Clinical consensus recommendations for the non-surgical treatment of children with Perthes' disease in the UK

Aims

The aim of this study was to produce clinical consensus recommendations about the non-surgical treatment of children with Perthes' disease. The recommendations are intended to support clinical practice in a condition for which there is no robust evidence to guide optimal care.

Methods

A two-round, modified Delphi study was conducted online. An advisory group of children's orthopaedic specialists consisting of physiotherapists, surgeons, and clinical nurse specialists designed a survey. In the first round, participants also had the opportunity to suggest new statements. The survey included statements related to 'Exercises', 'Physical activity', 'Education/information sharing', 'Input from other services', and 'Monitoring assessments'. The survey was shared with clinicians who regularly treat children with Perthes' disease in the UK using clinically relevant specialist groups and social media. A predetermined threshold of ≥ 75% for consensus was used for recommendation, with a threshold of between 70% and 75% being considered as 'points to consider'.

Results

A total of 40 participants took part in the first round, of whom 31 completed the second round. A total of 87 statements were generated by the advisory group and included in the first round, at the end of which 31 achieved consensus and were removed from the survey, and an additional four statements were generated. A total of 60 statements were included in the second round and 45 achieved the threshold for consensus from both rounds, with three achieving the threshold for 'points to consider'. The recommendations predominantly included self-management, particularly relating to advice about exercise and education for children with Perthes' disease and their families.

Conclusion

Children's orthopaedic specialists have reached consensus on recommendations for non-surgical treatment in Perthes' disease. These statements will support decisions made in clinical practice and act as a foundation to support clinicians in the absence of robust evidence. The dissemination of these findings and the best way of delivering this care needs careful consideration, which we will continue to explore.

Development and external validation of the eFalls tool: a multivariable prediction model for the risk of ED attendance or hospitalisation with a fall or fracture in older adults

BACKGROUND

Falls are common in older adults and can devastate personal independence through injury such as fracture and fear of future falls. Methods to identify people for falls prevention interventions are currently limited, with high risks of bias in published prediction models. We have developed and externally validated the eFalls prediction model using routinely collected primary care electronic health records (EHR) to predict risk of emergency department attendance/hospitalisation with fall or fracture within 1 year.

METHODS

Data comprised two independent, retrospective cohorts of adults aged ≥65 years: the population of Wales, from the Secure Anonymised Information Linkage Databank (model development); the population of Bradford and Airedale, England, from Connected Bradford (external validation). Predictors included electronic frailty index components, supplemented with variables informed by literature reviews and clinical expertise. Fall/fracture risk was modelled using multivariable logistic regression with a Least Absolute Shrinkage and Selection Operator penalty. Predictive performance was assessed through calibration, discrimination and clinical utility. Apparent, internal-external cross-validation and external validation performance were assessed across general practices and in clinically relevant subgroups.

RESULTS

The model's discrimination performance (c-statistic) was 0.72 (95% confidence interval, CI: 0.68 to 0.76) on internal-external cross-validation and 0.82 (95% CI: 0.80 to 0.83) on external validation. Calibration was variable across practices, with some over-prediction in the validation population (calibration-in-the-large, -0.87; 95% CI: -0.96 to -0.78). Clinical utility on external validation was improved after recalibration.

CONCLUSION

The eFalls prediction model shows good performance and could support proactive stratification for falls prevention services if appropriately embedded into primary care EHR systems.

"Waiting for the best day of your life". A qualitative interview study of patients' and clinicians' experiences of Perthes' disease

Aims

Perthes' disease is an idiopathic avascular necrosis of the developing femoral head, often causing deformity that impairs physical function. Current treatments aim to optimize the joint reaction force across the hip by enhancing congruency between the acetabulum and femoral head. Despite a century of research, there is no consensus regarding the optimal treatment. The aim of this study was to describe the experiences of children, their families, and clinicians when considering the treatment of Perthes' disease.

Methods

A qualitative study gathered information from children and their families affected by Perthes' disease, along with treating clinicians. Interviews followed a coding framework, with the interview schedule informed by behavioural theory and patient and public involvement. Transcripts were analyzed using the framework method.

Results

A total of 24 interviews took place, with 12 child/family dyads and 12 clinicians from UK NHS centres. Interviews identified widespread variation of routine care. Children/their families recounted positive experiences when included in the decision-making process for treatment. There is a strong desire from clinicians and children/families for consistent guidance from everyone involved in care, which should be based on clinical consensus.

Conclusion

This is the first study to describe how children/families and clinicians experienced receiving or providing treatment in Perthes' disease. The results indicate the need for robust evidence to support treatment decisions. Children and families valued feeling involved in the clinical decision-making process. Clinicians acknowledged the central importance of providing patient-centred care, particularly in the absence of robust evidence to guide the optimal treatment decisions. This study will inform a future Delphi project to develop clinical consensus guidelines for the treatment of Perthes' disease.

Multicenter review of a tadalafil suspension formulation in infants and children with pulmonary hypertension: a north american experience

Funding Acknowledgements

Type of funding sources: None.

Background

Pulmonary arterial hypertension (PAH) is a disease characterised by an increase in pulmonary vascular resistance and pulmonary artery pressure. Phosphodiesterase type 5 (PDE5) inhibitors, with sildenafil the earliest among them, are widely used in the management of pediatric PAH. There has more recently been a transition to once-daily tadalafil suspensions. Herein, we present a multicenter experience detailing safety, tolerability and haemodynamic data utilizing tadalafil suspension alone or in combination for the management of pediatric PAH.

Methods and materials

We performed a retrospective review of all infants and children at two North American paediatric PH centres between December 2013 and April 2022. We included all patients less than 9 years of age who were treated with a tadalafil suspension after an initial treatment with sildenafil. Demographic, clinical, imaging, and laboratory data were collected.

Results

Over the study period, 158 children were treated with tadalafil therapy: 41 (25.9%) had group 1 PAH, 81 (51.3%) had group 3 PH, and 33 (20.9%) had group 5 PH. The median initial dose of tadalafil was 1.0 mg/kg once daily with a median time to maximum dose of 1 day. The majority of patients required the suspension formulation due to an inability to take oral tablets or the need for nasogastric or nasojejunal feeding. We observed improvements in median echocardiographic parameters in the six months following initiation, namely, in RVFAC from 34.7% (Q1 = 31.0%, Q3 = 42.0%) to 37.0% (Q1 = 31.0%, Q3 = 44.0%) and in TAPSE from 1.0 (Q1 = 0.8, Q3 = 1.7) cm to 1.3 (Q1 = 1.0, Q3 = 1.7) cm. We observed median decreases in RVSp from 51.0 (Q1 = 35.0, Q3 = 69.0) mmHg to 37.0 (Q1 = 30.0, Q3 = 50.0) mmHg and in NT pro BNP levels from 439.0 (Q1 = 217.0, Q3 = 2051.0) ng/L to 313.0 (Q1 = 193.0, Q3 = 1110.0) ng/L. Tadalafil therapy was well tolerated over the six-month period: at baseline, only four patients (2.5%) reported gastrointestinal side effects, two (1.3%) reported adverse skin adverse effects (i.e., rash and flushing), and one (0.6%) reported adverse neurological effects. At six months, 150 patients (94.9%) reported no adverse effects.

