Research-ready data: the C-Surv data model

Research-ready data (data curated to a defined standard) increase scientific opportunity and rigour by integrating the data environment. The development of research platforms has highlighted the value of research-ready data, particularly for multi-cohort analyses. Following stakeholder consultation, a standard data model (C-Surv) optimised for data discovery, was developed using data from 5 population and clinical cohort studies. The model uses a four-tier nested structure based on 18 data themes selected according to user behaviour or technology. Standard variable naming conventions are applied to uniquely identify variables within the context of longitudinal studies. The data model was used to develop a harmonised dataset for 11 cohorts. This dataset populated the Cohort Explorer data discovery tool for assessing the feasibility of an analysis prior to making a data access request. Data preparation times were compared between cohort specific data models and C-Surv.It was concluded that adopting a common data model as a data standard for the discovery and analysis of research cohort data offers multiple benefits.

The impact of dementia, frailty and care home characteristics on SARS-CoV-2 incidence in a national cohort of Welsh care home residents during a period of high community prevalence

BACKGROUND

dementia may increase care home residents' risk of COVID-19, but there is a lack of evidence on this effect and on interactions with individual and care home-level factors.

METHODS

we created a national cross-sectional retrospective cohort of care home residents in Wales for 1 September to 31 December 2020. Risk factors were analysed using multi-level logistic regression to model the likelihood of SARS-CoV-2 infection and mortality.

RESULTS

the cohort included 9,571 individuals in 673 homes. Dementia was diagnosed in 5,647 individuals (59%); 1,488 (15.5%) individuals tested positive for SARS-CoV-2. We estimated the effects of age, dementia, frailty, care home size, proportion of residents with dementia, nursing and dementia services, communal space and region. The final model included the proportion of residents with dementia (OR for positive test 4.54 (95% CIs 1.55-13.27) where 75% of residents had dementia compared to no residents with dementia) and frailty (OR 1.29 (95% CIs 1.05-1.59) for severe frailty compared with no frailty). Analysis suggested 76% of the variation was due to setting rather than individual factors. Additional analysis suggested severe frailty and proportion of residents with dementia was associated with all-cause mortality, as was dementia diagnosis. Mortality analyses were challenging to interpret.

DISCUSSION

whilst individual frailty increased the risk of COVID-19 infection, dementia was a risk factor at care home but not individual level. These findings suggest whole-setting interventions, particularly in homes with high proportions of residents with dementia and including those with low/no individual risk factors may reduce the impact of COVID-19.

SARS-CoV-2 infection risk among 77,587 healthcare workers: a national observational longitudinal cohort study in Wales, United Kingdom, April to November 2020

OBJECTIVES

To better understand the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among healthcare workers, leading to recommendations for the prioritisation of personal protective equipment, testing, training and vaccination.

DESIGN

Observational, longitudinal, national cohort study.

SETTING

Our cohort were secondary care (hospital-based) healthcare workers employed by NHS Wales (United Kingdom) organisations from 1 April 2020 to 30 November 2020.

PARTICIPANTS

We included 577,756 monthly observations among 77,587 healthcare workers. Using linked anonymised datasets, participants were grouped into 20 staff roles. Additionally, each role was deemed either patient-facing, non-patient-facing or undetermined. This was linked to individual demographic details and dates of positive SARS-CoV-2 PCR tests.

MAIN OUTCOME MEASURES

We used univariable and multivariable logistic regression models to determine odds ratios (ORs) for the risk of a positive SARS-CoV-2 PCR test.

RESULTS

Patient-facing healthcare workers were at the highest risk of SARS-CoV-2 infection with an adjusted OR (95% confidence interval [CI]) of 2.28 (95% CI 2.10-2.47). We found that after adjustment, foundation year doctors (OR 1.83 [95% CI 1.47-2.27]), healthcare support workers [OR 1.36 [95% CI 1.20-1.54]) and hospital nurses (OR 1.27 [95% CI 1.12-1.44]) were at the highest risk of infection among all staff groups. Younger healthcare workers and those living in more deprived areas were at a higher risk of infection. We also observed that infection rates varied over time and by organisation.

CONCLUSIONS

These findings have important policy implications for the prioritisation of vaccination, testing, training and personal protective equipment provision for patient-facing roles and the higher risk staff groups.

A population-level study into health vulnerabilities of mothers and fathers involved in public law care proceedings in Wales, UK

ObjectivesUnder section 31 (s.31) of the UK Children Act 1989, public law care proceedings can be issued if there is concern a child is subject to, or at risk of significant harm. We examined health vulnerabilities of parents involved in public law care proceedings in the two-year period prior to involvement. ApproachOur study created an anonymised individual-level population-based cohort, with a matched comparison group of parents in Wales who were not subject to care proceedings, matched on age, sex and deprivation. Family court data provided by Cafcass Cymru were linked to population-level healthcare records held within the Secure Anonymised Information Linkage (SAIL) Databank. Demographic characteristics, overall health service use and health profiles of parents of children subject to s.31 care proceedings between 2011 and 2019 were examined. ResultsData were available for 8,821 parents involved in care proceedings between 2011 and 2019, with a comparison group of 32,006 parents. Nearly half (47.6%) of cohort parents resided in the most deprived quintile. Higher levels of healthcare use were found for cohort mothers and fathers compared to the comparison group across multiple healthcare settings, with the most pronounced differences for emergency department attendances (59.3% vs 37.0%). Health conditions with the largest variation between groups were related to mental health (43.6% vs 16.0%), substance use (19.4% vs 1.6%) and injuries (41.5% vs 23.6%). ConclusionThis study highlights the heightened socioeconomic and health vulnerabilities of parents who experience care proceedings concerning a child. Better understanding of the needs and vulnerabilities of this population may provide opportunities to improve a range of support and preventative interventions that respond to crises in the community.

Assessing the impacts of COVID-19 on Care Homes in Wales

ObjectivesA defining feature of the COVID-19 pandemic in many countries were the tragic extent to which care home residents were affected and the difficulty in preventing the introduction and subsequent spread of infection. ApproachUtilising linked data in the SAIL Databank we set out to develop a linked data platform as part of the ‘One Wales’ approach to generate evidence to inform policy makers on the key areas of transmission pathways, care home characteristics, excess mortality, and the impacts of vaccination. We used multi-sectoral linked data including routinely collected health data, administrative data and GIS generated metrics on care home characteristics and community infection rates to better understand how multiple factors impacted on care home residents. ResultsWe created a care home index with enhanced care home characteristics for all care homes in Wales and were able to link 15,773 care home residents in the SAIL Databank to 923 care homes. We were able to generate early evidence demonstrating an increased risk of mortality for care home residents during Wave 1 (adjusted HR 1.72 compared to 2016). We were able to show that hospital discharge in Wales during the initial stages of the pandemic, although significant, had a much smaller impact on subsequent infections than care home size and accounted for 1.8% of infected discharge events. We also showed that community prevalence, inpatient appointments and people living with dementia all contributed to increased risks of catching COVID in a care home. ConclusionThe response of the ‘One Wales’ team and the SAIL linked data platform facilitated meaningful insight on the impacts of COVID in social care settings in Wales. The evidence generated was used by policy makers from Welsh and UK Governments to inform policy direction as the pandemic progressed.

Annual risk of falls resulting in emergency department and hospital attendances for older people: an observational study of 781,081 individuals living in Wales (United Kingdom) including deprivation, frailty and dementia diagnoses between 2010 and 2020

BACKGROUND

falls are common in older people, but associations between falls, dementia and frailty are relatively unknown. The impact of the COVID-19 pandemic on falls admissions has not been studied.

AIM

to investigate the impact of dementia, frailty, deprivation, previous falls and the differences between years for falls resulting in an emergency department (ED) or hospital admission.

STUDY DESIGN

longitudinal cross-sectional observational study.

SETTING

older people (aged 65+) resident in Wales between 1 January 2010 and 31 December 2020.

METHODS

we created a binary (yes/no) indicator for a fall resulting in an attendance to an ED, hospital or both, per person, per year. We analysed the outcomes using multilevel logistic and multinomial models.

RESULTS

we analysed a total of 5,141,244 person years of data from 781,081 individuals. Fall admission rates were highest in 2012 (4.27%) and lowest in 2020 (4.27%). We found an increased odds ratio (OR [95% confidence interval]) of a fall admission for age (1.05 [1.05, 1.05] per year of age), people with dementia (2.03 [2.00, 2.06]) and people who had a previous fall (2.55 [2.51, 2.60]). Compared with fit individuals, those with frailty had ORs of 1.60 [1.58, 1.62], 2.24 [2.21, 2.28] and 2.94 [2.89, 3.00] for mild, moderate and severe frailty respectively. Reduced odds were observed for males (0.73 [0.73, 0.74]) and less deprived areas; most deprived compared with least OR 0.75 [0.74, 0.76].

