Combining international survey datasets to identify indicators of stress during the COVID-19 pandemic: A machine learning approach to improve generalization

Introduction

The magnitude and exceptional opportunity to research the psychological distress of shelter in place resulted in a publication frenzy on a smorgasbord of research studies of variable scientific robustness. Confinement, fear of contagion, social isolation, financial hardship, etc. equated to stratospheric stress levels. The decline in protective factors as a function of quarantine anecdotally reflected historic rates of anxiety and depression.

Objectives

In this study, we combined 12 variegate datasets and developed an algorithm to build a model to identify key predictors of pandemic-related stress with high accuracy and generalizability.

Methods

This study reports on existing published data. We first describe the International (Adamson et al., 2020) and then the Italian dataset (Flesia et al., 2020). The time-frame (first wave of lockdown), method (survey), measurement tool (Perceived Stress Scale), and outcome measures were extremely similar to enable consolidation of datasets (see Figure1). The Flesia et al., (2020) data set was integrated into the Adamson et al., (2020) dataset as the first step towards data validation construction of the ML predictive model.

Results

We aim to demonstrate the strength of combining cross-cultural datasets, and the applicability of ML algorithms to facilitate the process and generate a predictive model that identifies and validates key predictors of pandemic-related stress and accommodates for interaction with demographic, cultural, and other mitigating factors while concurrently having high generalizability.

Conclusions

We believe our model provides clinicians, researchers, and decision-makers with evidence to investigate the moderators and mediators of stress, and introduce novel interventions to mitigate the long-term effects of the COVID-19 pandemic.

Disclosure

No significant relationships.

1533 The Effect of Hip Fracture Anatomy and The Modality of Surgery on Red Blood Cell Transfusion and Mortality: A Retrospective Analysis

Introduction

Hip fractures are common, with most requiring surgical management. Blood loss occurs from the fracture and intraoperatively. Often, blood transfusions are required. Hip fractures can be classified by their anatomy: intracapsular, intertrochanteric or subtrochanteric fractures. This study assesses the effect of fracture pattern and operation performed on transfusion rates within our centre. We aim to identify the patients most likely to require transfusion early, to improve outcomes.

Method

A retrospective cohort study of 324 consecutive hip fracture patients presenting to a district general hospital over one year. Data was collected from electronic patient records, the local transfusion laboratory, and the national hip fracture database.

Results

324 hip fractures were divided into 188 (58%) intracapsular, 121 (37%) intertrochanteric and 15 (5%) subtrochanteric fractures. The most common operation performed was hemiarthroplasty (128), followed by dynamic hip screw fixation (75). 75 (23%) of all patients received a blood transfusion. 28 (15%) of intracapsular, 42 (35%) of intertrochanteric and 5 (33%) of subtrochanteric fractures received transfusions. 47% of long intramedullary nails, 45% of short intramedullary nails, 29% of dynamic hip screws, 18% of hemiarthroplasties and 9% of total hip arthroplasties resulted in blood transfusions. One-year mortality in the transfused cohort was 52% and 30.5% in non-transfused.

Conclusions

Almost a quarter of hip fracture patients received a blood transfusion, which was associated with an increased risk of mortality. Intertrochanteric fractures most commonly led to a transfusion. The operation most associated with transfusions were long intramedullary nailings, and total hip arthroplasties were the least.

534 ADVANCED COMMUNICATION SKILLS: TEACHING DURING A PANDEMIC

Introduction

In the first wave of the COVID-19 pandemic, it was recognised there would be an increased demand on clinicians to provide patients and relatives with bad news. The national ban on hospital visiting rapidly changed the way in which this news would be delivered. In recognition of these new challenges, our team sought to design a teaching course that could be implemented quickly and cost effectively, with the aim of improving clinician’s confidence around these difficult skills.