Conclusion

Tadalafil, a long-acting PDE5 inhibitor, when administered in a suspension formulation, has a safe and tolerable adverse effect profile once patients are established on sildenafil therapy. Following 6 months of once daily tadalafil suspension, alone or in combination, showed a trend towards improvement in clinical parameters, echocardiographic measurements, and laboratory results for pediatric PAH. All patient adverse effects were managed with non pharmacological measures and there was good patient compliance.

Cohort profile: the ESC EURObservational Research Programme Non-ST-segment elevation myocardial infraction (NSTEMI) Registry

AIMS

The European Society of Cardiology (ESC) EURObservational Research Programme (EORP) Non-ST-segment elevation myocardial infarction (NSTEMI) Registry aims to identify international patterns in NSTEMI management in clinical practice and outcomes against the 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without ST-segment-elevation.

METHODS AND RESULTS

Consecutively hospitalised adult NSTEMI patients (n = 3620) were enrolled between 11 March 2019 and 6 March 2021, and individual patient data prospectively collected at 287 centres in 59 participating countries during a two-week enrolment period per centre. The registry collected data relating to baseline characteristics, major outcomes (in-hospital death, acute heart failure, cardiogenic shock, bleeding, stroke/transient ischaemic attack, and 30-day mortality) and guideline-recommended NSTEMI care interventions: electrocardiogram pre- or in-hospital, pre-hospitalization receipt of aspirin, echocardiography, coronary angiography, referral to cardiac rehabilitation, smoking cessation advice, dietary advice, and prescription on discharge of aspirin, P2Y12 inhibition, angiotensin converting enzyme inhibitor (ACEi)/angiotensin receptor blocker (ARB), beta-blocker, and statin.

CONCLUSION

The EORP NSTEMI Registry is an international, prospective registry of care and outcomes of patients treated for NSTEMI, which will provide unique insights into the contemporary management of hospitalised NSTEMI patients, compliance with ESC 2015 NSTEMI Guidelines, and identify potential barriers to optimal management of this common clinical presentation associated with significant morbidity and mortality.

Clinical consensus regarding the importance of rapid reduction in depressive symptoms in major depressive disorder with acute suicidal ideation or behavior (MDSI)

Introduction

Patients with major depressive disorder (MDD) with acute suicidal ideation or behavior (MDSI) require immediate intervention. Though oral antidepressants can be effective at reducing depressive symptoms, they can take 4–6 weeks to reach full effect.

Objectives

This study aimed to identify unmet needs in the treatment of patients with MDSI, specifically exploring the potential clinical benefits of rapid reduction of depressive symptoms.

Methods

A Delphi panel consisting of practicing psychiatrists (n=12) from the US, Canada and EU was conducted between December 2020–June 2021. Panelists were screened to ensure they had sufficient experience with managing patients with MDD and MDSI. Panelists completed two survey rounds, and a virtual consensus meeting.

Results

This research confirmed current unmet needs in the treatment of patients with MDSI.

Hopelessness, functional impairment, worsening of MDD symptoms, recurrent hospitalization and higher risk of suicide attempt were considered as key consequences of the slow onset of action of oral antidepressants.

Treatment with rapid acting antidepressant was anticipated by panelists to provide short-term benefit such as rapid reduction of core MDD symptoms which may contribute to shorter hospital stays and improved patient engagement/compliance, allowing for earlier interventions and improved patient outcomes. For long-term benefits, panelists agreed that improved daily functioning and increased trust/confidence in treatment options, constitute key benefits of rapid-acting treatments

Conclusions

There is need for rapid-acting treatments which may help address key unmet needs and provide clinically meaningful benefits driven by the rapid relief of depressive symptoms particularly in patients with MDSI.

Disclosure

SB, ED, KJ, MO’H, QZ, MM, MH, SR, JA and DZ are employees of Janssen and hold stock in Johnson & Johnson Inc. AN is currently employed by Neurocrine Biosciences Inc. RP is an employee of Adelphi Values PROVE hired by Janssen.

OUP accepted manuscript

Background

Antimicrobial stewardship programmes (ASPs) have been widely implemented in medical practice to improve antimicrobial prescribing and reduce selection for multidrug-resistant pathogens.

Objectives

To implement different antimicrobial stewardship intervention packages in 135 veterinary practices and assess their impact on antimicrobial prescribing.

Methods

In October 2018, general veterinary clinics were assigned to one of three levels of ASP, education only (CON), intermediate (AMS1) or intensive (AMS2). De-identified prescribing data (1 October 2016 to 31 October 2020), sourced from VetCompass Australia, were analysed and a Poisson regression model fitted to identify the effect of the interventions on the incidence rates of antimicrobial prescribing.

Results

The overall incidence rate (IR) of antimicrobial prescribing for dogs and cats prior to the intervention was 3.7/100 consultations, which declined by 36% (2.4/100) in the implementation period, and by 50% (1.9/100) during the post-implementation period. Compared with CON, in AMS2 there was a 4% and 6% reduction in the overall IR of antimicrobial prescribing, and a 24% and 24% reduction in IR of high importance antimicrobial prescribing, attributable to the intervention in the implementation and post-implementation periods, respectively. A greater mean difference in the IR of antimicrobial prescribing was seen in high-prescribing clinics.

Conclusions

These AMS interventions had a positive impact in a large group of general veterinary practices, resulting in a decline in overall antimicrobial use and a shift towards use of antimicrobials rated as low importance, with the greatest impact in high-prescribing clinics.

Low endothelial shear stress, microcalcification activity and high-risk plaque features: merging computational flow modelling, OCT and 18F-NaF PET/CT

Background

Endothelial shear stress (ESS) has a critical role in endothelial function. Abnormal shear stress leads to endothelial dysfunction, which contributes to arterial plaque initiation and development. Four dimensional magnetic resonance can determine shear stress in the larger arteries but cannot resolve the detail needed to calculate shear stress in the coronary arteries and thus methods such as computational fluid dynamics (CFD) are required. Additionally, a key feature of biologically active plaques is microcalcification activity, and this can be detected using 18F-sodium fluoride (18F-NaF) positron emission tomography (PET). Furthermore, using high resolution optical coherence tomography (OCT), the high-risk features plaques can be visualized and quantified. We aimed to merge these three techniques to investigate if low ESS is associated with high-risk plaque features and active microcalcifications in acute coronary syndrome.

Methods

We began by merging OCT images with CTCA images to obtain detailed 3D reconstructions of the target vessel. We then simulated blood flow and calculated the ESS, from which we extracted the area of low ESS (<0.4 Pa). We quantified plaque features using OCT and measured the maximum 18F-NaF uptake, and compared data at both the coronary segment and whole artery level (Figure 1).

Results

We investigated 20 arteries from 18 patients which we obtained 38 coronary segments according to the SCCT guidelines. We found that areas of low ESS were were significantly and positively associated with high-risk plaque features: macrophage infiltration (segment, rs=0.33, p=0.043; artery, rs=0.46, p=0.041) and presence of cholesterol crystals (segment, rs=0.45, p=0.005; artery, rs=0.58, p=0.007). Vessel segments with thin-capped fibroatheroma had greater area of low ESS (20 vs 4%). The uptake of 18F-NaF was positively associated with the area of low ESS (segment, rs=0.52, p=0.001; artery, rs=0.64, p=0.002). We found that there were typically more plaque features found in regions of low ESS (Table 1).

