Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Does the Scottish pharmacist post-registration foundation programme change self-reported competence? A before and after questionnaire study

Introduction

The two-year Post-registration Foundation Programme for pharmacists in Scotland1, is based on an eight-element framework, and supports early career pharmacists to develop core competences relevant to all sectors of practice. Pharmacists have 6 monthly appraisals and are assessed by an online portfolio and a summative OSCE.

Aim

The aim of this paper is to describe the changes in pharmacists’ self-reported competence at the end-of-programme compared to baseline.

Methods

Eligible participants were pharmacists from any sector registering for the programme in September 2017/February 2018. They were invited by email to complete an online questionnaire at baseline and exit to assess their self-reported level of competence with 19 statements linked to the framework using a ten-point Likert scale (1 not at all confident ,10 very confident). Additional questions on expectations (baseline only) and experiences (end-of-programme only: resources used, general views on the programme and suggestions for improvement (open text) were included. No reminders were sent. Questionnaires were hosted on a Qualtrics platform. Data was collated in Excel then exported to an SPSS version 27 database. Analyses were based on the sub-sample who completed both questionnaires; frequencies and means/SD are reported and changes from baseline to end-of-programme compared using paired t test. Open-text responses were subjected to content analysis. Ethical approval was not required for this evaluation.

Results

Ninety-six pharmacists registered for the programme: 14 males; 11 Health Boards. To date 56 have completed the programme (5 community, 34 hospital, 15 hospital/primary-care and 2 primary-care). Baseline and end-of-programme questionnaires were completed by 73/96 pharmacists (76% response) and 54/87 (50 completers and 4 early exiters) (62.1% response) respectively. 37 pharmacists completed both questionnaires. At the end-of-programme there was improvement in self-reported competence across all statements compared to baseline. Based on a paired t-test changes were significant for all competencies at p&lt;0.001, apart from demonstrating a non-discriminatory attitude which was significant at p&lt;0.05 and was the competency at baseline with the highest self-reported competence (9.36, SD 1.16 cf 9.89, SD 0.32). Regular meetings with tutors/NES staff and support from colleagues and healthcare professionals were the resources rated most highly. Around 50% of participants rated the NES resource booklets, guidance documents and the assessment handbook essential/very useful. 15% found NES personnel input essential and 45% rated peer sessions essential/very useful. FPs commented that undertaking the training had; increased confidence, improved clinical skills, increased ability to reflect, furthered their career prospects and enabled progression to independent prescribing. It had also improved: knowledge and skills, patient care, ability to support other health care professionals. Suggestions for improvement related to the online portfolio, support, and the final assessment.

Discussion/Conclusion

Limitations include small numbers and programme delivery limited to Scotland. Overall, there was a marked improvement in all competency and practice statements at programme exit. Resources provided were generally rated useful and had been utilised. The training programme had also had a positive impact on confidence, reflective practice, and enabled progress to Independent Prescribing courses.

References

1. Post- registration Foundation Programme for Newly Qualified Pharmacists in Scotland https://nes.scot.nhs.uk/our-work/post-registration-foundation-programme-for-newly-qualified-pharmacists-in-scotland-autumn-2021-onwards/ Accessed October 12th, 2021

Foundation pharmacists’ experiences of personal development whilst undertaking the nes post-registration foundation programme: a qualitative study (Scotland)

Introduction

The NES post-registration Foundation Programme1 for pharmacists introduced in 1989, has recently been extended to primary-care and community sectors. The programme, approximately two years in duration, is based on a competency framework (six core elements & 2 sector specific). Foundation pharmacists (FPs) are assigned a tutor, have 6 monthly appraisals, and are assessed by an e-portfolio and OSCE.

Aim

The aim of this paper is to describe FPs’ experiences and personal development when undertaking the Programme. This study is part of larger mixed methods evaluation of the Programme.