CONCLUSIONS

falls prevention should be targeted to those at highest risk, and investigations into the reduction in admissions in 2020 is warranted.

COVID-19 risk factors amongst 14,786 care home residents: an observational longitudinal analysis including daily community positive test rates of COVID-19, hospital stays and vaccination status in Wales (UK) between 1 September 2020 and 1 May 2021

BACKGROUND

COVID-19 vaccinations have been prioritised for high risk individuals.

AIM

Determine individual-level risk factors for care home residents testing positive for SARS-CoV-2.

STUDY DESIGN

Longitudinal observational cohort study using individual-level linked data from the Secure Anonymised Information Linkage (SAIL) databank.

SETTING

Fourteen thousand seven hundred and eighty-six older care home residents (aged 65+) living in Wales between 1 September 2020 and 1 May 2021. Our dataset consisted of 2,613,341 individual-level daily observations within 697 care homes.

METHODS

We estimated odds ratios (ORs [95% confidence interval]) using multilevel logistic regression models. Our outcome of interest was a positive SARS-CoV-2 PCR test. We included time-dependent covariates for the estimated community positive test rate of COVID-19, hospital inpatient status, vaccination status and frailty. Additional covariates were included for age, sex and specialist care home services.

RESULTS

The multivariable regression model indicated an increase in age (OR 1.01 [1.00,1.01] per year), community positive test rate (OR 1.13 [1.12,1.13] per percent increase), hospital inpatients (OR 7.40 [6.54,8.36]), and residents in care homes with non-specialist dementia care (OR 1.42 [1.01,1.99]) had an increased odds of a positive test. Having a positive test prior to the observation period (OR 0.58 [0.49,0.68]) and either one or two doses of a vaccine (0.21 [0.17,0.25] and 0.05 [0.02,0.09], respectively) were associated with a decreased odds.

CONCLUSIONS

Care providers need to remain vigilant despite the vaccination rollout, and extra precautions should be taken when caring for the most vulnerable. Minimising potential COVID-19 infection for care home residents when admitted to hospital should be prioritised.

Intensity of COVID-19 in care homes following hospital discharge in the early stages of the UK epidemic

BACKGROUND

defining features of the COVID-19 pandemic in many countries were the tragic extent to which care home residents were affected and the difficulty in preventing the introduction and subsequent spread of infection. Management of risk in care homes requires good evidence on the most important transmission pathways. One hypothesised route at the start of the pandemic, prior to widespread testing, was the transfer of patients from hospitals that were experiencing high levels of nosocomial events.

METHODS

we tested the hypothesis that hospital discharge events increased the intensity of care home cases using a national individually linked health record cohort in Wales, UK. We monitored 186,772 hospital discharge events over the period from March to July 2020, tracking individuals to 923 care homes and recording the daily case rate in the homes populated by 15,772 residents. We estimated the risk of an increase in case rates following exposure to a hospital discharge using multi-level hierarchical logistic regression and a novel stochastic Hawkes process outbreak model.

FINDINGS

in regression analysis, after adjusting for care home size, we found no significant association between hospital discharge and subsequent increases in care home case numbers (odds ratio: 0.99, 95% CI: 0.82, 1.90). Risk factors for increased cases included care home size, care home resident density and provision of nursing care. Using our outbreak model, we found a significant effect of hospital discharge on the subsequent intensity of cases. However, the effect was small and considerably less than the effect of care home size, suggesting the highest risk of introduction came from interaction with the community. We estimated that approximately 1.8% of hospital discharged patients may have been infected.

INTERPRETATION

there is growing evidence in the UK that the risk of transfer of COVID-19 from the high-risk hospital setting to the high-risk care home setting during the early stages of the pandemic was relatively small. Although access to testing was limited to initial symptomatic cases in each care home at this time, our results suggest that reduced numbers of discharges, selection of patients and action taken within care homes following transfer all may have contributed to the mitigation. The precise key transmission routes from the community remain to be quantified.

Impact of COVID-19 pandemic on community medication dispensing: a national cohort analysis in Wales, UK

Background

Population-level information on dispensed medication provides insight on the distribution of treated morbidities, particularly if linked to other population-scale data at an individual-level.

Objective

To evaluate the impact of COVID-19 on dispensing patterns of medications.

Methods

Retrospective observational study using population-scale, individual-level dispensing records in Wales, UK. Total dispensed drug items for the population between 1 st January 2016 and 31 st December 2019 (3-years, pre-COVID-19) were compared to 2020 with follow up until 27 th July 2021 (COVID-19 period). We compared trends across all years and British National Formulary (BNF) chapters and highlighted the trends in three major chapters for 2019-21: 1-Cardiovascular system (CVD); 2-Central Nervous System (CNS); 3-Immunological & Vaccine. We developed an interactive dashboard to enable monitoring of changes as the pandemic evolves.

Result

Amongst all BNF chapters, 73,410,543 items were dispensed in 2020 compared to 74,121,180 items in 2019 demonstrating -0.96% relative decrease in 2020. Comparison of monthly patterns showed average difference (D) of -59,220 and average Relative Change (RC) of -0.74% between the number of dispensed items in 2020 and 2019. Maximum RC was observed in March 2020 (D = +1,224,909 and RC = +20.62), followed by second peak in June 2020 (D = +257,920, RC = +4.50%). A third peak was observed in September 2020 (D = +264,138, RC = +4.35%). Large increases in March 2020 were observed for CVD and CNS medications across all age groups. The Immunological and Vaccine products dropped to very low levels across all age groups and all months (including the March dispensing peak).

Conclusions

Reconfiguration of routine clinical services during COVID-19 led to substantial changes in community pharmacy drug dispensing. This change may contribute to a long-term burden of COVID-19, raising the importance of a comprehensive and timely monitoring of changes for evaluation of the potential impact on clinical care and outcomes.

A population level study into health vulnerabilities of mothers and fathers involved in public law care proceedings in Wales, UK between 2011 and 2019

IntroductionUnder section 31 of the Children Act 1989, public law care proceedings can be issued if there is concern a child is subject to, or at risk of significant harm, which can lead to removal of a child from parents. Appropriate and effective health and social support are required to potentially prevent some of the need for these proceedings. More comprehensive evidence of the health needs and vulnerabilities of parents will enable enhanced response from family courts and integrated other services. ObjectiveTo examine health vulnerabilities of parents involved in care proceedings in the two-year period prior to involvement. MethodsFamily court data provided by Cafcass Cymru were linked to population-based health records held within the Secure Anonymised Information Linkage Databank. Linked data were available for 8,821 parents of children involved in care proceedings between 2011 and 2019. Findings were benchmarked with reference to a comparison group of parents matched on sex, age, and deprivation (n = 32,006), not subject to care proceedings. Demographic characteristics, overall health service use, and health profiles of parents were examined. Descriptive and statistical tests of independence were used. ResultsNearly half of cohort parents (47.6%) resided in the most deprived quintile. They had higher levels of healthcare use compared to the comparison group across multiple healthcare settings, with the most pronounced differences for emergency department attendances (59.3% vs 37.0%). Health conditions with the largest variation between groups were related to mental health (43.6% vs 16.0%), substance use (19.4% vs 1.6%) and injuries (41.5% vs 23.6%). ConclusionThis study highlights the heightened socioeconomic and health vulnerabilities of parents who experience care proceedings concerning a child. Better understanding of the needs and vulnerabilities of this population may provide opportunities to improve a range of support and preventative interventions that respond to crises in the community.

A population level study into health vulnerabilities of mothers and fathers involved in public law care proceedings in Wales, UK between 2011 and 2019

Introduction

Under section 31 of the Children Act 1989, public law care proceedings can be issued if there is concern a child is subject to, or at risk of significant harm, which can lead to removal of a child from parents. Appropriate and effective health and social support are required to potentially prevent some of the need for these proceedings. More comprehensive evidence of the health needs and vulnerabilities of parents will enable enhanced response from family courts and integrated other services.

Objective

To examine health vulnerabilities of parents involved in care proceedings in the two-year period prior to involvement.