Conclusion

Here we provide the first data associating low ESS with both high-risk plaque features and active microcalcifications in patients with acute coronary syndrome. Although our sample size is small, these data are encouraging and could lead to better understanding of how best to deem a plaque “high risk”.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Royal Perth Hospital Medical Research Foundation Figure 1Table 1

652 Fate of The Contralateral Limb Following Major Lower Limb Amputation in Patients with Peripheral Arterial Disease And/Or Diabetes: Case Series from Two Regional Vascular Centres

Introduction

This is the first clinical case series to report time to ulceration, minor and major amputation of the contralateral limb (CLL) in the first 12 months following major lower limb amputation (LLA) in patients with peripheral arterial disease (PAD) and/or diabetes.

Method

Consecutive patient samples at two regional UK vascular centres were included; from 2010 to 2017 (site 1) and 2014 to 2016 (site 2). Data were extracted from electronic records for 12 months following index major LLA. Survival analyses are presented for the event of mortality in the total study population, plus major amputation-free survival, and complication-free survival in site 1 only; results are stratified by diabetes status.

Results

Of 381 patients reviewed (n = 197 site 1; n = 184 site 2), 208 (54.6%) were diagnosed with diabetes at the time of their index major LLA. The mean survival time of patients was lower in those without diabetes (HR: 0.64 [95% CI, 0.43 to 0.95], p=.03). The mean time to major amputation of the CLL or death in patients was lower in those without diabetes (HR: 0.65 [95% CI, 224 0.40 to 1.06]; p=.08). The median time to any complication of the CLL or death was greater in those without diabetes (HR: 1.25 [95% CI, 227 0.88 to 1.78]; p=.21).

Conclusions

Death rates were higher in patients without diabetes, whilst those with diabetes had high levels of CLL complications. Optimisation of care to protect the CLL following major LLA and guidance for carers, patients, and clinicians is required.

497 Targeting Improvements in The Elective Aneurysm Pathway in The Dorset and Wiltshire Vascular Network (DWVN)

Introduction

Two consecutive NVR reports identified the DWVN as the 7th slowest network to treat patients with AAAs. We aimed to detect if there were any significant delays in our pathway.

Method

We performed a retrospective audit of patients having elective open and endovascular repair. 144 patients who had AAA repair between 30/06/2016-01/08/2018 were included. Data were collected on the following stages: the date the AAA reached ≥55mm, referral date, date clinician reviewed, CT scan date, CPET testing date, MDT date and operation date. The time in days between each stage was recorded and any delays documented.

Results

At RBH the longest delay was between MDT and surgery (median 73 days, IQR 32 days-130 days). At DCH the major delay was between CPET and MDT (median 28.5 days, IQR 10 days-31 days). At SDH the longest stage was between MDT and operation (median of 88 days, IQR 37 days-154 days).

Examples of reasons for delays across the three hospitals included awaiting specialist opinions, patient being unwell and no ITU beds available.

Conclusions

The pathway for elective AAA treatment in the DWVN is slow across all three hospitals. The greatest delay is often between MDT and surgery. Targeting this stage could significantly shorten the pathway.

Tonsillitis, tonsillectomy, and deep neck space infections in England: the case for a new guideline for surgical and non-surgical management

INTRODUCTION

Tonsillectomy is a common surgical procedure performed chiefly for recurrent tonsillitis. The Scottish Intercollegiate Guidance Network (SIGN) introduced guidelines in 1998 to improve patient selection for tonsillectomy and reduce the potential harm to patients from surgical complications such as haemorrhage. Since the introduction of the guidance, the number of admissions for tonsillitis and its complications has increased. National Hospital Episode Statistics over a 20-year period were analysed to assess the trends in tonsillectomy, post-tonsillectomy haemorrhage, tonsillitis and its complications with reference to the guidance, procedures of limited clinical value and the associated costs and benefits.

MATERIALS AND METHODS

A literature search was conducted via PubMed and the Cochrane Library to identify relevant research. Hospital Episode Statistics data were interrogated and relevant data compared over time to assess trends related to the implementation of national guidance.

RESULTS

Over the period analysed, the incidence of deep neck space infections has increased almost five-fold, mediastinitis ten-fold and peritonsillar abscess by 1.7-fold compared with prior to SIGN guidance. Following procedures of limited clinical value implementation, the incidence of deep neck space infections has increased 2.4-fold, mediastinitis 4.1-fold and peritonsillar abscess 1.4-fold compared with immediately prior to clinical commissioning group rationing. The rate of tonsillectomy and associated haemorrhage (1-2%) has remained relatively constant at 46,299 (1999) compared with 49,447 (2009) and 49,141 (2016), despite an increase in the population of England by seven million over the 20-year period.

DISCUSSION

The rise in admissions for tonsillitis and its complications appears to correspond closely to the date of SIGN guidance and clinical commissioning group rationing of tonsillectomy and is on the background of a rise in the population of the UK. The move towards daycase tonsillectomy has reduced bed occupancy after surgery but this has been counteracted by an increase in admissions for tonsillitis and deep neck space infections, sometimes requiring lengthy intensive care stays and a protracted course of rehabilitation. The total cost of treating the complications of tonsillitis in England in 2017 is estimated to be around £73 million. The cost of tonsillectomy and treating post-tonsillectomy haemorrhage is £56 million by comparison. The total cost per annum for tonsillectomy prior to the introduction of SIGN guidance was estimated at £71 million with tonsillitis and its complications accounting for a further £8 million.

Evaluation of environmental and comfort improvements on affective welfare in heifer calves on smallholder dairy farms

A controlled trial on zero-grazed smallholder dairy farms was conducted to determine the effect of environmental and comfort improvements on sucking and lying behaviours in heifer calves on Kenyan smallholder dairy farms. The study involved 187 heifer calves from 150 farms in two Kenyan counties, 75 farms per county. Farms in one county received animal welfare training and improvements in the calf pen that included: 1) placement of rubber mats on the lying area; 2) fixing gaps/holes in the flooring and roofing; and 3) attaching a rubber nipple on the wall of the calf pen. During the 16-month data collection period, bimonthly farm visits were used to collect data on lying time (using accelerometers) and other animal- and farm-level factors. Multilevel mixed-effects linear regression was used to model daily lying times and frequency of lying bouts, with the animal as a random effect. Over the visits, daily lying times and lying bout durations averaged 12.6-86.7 min/bout, respectively, while the median for the frequency of lying bouts was between 30-46/day. Provision of rubber nipples for non-nutritive sucking lowered proportions of cross-sucking, self-sucking and object-sucking behaviours slightly but not significantly. In a final daily lying time model, superficial lymph node enlargement, body condition score and use of wood shaving/ sawdust/ crop waste as beddings had positive associations. In contrast, group housing and rubber mat use had negative associations with daily lying time. In an interaction term, lying time was significantly higher for calves on clean versus dirty floors if the age was <190 days but this difference diminished significantly in older animals. In a second interaction term, lying time was lower for calves with leaking versus non-leaking roofs, regardless of the pen floor level, but lying time was higher on elevated than non-elevated floors if the roof was intact. In the final model of the frequency of lying bouts, the use of a rubber mat, the years of experience in dairy farming, and calf body weight had negative associations. In contrast, body condition score had a positive association. In an interaction, the frequency of daily lying bouts was lower on clean floors than dirty floors, irrespective of tethering status, but when the floor was dirty, the lying bouts were higher for animals not tethered than the ones sometimes tethered. We conclude that the comfort improvements enhanced the welfare and lying experience of heifer calves on smallholder dairy farms.

