Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

P-323 Should We Measure Oxidative Stress Biomarkers In Follicular Fluid Of Women With Endometriosis Undergoing IVF?

Study question

Do levels of Oxidative stress (OS) biomarkers differ in the follicular fluid of women with endometriosis compared to tubal factor infertility?

Summary answer

8-Isoprostane is a promising biomarker in diagnosing oxidative stress in women with endometriosis opening a window of opportunity for improving outcomes.

What is known already

A delicate balance between oxidants and antioxidants is required for oocyte development and maturation. Any perturbation in the oocyte microenvironment which is the follicular fluid results in hampered oocyte quality and further affects the embryo development. As endometriosis causes destruction of the oocyte milieu, various OS biomarkers have been explored with inconclusive results. The present study aimed to compare these biomarkers in follicular fluid of women with endometriosis and tubal factor infertility undergoing in-vitro fertilization and correlate with ART outcomes.

Study design, size, duration

In a cross sectional study conducted at the assisted conception unit at a tertiary care hospital from 2017-2018 women undergoing their first IVF cycles for endometriosis and tubal factor infertility were recruited in the study. The study included a total of 107 patients with 50 in the endometriosis group (Group1) and 57 in the tubal group (Group 2).

Participants/materials, setting, methods

Follicular fluid from women undergoing IVF in both the groups was collected and evaluated for Oxidative stress biomarkers including Reactive Oxygen species (ROS), Total Antioxidant Capacity (TAC), 8-Isoprostane (8-IP) levels. ROS levels were detected by chemiluminescence and TAC and 8-IP using enzyme immunoassays.

Main results and the role of chance

Levels of ROS {(39.6 cpm vs 54.8 cpm) (p = 0.2)}were comparable in both the groups. Levels of 8-IP were significantly higher in group 1 as compared to the group 2 {(85.2  pg/ul vs 39.2  pg/ul) (p = 0.01)}. TAC levels were higher in endometriosis group compared to the tubal group {(5.4 mM of Trolox vs 4.1 mM of Trolox) (p = 0.005)} which could explain comparable ongoing clinical pregnancy rate in both groups (24.0% vs 24.5%, p = 0.34). There was no correlation of OS biomarkers with ART outcomes in tubal factor. Follicular fluid in Group 1 revealed a negative correlation of ROS with cleavage rate (r = - 0.42, p = 0.002) and positive correlation of TAC with fertilization rate (r = 0.44, p = 0.001) and Good grade embryos (r = 0.4, p = 0.001).

Limitations, reasons for caution

The main limitation is the inability to assess the dietary intake and blood oxidative stress biomarkers in both the groups.

Wider implications of the findings

OS biomarkers especially 8-IP could be useful in prognosticating IVF outcomes in women with endometriosis with a potential role of addition of antioxidants in culture media during IVF in these women.

Trial registration number

Not Applicable

AB0022 SELECTIVE ESTROGEN RECEPTOR MODULATORS AND TISSUE-SELECTIVE ESTROGEN COMPLEX DO NOT SHARE ESTROGENIC EFFECTS ON IGG SIALYLATION IN AUTOIMMUNE CONDITIONS

Background

Women entering menopause, with a decrease in estrogen levels, display an increased incidence of rheumatoid arthritis (RA). Estrogen (E2) treatment has beneficial effects on IgG pathogenicity by altering the sialylation grade which affect the binding ability to FcR1. E2 replacement may therefore be beneficial in pre-RA patients having autoantibodies. Exposure to estrogen is associated with negative side effects, therefore selective estrogen receptor modulators (SERMs) have been developed with estrogenic protective effect on bone but minimal impact on the reproductive system2. The SERM, Bazeodoxifene (BZA), as well as tissue-selective estrogen complex (TSEC), a combination of conjugated estrogen and BZA, have been approved for treatment of postmenopausal bone loss3-5

Objectives

The purpose of this study was to investigate the impact of BZA and TSEC on IgG sialylation grade which affects the pathogenicity as well as to determine the effects on total serum protein sialylation.