Methods

A teaching programme was created using senior geriatric and palliative care clinicians as simulated patients, open to any grade and speciality. Learners were required to break bad news (BBN) without any visual feedback, to simulate skills required when using the telephone. Surveys were collected to determine self–assessed confidence across four domains (Table 1) before, immediately after and 4–20 weeks after the course. Participants were asked to rank their confidence for each skill on a 5 point scale with 1 being very unsure and 5 being very confident.

Results

Pre-teaching scores showed an average of 3 (neither confident nor unsure) across all domains. After the course all domains improved, most notably around discussing end of life (EoL) care and discussing information over the phone.

Conclusion

This project has highlighted a lack of confidence across all skill levels when it comes to BBN. This confidence is easily improved by a short, cost-effective teaching course. It remains to be seen if this improved confidence translates to better communication with relatives.

Fungi are the predominant micro-organisms responsible for degradation of soil-buried polyester polyurethane over a range of soil water holding capacities

AIMS

To investigate the relationship between soil water holding capacity (WHC) and biodegradation of polyester polyurethane (PU) and to quantify and identify the predominant degrading micro-organisms in the biofilms on plastic buried in soil.

METHODS AND RESULTS

High numbers of both fungi and bacteria were recovered from biofilms on soil-buried dumb-bell-shaped pieces of polyester PU after 44 days at 15-100% WHC. The tensile strength of the polyester PU was reduced by up to 60% over 20-80% soil WHC, but no reduction occurred at 15, 90 or 100% soil WHC. A PU agar clearance assay indicated that fungi, but not bacteria were, the major degrading organisms in the biofilms on polyester PU and 10-30% of all the isolated fungi were able to degrade polyester PU in this assay. A 5.8S rDNA sequencing identified 13 strains of fungi representing the three major colony morphology types responsible for PU degradation. Sequence homology matches identified these strains as Nectria gliocladioides (five strains), Penicillium ochrochloron (one strain) and Geomyces pannorum (seven strains). Geomyces pannorum was the predominant organism in the biofilms comprising 22-100% of the viable polyester PU degrading fungi.

CONCLUSIONS

Polyester PU degradation was optimum under a wide range of soil WHC and the predominant degrading organisms were fungi.

SIGNIFICANCE AND IMPACT OF THE STUDY

By identifying the predominant degrading fungi in soil and studying the optimum WHC conditions for degradation of PU it allows us to better understand how plastics are broken down in the environment such as in landfill sites.

Green fluorescent protein as a novel indicator of antimicrobial susceptibility in Aureobasidium pullulans

Presently there is no method available that allows noninvasive and real-time monitoring of fungal susceptibility to antimicrobial compounds. The green fluorescent protein (GFP) of the jellyfish Aequoria victoria was tested as a potential reporter molecule for this purpose. Aureobasidium pullulans was transformed to express cytosolic GFP using the vector pTEFEGFP (A. J. Vanden Wymelenberg, D. Cullen, R. N. Spear, B. Schoenike, and J. H. Andrews, BioTechniques 23:686-690, 1997). The transformed strain Ap1 gfp showed bright fluorescence that was amenable to quantification using fluorescence spectrophotometry. Fluorescence levels in Ap1 gfp blastospore suspensions were directly proportional to the number of viable cells determined by CFU plate counts (r(2) > 0.99). The relationship between cell viability and GFP fluorescence was investigated by adding a range of concentrations of each of the biocides sodium hypochlorite and 2-n-octylisothiozolin-3-one (OIT) to suspensions of Ap1 gfp blastospores (pH 5 buffer). These biocides each caused a rapid (< 25-min) loss of fluorescence of greater than 90% when used at concentrations of 150 microg of available chlorine ml(-1) and 500 microg ml(-1), respectively. Further, loss of GFP fluorescence from A. pullulans cells was highly correlated with a decrease in the number of viable cells (r(2) > 0.92). Losses of GFP fluorescence and cell viability were highly dependent on external pH; maximum losses of fluorescence and viability occurred at pH 4, while reduction of GFP fluorescence was absent at pH 8.0 and was associated with a lower reduction in viability. When A. pullulans was attached to the surface of plasticized poly(vinylchloride) containing 500 ppm of OIT, fluorescence decreased more slowly than in cell suspensions, with > 95% loss of fluorescence after 27 h. This technique should have broad applications in testing the susceptibility of A. pullulans and other fungal species to antimicrobial compounds.