Application of sensitivity analysis in DYMOND/Dakota to fuel cycle transition scenarios

The ability to perform sensitivity analysis has been enabled for the nuclear fuel cycle simulator DYMOND through its coupling with the design and analysis toolkit Dakota. To test and demonstrate these new capabilities, a transition scenario and multi-parameter study were devised. The transition scenario represents a partial transition from the US nuclear fleet to a closed fuel cycle with small modular LWRs and fast reactors fueled by reprocessed used nuclear fuel. Four uncertain parameters in this transition were studied – start date of reprocessing, total reprocessing capacity, the nuclear energy demand growth, and the rate at which the fast reactors are deployed – with respect to their impact on four response metrics. The responses – total natural uranium consumed, maximum annual enrichment capacity required, total disposed mass, and total cost of the nuclear fuel cycle – were chosen based on measures known to be of interest in transition scenarios [2] and to be significantly impacted by the varying parameters. Analysis of this study was performed both from the direct sampling and through surrogate models developed in Dakota to calculate the global sensitivity measures Sobol’ indices. This example application of this new capability showed that the most consequential parameter to most metrics was the share of new build capacity that is fast reactors. However, for the cost metric, the scaling factor of the energy demand growth was significant and had synergistic behavior with the fast reactor new build share.

Constraints on the K_{S}^{0}→μ^{+}μ^{-} Branching Fraction

A search for the decay K_{S}^{0}→μ^{+}μ^{-} is performed using proton-proton collision data, corresponding to an integrated luminosity of 5.6  fb^{-1} and collected with the LHCb experiment during 2016, 2017, and 2018 at a center-of-mass energy of 13 TeV. The observed signal yield is consistent with zero, yielding an upper limit of B(K_{S}^{0}→μ^{+}μ^{-})<2.2×10^{-10} at 90% C.L.. The limit reduces to B(K_{S}^{0}→μ^{+}μ^{-})<2.1×10^{-10} at 90% C.L. once combined with the result from data taken in 2011 and 2012.

A systematic review of the non-surgical treatment of Perthes' disease

Aims

Perthes’ disease is a condition leading to necrosis of the femoral head. It is most common in children aged four to nine years, affecting around one per 1,200 children in the UK. Management typically includes non-surgical treatment options, such as physiotherapy with/without surgical intervention. However, there is significant variation in care with no consensus on the most effective treatment option.

Methods

This systematic review aims to evaluate the effectiveness of non-surgical interventions for the treatment of Perthes’ disease. Comparative studies (experimental or observational) of any non-surgical intervention compared directly with any alternative intervention (surgical, non-surgical or no intervention) were identified from: Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), EMcare, Allied and Complementary Medicine Database (AMED), and the Physiotherapy Evidence Database (PEDro). Data were extracted on interventions compared and methodological quality. For post-intervention primary outcome of radiological scores (Stulberg and/or Mose), event rates for poor scores were calculated with significance values. Secondary outcomes included functional measures, such as range of movement, and patient-reported outcomes such as health-related quality of life.

Results

In all, 15 studies (1,745 participants) were eligible for inclusion: eight prospective cohort studies, seven retrospective cohort studies, and no randomized controlled trials were identified. Non-surgical interventions largely focused on orthotic management (14/15 studies) and physical interventions such as muscle strengthening or stretching (5/15 studies). Most studies were of high/unknown risk of bias, and the range of patient outcomes was very limited, as was reporting of treatment protocols. Similar proportions of children achieving poor radiological outcomes were found for orthotic management and physical interventions, such as physiotherapy or weightbearing alteration, compared with surgical interventions or no intervention.

Conclusion

Evidence from non-randomized studies found no robust evidence regarding the most effective non-surgical interventions for the treatment of children with Perthes’ disease. Future research, employing randomized trial designs, and reporting a wider range of patient outcomes is urgently needed to inform clinical practice.

Cite this article: Bone Jt Open 2020;1-12:720–730.

A case review to describe variation in care following diagnosis of Perthes' disease

Aims

Perthes' disease is a condition which leads to necrosis of the femoral head. It is most commonly reported in children aged four to nine years, with recent statistics suggesting it affects around five per 100,000 children in the UK. Current treatment for the condition aims to maintain the best possible environment for the disease process to run its natural course. Management typically includes physiotherapy with or without surgical intervention. Physiotherapy intervention often will include strengthening/stretching programmes, exercise/activity advice, and, in some centres, will include intervention, such as hydrotherapy. There is significant variation in care with no consensus on which treatment option is best. The importance of work in this area has been demonstrated by the British Society for Children's Orthopaedic Surgery through the James Lind Alliance's prioritization of work to determine/identify surgical versus non-surgical management of Perthes' disease. It was identified as the fourth-highest priority for paediatric lower limb surgery research in 2018.

Methods

Five UK NHS centres, including those from the NEWS (North, East, West and South Yorkshire) orthopaedic group, contributed to this case review, with each entre providing clinical data from a minimum of five children. Information regarding both orthopaedic and physiotherapeutic management over a two-year post-diagnosis period was reviewed.

Results

Data were extracted from the clinical records of 32 children diagnosed with Perthes' disease; seven boys and 25 girls. The mean age of the children at diagnosis was 6.16 years (standard deviation (SD) 3.001). In all, 26 children were referred for physiotherapy. In the two-year period following diagnosis, children were seen a median of 7.5 times (interquartile range (IQR) 4.25 to 11) by an orthopaedic surgeon, and a median of 9.5 times (IQR 8 to 18.25) by a physiotherapist. One centre had operated on all of their children, while another had operated on none. Overall, 17 (53%) of the children were managed conservatively in the two-year follow-up period, and 15 (47%) of the children underwent surgery in the two-year follow-up period.

Conclusion

The results of this case review demonstrate a variation of care provided to children in the UK with Perthes' disease. Further national and international understanding of current care is required to underpin the rationale for different treatment options in children with Perthes' disease.Cite this article: Bone Joint Open 2020;1-11:691-695.

Randomised feasibility trial and embedded qualitative process evaluation of a new intervention to facilitate the involvement of older patients with multimorbidity in decision-making about their healthcare during general practice consultations: the VOLITION study protocol

BACKGROUND

The number of older people with multiple health problems is increasing worldwide. This creates a strain on clinicians and the health service when delivering clinical care to this patient group, who themselves carry a large treatment burden. Despite shared decision-making being acknowledged by healthcare organisations as a priority feature of clinical care, older patients with multimorbidity are less often involved in decision-making when compared with younger patients, with some evidence suggesting associated health inequalities. Interventions aimed at facilitating shared decision-making between doctors and patients are outdated in their assessments of today's older patient population who need support in prioritising complex care needs in order to maximise quality of life and day-to-day function.

AIMS

To undertake feasibility testing of an intervention ('VOLITION') aimed at facilitating the involvement of older patients with more than one long-term health problem in shared decision-making about their healthcare during GP consultations.To inform the design of a fully powered trial to assess intervention effectiveness.

METHODS

This study is a cluster randomised controlled feasibility trial with qualitative process evaluation interviews. Participants are patients, aged 65 years and above with more than one long-term health problem (multimorbidity), and the GPs that they consult with. This study aims to recruit 6 GP practices, 18 GPs and 180 patients. The intervention comprises two components: (i) a half-day training workshop for GPs in shared decision-making; and (ii) a leaflet for patients that facilitate their engagement with shared decision-making. Intervention implementation will take 2 weeks (to complete delivery of both patient and GP components), and follow-up duration will be 12 weeks (from index consultation and commencement of data collection to final case note review and process evaluation interview). The trial will run from 01/01/20 to 31/01/21; 1 year 31 days.