Methods

C57Bl6 mice were subjected to ovariectomy to stop the endogenous E2 production and mimicked the postmenopausal status. Mice were then treated with E2, BZA, TSEC, or vehicle, followed by ovalbumin (OVA) immunization to induce the IgG levels. Blood was collected before treatment started and at termination. In serum total IgG, OVA specific IgG and the degree of IgG-sialylation were quantified with ELISA. Sialyation of total serum proteins was determined with sialic acid assay quantification kit. Expression of sialyltransferase protein was analyzed in the bone marrow (BM) and spleen cell compartment using flow cytometry. The mRNA expression of glycosyltransferase was analyzed by qPCR analysis.

Results

Neither BZA nor TSEC significantly altered the total IgG levels or sialylation grade of IgG. Indeed, E2 significantly altered IgG sialylation. We showed that BZA increased sialyltransferase protein in plasma cells in a similar manner as E2. Further, neither E2, BZA or TSEC had any significant impact on sialic acids in whole serum protein and not in the mRNA expression of glycosyltransferase in the liver, BM, or gonadal fat.

Conclusion

In this study, we were not able to detect any alteration by TSEC or BZA treatment on IgG-sialylation grade and thereby pathogenicity of the IgG. Neither E2 nor BAZ or TSEC show any significant alteration on general sialylation, but our results suggest that further studies are required to understand E2, SERM, and TSEC full effect on protein sialylation in autoimmune conditions.

Keywords: IgG sialylation, protein glycosylation, SERMs

References

[1]Engdahl C, Bondt A, Harre U, et al. Estrogen induces St6gal1 expression and increases IgG sialylation in mice and patients with rheumatoid arthritis: a potential explanation for the increased risk of rheumatoid arthritis in postmenopausal women. Arthritis Research & Therapy. 2018/05/02 2018;20(1):84. doi:10.1186/s13075-018-1586-z

[2]Pinkerton JV, Thomas S. Use of SERMs for treatment in postmenopausal women. J Steroid Biochem Mol Biol. Jul 2014;142:142-54. doi:10.1016/j.jsbmb.2013.12.011

[3]Miller PD, Chines AA, Christiansen C, et al. Effects of bazedoxifene on BMD and bone turnover in postmenopausal women: 2-yr results of a randomized, double-blind, placebo-, and active-controlled study. J Bone Miner Res. Apr 2008;23(4):525-35. doi:10.1359/jbmr.071206

[4]Pinkerton JV, Pickar JH, Racketa J, Mirkin S. Bazedoxifene/conjugated estrogens for menopausal symptom treatment and osteoporosis prevention. Climacteric. Oct 2012;15(5):411-8. doi:10.3109/13697137.2012.696289

[5]Silverman SL, Christiansen C, Genant HK, et al. Efficacy of bazedoxifene in reducing new vertebral fracture risk in postmenopausal women with osteoporosis: results from a 3-year, randomized, placebo-, and active-controlled clinical trial. J Bone Miner Res. Dec 2008;23(12):1923-34. doi:10.1359/jbmr.080710

Disclosure of Interests

None declared

POS0351 NEITHER ANTI-CITRULLINATED PROTEIN ANTIBODIES (ACPA) NOR POLYCLONAL IgG ARE ASSOCIATED WITH BONE MASS, IN ELDERLY MEN

Background

Bone loss is associated with anti-citrullinated protein antibodies (ACPA) positivity in rheumatoid arthritis (RA) patients. This is shown in both in pre-clinical RA, and in more pronounced bone loss in serum positive patients compared to serum negative patients. Further, both ACPA and activated IgG stimulate osteoclastogenesis in vitro and in murine arthritis-mediated bone loss.

Objectives

Whether polyclonal IgG or autoantibodies are important for general bone architecture, and not only in arthritis-mediated bone loss, has not been determined but they may represent an important link between the immune system and bone.

Methods

Polyclonal IgG and ACPA were measured with ELISA in serum of 600 elderly men (mean age 80.2±3.5 years), in the cohort MrOS Gothenburg. In this cohort, bone was investigated with Dual-energy-x-ray absorptiometry (DXA) and high-resolution 3D peripheral quantitative computed tomography (HR-pQCT). In C57/BL6 mice, high dose heat-activated polyclonal IgG was repetitively injected systemically or intraarticularly, and the bone was investigated with DXA and micro-CT.