Methods

Eligible participants were pharmacists registering with the programme in September 2017/February 2018. NES staff sent emails inviting them to take part in either a focus group or interview (face-to-face or virtual) at baseline, mid-point, and-programme completion, to explore their expectations and experiences of the programme. Proceedings were digitally recorded, transcribed, and managed using NVivo. Analysis was inductive and thematic2 and synthesised in relation to Bandura’s Social Cognitive theory3 (SCT) which posits that learning and knowledge enhancement are related to interaction between environmental, person/cognitive, and behavioural factors. Facilitators and barriers to undertaking the Programme were identified. IRAS advised ethical approval was not required; NHS Research & Development approval was given.

Results

Ninety-six pharmacists registered for the Programme. In total 22 participated in 7 baseline focus groups, 7 in 2 midway focus group/3 in interviews, and 4 in end-of-programme interviews. At baseline environmental factors predominated in motivation to undertake the Programme such as the structured approach and robust support network (tutors, peers & NES). These also contributed to the perceived facilitators for programme completion. Conversely environmental factors linked to the external working environment could also be barriers. Person/cognitive factors were other motivators to undertaking the Programme because of perceived improved employability, and benefits of increased confidence. Finally, the behavioural domain also contributed to motivation with perceptions of benefits in both transferable and clinical skills. At midway, pharmacists confirmed their improvements in both the personal/cognitive domain (confidence, resilience, reflective practice) and the behavioural domain of clinical and transferable skills. Facilitators (support & resources) and barriers (lack of support, time, and feedback) were almost exclusively environmental. Comments around professional identity also emerged inextricably linked to FPs’ relationships with and recognition by other members of the HCP team. At programme end the views from the midway point remain unchanged. Perceived skills had increased largely in the behavioural domain but also in the person/cognitive domain with understanding the value of reflective practice emerging as a key area of improvement and being reported as influencing professional identity. Facilitators were solely reported in terms of environmental factors relating to extensive support networks and barriers again related to environmental factors which included lack of support, resources, and external influences. Views of the programme overall were very positive

Discussion/Conclusion

All three SCT factors influenced the learning and development of the FPs, but environmental influences dominated the barriers. As a qualitative study these results cannot be generalised, but they highlight areas to explore in more details for future programme delivery.

References

1. Post-registration Foundation Programme for Newly Qualified Pharmacists in Scotland. Available from: https://nes.scot.nhs.uk/our-work/post-registration-foundation-programme-for-newly-qualified-pharmacists-in-scotland-autumn-2021-onwards/ Accessed July 25, 2022

2. Braun, V., Clarke, V. Using thematic analysis in psychology. Qualitative Research in Psychology, 2006;3(2):77-101. ISSN 1478-0887. Available from: http://eprints.uwe.ac.uk/11735 Accessed October 12, 2021

3. Bandura, A. Social learning theory. Englewood Cliffs, N.J.: Prentice Hall; 1977.

Is the post-registration foundation programme fit for purpose for community pharmacists? An exploration of pharmacist experiences

Introduction

The two-year, NHS Education for Scotland (NES) post-registration foundation programme supports early career pharmacists in patient-facing sectors of practice. The experiential programme, based on an eight-element competency framework, also includes webinars, online resources, and tutor support. Learners complete an online evidence portfolio and undertake a summative OSCE.

Aim

The aim of this paper is to report the experiences of the community-pharmacist participants, with a focus on the ‘fitness-for-purpose’ of the programme.

Methods

This was a longitudinal mixed-methods study theoretically underpinned by Miller’s triangle and social cognitive theory. Eligible participants were all pharmacists registering for the programme in Scotland in September 2017 and February 2018, all participating Welsh community-pharmacists, and all tutors. Invitation packs were emailed by NES/HEIW staff with names forwarded to researchers following signed consent. Focus groups/interviews (face-to-face or virtual according to participant preference) were undertaken at start, mid-point and exit of programme, to explore expectations (benefits, social gains, professional identify), experiences (challenges, facilitators, meeting of learners’ needs) and barriers. Proceedings were digitally recorded, transcribed verbatim and managed using NVivo. Thematic analysis (1) was based on social cognitive theory (transferable behavioural skills and professional attitudes). An inductive analysis additionally identified emergent themes. Participants in Scotland were invited to complete an on-line base-line questionnaire to describe their self-assessed competence against the NES Foundation framework (personal and professional practice, membership of healthcare team, communication, patient centred approach to practice). Data was analysed in SPSS using descriptive statistics. Themes from qualitative and quantitative data were integrated. IRAS ethical approval was not required; NHS Research & Development approval was given.

