Publications by authors named "Copas A"

While the impact of social restrictions on sexual and romantic life early in the COVID-19 pandemic has been widely studied, little is known about impacts beyond the initial months. We analyzed responses from 2,098 British adults (aged 18-59) taking part in the Natsal-COVID study (Waves 1 and 2). Participants were recruited via a web panel and surveyed twice: four months and one year after the start of the UK's first national lockdown (July 2020 and March 2021).

View Article and Find Full Text PDF

Background: There are numerous approaches available to analyse data from cluster randomised trials. These include cluster-level summary methods and individual-level methods accounting for clustering, such as generalised estimating equations and generalised linear mixed models. There has been much methodological work showing that estimates of treatment effects can vary depending on the choice of approach, particularly when estimating odds ratios, essentially because the different approaches target different estimands.

View Article and Find Full Text PDF
Article Synopsis
  • This study examines the effectiveness of third-trimester ultrasound in detecting small-for-gestational age (SGA) babies, highlighting concerns about low detection rates and risks associated with false results.
  • Researchers analyzed data from the DESiGN trial, focusing on stillbirth and neonatal morbidity outcomes among pregnancies classified as either false-negative, true-positive, false-positive, or true-negative for SGA.
  • Findings revealed that false-negative SGA results significantly increased the risk of stillbirth compared to true-positive diagnoses, while the implications of false-positive results were also evaluated, indicating potential risks in misclassification during antenatal screening.
View Article and Find Full Text PDF

Introduction: Counseling, together with iron and folic acid supplements, can improve hemoglobin levels in pregnant women, but few interventions have tested a virtual method of delivering counseling. We hypothesized that a virtual counseling intervention delivered via a mobile device (mHealth) would prevent and treat anemia, compared with routine antenatal care (ANC).

Methods: Virtual antenatal intervention for improved diet and iron intake (VALID) was a non-blinded parallel group two-arm, individually randomized superiority trial (1:1 allocation).

View Article and Find Full Text PDF

VIVALDI (ISRCTN14447421) is a government-funded longitudinal open observational cohort study of staff and residents in care homes for older people in England. The study aimed to describe epidemiology (including seroprevalence) and immune responses to COVID-19 in a subset of care homes, in the context of extremely high mortality in this setting, in the first 12-18 months of the pandemic. Data linkage to routine health data was undertaken for all staff and residents and a subset of individuals who consented to sequential blood sampling to investigate SARS-CoV-2 immunity.

View Article and Find Full Text PDF

Astrocytes are the most abundant type of glial cell in the central nervous system and they play pivotal roles in both normal health and disease. Their dysfunction is detrimental to many brain related pathologies. Under pathological conditions, such as Alzheimer's disease, astrocytes adopt an activated reactive phenotype which can contribute to disease progression.

View Article and Find Full Text PDF

Objective: To identify whether maternal and pregnancy characteristics associated with stillbirth differ between preterm and term stillbirth.

Design: Secondary cohort analysis of the DESiGN RCT.

Setting: Thirteen UK maternity units.

View Article and Find Full Text PDF

Background: During the COVID-19 pandemic, online sexual health service delivery increased across Britain. We investigated inequalities in STI testing access and methods of access during the first year of the pandemic.

Methods: Natsal-COVID, an online-survey of people 18-59 years in Britain, explored sexual health experiences in the first year of the pandemic.

View Article and Find Full Text PDF

Background: Control of latent tuberculosis infection (LTBI) is a priority in the World Health Organization strategy to eliminate TB. Many high-income, low TB incidence countries have prioritised LTBI screening and treatment in recent migrants. We tested whether a novel model of care, based entirely within primary care, was effective and safe compared to secondary care.

View Article and Find Full Text PDF

Care home residents are vulnerable to severe outcomes from infections such as COVID-19 and influenza. However, measures to control outbreaks, such as care home closures to visitors and new admissions, have a detrimental impact on their quality of life. Many infections and outbreaks could be prevented but the first step is to measure them reliably.

View Article and Find Full Text PDF
Article Synopsis
  • The study aimed to examine the prevalence of non-communicable diseases, particularly diabetes, among household contacts of individuals with tuberculosis (TB).
  • A systematic review identified 39 studies, with 14 providing individual participant data and 25 offering aggregated data; the results showed a pooled diabetes prevalence of 8.8% among those tested properly.
  • Findings indicate that diabetes prevalence among household contacts is likely underestimated, highlighting the importance of targeted interventions during TB contact investigations to identify and address these health issues.
View Article and Find Full Text PDF

Background: Data on the prevalence of non-communicable diseases (NCDs) in TB household contacts (HHCs) are limited, yet important to inform integrated screening and care for NCD within contact investigations. It is also unclear if screening these contacts reveals more people with NCDs than individuals in the same neighbourhood.

Method: We conducted a pilot cross-sectional study in South Africa and Tanzania, enrolling adult HHCs of TB and individuals in neighbourhood households (controls).