Methods

Family court data provided by Cafcass Cymru were linked to population-based health records held within the Secure Anonymised Information Linkage Databank. Linked data were available for 8,821 parents of children involved in care proceedings between 2011 and 2019. Findings were benchmarked with reference to a comparison group of parents matched on sex, age, and deprivation (n = 32,006), not subject to care proceedings. Demographic characteristics, overall health service use, and health profiles of parents were examined. Descriptive and statistical tests of independence were used.

Results

Nearly half of cohort parents (47.6%) resided in the most deprived quintile. They had higher levels of healthcare use compared to the comparison group across multiple healthcare settings, with the most pronounced differences for emergency department attendances (59.3% vs 37.0%). Health conditions with the largest variation between groups were related to mental health (43.6% vs 16.0%), substance use (19.4% vs 1.6%) and injuries (41.5% vs 23.6%).

Conclusion

This study highlights the heightened socioeconomic and health vulnerabilities of parents who experience care proceedings concerning a child. Better understanding of the needs and vulnerabilities of this population may provide opportunities to improve a range of support and preventative interventions that respond to crises in the community.

COVID-19 vaccine uptake, effectiveness, and waning in 82,959 health care workers: A national prospective cohort study in Wales

BACKGROUND

While population estimates suggest high vaccine effectiveness against SARS-CoV-2 infection, the protection for health care workers, who are at higher risk of SARS-CoV-2 exposure, is less understood.

METHODS

We conducted a national cohort study of health care workers in Wales (UK) from 7 December 2020 to 30 September 2021. We examined uptake of any COVID-19 vaccine, and the effectiveness of BNT162b2 mRNA (Pfizer-BioNTech) against polymerase chain reaction (PCR) confirmed SARS-CoV-2 infection. We used linked and routinely collected national-scale data within the SAIL Databank. Data were available on 82,959 health care workers in Wales, with exposure extending to 26 weeks after second doses.

RESULTS

Overall vaccine uptake was high (90%), with most health care workers receiving theBNT162b2 vaccine (79%). Vaccine uptake differed by age, staff role, socioeconomic status; those aged 50-59 and 60+ years old were 1.6 times more likely to get vaccinated than those aged 16-29. Medical and dental staff, and Allied Health Practitioners were 1.5 and 1.1 times more likely to get vaccinated, compared to nursing and midwifery staff. The effectiveness of the BNT162b2 vaccine was found to be strong and consistent across the characteristics considered; 52% three to six weeks after first dose, 86% from two weeks after second dose, though this declined to 53% from 22 weeks after the second dose.

CONCLUSIONS

With some variation in rate of uptake, those who were vaccinated had a reduced risk of PCR-confirmed SARS-CoV-2 infection, compared to those unvaccinated. Second dose has provided stronger protection for longer than first dose but our study is consistent with waning from seven weeks onwards.

Validating the QCOVID risk prediction algorithm for risk of mortality from COVID-19 in the adult population in Wales, UK

Introduction

COVID-19 risk prediction algorithms can be used to identify at-risk individuals from short-term serious adverse COVID-19 outcomes such as hospitalisation and death. It is important to validate these algorithms in different and diverse populations to help guide risk management decisions and target vaccination and treatment programs to the most vulnerable individuals in society.

Objectives

To validate externally the QCOVID risk prediction algorithm that predicts mortality outcomes from COVID-19 in the adult population of Wales, UK.

Methods

We conducted a retrospective cohort study using routinely collected individual-level data held in the Secure Anonymised Information Linkage (SAIL) Databank. The cohort included individuals aged between 19 and 100 years, living in Wales on 24th January 2020, registered with a SAIL-providing general practice, and followed-up to death or study end (28th July 2020). Demographic, primary and secondary healthcare, and dispensing data were used to derive all the predictor variables used to develop the published QCOVID algorithm. Mortality data were used to define time to confirmed or suspected COVID-19 death. Performance metrics, including R2 values (explained variation), Brier scores, and measures of discrimination and calibration were calculated for two periods (24th January-30th April 2020 and 1st May-28th July 2020) to assess algorithm performance.

Results

1,956,760 individuals were included. 1,192 (0.06%) and 610 (0.03%) COVID-19 deaths occurred in the first and second time periods, respectively. The algorithms fitted the Welsh data and population well, explaining 68.8% (95% CI: 66.9-70.4) of the variation in time to death, Harrell's C statistic: 0.929 (95% CI: 0.921-0.937) and D statistic: 3.036 (95% CI: 2.913-3.159) for males in the first period. Similar results were found for females and in the second time period for both sexes.

Conclusions

The QCOVID algorithm developed in England can be used for public health risk management for the adult Welsh population.

Investigating the uptake, effectiveness and safety of COVID-19 vaccines: protocol for an observational study using linked UK national data

INTRODUCTION

The novel coronavirus SARS-CoV-2, which emerged in December 2019, has caused millions of deaths and severe illness worldwide. Numerous vaccines are currently under development of which a few have now been authorised for population-level administration by several countries. As of 20 September 2021, over 48 million people have received their first vaccine dose and over 44 million people have received their second vaccine dose across the UK. We aim to assess the uptake rates, effectiveness, and safety of all currently approved COVID-19 vaccines in the UK.

METHODS AND ANALYSIS

We will use prospective cohort study designs to assess vaccine uptake, effectiveness and safety against clinical outcomes and deaths. Test-negative case-control study design will be used to assess vaccine effectiveness (VE) against laboratory confirmed SARS-CoV-2 infection. Self-controlled case series and retrospective cohort study designs will be carried out to assess vaccine safety against mild-to-moderate and severe adverse events, respectively. Individual-level pseudonymised data from primary care, secondary care, laboratory test and death records will be linked and analysed in secure research environments in each UK nation. Univariate and multivariate logistic regression models will be carried out to estimate vaccine uptake levels in relation to various population characteristics. VE estimates against laboratory confirmed SARS-CoV-2 infection will be generated using a generalised additive logistic model. Time-dependent Cox models will be used to estimate the VE against clinical outcomes and deaths. The safety of the vaccines will be assessed using logistic regression models with an offset for the length of the risk period. Where possible, data will be meta-analysed across the UK nations.

ETHICS AND DISSEMINATION

We obtained approvals from the National Research Ethics Service Committee, Southeast Scotland 02 (12/SS/0201), the Secure Anonymised Information Linkage independent Information Governance Review Panel project number 0911. Concerning English data, University of Oxford is compliant with the General Data Protection Regulation and the National Health Service (NHS) Digital Data Security and Protection Policy. This is an approved study (Integrated Research Application ID 301740, Health Research Authority (HRA) Research Ethics Committee 21/HRA/2786). The Oxford-Royal College of General Practitioners Clinical Informatics Digital Hub meets NHS Digital's Data Security and Protection Toolkit requirements. In Northern Ireland, the project was approved by the Honest Broker Governance Board, project number 0064. Findings will be made available to national policy-makers, presented at conferences and published in peer-reviewed journals.

Anxiety and depression among children and young people involved in family justice court proceedings: longitudinal national data linkage study

BACKGROUND

Little is known about mental health problems of children and young people (CYP) involved with public and private law family court proceedings, and how these CYP fare compared to those not involved in these significant disruptions to family life.

AIMS

This study examined records of depression/anxiety in CYP involved in public and private law proceedings using linked population-level data across Wales.

METHOD

Retrospective e-cohort study. We calculated the incidence of primary-care-recorded depression/anxiety among CYP involved in these proceedings and in a comparison group, using Poisson regression. Depression/anxiety outcomes following proceedings were evaluated using pairwise Cox regression, with age- and gender-matched controls of CYP who had no involvement with the courts.

RESULTS

CYP in the public group had twice the risk of depression (adjusted incidence rate ratio aIRR = 2.2; 95% CI 1.9-2.6) and 20% higher risk of anxiety (aIRR = 1.2; 95% CI 1.0-1.5) relative to the comparison group. The private group had 60% higher risk of depression (aIRR = 1.6; 95% CI 1.4-1.7) and 30% higher risk of anxiety (aIRR = 1.3; 95% CI 1.2-1.4). Following private law proceedings, CYP were more likely to have depression (hazard ratio HR = 1.9; 95% CI 1.7-2.1), and anxiety (HR = 1.4; 95% CI 1.2-1.6) than the control group. Following public proceedings, CYP were more likely to have depression (HR = 2.1; 95% CI 1.7-2.5). Incidence of anxiety or depression following court proceedings was around 4%.

CONCLUSIONS

Findings highlight the vulnerability of CYP involved in family court proceedings and increased risk of depression and anxiety. Schools, health professionals, social and family support workers have a role to play in identifying needs and ensuring CYP receive appropriate support before, during and after proceedings.