Results

No association was determined between existing serum polyclonal IgG and ACPA, with the measured bone parameters, not total bone density, trabecular or cortical bone in the MrOS cohort. Systemic injection of activated IgG in mice did not affect general bone health, not total, trabecular, or cortical bone. Intraarticular injection of activated IgG was shown to give a local reduction in trabecular bone density of the tibia.

Conclusion

These data indicate that serum polyclonal IgG and ACPA do not influence general bone health in elderly men. However, in mice injection with activated IgG intraarticularly leads to a local reduction in trabecular bone. In conclusion, our data imply that ACPA and activated IgG need to be present in close connection to the bone, e.g., in the synovial area, to be able to mediate a reduction in bone mass.

Disclosure of Interests

Merja Nurkkala: None declared, Marie Lagerquist: None declared, Priti Gupta: None declared, Dan Mellström: None declared, Claes Ohlsson Grant/research support from: Novo Nordisk, Cecilia Engdahl: None declared

Giant celiac artery aneurysm – a rare experience

Giant celiac artery aneurysm is a rare entity. We describe a case of a 45-year-old male with chronic kidney disease who presented with abdominal pain for the past 6 months. CT showed a celiac artery aneurysm of size 6×6.2cm involving the common hepatic artery and compressing the portal vein posteriorly. During the procedure the supra celiac aorta was exposed, and the neck of the aneurysm was identified. After taking control of branches of the celiac and common hepatic arteries, the neck of the aneurysm was clamped and divided. In view of diminished flow in the hepatic arteries aorto hepatic bypass was done using PTFE graft from supra celiac aorta to right hepatic artery; as there was retrograde flow from the left hepatic artery it was ligated. Post operatively the patient's liver functions were normal, and he was followed up by Doppler sonography which detected good flow in the hepatic artery distal to anastomosis. Celiac artery aneurysms are rare, and management options vary from the endovascular to surgery; regardless of the approach used, revascularisation is needed if there is no adequate collateral flow.

Developing a competency-based undergraduate logbook for pediatrics: Process and lessons

With the first MBBS batch admitted under the new National Medical Commission (NMC) undergraduate curriculum entering pediatric clinical posting soon, creation of a Pediatric logbook in consonance with this competency-based curriculum was felt to be a need of the hour. No such document is yet available in the public domain. The logbook template, created after enormous brainstorming amongst authors, includes 176 Shows (S), Shows How (SH) and Perform (P) level competencies. These were further segregated into certifiable (23), affective domain (25) and clinic/field visits (9) leaving 51 as documentable competencies. The institutions may use this template to build their own institute-specific logbook based on the infrastructure, faculty strength, clinical patient load, student intake and preferred assessment method(s). It would also be worthwhile to integrate this with the internship logbook (and later the postgraduate one for students opting for post-graduation in pediatrics) to provide a longitudinal record of each student's trajectory of learning.

The development of QERM scoring system for comprehensive assessment of the Quality of Empirical Research in Medicine - Part 1

Purpose

Whereas a large number of features are mentioned to connote the quality of medical research, no tool is available to comprehensively measure it objectively across different types of studies. Also, all the available tools are for reporting, and none includes quality of the inputs and the process of research. The present paper is aimed to initiate a discussion on the need to develop such a comprehensive scoring system (in the first place), to show that it is feasible, and to describe the process of developing a credible system.

Method

An expert group comprising researchers, reviewers, and editors of medical journals extensively reviewed the literature on the quality of medical research and held detailed discussions to parse quality at all stages of medical research into specific domains and items that can be assigned scores on the pattern of quality-of-life score.

Results

Besides identifying the domains of the quality of medical research, a comprehensive tool for scoring emerged that can be possibly used to objectively measure the quality of empirical research comprising surveys, trials, and observational studies. Thus, this can be used as a tool to assess Quality of Empirical Research in Medicine (QERM). The expert group confirmed its face and content validity. The tool can be used by the researchers for self-assessment and improvement before submission of a paper for publication, and the reviewers and editors can use this for assessing the submissions. Published papers can also be rated such as those included in a meta-analysis.