DISCUSSION

Shared decision-making for older people with multimorbidity in general practice is under-researched. Emerging clinical guidelines advise a patient-centred approach, to reduce treatment burden and focus on quality of life alongside disease control. The systematic development, testing and evaluation of an intervention is warranted and timely. This study will test the feasibility of implementing a new intervention in UK general practice for future evaluation as a part of routine care.

TRIAL REGISTRATION

CLINICAL TRIALS.GOV registration number NCT03786315, registered 24/12/18.

Measurement of CP-Averaged Observables in the B^{0}→K^{*0}μ^{+}μ^{-} Decay

An angular analysis of the B^{0}→K^{*0}(→K^{+}π^{-})μ^{+}μ^{-} decay is presented using a dataset corresponding to an integrated luminosity of 4.7  fb^{-1} of pp collision data collected with the LHCb experiment. The full set of CP-averaged observables are determined in bins of the invariant mass squared of the dimuon system. Contamination from decays with the K^{+}π^{-} system in an S-wave configuration is taken into account. The tension seen between the previous LHCb results and the standard model predictions persists with the new data. The precise value of the significance of this tension depends on the choice of theory nuisance parameters.

Observation of New Ξ_{c}^{0} Baryons Decaying to Λ_{c}^{+}K^{-}

The Λ_{c}^{+}K^{-} mass spectrum is studied with a data sample of pp collisions at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 5.6  fb^{-1} collected by the LHCb experiment. Three Ξ_{c}^{0} states are observed with a large significance and their masses and natural widths are measured to be m[Ξ_{c}(2923)^{0}]=2923.04±0.25±0.20±0.14  MeV, Γ[Ξ_{c}(2923)^{0}]=7.1±0.8±1.8  MeV, m[Ξ_{c}(2939)^{0}]=2938.55±0.21±0.17±0.14  MeV, Γ[Ξ_{c}(2939)^{0}]=10.2±0.8±1.1  MeV, m[Ξ_{c}(2965)^{0}]=2964.88±0.26±0.14±0.14  MeV, Γ[Ξ_{c}(2965)^{0}]=14.1±0.9±1.3  MeV, where the uncertainties are statistical, systematic, and due to the limited knowledge of the Λ_{c}^{+} mass. The Ξ_{c}(2923)^{0} and Ξ_{c}(2939)^{0} baryons are new states. The Ξ_{c}(2965)^{0} state is in the vicinity of the known Ξ_{c}(2970)^{0} baryon; however, their masses and natural widths differ significantly.

Loneliness, Social Isolation, and Objectively Measured Physical Activity in Rural-Living Older Adults

This cross-sectional, observational study examined whether objectively measured physical activity (PA) and specific activities are associated with loneliness and social isolation (SI) in rural-living older adults. A total of 112 participants (Mage = 72.8 [SD = 6.6], 51.8% female) from 23 villages in Wiltshire, United Kingdom, completed questionnaires, 7-day accelerometry, and activity diaries. Regression analysis was used to test associations between objectively measured light PA, moderate to vigorous PA, and total PA; loneliness; and SI from family, neighbors, or friends and to explore these associations using specific activities. Daily mean light, moderate to vigorous, and total PA were not associated with loneliness or SI. Volunteering, accompanying others, and sports/exercise were associated with lower SI from neighbors (odds ratio = 0.23, 95% CI [0.06, 0.91]), family (odds ratio = 0.39, 95% CI [0.22, 0.68]), and friends (odds ratio = 0.56, 95% CI [0.33, 0.97]), respectively. There were no associations between loneliness, SI, and objectively measured PA. The contribution of PA to loneliness and SI needs to be further investigated with larger and diverse samples of rural-living older adults.

Search for the Rare Decays B_{s}^{0}→e^{+}e^{-} and B^{0}→e^{+}e^{-}

A search for the decays B_{s}^{0}→e^{+}e^{-} and B^{0}→e^{+}e^{-} is performed using data collected with the LHCb experiment in proton-proton collisions at center-of-mass energies of 7, 8, and 13 TeV, corresponding to integrated luminosities of 1, 2, and 2  fb^{-1}, respectively. No signal is observed. Assuming no contribution from B^{0}→e^{+}e^{-} decays, an upper limit on the branching fraction B(B_{s}^{0}→e^{+}e^{-})<9.4(11.2)×10^{-9} is obtained at 90(95)% confidence level. If no B_{s}^{0}→e^{+}e^{-} contribution is assumed, a limit of B(B^{0}→e^{+}e^{-})<2.5(3.0)×10^{-9} is determined at 90(95)% confidence level. These upper limits are more than one order of magnitude lower than the previous values.

1212 A Systematic Assessment Of Engagement, Functionality, Aesthetics, Information, And Recommendation Features In Sleep Mobile Applications

Introduction

Initial download and use of sleep tracking is very high, but prolonged use is very low. Poor prolonged use may be attributable to several factors such as engagement, functionality, aesthetics, information, and recommendation. We appraised these five factors in 16 consumer- and research/medical- grade digital sleep devices.

Methods

Three reviewers independently assessed 16 consumer- and medical-grade sleep digital devices using the Mobile Application Rating Scale (MARS) App quality ratings, which measures engagement (engagement, entertainment, interest, customization, interactivity, target group), functionality (functionality, performance, ease of use, navigation, gestural design), aesthetics (layout, graphics, visual appeal), information (Accuracy. Goals, Quality of information, Quantity of information, Visual information, Credibility, and Evidence base) and recommended on a Likert scale, with 1- Inadequate to 5 Excellent. Each subcategory is rated on a 1-5 Likert scale which is summed for each category: engagement (30), functionality (25), aesthetics (15), information (35) and recommended (yes or no).

Results

Devices that had the highest engagement score were Fitbit (27), Apple Watch (27), Garmin (27), and Dreem 2 headband (25.5). Apple Watch (30) had highest score; while Fitbit (13), Apple Watch (13), Garmin (13), Samsung Gear (13) had highest aesthetic score. While for information, ActiGraph (35), SOMNOwatch plus (35), CleveMed SleepView Monitor (35), CleveMed Sapphire PSG (35), SOMNOscreen plus (35), Nox T3 Sleep Monitor (35) and Nox A1 PSG System (35) had the highest ratings. The Dreem 2 headband has the potential induce prolong use among users with and without sleep disorders, based on high scores on engagement (25.5), Functionality (20.5), and Information (26.5).

Conclusion

Consumer- and research-grade digital devices that measure sleep have varying levels of engagement, functionality, aesthetics, information and recommendations to facilitate prolong use. Consumer grade devices had higher engagement, functionality and aesthetics scores, while research grade devices had higher information and recommendation scores. If consumer- and research-grade devices are to have prolonged use, standardization is needed across the five MARS components.

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K01HL135452, R01MD007716, R01HL142066, and K07AG052685

Measurement of f_{s}/f_{u} Variation with Proton-Proton Collision Energy and B-Meson Kinematics

The ratio of the B_{s}^{0} and B^{+} fragmentation fractions f_{s} and f_{u} is studied with B_{s}^{0}→J/ψϕ and B^{+}→J/ψK^{+} decays using data collected by the LHCb experiment in proton-proton collisions at 7, 8, and 13 TeV center-of-mass energies. The analysis is performed in bins of B-meson momentum, longitudinal momentum, transverse momentum, pseudorapidity, and rapidity. The fragmentation-fraction ratio f_{s}/f_{u} is observed to depend on the B-meson transverse momentum with a significance of 6.0σ. This dependency is driven by the 13 TeV sample (8.7σ), while the results for the other collision energies are not significant when considered separately. Furthermore, the results show a 4.8σ evidence for an increase of f_{s}/f_{u} as a function of collision energy.