Results

96 pharmacists registered for the programme: 18 community-pharmacists in Scotland (11 health boards); 14 community pharmacists in Wales. In Scotland 15 community-pharmacists completed questionnaires: 9 expected an ‘increase in confidence’ and 11 to provide ‘better patient care’. Self-assessed competence against the framework was generally high. Across Scotland and Wales, 12 focus-groups (involving 19 community-pharmacists), 12 community-pharmacist interviews, 10 tutor focus-groups (8 community-pharmacist tutors) and 3 community-pharmacist tutor interviews were conducted.

At midpoint and exit pharmacists and tutors reported increased confidence, the ability to reflect and pride in their achievement. Barriers: included lack of protected time; workload; and lack of support (tutor and employer). There were also programme issues (practicalities of portfolio; workplace-based assessment, no access to medical records); and cultural issues in community-pharmacy (‘speed & safety’; lack of recognition). Reasons for dropping out of the programme included: moved geographical area; too experienced; workload pressures; no incentive; no employer support. Four community-pharmacists in Scotland and none in Wales completed the programme.

Conclusion

Study limitations include the small numbers, programme delivery limited to Scotland and Wales, and limited response rate to focus-groups/interviews, exacerbated by COVID19. Overall community pharmacist expectations were met, and they perceived the programme was fit-for-purpose and worthwhile. However, barriers particularly related to the community pharmacy context, may have led to the high drop-out rate. These findings should be considered as the new UK-wide RPS curriculum for foundation pharmacists (2) is implemented in Scotland, to optimise its successful delivery.

References

(1) Braun, V. and Clarke, V. Using thematic analysis in psychology. Qualitative Research in Psychology. [Internet]. 2006; 3 (2): 77-101. ISSN 1478-0887 Available from: http://eprints.uwe.ac.uk/11735

(2) Post- registration Foundation Programme for Newly Qualified Pharmacists in Scotland [Internet] https://nes.scot.nhs.uk/our-work/post-registration-foundation-programme-for-newly-qualified-pharmacists-in-scotland-autumn-2021-onwards Accessed October 12, 2021.

Ethical Issues of Social Media Usage in Healthcare

OBJECTIVE

Social media, web and mobile technologies are increasingly used in healthcare and directly support patientcentered care. Patients benefit from disease self-management tools, contact to others, and closer monitoring. Researchers study drug efficiency, or recruit patients for clinical studies via these technologies. However, low communication barriers in socialmedia, limited privacy and security issues lead to problems from an ethical perspective. This paper summarizes the ethical issues to be considered when social media is exploited in healthcare contexts.

METHODS

Starting from our experiences in social-media research, we collected ethical issues for selected social-media use cases in the context of patient-centered care. Results were enriched by collecting and analyzing relevant literature and were discussed and interpreted by members of the IMIA Social Media Working Group.

RESULTS

Most relevant issues in social-media applications are confidence and privacy that need to be carefully preserved. The patient-physician relationship can suffer from the new information gain on both sides since private information of both healthcare provider and consumer may be accessible through the Internet. Physicians need to ensure they keep the borders between private and professional intact. Beyond, preserving patient anonymity when citing Internet content is crucial for research studies.

CONCLUSION

Exploiting medical social-media in healthcare applications requires a careful reflection of roles and responsibilities. Availability of data and information can be useful in many settings, but the abuse of data needs to be prevented. Preserving privacy and confidentiality of online users is a main issue, as well as providing means for patients or Internet users to express concerns on data usage.