Conclusion

It is feasible to devise a comprehensive scoring system comprising domains and items for assessing the quality of medical research end-to-end from choosing a problem to publication. The proposed scoring system needs to be reviewed by the researchers and needs to be validated.

Mandibular metastasis of follicular thyroid carcinoma: A case report along with the concise review of literature

Metastasis is one of the most common consequences of malignant tumors, and it is one of the leading causes of morbidity and mortality. Metastatic cancers to oral cavity are extremely rare. Moreover, the true incidence has yet to be determined. Despite their rarity, they are important clinically, since they can be the first and the only evidence of spread in many situations. Breast, kidney, lung, prostate and gastrointestinal tract are the most common sources of metastases in the oral cavity. Thyroid carcinoma is the most prevalent type of endocrine cancer, yet it rarely spreads to the oral cavity. After papillary thyroid carcinoma, follicular thyroid carcinoma is the second-most frequent kind of thyroid cancer. Jawbones are more commonly affected than soft tissues. Literature research revealed that till date, 44 cases of metastatic follicular thyroid cancer to the jawbones have been documented with mandibular preponderance (40 cases). With the rising occurrence of oral metastatic tumors in recent years, it has become increasingly important to diagnose them early to avoid future consequences. We present here an unusual case of metastatic follicular thyroid cancer in the mandible of an elderly adult along with a comprehensive review of the literature.

Assessment of prescribing pattern of drugs and completeness of prescriptions as per the World Health Organization prescribing indicators in various Indian tertiary care centers: A multicentric study by Rational Use of Medicines Centers-Indian Council of Medical Research network under National Virtual Centre Clinical Pharmacology activity

OBJECTIVE

The rational use of medicines as per the World Health Organization (WHO) should be practiced globally. However, data regarding the completeness of the prescriptions and their rational use is lacking from developing countries like India. Thus, the aim of this study was to assess the prescribing patterns of drugs and completeness of prescriptions as per WHO core drug use and complementary indicators to provide real-life examples for the Indian Council of Medical Research (ICMR) online prescribing skill course for medical graduates.

METHODS

Prescriptions of the patients, fulfilling inclusion criteria, attending Outpatient Departments of various specialties of tertiary care hospitals, were collected by thirteen ICMR Rational use of medicines centers located in tertiary care hospitals, throughout India. Prescriptions were evaluated for rational use of medicines according to the WHO guidelines and for appropriateness as per standard treatment guidelines using a common protocol approved by local Ethics committees.

RESULTS

Among 4838 prescriptions, an average of about three drugs (3.34) was prescribed to the patients per prescription. Polypharmacy was noted in 83.05% of prescriptions. Generic drugs were prescribed in 47.58% of the prescriptions. Further, antimicrobials were prescribed in 17.63% of the prescriptions and only 4.98% of prescriptions were with injectables. During the prescription evaluation, 38.65% of the prescriptions were incomplete due to multiple omissions such as dose, duration, and formulation.

CONCLUSION

Most of the parameters in the present study were out of the range of WHO-recommended prescribing indicators. Therefore, effective intervention program, like training, for the promotion of rational drug use practice was recommended to improve the prescribing pattern of drugs and the quality of prescriptions all over the country.

Effectiveness of blockchain to solve the interoperability challenges in healthcare

This study aims to explore the potential of Blockchain to transformhealthcare, build the patient-driven healthcare ecosystem ratherthan the current institutional driven and enhance the privacy, security,and interoperability of healthcare data and check the counterfeitdrugs. Interview excerpts from Industry experts/developersin the field of IT and experience from the implementation of thetechnology in the financial world will help understand its viabilityin healthcare. Consulting with domain experts is a qualitative processthat involves comprehending the perception of the experts.The research paper will help the healthcare sector lay down futurebusiness strategies to redefine its businesses by overcoming theincreasing threat on patients’ private data and resolving complexsupply chain issues. A decentralized ledger can prevent massiverevenue loss due to counterfeit drugs to track and verify eachdrug’s movement on the unchangeable record. The primary andsecondary research is original, adding its authenticity with interviewexcerpts of domain experts. The results of this research paperwill help identify the transparency, immutability, cost-saving, andstreamlining of business to be brought by Blockchain in healthcare. It would be the transformational journey from innovation tomarket the quality products to the end consumer.

