −0.007, 95% CI: −0.043, 0.030; P = 0.72). In ACCORD-BP, participants in the highest subgroup of predicted benefit had significant absolute CVD risk reduction, but the overall ACCORD-BP participant sample was skewed towards participants with less predicted benefit and more predicted risk than in SPRINT. The models chosen through traditional backwards selection had similar ability to identify absolute risk difference for CVD as the elastic net models, but poorer ability to correctly identify absolute risk difference for serious adverse events. A key limitation of the analysis is the limited sample size of the ACCORD-BP trial, which expanded confidence intervals for ARI among persons with type 2 diabetes. Additionally, it is not possible to mechanistically explain the physiological relationships explaining the heterogeneous treatment effects captured by the models, since the study was an observational secondary data analysis.

Conclusions

We found that predictive models could help identify subgroups of participants in both SPRINT and ACCORD-BP who had lower versus higher ARRs in CVD events/deaths with intensive BP treatment, and participants who had lower versus higher ARIs in serious adverse events.

Improving tuberculosis diagnosis: Better tests or better healthcare?

PLoS Medicine - Ma, 17/10/2017 - 23:00

by Sumona Datta, Matthew J. Saunders, Marco A. Tovar, Carlton A. Evans

In a Perspective accompanying Sylvia and colleagues, Carlton Evans and colleagues discuss the challenge of squaring policies around tuberculosis diagnosis with the realities of clinical practice in small villages and low-resource settings.

Tuberculosis detection and the challenges of integrated care in rural China: A cross-sectional standardized patient study

PLoS Medicine - Ma, 17/10/2017 - 23:00

by Sean Sylvia, Hao Xue, Chengchao Zhou, Yaojiang Shi, Hongmei Yi, Huan Zhou, Scott Rozelle, Madhukar Pai, Jishnu Das

Background

Despite recent reductions in prevalence, China still faces a substantial tuberculosis (TB) burden, with future progress dependent on the ability of rural providers to appropriately detect and refer TB patients for further care. This study (a) provides a baseline assessment of the ability of rural providers to correctly manage presumptive TB cases; (b) measures the gap between provider knowledge and practice and; (c) evaluates how ongoing reforms of China’s health system—characterized by a movement toward “integrated care” and promotion of initial contact with grassroots providers—will affect the care of TB patients.

Methods/Findings

Unannounced standardized patients (SPs) presenting with classic pulmonary TB symptoms were deployed in 3 provinces of China in July 2015. The SPs successfully completed 274 interactions across all 3 tiers of China’s rural health system, interacting with providers in 46 village clinics, 207 township health centers, and 21 county hospitals. Interactions between providers and standardized patients were assessed against international and national standards of TB care. Using a lenient definition of correct management as at least a referral, chest X-ray or sputum test, 41% (111 of 274) SPs were correctly managed. Although there were no cases of empirical anti-TB treatment, antibiotics unrelated to the treatment of TB were prescribed in 168 of 274 interactions or 61.3% (95% CI: 55%–67%). Correct management proportions significantly higher at county hospitals compared to township health centers (OR 0.06, 95% CI: 0.01–0.25, p < 0.001) and village clinics (OR 0.02, 95% CI: 0.0–0.17, p < 0.001). Correct management in tests of knowledge administered to the same 274 physicians for the same case was 45 percentage points (95% CI: 37%–53%) higher with 24 percentage points (95% CI: −33% to −15%) fewer antibiotic prescriptions. Relative to the current system, where patients can choose to bypass any level of care, simulations suggest that a system of managed referral with gatekeeping at the level of village clinics would reduce proportions of correct management from 41% to 16%, while gatekeeping at the level of the township hospital would retain correct management close to current levels at 37%. The main limitations of the study are 2-fold. First, we evaluate the management of a one-time new patient presenting with presumptive TB, which may not reflect how providers manage repeat patients or more complicated TB presentations. Second, simulations under alternate policies require behavioral and statistical assumptions that should be addressed in future applications of this method.

Conclusions

There were significant quality deficits among village clinics and township health centers in the management of a classic case of presumptive TB, with higher proportions of correct case management in county hospitals. Poor clinical performance does not arise only from a lack of knowledge, a phenomenon known as the “know-do” gap. Given significant deficits in quality of care, reforms encouraging first contact with lower tiers of the health system can improve efficiency only with concomitant improvements in appropriate management of presumptive TB patients in village clinics and township health centers.