Core requirements for successful data linkage: an example of a triangulation method

OBJECTIVES

The aim was to explore the views of professional stakeholders and healthcare professionals (HCPs) on the linkage of UK National Health Service (NHS) data for paediatric pharmacovigilance purposes and to make recommendations for such a system.

METHODS

A mixed methods approach including a literature review, interviews, focus groups and a three-round Delphi survey with HCPs in Scotland was followed by a triangulation process using a systematic protocol. The survey was structured using the Theoretical Domains Framework of behaviour change. Items retained after applying the matrix-based triangulation process were thematically coded. Ethical approval was granted by the North of Scotland Research Ethics Service.

RESULTS

Results from 18 papers, 23 interviewees, 23 participants of focus groups and 61 completed questionnaires in the Delphi survey contributed to the triangulation process. A total of 25 key findings from all four studies were identified during triangulation. There was good convergence; 21 key findings were agreed and remained to inform recommendations. The items were coded as practical/technical (eg, decision about the unique patient identifier to use), mandatory (eg, governed by statute), essential (consistently mentioned in all studies and therefore needed to ensure professional support) or preferable.

CONCLUSIONS

The development of a paediatric linked database has support from professional stakeholders and HCPs in Scotland. The triangulation identified three sets of core requirements for a new system of data linkage. An additional fourth set of 'preferable' requirements might increase engagement of HCPs and their support for the new system.

Characterization of transient noise in Advanced LIGO relevant to gravitational wave signal GW150914

On September 14, 2015, a gravitational wave signal from a coalescing black hole binary system was observed by the Advanced LIGO detectors. This paper describes the transient noise backgrounds used to determine the significance of the event (designated GW150914) and presents the results of investigations into potential correlated or uncorrelated sources of transient noise in the detectors around the time of the event. The detectors were operating nominally at the time of GW150914. We have ruled out environmental influences and non-Gaussian instrument noise at either LIGO detector as the cause of the observed gravitational wave signal.

GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence

We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes. The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC. The signal was initially identified within 70 s by an online matched-filter search targeting binary coalescences. Subsequent off-line analyses recovered GW151226 with a network signal-to-noise ratio of 13 and a significance greater than 5σ. The signal persisted in the LIGO frequency band for approximately 1 s, increasing in frequency and amplitude over about 55 cycles from 35 to 450 Hz, and reached a peak gravitational strain of 3.4_{-0.9}^{+0.7}×10^{-22}. The inferred source-frame initial black hole masses are 14.2_{-3.7}^{+8.3}M_{⊙} and 7.5_{-2.3}^{+2.3}M_{⊙}, and the final black hole mass is 20.8_{-1.7}^{+6.1}M_{⊙}. We find that at least one of the component black holes has spin greater than 0.2. This source is located at a luminosity distance of 440_{-190}^{+180}  Mpc corresponding to a redshift of 0.09_{-0.04}^{+0.03}. All uncertainties define a 90% credible interval. This second gravitational-wave observation provides improved constraints on stellar populations and on deviations from general relativity.

Properties of the Binary Black Hole Merger GW150914

On September 14, 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) detected a gravitational-wave transient (GW150914); we characterize the properties of the source and its parameters. The data around the time of the event were analyzed coherently across the LIGO network using a suite of accurate waveform models that describe gravitational waves from a compact binary system in general relativity. GW150914 was produced by a nearly equal mass binary black hole of masses 36_{-4}^{+5}M_{⊙} and 29_{-4}^{+4}M_{⊙}; for each parameter we report the median value and the range of the 90% credible interval. The dimensionless spin magnitude of the more massive black hole is bound to be <0.7 (at 90% probability). The luminosity distance to the source is 410_{-180}^{+160}  Mpc, corresponding to a redshift 0.09_{-0.04}^{+0.03} assuming standard cosmology. The source location is constrained to an annulus section of 610  deg^{2}, primarily in the southern hemisphere. The binary merges into a black hole of mass 62_{-4}^{+4}M_{⊙} and spin 0.67_{-0.07}^{+0.05}. This black hole is significantly more massive than any other inferred from electromagnetic observations in the stellar-mass regime.