View Article and Find Full Text PDF

Background: Approximately 200 000 South Africans acquired HIV in 2021 despite the availability of universal HIV test and treat and pre-exposure prophylaxis (PrEP). The aim of this study was to test the effectiveness of sexual and reproductive health services or peer support, or both, on the uptake of serostatus neutral HIV services or reduction of sexually transmissible HIV.

Methods: We did an open-label, 2 × 2 randomised factorial trial among young people in a mostly rural area of KwaZulu-Natal, South Africa.

View Article and Find Full Text PDF

Non-inferiority trials compare the efficacy of a new treatment with an existing one where the new treatment is expected to have broadly similar efficacy to the existing treatment, but where other benefits might make the new treatment desirable. These trials might aim to demonstrate that a new treatment is either an alternative to, or a replacement for, the current treatment. In this article, how treatment comparisons can be based only on efficacy, or on both efficacy and other benefits, is explained, and guidance on how to choose the correct objective for a trial is given.

View Article and Find Full Text PDF

Combination HIV prevention packages have reduced HIV incidence and improved HIV-related outcomes among young people. However, there is limited data on how package components interact to promote HIV-related prevention behaviours. We described the uptake of HIV prevention interventions supported by Determined, Resilient, Empowered, AIDS-free, Motivated and Safe (DREAMS) Partnership and assessed the association between uptake and HIV-related behaviours among young people in rural KwaZulu-Natal, South Africa.

View Article and Find Full Text PDF

Background: We have previously demonstrated that older residents of long-term care facilities (LTCF) in the UK show levels of anti-spike antibodies that are comparable to the general population following primary series and booster vaccination for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, data on the humoral response to other SARS-CoV-2 proteins associated with natural infection are scarce in this vulnerable population.

Methods: We measured quantitative levels of anti-nucleocapsid antibodies in blood samples taken from LTCF residents and staff after initial and repeat SARS-CoV-2 infections, between December 2020 and March 2023.

View Article and Find Full Text PDF
Article Synopsis
  • Estimands help clarify treatment effects in research, especially in cluster-randomised trials where additional factors must be defined.
  • The paper defines estimands using potential outcomes notation and examines the differences between them along with associated estimators and their assumptions.
  • A re-analysis of a published cluster-randomised trial illustrates that different estimands and estimators can significantly influence the interpretation of results and treatment effect estimates.
View Article and Find Full Text PDF

Background: During the COVID-19 pandemic, patients may have delayed seeking healthcare for urinary tract infections (UTIs). This could have resulted in more severe presentation to hospital and different antibiotic usage.

Objectives: We explored evidence for such changes through existing national indicators of prescribing, and routine clinical data collected in the electronic health record (EHR).

View Article and Find Full Text PDF
Article Synopsis
  • In cluster randomized trials, people in the same group (or cluster) usually have more similar results compared to people from different groups.
  • It's important to consider this similarity when analyzing the results to avoid making the wrong conclusions.
  • The paper explains how to properly analyze these trials, deal with small groups, and handle missing information.
View Article and Find Full Text PDF

The cluster randomized trial allows a randomized evaluation when it is either not possible to randomize the individual or randomizing individuals would put the trial at high risk of contamination across treatment arms. There are many variations of the cluster randomized design, including the parallel design with or without baseline measures, the cluster randomized cross-over design, the stepped-wedge cluster randomized design, and more recently-developed variants such as the batched stepped-wedge design and the staircase design. Once it has been clearly established that there is a need for cluster randomization, one ever important question is which form the cluster design should take.

View Article and Find Full Text PDF

Tuberculosis (TB) and non-communicable diseases (NCD) share predisposing risk factors. TB-associated NCD might cluster within households affected with TB requiring shared prevention and care strategies. We conducted an individual participant data meta-analysis of national TB prevalence surveys to determine whether NCD cluster in members of households with TB.

View Article and Find Full Text PDF
Article Synopsis
  • In Uganda, many women face unintended pregnancies and a lack of contraceptive methods, which can lead to health problems.
  • A study looked at data from 18,506 women and found that nearly 44.5% of pregnancies were unplanned, and about 21% of women needed better access to contraception.
  • It showed that women who have unmet contraceptive needs are nearly four times more likely to have unintended pregnancies, and other factors like age, education, and household wealth also play a role.
View Article and Find Full Text PDF

Objectives: To describe the built environment in long-term care facilities (LTCF) and its association with introduction and transmission of SARS-CoV-2 infection.

Design: Cross-sectional survey with linkage to routine surveillance data.

Setting And Participants: LTCFs in England caring for adults ≥65 years old, participating in the VIVALDI study (ISRCTN14447421) were eligible.

View Article and Find Full Text PDF

Introduction: Care home residents have experienced significant morbidity, mortality and disruption following outbreaks of SARS-CoV-2. Regular SARS-CoV-2 testing of care home staff was introduced to reduce transmission of infection, but it is unclear whether this remains beneficial. This trial aims to investigate whether use of regular asymptomatic staff testing, alongside funding to reimburse sick pay for those who test positive and meet costs of employing agency staff, is a feasible and effective strategy to reduce COVID-19 impact in care homes.

View Article and Find Full Text PDF