Isospin Amplitudes in Λ_{b}^{0}→J/ψΛ(Σ^{0}) and Ξ_{b}^{0}→J/ψΞ^{0}(Λ) Decays

Ratios of isospin amplitudes in hadron decays are a useful probe of the interplay between weak and strong interactions and allow searches for physics beyond the standard model. We present the first results on isospin amplitudes in b-baryon decays, using data corresponding to an integrated luminosity of 8.5  fb^{-1}, collected with the LHCb detector in pp collisions at center of mass energies of 7, 8, and 13 TeV. The isospin amplitude ratio |A_{1}(Λ_{b}^{0}→J/ψΣ^{0})/A_{0}(Λ_{b}^{0}→J/ψΛ)|, where the subscript on A indicates the final-state isospin, is measured to be less than 1/21.8 at 95% confidence level. The Cabibbo suppressed Ξ_{b}^{0}→J/ψΛ decay is observed for the first time, allowing for the measurement |A_{0}(Ξ_{b}^{0}→J/ψΛ)/A_{1/2}(Ξ_{b}^{0}→J/ψΞ^{0})|=0.37±0.06±0.02, where the uncertainties are statistical and systematic, respectively.

First Observation of Excited Ω_{b}^{-} States

We report four narrow peaks in the Ξ_{b}^{0}K^{-} mass spectrum obtained using pp collisions at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9  fb^{-1} recorded by the LHCb experiment. Referring to these states by their mass, the mass values are m[Ω_{b}(6316)^{-}]=6315.64±0.31±0.07±0.50  MeV, m[Ω_{b}(6330)^{-}]=6330.30±0.28±0.07±0.50  MeV, m[Ω_{b}(6340)^{-}]=6339.71±0.26±0.05±0.50  MeV, m[Ω_{b}(6350)^{-}]=6349.88±0.35±0.05±0.50  MeV, where the uncertainties are statistical, systematic, and the last is due to the knowledge of the Ξ_{b}^{0} mass. The natural widths of the three lower mass states are consistent with zero, and the 90% confidence-level upper limits are determined to be Γ[Ω_{b}(6316)^{-}]<2.8  MeV, Γ[Ω_{b}(6330)^{-}]<3.1  MeV and Γ[Ω_{b}(6340)^{-}]<1.5  MeV. The natural width of the Ω_{b}(6350)^{-} peak is 1.4_{-0.8}^{+1.0}±0.1  MeV, which is 2.5σ from zero and corresponds to an upper limit of 2.8 MeV. The peaks have local significances ranging from 3.6σ to 7.2σ. After accounting for the look-elsewhere effect, the significances of the Ω_{b}(6316)^{-} and Ω_{b}(6330)^{-} peaks are reduced to 2.1σ and 2.6σ, respectively, while the two higher mass peaks exceed 5σ. The observed peaks are consistent with expectations for excited Ω_{b}^{-} resonances.

Search for A^{'}→μ^{+}μ^{-} Decays

Searches are performed for both promptlike and long-lived dark photons, A^{'}, produced in proton-proton collisions at a center-of-mass energy of 13 TeV. These searches look for A^{'}→μ^{+}μ^{-} decays using a data sample corresponding to an integrated luminosity of 5.5  fb^{-1} collected with the LHCb detector. Neither search finds evidence for a signal, and 90% confidence-level exclusion limits are placed on the γ-A^{'} kinetic mixing strength. The promptlike A^{'} search explores the mass region from near the dimuon threshold up to 70 GeV and places the most stringent constraints to date on dark photons with 214<m(A^{'})≲740  MeV and 10.6<m(A^{'})≲30  GeV. The search for long-lived A^{'}→μ^{+}μ^{-} decays places world-leading constraints on low-mass dark photons with lifetimes O(1)  ps.

Observation of Several Sources of CP Violation in B^{+}→π^{+}π^{+}π^{-} Decays

Observations are reported of different sources of CP violation from an amplitude analysis of B^{+}→π^{+}π^{+}π^{-} decays, based on a data sample corresponding to an integrated luminosity of 3  fb^{-1} of pp collisions recorded with the LHCb detector. A large CP asymmetry is observed in the decay amplitude involving the tensor f_{2}(1270) resonance, and in addition significant CP violation is found in the π^{+}π^{-}S wave at low invariant mass. The presence of CP violation related to interference between the π^{+}π^{-}S wave and the P wave B^{+}→ρ(770)^{0}π^{+} amplitude is also established; this causes large local asymmetries but cancels when integrated over the phase space of the decay. The results provide both qualitative and quantitative new insights into CP -violation effects in hadronic B decays.

Search for Lepton-Flavor Violating Decays B^{+}→K^{+}μ^{±}e^{∓}

A search for the lepton-flavor violating decays B^{+}→K^{+}μ^{±}e^{∓} is performed using a sample of proton-proton collision data, collected with the LHCb experiment at center-of-mass energies of 7 and 8 TeV and corresponding to an integrated luminosity of 3  fb^{-1}. No significant signal is observed, and upper limits on the branching fractions are set as B(B^{+}→K^{+}μ^{-}e^{+})<7.0(9.5)×10^{-9} and B(B^{+}→K^{+}μ^{+}e^{-})<6.4(8.8)×10^{-9} at 90% (95)% confidence level. The results improve the current best limits on these decays by more than one order of magnitude.

Measurement of Charged Hadron Production in Z-Tagged Jets in Proton-Proton Collisions at sqrt[s]=8 TeV

The production of charged hadrons within jets recoiling against a Z boson is measured in proton-proton collision data at sqrt[s]=8  TeV recorded by the LHCb experiment. The charged-hadron structure of the jet is studied longitudinally and transverse to the jet axis for jets with transverse momentum p_{T}>20  GeV and in the pseudorapidity range 2.5<η<4. These are the first measurements of jet hadronization at these forward rapidities and also the first where the jet is produced in association with a Z boson. In contrast to previous hadronization measurements at the Large Hadron Collider, which are dominated by gluon jets, these measurements probe predominantly light-quark jets which are found to be more longitudinally and transversely collimated with respect to the jet axis when compared to the previous gluon dominated measurements. Therefore, these results provide valuable information on differences between quarks and gluons regarding nonperturbative hadronization dynamics.

Amplitude Analysis of B^{±}→π^{±}K^{+}K^{-} Decays

The first amplitude analysis of the B^{±}→π^{±}K^{+}K^{-} decay is reported based on a data sample corresponding to an integrated luminosity of 3.0  fb^{-1} of pp collisions recorded in 2011 and 2012 with the LHCb detector. The data are found to be best described by a coherent sum of five resonant structures plus a nonresonant component and a contribution from ππ↔KK S-wave rescattering. The dominant contributions in the π^{±} K^{∓} and K^{+} K^{-} systems are the nonresonant and the B^{±}→ρ(1450)^{0}π^{±} amplitudes, respectively, with fit fractions around 30%. For the rescattering contribution, a sizable fit fraction is observed. This component has the largest CP asymmetry reported to date for a single amplitude of (-66±4±2)%, where the first uncertainty is statistical and the second systematic. No significant CP violation is observed in the other contributions.