GW150914: First results from the search for binary black hole coalescence with Advanced LIGO

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) simultaneously observed the binary black hole merger GW150914. We report the results of a matched-filter search using relativistic models of compact-object binaries that recovered GW150914 as the most significant event during the coincident observations between the two LIGO detectors from September 12 to October 20, 2015. GW150914 was observed with a matched filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203000 years, equivalent to a significance greater than 5.1 σ.

GW150914: First results from the search for binary black hole coalescence with Advanced LIGO

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) simultaneously observed the binary black hole merger GW150914. We report the results of a matched-filter search using relativistic models of compact-object binaries that recovered GW150914 as the most significant event during the coincident observations between the two LIGO detectors from September 12 to October 20, 2015. GW150914 was observed with a matched filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203000 years, equivalent to a significance greater than 5.1 σ.

Tests of General Relativity with GW150914

The LIGO detection of GW150914 provides an unprecedented opportunity to study the two-body motion of a compact-object binary in the large-velocity, highly nonlinear regime, and to witness the final merger of the binary and the excitation of uniquely relativistic modes of the gravitational field. We carry out several investigations to determine whether GW150914 is consistent with a binary black-hole merger in general relativity. We find that the final remnant's mass and spin, as determined from the low-frequency (inspiral) and high-frequency (postinspiral) phases of the signal, are mutually consistent with the binary black-hole solution in general relativity. Furthermore, the data following the peak of GW150914 are consistent with the least-damped quasinormal mode inferred from the mass and spin of the remnant black hole. By using waveform models that allow for parametrized general-relativity violations during the inspiral and merger phases, we perform quantitative tests on the gravitational-wave phase in the dynamical regime and we determine the first empirical bounds on several high-order post-Newtonian coefficients. We constrain the graviton Compton wavelength, assuming that gravitons are dispersed in vacuum in the same way as particles with mass, obtaining a 90%-confidence lower bound of 10^{13}  km. In conclusion, within our statistical uncertainties, we find no evidence for violations of general relativity in the genuinely strong-field regime of gravity.

GW150914: Implications for the Stochastic Gravitational-Wave Background from Binary Black Holes

The LIGO detection of the gravitational wave transient GW150914, from the inspiral and merger of two black holes with masses ≳30M_{⊙}, suggests a population of binary black holes with relatively high mass. This observation implies that the stochastic gravitational-wave background from binary black holes, created from the incoherent superposition of all the merging binaries in the Universe, could be higher than previously expected. Using the properties of GW150914, we estimate the energy density of such a background from binary black holes. In the most sensitive part of the Advanced LIGO and Advanced Virgo band for stochastic backgrounds (near 25 Hz), we predict Ω_{GW}(f=25  Hz)=1.1_{-0.9}^{+2.7}×10^{-9} with 90% confidence. This prediction is robustly demonstrated for a variety of formation scenarios with different parameters. The differences between models are small compared to the statistical uncertainty arising from the currently poorly constrained local coalescence rate. We conclude that this background is potentially measurable by the Advanced LIGO and Advanced Virgo detectors operating at their projected final sensitivity.

GW150914: The Advanced LIGO Detectors in the Era of First Discoveries

Following a major upgrade, the two advanced detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) held their first observation run between September 2015 and January 2016. With a strain sensitivity of 10^{-23}/sqrt[Hz] at 100 Hz, the product of observable volume and measurement time exceeded that of all previous runs within the first 16 days of coincident observation. On September 14, 2015, the Advanced LIGO detectors observed a transient gravitational-wave signal determined to be the coalescence of two black holes [B. P. Abbott et al., Phys. Rev. Lett. 116, 061102 (2016)], launching the era of gravitational-wave astronomy. The event, GW150914, was observed with a combined signal-to-noise ratio of 24 in coincidence by the two detectors. Here, we present the main features of the detectors that enabled this observation. At full sensitivity, the Advanced LIGO detectors are designed to deliver another factor of 3 improvement in the signal-to-noise ratio for binary black hole systems similar in mass to GW150914.