COVID-19 infection risk amongst 14,104 vaccinated care home residents: a national observational longitudinal cohort study in Wales, UK, December 2020-March 2021

BACKGROUND

vaccinations for COVID-19 have been prioritised for older people living in care homes. However, vaccination trials included limited numbers of older people.

AIM

we aimed to study infection rates of SARS-CoV-2 for older care home residents following vaccination and identify factors associated with increased risk of infection.

STUDY DESIGN AND SETTING

we conducted an observational data-linkage study including 14,104 vaccinated older care home residents in Wales (UK) using anonymised electronic health records and administrative data.

METHODS

we used Cox proportional hazards models to estimate hazard ratios (HRs) for the risk of testing positive for SARS-CoV-2 infection following vaccination, after landmark times of either 7 or 21 days post-vaccination. We adjusted HRs for age, sex, frailty, prior SARS-CoV-2 infections and vaccination type.

RESULTS

we observed a small proportion of care home residents with positive polymerase chain reaction (tests following vaccination 1.05% (N = 148), with 90% of infections occurring within 28 days. For the 7-day landmark analysis we found a reduced risk of SARS-CoV-2 infection for vaccinated individuals who had a previous infection; HR (95% confidence interval) 0.54 (0.30, 0.95). For the 21-day landmark analysis, we observed high HRs for individuals with low and intermediate frailty compared with those without; 4.59 (1.23, 17.12) and 4.85 (1.68, 14.04), respectively.

CONCLUSIONS

increased risk of infection after 21 days was associated with frailty. We found most infections occurred within 28 days of vaccination, suggesting extra precautions to reduce transmission risk should be taken in this time frame.

Staff-pupil SARS-CoV-2 infection pathways in schools in Wales: a population-level linked data approach

Background

Better understanding of the role that children and school staff play in the transmission of SARS-CoV-2 is essential to guide policy development on controlling infection while minimising disruption to children's education and well-being.

Methods

Our national e-cohort (n=464531) study used anonymised linked data for pupils, staff and associated households linked via educational settings in Wales. We estimated the odds of testing positive for SARS-CoV-2 infection for staff and pupils over the period August- December 2020, dependent on measures of recent exposure to known cases linked to their educational settings.

Results

The total number of cases in a school was not associated with a subsequent increase in the odds of testing positive (staff OR per case: 0.92, 95% CI 0.85 to 1.00; pupil OR per case: 0.98, 95% CI 0.93 to 1.02). Among pupils, the number of recent cases within the same year group was significantly associated with subsequent increased odds of testing positive (OR per case: 1.12, 95% CI 1.08 to 1.15). These effects were adjusted for a range of demographic covariates, and in particular any known cases within the same household, which had the strongest association with testing positive (staff OR: 39.86, 95% CI 35.01 to 45.38; pupil OR: 9.39, 95% CI 8.94 to 9.88).

Conclusions

In a national school cohort, the odds of staff testing positive for SARS-CoV-2 infection were not significantly increased in the 14-day period after case detection in the school. However, pupils were found to be at increased odds, following cases appearing within their own year group, where most of their contacts occur. Strong mitigation measures over the whole of the study period may have reduced wider spread within the school environment.

Socio-economic predictors of time to care home admission in people living with dementia in Wales: A routine data linkage study

OBJECTIVES

Limited research has shown that people with dementia (PwD) from lower socio-economic backgrounds can face difficulties in accessing the right care at the right time. This study examined whether socio-economic status (SES) and rural versus urban living location are associated with the time between diagnosis and care home admission in PwD living in Wales, UK.

METHODS/DESIGN

This study linked routine health data and an e-cohort of PwD who have been admitted into a care home between 2000 and 2018 living in Wales. Survival analysis explored the effects of SES, living location, living situation, and frailty on the time between diagnosis and care home admission.

RESULTS

In 34,514 PwD, the average time between diagnosis and care home admission was 1.5 (±1.4) years. Cox regression analysis showed that increased age, living alone, frailty, and living in less disadvantaged neighbourhoods were associated with faster rate to care home admission. Living in rural regions predicted a slower rate until care home admission.

CONCLUSIONS

This is one of the first studies to show a link between socio-economic factors on time to care home admission in dementia. Future research needs to address variations in care needs between PwD from different socio-economic and geographical backgrounds.

Creating A Research Ready Data Asset and Empowering Dynamic and Efficient Research: The Sail Dementia E-Cohort (SDEC)

IntroductionResearch can often be slow to start and require duplication of effort which in lots of cases has previously been completed to generate research-ready-data-assets (RRDA). Within the UK, two programmes: Dementias Platform UK (DPUK) that brings together over 50 different dementia-related cohorts and Secure Anonymised Information Linkage (SAIL) Databank, which provides access to longitudinal population-scale person-level data for every person in Wales have tried to tackle this challenge of creation, use and management of RRDA’s. Objectives and ApproachCombining clinical, data and management expertise from DPUK and SAIL, we hoped to construct a RRDA that was easily accessible and well described for a dementia e-cohort. Welsh residents with available primary care records were included, with clinical and demographic information including follow-up times, several dementia indicators using validated diagnostic code lists, information on every dementia-related diagnostic event and several covariates and co-morbidities. SDeC was made available to researchers and can be modified according to appropriate study designs, with learning from projects used to update the SDeC to improve future uses. Interactive visualisations effectively summarise cohort characteristics, aiding researchers to quickly determine cohort eligibility for dementia studies. ResultsSDeC contains data from 4.6 million participants in SAIL, with 1.5 million meeting cohort inclusion criteria, resulting in 24.3 million person-years of follow-up. Of these, 146,323 (10%) developed all-cause dementia during follow-up, with 90,150 (60%) having dementia subtype codes. We made this resource available to researchers who had never used SAIL before, with limited experience of population-scale routine-data, and projects have proceeded with one managing to proceed from point of initial access to submission of publication in less than 6-months. Conclusion / ImplicationsSDeC provides a reproducible dynamic method for completing dementia research, and expediting learning and understanding of the use of these data, with further developments and maintenance planned to increase the complexity and detail available to researchers over time.

DPUK Cohort Explorer: An Interactive Visualisation Tool

IntroductionThe Dementias Platform UK (DPUK) Cohort Explorer is an interactive, online visualisation tool that allows users to explore data for a number of DPUK cohorts. Over 30 variables across cohorts have been harmonised, including information on demographics, lifestyle, cognition, health, and genetic biomarkers. Objectives and ApproachThe tool has been developed to complement existing DPUK cohort metadata to provide a visual representation of participant numbers and field-level information for a selection of cohorts. This enables users to determine a cohort’s eligibility before applying for access to a cohort’s data, and aid in shaping potential hypotheses. Developed using Microsoft PowerBI, the Explorer hosts a subset of the cohort’s baseline, harmonised data, allowing a user to interrogate the visualisations of the uploaded data in a secure manner on the DPUK Data Portal website. Visualisations are linked so that participant numbers and distributions can be explored interactively. ResultsThis approach allows the user to explore the harmonised data across a number of cohorts simultaneously whilst setting and adjusting filters that are of interest to the user’s search criteria. This provides a better understanding of the real-world data and enables the user to determine the feasibility of each cohort for potential studies, whilst facilitating meaningful comparisons across cohorts. The tool currently visualises five DPUK cohorts with a total of 82,391 participants, however it is being incrementally developed with more cohorts being added continually. Conclusion / ImplicationsBy combing an easy-to-use, interactive dashboard with harmonised sets of real-world data, the tool allows the user to explore, interrogate and better understand field-level information in a secure manner with zero data transfer. This provides more insight for the user when applying for access to a cohort dataset using the DPUK Data Portal and may help the user to make more informed decisions and/or hypotheses.

Understanding and responding to COVID-19 in Wales: protocol for a privacy-protecting data platform for enhanced epidemiology and evaluation of interventions

INTRODUCTION

The emergence of the novel respiratory SARS-CoV-2 and subsequent COVID-19 pandemic have required rapid assimilation of population-level data to understand and control the spread of infection in the general and vulnerable populations. Rapid analyses are needed to inform policy development and target interventions to at-risk groups to prevent serious health outcomes. We aim to provide an accessible research platform to determine demographic, socioeconomic and clinical risk factors for infection, morbidity and mortality of COVID-19, to measure the impact of COVID-19 on healthcare utilisation and long-term health, and to enable the evaluation of natural experiments of policy interventions.