Fungal colonization and biodeterioration of plasticized polyvinyl chloride

Significant substratum damage can occur when plasticized PVC (pPVC) is colonized by microorganisms. We investigated microbial colonization of pPVC in an in situ, longitudinal study. Pieces of pPVC containing the plasticizers dioctyl phthalate and dioctyl adipate (DOA) were exposed to the atmosphere for up to 2 years. Fungal and bacterial populations were quantified, and colonizing fungi were identified by rRNA gene sequencing and morphological characteristics. Aureobasidium pullulans was the principal colonizing fungus, establishing itself on the pPVC between 25 and 40 weeks of exposure. A group of yeasts and yeast-like fungi, including Rhodotorula aurantiaca and Kluyveromyces spp., established themselves on the pPVC much later (after 80 weeks of exposure). Numerically, these organisms dominated A. pullulans after 95 weeks, with a mean viable count +/- standard error of 1,000 +/- 200 yeast CFU cm(-2), compared to 390 +/- 50 A. pullulans CFU cm(-2). No bacterial colonization was observed. We also used in vitro tests to characterize the deteriogenic properties of fungi isolated from the pPVC. All strains of A. pullulans tested could grow with the intact pPVC formulation as the sole source of carbon, degrade the plasticizer DOA, produce extracellular esterase, and cause weight loss of the substratum during growth in vitro. In contrast, several yeast isolates could not grow on pPVC or degrade DOA. These results suggest that microbial succession may occur during the colonization of pPVC and that A. pullulans is critical to the establishment of a microbial community on pPVC.

Plasticizers increase adhesion of the deteriogenic fungus Aureobasidium pullulans to polyvinyl chloride

Initial adhesion of fungi to plasticized polyvinyl chloride (pPVC) may determine subsequent colonization and biodeterioration processes. The deteriogenic fungus Aureobasidium pullulans was used to investigate the physicochemical nature of adhesion to both unplasticized PVC (uPVC) and pPVC containing the plasticizers dioctyl phthalate (DOP) and dioctyl adipate (DOA). A quantitative adhesion assay using image analysis identified fundamental differences in the mechanism of adhesion of A. pullulans blastospores to these substrata. Adhesion to pPVC was greater than that to uPVC by a maximum of 280% after a 4-h incubation with 10(8) blastospores ml(-1). That plasticizers enhance adhesion to PVC was confirmed by incorporating a dispersion of both DOA and DOP into the blastospore suspension. Adhesion to uPVC was increased by up to 308% in the presence of the dispersed plasticizers. Hydrophobic interactions were found to dominate adhesion to uPVC because (i) a strong positive correlation was observed between substratum hydrophobicity (measured by using a dynamic contact angle analyzer) and adhesion to a range of unplasticized polymers including uPVC, and (ii) neither the pH nor the electrolyte concentration of the suspension buffer, both of which influence electrostatic interactions, affected adhesion to uPVC. In contrast, adhesion to pPVC is principally controlled by electrostatic interactions. Enhanced adhesion to pPVC occurred despite a relative reduction of 13 degrees in the water contact angle of pPVC compared to that of uPVC. Furthermore, adhesion to pPVC was strongly dependent on both the pH and electrolyte concentration of the suspension medium, reaching maximum levels at pH 8 and with an electrolyte concentration of 10 mM NaCl. Plasticization with DOP and DOA therefore increases adhesion of A. pullulans blastospores to pPVC through an interaction mediated by electrostatic forces.