Comparative analysis of the diagnostic performance of five commercial COVID-19 qRT PCR kits used in India

To meet the unprecedented requirement of diagnostic testing for SARS-CoV-2, a large number of diagnostic kits were authorized by concerned authorities for diagnostic use within a short period of time during the initial phases of the ongoing pandemic. We undertook this study to evaluate the inter-test agreement and other key operational features of 5 such commercial kits that have been extensively used in India for routine diagnostic testing for COVID-19. The five commercial kits were evaluated, using a panel of positive and negative respiratory samples, considering the kit provided by National Institute of Virology, Indian Council of Medical Research (2019-nCoV Kit) as the reference. The positive panel comprised of individuals who fulfilled the 3 criteria of being clinically symptomatic, having history of contact with diagnosed cases and testing positive in the reference kit. The negative panel included both healthy and disease controls, the latter being drawn from individuals diagnosed with other respiratory viral infections. The same protocol of sample collection, same RNA extraction kit and same RT-PCR instrument were used for all the kits. Clinical samples were collected from a panel of 92 cases and 60 control patients, who fulfilled our inclusion criteria. The control group included equal number of healthy individuals and patients infected with other respiratory viruses (n = 30, in each group). We observed varying sensitivity and specificity among the evaluated kits, with LabGun COVID-19 RT-PCR kit showing the highest sensitivity and specificity (94% and 100% respectively), followed by TaqPath COVID-19 Combo and Allplex 2019-nCoV assays. The extent of inter-test agreement was not associated with viral loads of the samples. Poor correlation was observed between Ct values of the same genes amplified using different kits. Our findings reveal the presence of wide heterogeneity and sub-optimal inter-test agreement in the diagnostic performance of the evaluated kits and hint at the need of adopting stringent standards for fulfilling the quality assurance requirements of the COVID-19 diagnostic process.

The vascular clock: a new insight into endothelial cells and pericytes crosstalk

Background/Introduction

Circadian rhythms, defined as biological oscillations with a period of circa 24h, regulate many physiological processes in the cardiovascular system, such as vascular function, vascular tone, blood pressure, heart rate and thrombus formation [1]. The vasculature responds to the main pacemaker located in the brain, but it also possesses its own clock. Indeed, a molecular clock has been identified in endothelial cells (EC) and smooth muscle cells (SMC). The disruption of the circadian clock profoundly affects cardiovascular functionality with adverse cardiovascular events such as myocardial infarction or stroke showing a 24h rhythmicity with a peak incidence in the early morning. Among several mechanisms affected by circadian dysregulation, angiogenesis plays a fundamental role in homeostasis and development of new blood vessels. EC and pericytes (PC) are the two main cell populations in the capillaries, and their physical and paracrine interaction drives and regulates the sprouting. However, the presence and the role of circadian rhythms in pericytes and whether the molecular clock affects the endothelial/pericyte interactions remain unexplored.

Purpose

The aim of this study is to identify a molecular clock in human vascular pericytes and elucidate the impact of the circadian clock on the formation of new blood vessels.

Methods

Human primary PC were synchronised and the rhythmicity of clock genes measured by luminescence, immunofluorescence, and qPCR. Synchronised PC were co-cultured with Bmal1::LUC human primary EC. The effect of PC synchronisation and circadian clock disruption by shRNA on EC clock genes and angiogenic potential were measured by luminescence and Matrigel assay, respectively. A macroporous polyurethane scaffold was developed for 3D co-cultures.

Results

PC presented rhythmic expression of the principal circadian genes with a circa 24h period but in our experimental setting, EC did not show circadian rhythmicity. Synchronised PC supported the rhythmic expression of the clock gene Bmal1 in EC in a contact co-culture system, suggesting a secondary form of EC molecular clock regulation. Non-contact co-cultures failed to synchronise EC. Furthermore, when the clock was disrupted in PC, their capacity to support EC's tube-forming capacity on Matrigel was impaired; clock disruption in EC did not affect angiogenesis, supporting the hypothesis that a disrupted clock in perivascular cells affects angiogenesis. In a 3D tissue engineering scaffold seeded with both EC and PC, the synchronisation of the clock led to the development of organised vascular-like structures around the scaffold's pores, as compared to the non-synchronised condition where cells appeared disorganised.