METHODS AND ANALYSIS

Two privacy-protecting population-level cohorts have been created and derived from multisourced demographic and healthcare data. The C20 cohort consists of 3.2 million people in Wales on the 1 January 2020 with follow-up until 31 May 2020. The complete cohort dataset will be updated monthly with some individual datasets available daily. The C16 cohort consists of 3 million people in Wales on the 1 January 2016 with follow-up to 31 December 2019. C16 is designed as a counterfactual cohort to provide contextual comparative population data on disease, health service utilisation and mortality. Study outcomes will: (a) characterise the epidemiology of COVID-19, (b) assess socioeconomic and demographic influences on infection and outcomes, (c) measure the impact of COVID-19 on short -term and longer-term population outcomes and (d) undertake studies on the transmission and spatial spread of infection.

ETHICS AND DISSEMINATION

The Secure Anonymised Information Linkage-independent Information Governance Review Panel has approved this study. The study findings will be presented to policy groups, public meetings, national and international conferences, and published in peer-reviewed journals.

The Secure Anonymised Information Linkage databank Dementia e-cohort (SAIL-DeC)

Introduction Dementia Platform UK (DPUK) brings together over 50 different dementia-related cohorts. Most studies have restricted follow-up times and all are based on information from people who volunteer time and data for research. Participants are therefore often not representative of the 'wider population' and generalization of results is complicated. The Secure Anonymised Information Linkage databank (SAIL) holds long-time information on every person in Wales registered with the national health service, so generalization of study results is easier; however, data management and analysis of SAIL data is not trivial. We used data from SAIL to construct an easily accessible, well described dementia e-cohort. Methods With some age restrictions, all Welsh residents for whom primary care data were available were included. Within SAIL, a table was created holding demographic information for every participant including follow-up times and several dementia indicators. Using validated diagnostic code lists, this table was linked to information on every dementia-related diagnostic event and several covariates and co-morbidites. SAIL-DeC can be modified according to varying study designs using annotated SQL-based scripts. Information on SAIL-DeC can easily be updated and linked to additional data on the SAIL database. Interactive visualisations effectively summarise cohort characteristics, aiding researchers to quickly determine cohort eligibility for dementia studies. Results From 4.4 million participants in SAIL, 1.2 million met the cohort inclusion criteria, resulting in 18.8 million person-years of follow-up. Of these, 129,650 (10%) developed all-cause dementia during follow-up, with 77,978 (60%) having dementia subtype codes. Seventy-nine percent of participants who developed dementia died during follow-up. Median survival was 12.3 years for participants diagnosed with dementia when aged 50-60, 6.8 years when aged 60-70, 4.2 years when aged 70-80 and 2.4 years when aged 80-90. Conclusions We have created a generalisable, national dementia e-cohort, aimed at facilitating epidemiological dementia research.

Macro-to-nanoscale investigation of wall-plate joints in the acorn barnacle Semibalanus balanoides: correlative imaging, biological form and function, and bioinspiration

Correlative imaging combines information from multiple modalities (physical-chemical-mechanical properties) at various length scales (centimetre to nanometre) to understand the complex biological materials across dimensions (2D-3D). Here, we have used numerous coupled systems: X-ray microscopy (XRM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), optical light microscopy (LM) and focused ion beam (FIB-SEM) microscopy to ascertain the microstructural and crystallographic properties of the wall-plate joints in the barnacle Semibalanus balanoides. The exoskeleton is composed of six interlocking wall plates, and the interlocks between neighbouring plates (alae) allow barnacles to expand and grow while remaining sealed and structurally strong. Our results indicate that the ala contain functionally graded orientations and microstructures in their crystallography, which has implications for naturally functioning microstructures, potential natural strengthening and preferred oriented biomineralization. Elongated grains at the outer edge of the ala are oriented perpendicularly to the contact surface, and the c-axis rotates with the radius of the ala. Additionally, we identify for the first time three-dimensional nanoscale ala pore networks revealing that the pores are only visible at the tip of the ala and that pore thickening occurs on the inside (soft bodied) edge of the plates. The pore networks appear to have the same orientation as the oriented crystallography, and we deduce that the pore networks are probably organic channels and pockets, which are involved with the biomineralization process. Understanding these multiscale features contributes towards an understanding of the structural architecture in barnacles, but also their consideration for bioinspiration of human-made materials. The work demonstrates that correlative methods spanning different length scales, dimensions and modes enable the extension of the structure-property relationships in materials to form and function of organisms.

Data Services for Cohort Studies: Increasing the impact of existing research studies and epidemiological readiness

IntroductionThe Dementias Platform UK (DPUK) Data Portal is a secure, accessible environment facilitating provision of rich data towards the largest Dementia, cognition and ageing community of cohort studies in the world. DPUK is also providing services for cohort studies and researchers to maximise the research potential of the programme’s community. Objectives and ApproachAs part of the engagement of DPUK cohorts with the Data Portal, cohorts will upload data onto the DPUK instance of UK Secure eResearch Platform infrastructure. The Data Portal allows access to a collaborative working space that allows cohorts to enrich their own data, perform their own analysis, and enhance the research potential of their data whilst making use of expertise at various DPUK sites, such as data linking, curation and multi-modal specialism. Cohort data divided into ontologies allows researchers to access data specific to their study needs and can be requested from multiple cohorts simultaneously. ResultsBy utilising the Data Portal researchers have access to cohort data that has been prepared for dementia epidemiology using the agreed ontologies, providing more rapid access to cohort data that otherwise may be large and complex. The knowledge and experience of DPUK staff and collaborators can also help to guide nascent cohorts and feasibility studies into producing research-ready datasets, enabling them to achieve greater impact with their data. A range of analytical tools are provided on the Data Portal making analysis of a cohort’s own data or multiple independent datasets more accessible. Alongside data curation, DPUK also facilitates data linkage to routine sources, beginning with a Wales-wide use case that will expand to the UK over the course of the project. Conclusion/ImplicationsData from international sources accessible using a central platform permits international collaboration, with ontologies allowing previously disparate data to be combined and analysed to build knowledge and research impact. DPUK projects create policy leading results and operational research standards, enhancing cohort impact and discovery of benefits for Dementia patients.

Dementias Platform UK (DPUK) Data Portal - World-leading infrastructure facilitating innovative multi-modal research

IntroductionModern team science requires effective sharing of data and skills. The DPUK Data Portal is a collection of tools, datasets and networks that allows for epidemiologists and specialist researchers alike to access, analyse and investigate cohort and different modalities of routine data across UK and international sources. Objectives and ApproachThe Portal is housed on an instance of UKSeRP (UK Secure eResearch Platform), that allows customisable infrastructure to be used for multi-modal research (thus far live in genetics, imaging and clinical data) for researchers across the world using remote access technology whilst allowing governance to remain with the data provider. A central team at Swansea University is responsible for data curation and processing, and runs an access procedure for researchers to apply to use data from multiple sources to be analysed in a central analysis environment. Other modalities are similarly hosted, with input from partner sites in Cardiff and Oxford. ResultsDPUK facilitates data access and research on 49 cohorts, 40 UK-based and 9 international. The centralised repository model including remote access and ability to store and make available different modalities of data, from phenotypic data, to genetic and imaging data, has allowed DPUK to begin to support research of varying topics, from those studying cognitive decline and Dementia as a disease, to those maturing analytical models. By providing access to data platforms specialising in genetics, imaging and routine clinical data, as well as to specialists in disease and biology to aid with its understanding, DPUK has realised a large-scale research exercise combining major data modalities on a central platform, and allow access to such rich data across the world under an umbrella of robust governance. Conclusion/ImplicationsGlobally, cohorts are pooling data, expertise and desire to enrich their own aims in partnership with a federated research community to enable in-depth scrutiny of the biological origins of dementia and the development and evaluation of novel approach to disease prevention and cure.