Elevated blood pressure and risk of mitral regurgitation: A longitudinal cohort study of 5.5 million United Kingdom adults

PLoS Medicine - Ma, 17/10/2017 - 23:00

by Kazem Rahimi, Hamid Mohseni, Catherine M. Otto, Nathalie Conrad, Jenny Tran, Milad Nazarzadeh, Mark Woodward, Terence Dwyer, Stephen MacMahon

Background

Mitral regurgitation in people without prior cardiac disease is considered a degenerative disease with no established risk factors for its prevention. We aimed to test the hypothesis that elevated systolic blood pressure (SBP) across its usual spectrum is associated with higher risk of mitral regurgitation.

Methods and findings

We used linked electronic health records from the United Kingdom Clinical Practice Research Datalink (CPRD) from 1 January 1990 to 31 December 2015. CPRD covers approximately 7% of the current UK population and is broadly representative of the population by age, sex, and ethnicity. About 5.5 million UK patients with no known cardiovascular or valve disease at baseline were included in this cohort study. We investigated the relationship between blood pressure (BP) and risk of mitral regurgitation using Cox regression models. Our primary exposure variable was SBP and our primary outcome was incident reports of mitral regurgitation, which were identified from hospital discharge reports or primary care records.Of the 5,553,984 patients in the CPRD that met our inclusion criteria, during the 10-year follow-up period, 28,655 (0.52%) were diagnosed with mitral regurgitation and a further 1,262 (0.02%) were diagnosed with mitral stenosis. SBP was continuously related to the risk of mitral regurgitation with no evidence of a nadir down to 115 mmHg (p < 0.001). Each 20 mmHg increment in SBP was associated with a 26% higher risk of mitral regurgitation (hazard ratio [HR] 1.26; CI 1.23, 1.29). The observed association was partially mediated by diseases affecting the left ventricle during follow-up (myocardial infarction [MI], ischaemic heart disease [IHD], cardiomyopathy, and heart failure). However, the percentage of excess risk mediated (PERM) by these proximate causes of secondary mitral regurgitation was only 13% (CI 6.1%, 20%), and accounting for them had little effect on the long-term association between SBP and mitral regurgitation (mediator-adjusted HR 1.22; CI 1.20, 1.25; p < 0.001). Associations were similar for each 10 mmHg increment in diastolic blood pressure (DBP) (p < 0.001) or each 15 mmHg increment in pulse pressure (PP) (p < 0.001). By contrast, there was no association between SBP and risk of mitral stenosis (HR per 20 mmHg higher SBP 1.03; CI 0.93, 1.14; p = 0.58). These analyses are based on routinely collected data from health records which may be sensitive to measurement errors, and the observed associations may not be generalizable to less severe and subclinical cases of mitral regurgitation.

Conclusions

Long-term exposure to elevated BP across its whole spectrum is associated with an increased risk of primary and secondary mitral regurgitation. These findings suggest that BP control may be of importance in the prevention of mitral regurgitation.

A gaggle of 7 moons keep Saturn’s rings from breaking apart

New Scientist - Ma, 17/10/2017 - 21:08
The gravity from seven of its moons stops Saturn’s bright outer ring from spreading out and dispersing into space, according to Cassini spacecraft measurements

Online dating may be breaking down society’s racial divisions

New Scientist - Ma, 17/10/2017 - 19:40
Racial segregation has eased in the US over the past two decades. Could hooking up online be responsible?

Roadside barrier that folds like origami blocks traffic noise

New Scientist - Ma, 17/10/2017 - 18:10
Traffic noise has many frequencies, making it hard to suppress. A new barrier with movable folds can change its acoustic properties in response to traffic patterns

Four brain genes help explain obsessive compulsive disorder

New Scientist - Ma, 17/10/2017 - 18:00
OCD has been linked to genes active in a brain circuit involved in learning and decisions. The finding may help explain why the condition can run in families

Sex addiction isn’t an illness, treating it as one is a bad idea

New Scientist - Ma, 17/10/2017 - 17:10
Harvey Weinstein is being treated for sex addiction, but many health professionals say it isn't a real illness and addiction-style therapy doesn't help

How to clean up the dirty water Puerto Ricans are drinking

New Scientist - Ma, 17/10/2017 - 15:35
Nearly a month after Hurricane Maria, many people on Puerto Rico are still without clean drinking water and have resorted to wells on a contaminated site

Horses bred to look like cartoons are part of a worrying trend

New Scientist - Ma, 17/10/2017 - 14:30
A colt with googly eyes and a very "dished" head is the latest example of a trend for animals with "cute" looks that raise health risks, says Danny Chambers

Ophelia shows many hurricanes could reach Europe in the future

New Scientist - Ma, 17/10/2017 - 13:56
Tropical cyclones often get to Europe but normally they have weakened by the time they get there. Not any more, thanks to climate change
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