Search for the Lepton-Flavor-Violating Decays B_{s}^{0}→τ^{±}μ^{∓} and B^{0}→τ^{±}μ^{∓}

Results are reported from a search for the rare decays B_{s}^{0}→τ^{±}μ^{∓} and B^{0}→τ^{±}μ^{∓}, where the τ lepton is reconstructed in the channel τ^{-}→π^{-}π^{+}π^{-}ν_{τ}. These processes are effectively forbidden in the standard model, but they can potentially occur at detectable rates in models of new physics that can induce lepton-flavor-violating decays. The search is based on a data sample corresponding to 3  fb^{-1} of proton-proton collisions recorded by the LHCb experiment in 2011 and 2012. The event yields observed in the signal regions for both processes are consistent with the expected standard model backgrounds. Because of the limited mass resolution arising from the undetected τ neutrino, the B_{s}^{0} and B^{0} signal regions are highly overlapping. Assuming no contribution from B^{0}→τ^{±}μ^{∓}, the upper limit B(B_{s}^{0}→τ^{±}μ^{∓})<4.2×10^{-5} is obtained at 95% confidence level. If no contribution from B_{s}^{0}→τ^{±}μ^{∓} is assumed, a limit of B(B^{0}→τ^{±}μ^{∓})<1.4×10^{-5} is obtained at 95% confidence level. These results represent the first limit on B(B_{s}^{0}→τ^{±}μ^{∓}) and the most stringent limit on B(B^{0}→τ^{±}μ^{∓}).

Observation of New Resonances in the Λ_{b}^{0}π^{+}π^{-} System

We report the observation of a new structure in the Λ_{b}^{0}π^{+}π^{-} spectrum using the full LHCb data set of pp collisions, corresponding to an integrated luminosity of 9  fb^{-1}, collected at sqrt[s]=7, 8, and 13 TeV. A study of the structure suggests its interpretation as a superposition of two almost degenerate narrow states. The masses and widths of these states are measured to be m_{Λ_{b}(6146)^{0}}=6146.17±0.33±0.22±0.16  MeV,m_{Λ_{b}(6152)^{0}}=6152.51±0.26±0.22±0.16  MeV,Γ_{Λ_{b}(6146)^{0}}=2.9±1.3±0.3  MeV,Γ_{Λ_{b}(6152)^{0}}=2.1±0.8±0.3  MeV,with a mass splitting of Δm=6.34±0.32±0.02  MeV, where the first uncertainty is statistical, the second systematic. The third uncertainty for the mass measurements derives from the knowledge of the mass of the Λ_{b}^{0} baryon. The measured masses and widths of these new excited states suggest their possible interpretation as a doublet of Λ_{b}(1D)^{0} states.

Measurement of CP-Violating and Mixing-Induced Observables in B_{s}^{0}→ϕγ Decays

A time-dependent analysis of the B_{s}^{0}→ϕγ decay rate is performed to determine the CP -violating observables S_{ϕγ} and C_{ϕγ} and the mixing-induced observable A_{ϕγ}^{Δ}. The measurement is based on a sample of pp collision data recorded with the LHCb detector, corresponding to an integrated luminosity of 3  fb^{-1} at center-of-mass energies of 7 and 8 TeV. The measured values are S_{ϕγ}=0.43±0.30±0.11, C_{ϕγ}=0.11±0.29±0.11, and A_{ϕγ}^{Δ}=-0.67_{-0.41}^{+0.37}±0.17, where the first uncertainty is statistical and the second systematic. This is the first measurement of the observables S and C in radiative B_{s}^{0} decays. The results are consistent with the standard model predictions.

First Observation of the Radiative Decay Λ_{b}^{0}→Λγ

The radiative decay Λ_{b}^{0}→Λγ is observed for the first time using a data sample of proton-proton collisions corresponding to an integrated luminosity of 1.7  fb^{-1} collected by the LHCb experiment at a center-of-mass energy of 13 TeV. Its branching fraction is measured exploiting the B^{0}→K^{*0}γ decay as a normalization mode and is found to be B(Λ_{b}^{0}→Λγ)=(7.1±1.5±0.6±0.7)×10^{-6}, where the quoted uncertainties are statistical, systematic, and systematic from external inputs, respectively. This is the first observation of a radiative decay of a beauty baryon.

Observation of an Excited B_{c}^{+} State

Using pp collision data corresponding to an integrated luminosity of 8.5  fb^{-1} recorded by the LHCb experiment at center-of-mass energies of sqrt[s]=7, 8, and 13 TeV, the observation of an excited B_{c}^{+} state in the B_{c}^{+}π^{+}π^{-} invariant-mass spectrum is reported. The observed peak has a mass of 6841.2±0.6(stat)±0.1(syst)±0.8(B_{c}^{+})  MeV/c^{2}, where the last uncertainty is due to the limited knowledge of the B_{c}^{+} mass. It is consistent with expectations of the B_{c}^{*}(2^{3}S_{1})^{+} state reconstructed without the low-energy photon from the B_{c}^{*}(1^{3}S_{1})^{+}→B_{c}^{+}γ decay following B_{c}^{*}(2^{3}S_{1})^{+}→B_{c}^{*}(1^{3}S_{1})^{+}π^{+}π^{-}. A second state is seen with a global (local) statistical significance of 2.2σ (3.2σ) and a mass of 6872.1±1.3(stat)±0.1(syst)±0.8(B_{c}^{+})  MeV/c^{2}, and is consistent with the B_{c}(2^{1}S_{0})^{+} state. These mass measurements are the most precise to date.

Measurement of the Mass Difference Between Neutral Charm-Meson Eigenstates

We report a measurement of the mass difference between neutral charm-meson eigenstates using a novel approach that enhances sensitivity to this parameter. We use 2.3×10^{6} D^{0}→K_{S}^{0}π^{+}π^{-} decays reconstructed in proton-proton collisions collected by the LHCb experiment in 2011 and 2012. Allowing for CP violation in mixing and in the interference between mixing and decay, we measure the CP-averaged normalized mass difference x_{CP}=[2.7±1.6(stat)±0.4(syst)]×10^{-3} and the CP-violating parameter Δx=[-0.53±0.70(stat)±0.22(syst)]×10^{-3}. The results are consistent with CP symmetry. These determinations are the most precise from a single experiment and, combined with current world-average results, yield the first evidence that the masses of the neutral charm-meson eigenstates differ.

Observation of a Narrow Pentaquark State, P_{c}(4312)^{+}, and of the Two-Peak Structure of the P_{c}(4450)^{+}

A narrow pentaquark state, P_{c}(4312)^{+}, decaying to J/ψp, is discovered with a statistical significance of 7.3σ in a data sample of Λ_{b}^{0}→J/ψpK^{-} decays, which is an order of magnitude larger than that previously analyzed by the LHCb Collaboration. The P_{c}(4450)^{+} pentaquark structure formerly reported by LHCb is confirmed and observed to consist of two narrow overlapping peaks, P_{c}(4440)^{+} and P_{c}(4457)^{+}, where the statistical significance of this two-peak interpretation is 5.4σ. The proximity of the Σ_{c}^{+}D[over ¯]^{0} and Σ_{c}^{+}D[over ¯]^{*0} thresholds to the observed narrow peaks suggests that they play an important role in the dynamics of these states.