Osteoporosis and fracture risk - a linked data study in Wales

IntroductionOsteoporosis is a global disease with a 30-40% lifetime fracture risk according to the World Health Organisation. Over half a million people receive treatment for fragility fractures annually in the UK. Osteoporosis incidence is rising with aging populations; however, medical secondary prevention treatment may reduce fracture risk. Objectives and ApproachPrimary aims were to investigate if secondary medical prevention treatment following an index fracture was associated with survival and subsequent fracture risk, evaluated using a pseudonymised population based e-cohort study design. Patients aged ≥60 years with an index fragility fracture at any anatomical location were identified from the Secure Anonymised Information Linkage (SAIL) databank. Fracture data were identified from secondary care datasets (emergency department and inpatient) and the National Hip Fracture Register data. In addition linkages were made to primary care datasets for medical prescription and Office for National Statistics records for mortality, supplementing data on demographic characteristics and co-morbidity. ResultsThe cohort comprised 81,252 cases between April 2009 and December 2016 of median age 78 years (range 60-109) and 22,896 (28%) males. Medical secondary prevention treatment was received by 29,393 cases (36%). Subsequent fractures were reported for 10,907 cases (14%) and 29,026 cases (36%) died during the study period. For those that received medical prevention, the subsequent fracture and mortality rates were 15% and 28% respectively compared to 12% and 31% for those that did not receive the prevention treatment. Further analyses will include a discrete time competing risks model. Conclusion/ImplicationsA population based e-cohort was successfully created by linking data across multiple datasets. Preliminary findings identified that <50% of eligible patients receive secondary medical prevention treatment after an index fragility fracture. These findings may help inform and unify treatment pathways for those at risk of fragility fractures.

Cohort study of osteoporosis and fracture risk in Wales: does secondary prevention achieve any benefit?

BackgroundOsteoporosis is a global disease with a 30-40% lifetime fracture risk according to the World Health Organisation. Incidence is rising with aging populations; however, medical secondary prevention treatment may reduce fracture risk. ObjectivesThe primary aim was to investigate if secondary medical prevention treatment following an index fracture was associated with survival and subsequent fracture risk. MethodsPatients aged ≥60 years with an index fragility fracture at any anatomical location were identified from the Secure Anonymised Information Linkage (SAIL) databank. A population based e-cohort was created by linking fracture data identified from secondary care datasets and the National Hip Fracture Register data, with linkages to primary care datasets for medical prescription and Office for National Statistics records for mortality. FindingsThe cohort comprised 81,252 cases between April 2009 and December 2016 of median age 78 years and 22,896 (28%) males. Medical secondary prevention treatment was received by 29,393 cases (36%). Subsequent fractures were reported for 10,907 cases (13%) and 29,026 cases (36%) died during the study period. ConclusionsPreliminary findings identified that <50% of eligible patients receive secondary medical prevention treatment after an index fragility fracture. These findings may help inform and unify treatment pathways for those at risk of fragility fractures.

Three-dimensional computational model of a blood oxygenator reconstructed from micro-CT scans

Cardiopulmonary bypass procedures are one of the most common operations and blood oxygenators are the centre piece for the heart-lung machines. Blood oxygenators have been tested as entire devices but intricate details on the flow field inside the oxygenators remain unknown. In this study, a novel method is presented to analyse the flow field inside oxygenators based on micro Computed Tomography (μCT) scans. Two Hollow Fibre Membrane (HFM) oxygenator prototypes were scanned and three-dimensional full scale models that capture the device-specific fibre distributions are set up for computational fluid dynamics analysis. The blood flow through the oxygenator is modelled as a non-Newtonian fluid. The results were compared against the flow solution through an ideal fibre distribution and show the importance of a uniform distribution of fibres and that the oxygenators analysed are not susceptible to flow directionality as mass flow versus area remain the same. However the pressure drop across the oxygenator is dependent on flow rate and direction. By comparing residence time of blood against the time frame to fully saturate blood with oxygen we highlight the potential of this method as design optimisation tool. In conclusion, image-based reconstruction is found to be a feasible route to assess oxygenator performance through flow modelling. It offers the possibility to review a product as manufactured rather than as designed, which is a valuable insight as a precursor to the approval processes. Finally, the flow analysis presented may be extended, at computational cost, to include species transport in further studies.

Primary hepatic lymphoma: favorable outcome after combination chemotherapy

BACKGROUND

Primary hepatic non-Hodgkin lymphoma (PHL) is a rare and difficult to diagnose lymphoproliferative disorder of unknown etiology. It is believed that the prognosis in affected patients is dismal, consisting of early recurrence and short survival.

METHODS

A retrospective cohort review of patients with PHL diagnosed between 1974 and 1995 at a university cancer center was performed.

RESULTS

Twenty-four patients with PHL were identified. Typically, the disease occurred in middle-aged men (median age, 50 years). The primary presenting complaint was right upper quadrant abdominal pain, with hepatomegaly found at physical examination. Serum liver enzymes, lactate dehydrogenase, and beta-2-microglobulin levels all were elevated, but alpha-fetoprotein and carcinoembryonic antigen levels were within normal range. Hypercalcemia was found in 6 of 15 patients who were tested. Six of 10 patients who were tested were positive for the hepatitis C virus (HCV). Liver scans demonstrated either a solitary lesion or multiple lesions. Pathologic examination revealed diffuse large cell lymphoma in 23 patients (96%). Combination chemotherapy was the mainstay of treatment; surgery consisted of diagnostic biopsy. The complete remission rate was 83.3%, and the 5-year cause specific and failure free survival rates were 87.1% and 70.1%, respectively. HCV infection did not appear to influence the outcome of therapy.

CONCLUSIONS

The outcome of patients with PHL who are treated with combination chemotherapy may be more favorable than that reported elsewhere. The frequent association of PHL with HCV infection observed in this series warrants further investigation.

Primary hepatic lymphoma: favorable outcome after combination chemotherapy

BACKGROUND

Primary hepatic non-Hodgkin lymphoma (PHL) is a rare and difficult to diagnose lymphoproliferative disorder of unknown etiology. It is believed that the prognosis in affected patients is dismal, consisting of early recurrence and short survival.

METHODS

A retrospective cohort review of patients with PHL diagnosed between 1974 and 1995 at a university cancer center was performed.

RESULTS

Twenty-four patients with PHL were identified. Typically, the disease occurred in middle-aged men (median age, 50 years). The primary presenting complaint was right upper quadrant abdominal pain, with hepatomegaly found at physical examination. Serum liver enzymes, lactate dehydrogenase, and beta-2-microglobulin levels all were elevated, but alpha-fetoprotein and carcinoembryonic antigen levels were within normal range. Hypercalcemia was found in 6 of 15 patients who were tested. Six of 10 patients who were tested were positive for the hepatitis C virus (HCV). Liver scans demonstrated either a solitary lesion or multiple lesions. Pathologic examination revealed diffuse large cell lymphoma in 23 patients (96%). Combination chemotherapy was the mainstay of treatment; surgery consisted of diagnostic biopsy. The complete remission rate was 83.3%, and the 5-year cause specific and failure free survival rates were 87.1% and 70.1%, respectively. HCV infection did not appear to influence the outcome of therapy.

CONCLUSIONS

The outcome of patients with PHL who are treated with combination chemotherapy may be more favorable than that reported elsewhere. The frequent association of PHL with HCV infection observed in this series warrants further investigation.

Primary hepatic lymphoma: favorable outcome after combination chemotherapy

BACKGROUND

Primary hepatic non-Hodgkin lymphoma (PHL) is a rare and difficult to diagnose lymphoproliferative disorder of unknown etiology. It is believed that the prognosis in affected patients is dismal, consisting of early recurrence and short survival.

METHODS

A retrospective cohort review of patients with PHL diagnosed between 1974 and 1995 at a university cancer center was performed.

RESULTS

Twenty-four patients with PHL were identified. Typically, the disease occurred in middle-aged men (median age, 50 years). The primary presenting complaint was right upper quadrant abdominal pain, with hepatomegaly found at physical examination. Serum liver enzymes, lactate dehydrogenase, and beta-2-microglobulin levels all were elevated, but alpha-fetoprotein and carcinoembryonic antigen levels were within normal range. Hypercalcemia was found in 6 of 15 patients who were tested. Six of 10 patients who were tested were positive for the hepatitis C virus (HCV). Liver scans demonstrated either a solitary lesion or multiple lesions. Pathologic examination revealed diffuse large cell lymphoma in 23 patients (96%). Combination chemotherapy was the mainstay of treatment; surgery consisted of diagnostic biopsy. The complete remission rate was 83.3%, and the 5-year cause specific and failure free survival rates were 87.1% and 70.1%, respectively. HCV infection did not appear to influence the outcome of therapy.

CONCLUSIONS

The outcome of patients with PHL who are treated with combination chemotherapy may be more favorable than that reported elsewhere. The frequent association of PHL with HCV infection observed in this series warrants further investigation.

Mirizzi syndrome: an extra hazard for laparoscopic surgery

BACKGROUND

Mirizzi Syndrome (MS) is an important but uncommon complication of gallstones characterized by narrowing of the common hepatic duct (CHD) due to mechanical compression or inflammation. This study aimed to assess the impact of preoperative and intraoperative diagnosis of MS on the performance, safety and efficacy of laparoscopic cholecystectomy.