Conclusion

This study defines for the first time the existence of an endogenous molecular circadian clock in perivascular cells and suggests implications for circadian clock synchronisation in physiological and therapeutic angiogenesis.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): University of Surrey Doctoral CollegeUniversity of Surrey Bioprocess and Biochemical Engineering (BioProChem) Group.

Clustered papulonodular lesions in an infant

Non-Langerhans cell histiocytosis is a collective term encompassing a vast group of benign proliferative disorders of histiocytes, macrophages and dendritic cells that do not meet the criteria of Langerhans cell histiocytosis. We describe a case of juvenile xanthogranuloma with an unusual clustered distribution.

Reducing mortality in mucormycosis of the head and neck in diabetic patients: A CARE case series

INTRODUCTION

Rhinocerebral mucormycosis is extremely fatal, with mortality rates ranging from 85-93% despite the best treatment in immunocompromised patients. We emphasize the importance of early diagnosis, repeated debridement, and aggressive antifungal treatment to reduce mortality.

CASE SUMMARY

We report six cases (five male and one female), with a mean age of 51 years who were diagnosed to have mucormycosis from 2017 to 2019. All patients were diabetic. Intracranial involvement and orbital involvement were found in four cases. Facial nerve palsy was seen in two cases, one without any apparent otological involvement. Aggressive serial debridement and amphotericin B was started. Posaconazole was added subsequently to the treatment in two cases. One patient succumbed to the disease five months after discharge. The other five patients are on regular follow-up for a mean duration of 14 months at the end of which two had residual disease which was under control.

DISCUSSION

Repeated surgical debridement with an early aggressive and combination antifungal therapy can result in good outcomes even in advanced mucormycosis. Concurrent management of the underlying pathology, monitoring of liver and kidney functions, and therapeutic drug monitoring are useful to ensure smooth and effective treatment.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Cost-effectiveness of mifepristone and misoprostol versus misoprostol alone for the management of missed miscarriage: an economic evaluation based on the MifeMiso trial

OBJECTIVE

To assess the cost-effectiveness of mifepristone and misoprostol (MifeMiso) compared with misoprostol only for the medical management of a missed miscarriage.

DESIGN

Within-trial economic evaluation and model-based analysis to set the findings in the context of the wider economic evidence for a range of comparators. Incremental costs and outcomes were calculated using nonparametric bootstrapping and reported using cost-effectiveness acceptability curves. Analyses were performed from the perspective of the UK's National Health Service (NHS).

SETTING

Twenty-eight UK NHS early pregnancy units.

SAMPLE

A cohort of 711 women aged 16-39 years with ultrasound evidence of a missed miscarriage.

METHODS

Treatment with mifepristone and misoprostol or with matched placebo and misoprostol tablets.

MAIN OUTCOME MEASURES

Cost per additional successfully managed miscarriage and quality-adjusted life years (QALYs).

RESULTS

For the within-trial analysis, MifeMiso intervention resulted in an absolute effect difference of 6.6% (95% CI 0.7-12.5%) per successfully managed miscarriage and a QALYs difference of 0.04% (95% CI -0.01 to 0.1%). The average cost per successfully managed miscarriage was lower in the MifeMiso arm than in the placebo and misoprostol arm, with a cost saving of £182 (95% CI £26-£338). Hence, the MifeMiso intervention dominated the use of misoprostol alone. The model-based analysis showed that the MifeMiso intervention is preferable, compared with expectant management, and this is the current medical management strategy. However, the model-based evidence suggests that the intervention is a less effective but less costly strategy than surgical management.

CONCLUSIONS

The within-trial analysis found that based on cost-effectiveness grounds, the MifeMiso intervention is likely to be recommended by decision makers for the medical management of women presenting with a missed miscarriage.

TWEETABLE ABSTRACT

The combination of mifepristone and misoprostol is more effective and less costly than misoprostol alone for the management of missed miscarriages.