Observation of CP Violation in Charm Decays

A search for charge-parity (CP) violation in D^{0}→K^{-}K^{+} and D^{0}→π^{-}π^{+} decays is reported, using pp collision data corresponding to an integrated luminosity of 5.9  fb^{-1} collected at a center-of-mass energy of 13 TeV with the LHCb detector. The flavor of the charm meson is inferred from the charge of the pion in D^{*}(2010)^{+}→D^{0}π^{+} decays or from the charge of the muon in B[over ¯]→D^{0}μ^{-}ν[over ¯]_{μ}X decays. The difference between the CP asymmetries in D^{0}→K^{-}K^{+} and D^{0}→π^{-}π^{+} decays is measured to be ΔA_{CP}=[-18.2±3.2(stat)±0.9(syst)]×10^{-4} for π-tagged and ΔA_{CP}=[-9±8(stat)±5(syst)]×10^{-4} for μ-tagged D^{0} mesons. Combining these with previous LHCb results leads to ΔA_{CP}=(-15.4±2.9)×10^{-4}, where the uncertainty includes both statistical and systematic contributions. The measured value differs from zero by more than 5 standard deviations. This is the first observation of CP violation in the decay of charm hadrons.

Search for CP Violation in D_{s}^{+}→K_{S}^{0}π^{+}, D^{+}→K_{S}^{0}K^{+}, and D^{+}→ϕπ^{+} Decays

A search for charge-parity (CP) violation in Cabibbo-suppressed D_{s}^{+}→K_{S}^{0}π^{+}, D^{+}→K_{S}^{0}K^{+}, and D^{+}→ϕπ^{+} decays is reported using proton-proton collision data, corresponding to an integrated luminosity of 3.8  fb^{-1}, collected at a center-of-mass energy of 13 TeV with the LHCb detector. High-yield samples of kinematically and topologically similar Cabibbo-favored D_{(s)}^{+} decays are analyzed to subtract nuisance asymmetries due to production and detection effects, including those induced by CP violation in the neutral kaon system. The results areA_{CP}(D_{s}^{+}→K_{S}^{0}π^{+})=(1.3±1.9±0.5)×10^{-3},A_{CP}(D^{+}→K_{S}^{0}K^{+})=(-0.09±0.65±0.48)×10^{-3},A_{CP}(D^{+}→ϕπ^{+})=(0.05±0.42±0.29)×10^{-3},where the first uncertainties are statistical and the second systematic. They are the most precise measurements of these quantities to date, and are consistent with CP symmetry. A combination with previous LHCb measurements, based on data collected at 7 and 8 TeV, is also reported.

Observation of B_{(s)}^{0}→J/ψpp[over ¯] Decays and Precision Measurements of the B_{(s)}^{0} Masses

The first observation of the decays B_{(s)}^{0}→J/ψpp[over ¯] is reported, using proton-proton collision data corresponding to an integrated luminosity of 5.2  fb^{-1}, collected with the LHCb detector. These decays are suppressed due to limited available phase space, as well as due to Okubo-Zweig-Iizuka or Cabibbo suppression. The measured branching fractions are B(B^{0}→J/ψpp[over ¯])=[4.51±0.40(stat)±0.44(syst)]×10^{-7}, B(B_{s}^{0}→J/ψpp[over ¯])=[3.58±0.19(stat)±0.39(syst)]×10^{-6}. For the B_{s}^{0} meson, the result is much higher than the expected value of O(10^{-9}). The small available phase space in these decays also allows for the most precise single measurement of both the B^{0} mass as 5279.74±0.30(stat)±0.10(syst)  MeV and the B_{s}^{0} mass as 5366.85±0.19(stat)±0.13(syst)  MeV.

Search for Lepton-Universality Violation in B^{+}→K^{+}ℓ^{+}ℓ^{-} Decays

A measurement of the ratio of branching fractions of the decays B^{+}→K^{+}μ^{+}μ^{-} and B^{+}→K^{+}e^{+}e^{-} is presented. The proton-proton collision data used correspond to an integrated luminosity of 5.0  fb^{-1} recorded with the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV. For the dilepton mass-squared range 1.1<q^{2}<6.0  GeV^{2}/c^{4} the ratio of branching fractions is measured to be R_{K}=0.846_{-0.054}^{+0.060}_{-0.014}^{+0.016}, where the first uncertainty is statistical and the second systematic. This is the most precise measurement of R_{K} to date and is compatible with the standard model at the level of 2.5 standard deviations.

Model-Independent Observation of Exotic Contributions to B^{0}→J/ψK^{+}π^{-} Decays

An angular analysis of B^{0}→J/ψK^{+}π^{-} decays is performed, using proton-proton collision data corresponding to an integrated luminosity of 3  fb^{-1} collected with the LHCb detector. The m(K^{+}π^{-}) spectrum is divided into fine bins. In each m(K^{+}π^{-}) bin, the hypothesis that the three-dimensional angular distribution can be described by structures induced only by K^{*} resonances is examined, making minimal assumptions about the K^{+}π^{-} system. The data reject the K^{*}-only hypothesis with a large significance, implying the observation of exotic contributions in a model-independent fashion. Inspection of the m(J/ψπ^{-}) vs m(K^{+}π^{-}) plane suggests structures near m(J/ψπ^{-})=4200 and 4600 MeV.

First Measurement of Charm Production in its Fixed-Target Configuration at the LHC

The first measurement of heavy-flavor production by the LHCb experiment in its fixed-target mode is presented. The production of J/ψ and D^{0} mesons is studied with beams of protons of different energies colliding with gaseous targets of helium and argon with nucleon-nucleon center-of-mass energies of sqrt[s_{NN}]=86.6 and 110.4 GeV, respectively. The J/ψ and D^{0} production cross sections in pHe collisions in the rapidity range [2, 4.6] are found to be σ_{J/ψ}=652±33(stat)±42(syst)   nb/nucleon and σ_{D^{0}}=80.8±2.4(stat)±6.3(syst)  μb/nucleon, where the first uncertainty is statistical and the second is systematic. No evidence for a substantial intrinsic charm content of the nucleon is observed in the large Bjorken-x region.

Measurement of the Charm-Mixing Parameter y_{CP}

A measurement of the charm-mixing parameter y_{CP} using D^{0}→K^{+}K^{-}, D^{0}→π^{+}π^{-}, and D^{0}→K^{-}π^{+} decays is reported. The D^{0} mesons are required to originate from semimuonic decays of B^{-} and B[over ¯]^{0} mesons. These decays are partially reconstructed in a data set of proton-proton collisions at center-of-mass energies of 7 and 8 TeV collected with the LHCb experiment and corresponding to an integrated luminosity of 3  fb^{-1}. The y_{CP} parameter is measured to be (0.57±0.13(stat)±0.09(syst))%, in agreement with, and as precise as, the current world-average value.

Observation of Two Resonances in the Λ_{b}^{0}π^{±} Systems and Precise Measurement of Σ_{b}^{±} and Σ_{b}^{*±} Properties

The first observation of two structures consistent with resonances in the final states Λ_{b}^{0}π^{-} and Λ_{b}^{0}π^{+} is reported using samples of pp collision data collected by the LHCb experiment at sqrt[s]=7 and 8 TeV, corresponding to an integrated luminosity of 3  fb^{-1}. The ground states Σ_{b}^{±} and Σ_{b}^{*±} are also confirmed and their masses and widths are precisely measured.