Observation of Gravitational Waves from a Binary Black Hole Merger

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10(-21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410(-180)(+160)  Mpc corresponding to a redshift z=0.09(-0.04)(+0.03). In the source frame, the initial black hole masses are 36(-4)(+5)M⊙ and 29(-4)(+4)M⊙, and the final black hole mass is 62(-4)(+4)M⊙, with 3.0(-0.5)(+0.5)M⊙c(2) radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

Prospects for Observing and Localizing Gravitational-Wave Transients with Advanced LIGO and Advanced Virgo

We present a possible observing scenario for the Advanced LIGO and Advanced Virgo gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We determine the expected sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron-star systems, which are considered the most promising for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and 90% credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5 deg2 to 20 deg2 will require at least three detectors of sensitivity within a factor of ∼ 2 of each other and with a broad frequency bandwidth. Should the third LIGO detector be relocated to India as expected, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

Improved upper limits on the stochastic gravitational-wave background from 2009-2010 LIGO and Virgo data

Gravitational waves from a variety of sources are predicted to superpose to create a stochastic background. This background is expected to contain unique information from throughout the history of the Universe that is unavailable through standard electromagnetic observations, making its study of fundamental importance to understanding the evolution of the Universe. We carry out a search for the stochastic background with the latest data from the LIGO and Virgo detectors. Consistent with predictions from most stochastic gravitational-wave background models, the data display no evidence of a stochastic gravitational-wave signal. Assuming a gravitational-wave spectrum of Ω_{GW}(f)=Ω_{α}(f/f_{ref})^{α}, we place 95% confidence level upper limits on the energy density of the background in each of four frequency bands spanning 41.5-1726 Hz. In the frequency band of 41.5-169.25 Hz for a spectral index of α=0, we constrain the energy density of the stochastic background to be Ω_{GW}(f)<5.6×10^{-6}. For the 600-1000 Hz band, Ω_{GW}(f)<0.14(f/900  Hz)^{3}, a factor of 2.5 lower than the best previously reported upper limits. We find Ω_{GW}(f)<1.8×10^{-4} using a spectral index of zero for 170-600 Hz and Ω_{GW}(f)<1.0(f/1300  Hz)^{3} for 1000-1726 Hz, bands in which no previous direct limits have been placed. The limits in these four bands are the lowest direct measurements to date on the stochastic background. We discuss the implications of these results in light of the recent claim by the BICEP2 experiment of the possible evidence for inflationary gravitational waves.

Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

Constraints on cosmic strings from the LIGO-Virgo gravitational-wave detectors

Cosmic strings can give rise to a large variety of interesting astrophysical phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by cusps are a promising observational signature. In this Letter we present a search for GWs from cosmic string cusps in data collected by the LIGO and Virgo gravitational wave detectors between 2005 and 2010, with over 625 days of live time. We find no evidence of GW signals from cosmic strings. From this result, we derive new constraints on cosmic string parameters, which complement and improve existing limits from previous searches for a stochastic background of GWs from cosmic microwave background measurements and pulsar timing data. In particular, if the size of loops is given by the gravitational backreaction scale, we place upper limits on the string tension Gμ below 10(-8) in some regions of the cosmic string parameter space.

Views of healthcare professionals to linkage of routinely collected healthcare data: a systematic literature review

Objective

To review the literature on the views of healthcare professionals to the linkage of healthcare data and to identify any potential barriers and/or facilitators to participation in a data linkage system.

Methods

Published papers describing the views of healthcare professionals (HCPs) to data sharing and linkage were identified by searches of Medline, EMBASE, SCOPUS, CINAHL, and PsychINFO. The searches were limited to papers published in the English language from 2001 to 2011.

Results

A total of 2917 titles were screened. From these, 18 papers describing the views of HCPs about data linkage or data sharing of routinely collected healthcare data at an individual patient level were included. Views were generally positive, and potential benefits were reported. Facilitators included having trust in the system including data governance, reliability, and feedback. Some negative views, identified as barriers were also expressed including costs, data governance, technical issues, and privacy concerns. Effects on the physician–patient relationship, and workload were also identified as deterrent.