Population genetics of STR loci in Caucasians

STR loci are becoming increasingly important in forensic casework. In order to be used fairly and efficiently, the population genetics of these loci must be investigated and the implications for forensic inference assessed. A key population genetics parameter is the "coancestry coefficient", or FST, which is the correlation between two genes sampled from distinct individuals within a subpopulation. We present analyses of STR data, at geographic scales which range from national to regional, from the UK and other European sources. We implement a likelihood-based method of estimating FST, which has important advantages over alternative methods: it allows a range of plausible values to be assessed, rather than presenting a single point estimate, and it allows a subpopulation to be compared with a larger population from which a database has been drawn, which is the relevant comparison in forensic work. Our results suggest that values of FST appropriate to forensic applications in Europe are too large to be ignored. With appropriate allowance, however, it is possible to make use of STR evidence in a way which is efficient yet avoids overstatement of evidential strength.

Experiences with single locus DNA probes in casework

DNA profiling in this laboratory has been employed primarily in cases of sexual assault and the largest category of items examined has been internal vaginal swabs. 79% of these gave a profile which was different from that of the victim. Results have been obtained from swabs taken up to 70 h after intercourse. In cases where DNA results were obtained, one or more suspects were excluded in 29% of the cases.

Allele frequency distributions of four variable number tandem repeat (VNTR) loci in the London area

Allele frequency distributions of four hypervariable minisatellite loci were obtained from a large sample of individuals in the London area. The sample is subdivided into three major ethnic groups; Caucasian, Afro-Caribbean and Asian, and histograms for these groups are displayed for comparison. The distributions are discussed in relation to mutation rates, heterozygosity and the computer analysis and processing of results.

Rapid culture confirmation of herpes simplex virus by a monoclonal antibody-based enzyme immunoassay

Rapid confirmation of herpes simplex virus (HSV) is essential in many clinical settings. Viral isolation in cell culture is the standard method for diagnosing HSV infection, with confirmation by specific immunological staining. The performance of the Rapid Absorbent Matrix Pad (RAMP) HSV culture confirmation test was evaluated with specimens obtained from 71 patients with suspected HSV infection and inoculated into African green monkey kidney cell lines. Forty-one culture-positive specimens were confirmed to be HSV by both the RAMP HSV test and the Bartels HSV immunoperoxidase test. Thirty immunoperoxidase-negative specimens were also negative in the RAMP HSV test. The sensitivity and specificity of the RAMP HSV test were 100%. Twelve specimens positive for cytomegalovirus, adenovirus, or enterovirus tested negative by the RAMP HSV test. Thus, the RAMP HSV test was faster than, easier to perform than, as sensitive as, and as specific as other well-documented confirmation methods.

Assessment of a video system for scanning DNA autoradiographs

A video based scanning system had been developed for processing DNA autoradiographs (T. Catterick and J.R. Russell, Lab. Microcomput. (1991), in press). Before the scanner was used in casework it was necessary to assess its performance. Test DNA samples containing fragments (alleles) of known kilobase size were run against the primary (Amersham, U.K.) calibration ladder. The resulting autoradiographs were processed with the new video scanner and also using manual, ruler based measurements. Comparisons were then made between these experimental results and also with the known kilobase values quoted by the supplier of the test samples.

Age related differences in left and right hand skill and in visuo-spatial performance: their possible relationships to the hypothesis that the right hemisphere ages more rapidly than the left

Young and old right handed people were disproportionately worse with their left hand when speed was stressed but showed no especial difficulty when accuracy of performance was emphasised. Both groups of people were also tested on the AH4 test of cognitive abilities. As frequently reported by Rabbitt, the old were disproportionately worse on the visuo-spatial part than on the verbal part compared with the young, even though both parts required "fluid" abilities and even though both were given under time constraints. There was no correlation amongst the elderly people between speed stressed deficits in their left hand performance and their deficits on the visuo-spatial part of the AH4. Both fine control of the left hand and fingers and visuo-spatial performance are likely to be mediated by the right cerebral hemisphere and the implications of these results for a variety of possible views about selective aging of the right hemisphere are discussed.