METHODS

From a consecutive series of 1,281 patients having surgery for gall bladder disease between 1990 and 1998, nine patients with MS were identified from a prospective database and their clinical progress examined.

RESULTS

Five out of the nine patients with MS presented with pain (2/5 were also jaundiced), and four presented with acute cholecystitis. Liver function tests were abnormal in all patients. Preoperative diagnosis of MS based on ultrasound was made in only two patients, and in a third on findings of a nasobiliary cholangiogram. In six patients, the diagnosis was intraoperative. In seven patients cholecystectomy was completed by laparoscopy. Two patients needed conversion to open cholecystectomy. In two patients the common bile duct was mistaken for the cystic duct and the error was recognized on relaxation of traction on the gall bladder in one, but in the other a duct injury occurred that was not recognized until the postoperative period.

CONCLUSIONS

Preoperative diagnosis of MS is difficult, and a high index of suspicion is necessary to avoid serious complications. Once the diagnosis is known, successful laparoscopic management is possible but care should be taken to avoid duct injury.

Femoral venous flow during laparoscopic gynecologic surgery

The lower-limb venous return, assessed by the peak systolic venous velocities (PSVV) of the left common femoral vein, was recorded at different stages of operation for five patients undergoing major gynecologic operative laparoscopy. The average baseline PSVV was 23.1 cm/s. After positioning the patient in the Trendelenburg position, the PSVV increased to an average of 31.5 cm/s; this was a statistically significant increase. Creation of the pneumoperitoneum changed the waveform from a normal phasic pattern to a dampened, continuous, monophasic waveform. The average PSVV was reduced to 15.9 cm/s; this dampening was statistically significant. Further dampening was evident 1 hour intraoperatively, and the flow became intermittent, with cycles of dampened flow followed by periods of absent flow; these changes in PSVV were not statistically significant. Calf compressors did not increase the femoral PSVV at the beginning of operation, nor at I hour intraoperatively; the decrease was not statistically significant. After release of the pneumoperitoneum, the baseline waveform pattern and velocity returned. The Trendelenburg position used for gynecologic operative laparoscopy was associated with a statistically significant increase in the lower-limb PSVV. This increase did not fully counteract the dampening effect of a pneumoperitoneum on lower-limb PSVV. The authors' study did not support the benefit previously reported on the use of pneumatic calf compressors. The authors therefore recommend continuing the practice of antithrombotic measures for patients undergoing gynecologic operative laparoscopy.

Phase I study of fludarabine and paclitaxel for the treatment of low-grade non-Hodgkin's lymphoma

We conducted a phase I clinical trial of a new combination of fludarabine and paclitaxel in which 19 patients with histologically confirmed recurrent low-grade non-Hodgkin's lymphoma (NHL) were treated at five dose levels. Fludarabine was administered intravenously by bolus for 5 days and paclitaxel was given by intravenous (I.V.) continuous infusion for 96 or 72 hours starting day 1. Courses were repeated every 4 weeks. Patients whose disease responded received a maximum of six courses. All 19 patients received at least one course and could be evaluated for toxic effects, and 18 patients could be evaluated for response. The maximum tolerated dose (MTD) was 20 mg/m2/day I.V. bolus for 5 days of fludarabine plus 60 mg/m2/day I.V. of paclitaxel given as a continuous infusion over 72 hours. The limiting toxic effect was neutropenic fever, which was observed in five of the seven patients treated at the highest dose level. Grade 3 non-hematologic toxic effects of stomatitis (14%), neuropathy (14%), and hypotension (14%) were also observed at the highest dose level. No grade 4 non-hematologic toxic effects or treatment-related deaths occurred. One patient had herpes zoster infection of the skin 1 year after the completion of therapy. The overall response rate was 50%, with the two patients whose disease completely responded remaining disease free at 22 and 17 months. Patients with no prior exposure to either paclitaxel or fludarabine had 62% response rate. We conclude that the combination of fludarabine and paclitaxel appears to have promising activity for the treatment of recurrent low-grade NHL.

Paclitaxel activity for the treatment of non-Hodgkin's lymphoma: final report of a phase II trial

In order to determine the activity of paclitaxel in patients with relapsed or refractory non-Hodgkin's lymphoma (NHL), we conducted a phase II clinical trial in which eligible patients received paclitaxel 200 mg/m2 intravenously over 3 h. Treatment was repeated every 3 weeks. Patients achieving complete or partial responses after two courses of paclitaxel continued to receive therapy for a maximum of eight courses, otherwise they were removed from the study. Of 96 evaluable patients, 45 (47%) had primary refractory disease, and 51 (53%) had relapsed lymphoma. The median number of prior treatment regimens was two (range one to 10 regimens). 45 patients had lowgrade, 44 had intermediate-grade, and seven had mantle cell lymphoma. 24/96 patients responded (10 complete and 14 partial remissions) for an overall response rate of 25% (95% CI 17-35%). Patients with relapsed lymphoma had a higher response rate than those with primary refractory disease (19/51 = 37% v 5/45 = 11%; P < 0.01), and patients with relapsed intermediate-grade lymphoma had a higher response than those with relapsed low-grade lymphoma (9/18 = 50% v 10/31 = 32%; P = 0.22). The treatment was very well tolerated with the most common side-effects being alopecia (100%), peripheral neuropathy (35% of > or = grade II), and arthralgia/myalgia (25% of > or = grade II). After the first course of paclitaxel, grade III/IV thrombocytopenia and neutropenia were observed in 21% and 23% of the patients respectively. 23 episodes of neutropenic fever developed after 250 courses of paclitaxel therapy (8%). We conclude that paclitaxel, at this dose and schedule, is an active new drug for the treatment of non-Hodgkin's lymphoma. The activity of paclitaxel combination programmes are currently under investigation.

Paclitaxel (Taxol) for the treatment of lymphoma

Paclitaxel (Taxol) was recently tested in patients with relapsed and refractory lymphoma in two phase II clinical trials using two different infusion schedules. The first, reported from the NCI (USA), used a 96-hour intravenous continuous infusion schedule, and the second, from our group, used a 3-hour infusion. In the NCI trial, 29 evaluable patients were treated with 140 mg/m2 every three weeks, which achieved a 17% response rate (all PRs); while we treated 96 evaluable patients with 200 mg/m/ every three weeks, which achieved a 25% response rate (10 CRs and 14 PRs, 95% CI: 17%-35%). In our trial, patients with relapsed (not primary refractory) intermediate-grade lymphoma had a response rate of 50%, and those with relapsed low-grade lymphoma had a response rate of 31%. In a follow-up trial, 12 patients who failed to respond to 3-hour infusion of paclitaxel were crossed over to receive paclitaxel by 96-hour infusion. None of the 12 evaluable patients achieved a major clinical response. Similarly, of 25 patients treated with cyclosporine A and paclitaxel after failing therapy with single-agent paclitaxel, only one patient (4%) responded. We conclude that paclitaxel has a promising single-agent activity, most prominently in patients with relapsed intermediate-grade lymphoma. Paclitaxel-based combination programs are currently being evaluated in our institution.

Ultrasound-guided parathyroid aspiration to diagnose parathyroid adenomas

AIM

To ascertain the accuracy of ultrasound-guided fine needle aspiration and parathyroid hormone assay in the identification of parathyroid adenomas.

DESIGN

Case study.

SETTING

Tertiary referral clinic.

PATIENTS

12 subjects, consisting of 10 female and two male patients, with documented primary hyperaparathyroidism.

INTERVENTION

Ultrasonography of the parathyroid glands was performed using an Acuson XP 128 machine with a linear array 7.5 MHz multihertz probe. Following accurate localization of the parathyroid lesion, fine needle aspiration was performed using a 23 gauge needle, and parathyroid hormone assay was performed on the aspirate. Preoperative localization was compared with intra-operative findings.

RESULTS

Ultrasound examination detected 10 out of a possible 12 parathyroid adenomas (83% sensitivity), while ultrasound-guided fine needle aspiration only confirmed nine out of the 12 adenomas (75% sensitivity).

CONCLUSIONS

While ultrasound-guided fine needle aspiration may be simple and with minimal morbidity, it does not appear to provide any advantage over ultrasound examination alone for the localization of parathyroid adenomas. It has a potential role in defining the nature of ultrasonically localized nodules.