Discussion

From the published literature included in this review, the views of HCPs were in general positive towards data sharing for public health purposes. The identification of barriers to contributing to a data linkage system allows these to be addressed in a planned data linkage project for pharmacovigilance. The main barriers identified were concerns about costs, governance and interference with the prescriber–patient relationship. These would have to be addressed if healthcare professionals are to support a data linkage system to improve patient safety.

SK2 and SK3 expression differentially affect firing frequency and precision in dopamine neurons

The firing properties of dopamine (DA) neurons in the substantia nigra (SN) pars compacta are strongly influenced by the activity of apamin-sensitive small conductance Ca(2+)-activated K(+) (SK) channels. Of the three SK channel genes expressed in central neurons, only SK3 expression has been identified in DA neurons. The present findings show that SK2 was also expressed in DA neurons. Immuno-electron microscopy (iEM) showed that SK2 was primarily expressed in the distal dendrites, while SK3 was heavily expressed in the soma and, to a lesser extent, throughout the dendritic arbor. Electrophysiological recordings of the effects of the SK channel blocker apamin on DA neurons from wild type and SK(-/-) mice show that SK2-containing channels contributed to the precision of action potential (AP) timing, while SK3-containing channels influenced AP frequency. The expression of SK2 in DA neurons may endow distinct signaling and subcellular localization to SK2-containing channels.

Cricotracheal separation: a review and a case with bilateral recovery of recurrent laryngeal nerve function

Cricotracheal separation (CTS) is an uncommon injury, with a high index of suspicion required to establish the diagnosis. Computerized tomography (CT) plays a role in diagnosis but cannot necessarily be relied upon. Bilateral recurrent laryngeal nerve (RLN) palsies are usually associated with this type of injury. We recently treated a patient with CTS in whom one RLN was intact from the time of the injury and the other nerve recovered within three months. Computed tomography was inconclusive.

Early open repair of the injury and frequent follow-up examinations led to successful decannulation after six weeks and excellent short-term voice and airway outcomes.

A detailed discussion of this unusual case is followed by a review of the current literature on CTS, with particular emphasis on significant management dilemmas and controversies.

Clinical suspicion remains more sensitive than investigations in diagnosing CTS. Permanent bilateral RLN palsies are not inevitable following these injuries.

The health and lifestyle of Scottish fishermen: a need for health promotion

It has long been known that fishing is one of the most dangerous occupations. In the year 2001, 33 boats were lost and 10 fishermen killed in UK waters. Despite the dangerous nature of the occupation, very little research has been conducted on fishermen's health and safety. The few studies that have been conducted are spread widely around the globe, and tend to focus on mortality rates and accidents. Few studies considered fishermen's lifestyle behaviours. To address this gap in current knowledge research was conducted to gain an understanding of health and lifestyle issues affecting Scottish fishermen. Data was collected using a postal questionnaire survey in the Scottish fishing population and health diaries in a small subsample. High rates of smoking were prevalent and passive smoking was a considerable problem. Fewer fishermen drank alcohol compared to the general population, but fishermen lacked knowledge about what safe levels of alcohol consumption were. Diet was lacking in fruit and vegetables, and meals were eaten at very erratic intervals. Fishermen may benefit from health promotion and education in the areas of smoking, diet and alcohol consumption.

The health of fishermen in the catching sector of the fishing industry: a gap analysis

Offshore fishing is a sizeable industry in the UK and it is one of the most dangerous occupations. Long hours, extreme weather and working with heavy machinery contribute to a high mortality rate in fishermen. Despite a long-standing acknowledgement of the dangers and high mortality associated with fishing, there has been little research in this field. Although there have been developments within the industry in terms of safety, there has been little emphasis on the relationship between health, the environment and performance at work. This paper reviews the international literature on the health of fishermen, and describes the main findings and highlights gaps in current evidence. Areas for further research that would inform the future development of an evidence-based occupational health service for the offshore fishing industry are discussed.