Cyclosporin A does not reverse clinical resistance to paclitaxel in patients with relapsed non-Hodgkin's lymphoma

PURPOSE

Cyclosporin A has been shown to reverse paclitaxel resistance in vitro by inhibiting P-gp function. Therefore, we determined whether addition of cyclosporine to paclitaxel reversed clinical paclitaxel resistance in patients with non-Hodgkin's lymphoma (NHL).

PATIENTS AND METHODS

Patients with relapsed NHL were eligible if they had no intervening treatment after failure to respond to paclitaxel (200 mg/m2 over 3 hours), and if they had adequate marrow, renal, and hepatic function, no serious cardiac disease, no CNS involvement, and no antibodies to human immunodeficiency virus-1. A cyclosporin A bolus dose (5 mg/kg over 3 hours) was followed by intravenous infusion (15 mg/kg) over 24 hours. Six hours after the beginning of cyclosporin A, the immediately preceding paclitaxel dose was administered over 3 hours. All patients were premedicated with dexamethasone, diphenhydramine, and cimetidine. Response was assessed after two cycles, and those patients who achieved at least a partial response received a maximum of six courses.

RESULTS

All 26 patients entered were assessable for toxicity and 25 were assessable for response. One patient whose disease had progressed during paclitaxel treatment had a partial remission after the addition of cyclosporin A (response rate, 4%; 95% confidence interval, 1% to 20%). Disease progressed in 17 patients (71%) and did not respond in seven (25%). Serum cyclosporin A A levels measured at the time of initiation of paclitaxel infusion were greater than 2,000 ng/mL during 81% of cycles. Treatment toxicity included peripheral neuropathy in 57%, myalgia or arthralgia in 30%, neutropenia in 53%, neutropenic fever in 8%, and thrombocytopenia in 42% of patients. One patient with preexisting asthma had an acute bronchospasm during the first cycle and was removed from the study. There were no renal or hepatic toxicity and no infectious or hemorrhagic deaths.

CONCLUSION

Cyclosporin A administered on this schedule did not reverse established clinical resistance to paclitaxel, which suggests that P-gp-mediated drug efflux is unlikely to be the only cause of paclitaxel resistance in this patient population.

The pharmacokinetics of the oxytocin antagonist atosiban in pregnant women with preterm uterine contractions

OBJECTIVE

Our purpose was to evaluate the pharmacokinetics of atosiban, an oxytocin antagonist, during and after intravenous infusion in pregnant patients having at least six contractions per hour. The relationship between atosiban infusion and uterine activity was also assessed.

STUDY DESIGN

Plasma samples from eight pregnant patients treated with intravenous atosiban (300 micrograms/min for 6 to 12 hours) were analyzed for atosiban concentration by a specific radioimmunoassay procedure. Contraction rate data were obtained by external tocodynamometry for 1 hour before the infusion and during the subsequent infusion.

RESULTS

The average steady-state plasma concentrations of patients receiving intravenous atosiban were 442 +/- 73 ng/ml (mean +/- SD), with steady state achieved by 1 hour after the start of the infusion. After the completion of the infusion, plasma concentrations declined rapidly in a biexponential manner with initial and terminal half-life estimates of 13 +/- 3 and 102 +/- 18 minutes, respectively. The effective half-life was 18 +/- 3 minutes. The plasma clearance of atosiban was relatively high (42 L/hr) and the volume of distribution (approximately 18 L) was consistent with distribution into extracellular fluid. Of the seven patients evaluated for uterine activity, the mean contraction rate decreased by 75% during the third hour of treatment and remained low until treatment termination.

CONCLUSION

On the basis of earlier published reports, the pharmacokinetics of atosiban in pregnant patients are similar to those in nonpregnant women. Although the patient population was small, a consistent reduction in uterine activity was observed during atosiban infusion.

Three-hour paclitaxel infusion in patients with refractory and relapsed non-Hodgkin's lymphoma

PURPOSE

Paclitaxel (Taxol; Bristol-Myers Squibb Co, Princeton, NJ) is a novel antimicrotubule agent with anti-tumor activity against ovarian and breast carcinomas. Its activity when administered as a 3-hour intravenous infusion in patients with relapsed non-Hodgkin's lymphoma (NHL) has not been studied.

PATIENTS AND METHODS

Patients with relapsed NHL were treated with a 3-hour infusion of 200 mg/m2 of Taxol every 3 weeks in an outpatient setting. All patients received premedication (dexamethasone, diphenhydramine, and cimetidine) to prevent allergic reactions. Responses were assessed after two courses of therapy, and patients who achieved at least partial remission (PR) continued to receive Taxol for a maximum of eight courses.

RESULTS

Of 60 eligible patients, 54 (90%) were assessable for treatment toxicity and 53 (88%) were for treatment response (22 with primary refractory and 31 with relapsed disease). Twelve patients (23%) achieved a PR (n = 6) or complete remission (CR; n = 6) (95% confidence interval, 12% to 36%). Responses were observed in intermediate-grade (31%), low-grade (14%), and mantle-cell (17%) lymphomas. In the intermediate-grade lymphomas, there was a trend for a higher response rate in relapsed versus primary refractory disease (54% v 13%; P = .08). Treatment-related toxicity included alopecia (100%), peripheral neuropathy (37%), myalgia or arthralgia (25%), and neutropenic fever (11%). None of the patients had allergic reactions or cardiac toxicity.

CONCLUSION

At this dose and schedule, Taxol is an active agent in patients with relapsed NHL and can be safely administered in an outpatient setting. Combination programs with Taxol should be investigated for treatment of NHL.

Venous stasis during laparoscopic cholecystectomy

The objectives of this research were (a) to determine the effect of insufflation at laparoscopic cholecystectomy to 12 mm Hg on femoral venous blood flow; and (b) to assess the function of intermittent pneumatic compressors (IPC) and intermittent electric calf stimulators (IECS) in the presence of a pneumoperitoneum. Measures of baseline venous blood flow velocity, femoral vein diameter, and maximum blood flow velocity achieved by IPC or IECS were made in the presence or absence of a pneumoperitoneum of 12 mm Hg. The ICP and IECS were randomly allocated to either leg. All measures were made by an experienced sonologist. Insufflation to 12 mm Hg caused a statically significant decrease in femoral blood flow velocity and was accompanied by a significant increase in femoral vein diameter. The IPC and IECS were able to achieve pulsatile venous blood flow despite the presence of a pneumoperitoneum, but they had no effect on the depressed baseline blood flow velocity. We concluded that insufflation to 12 mm Hg causes significant venous stasis in the lower limb and that IPC and IECS cannot completely eliminate this stasis. Further research needs to be done to clarify the optimal methods of prophylaxis in view of the implications for deep venous thrombosis.

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Multivariate analysis of prognostic factors in stage IV follicular low-grade lymphoma: a risk model

We analyzed the records of 96 previously untreated patients with stage IV follicular low-grade lymphoma (FLGL) uniformly treated with cyclophosphamide, doxorubicin, vincristine, prednisone, and bleomycin (CHOP-Bleo) chemotherapy from 1972 to 1982. The overall complete remission (CR) rate was 77%. At a median follow-up of 138 months, the 10-year cause-specific survival rate was 42% with a median survival of 100 months. Failure-free survival (FFS) was 15% at 10 years with a median FFS of 30 months. Multivariate analysis showed peripheral lymph node size (LN), degree of marrow involvement, and sex, in that order, to be important for FFS, while the number of extranodal sites (#ENS), LN, sex, and degree of marrow involvement were important for cause-specific survival. We devised a tumor burden (TB) model, incorporating #ENS, LN, and degree of marrow involvement. Three groups were identified with statistically significant differences in cause-specific survival and FFS. Those with low TB (one ENS exclusive of extensive marrow and nodal disease less than 5 cm) had a 10-year cause-specific survival of 73% compared with 24% for patients with high TB (greater than or equal to two ENS and nodal disease greater than or equal to 5 cm) (P less than .001) and 40% for those with intermediate TB (either greater than or equal to 2 ENS, or extensive marrow only, or nodal disease greater than 5 cm) (P = .050). Patients with low TB had a 10-year FFS rate of 32%, while the intermediate and high TB groups had 10% and 9% FFS, respectively (P = .003). Because sex was a very strong prognostic variable, we created a risk model for survival and FFS based on TB and sex. Females with low TB had the best prognosis (92% survival and 50% FFS at 10 years) and males with high TB had the worst outlook (median survival and FFS, 43 and 12 months, respectively). Other TB-sex combinations defined two groups with statistically significant differences in survival but comparable FFS. This model should aid in the design and analysis of future trials.