An Epidemiological Study of Lung Cancer and Selected Other Cancers among Namibian Uranium Workers.

The Rössing Uranium Limited (RUL) open-cast uranium mine in Namibia has operated since 1976. Studies of underground uranium miners from Europe and North America have shown increased cancer risks (principally lung cancer). We explored the association between radiation doses and selected cancers in RUL mineworkers.

Phytoestrogen intake and other dietary risk factors for low motile sperm count and poor sperm morphology.

Background: Few potentially modifiable risk factors of male infertility have been identified, and while different diets and food groups have been associated with male infertility, evidence linking dietary factors including phytoestrogens and semen quality is limited and contradictory.

Objectives: To study the associations between phytoestrogen intake and other dietary factors and semen quality.

Materials And Methods: A case-referent study was undertaken of the male partners, of couples attempting conception with unprotected intercourse for 12 months or more without success, recruited from 14 UK assisted reproduction clinics.

Scores Obtained from a Simple Cognitive Test of Visuospatial Episodic Memory Performed Decades before Death Are Associated with the Ultimate Presence of Alzheimer Disease Pathology.

Background: Community- or population-based longitudinal studies of cognitive ability with a brain donation end point offer an opportunity to examine relationships between pathology and cognitive state prior to death. Discriminating the earliest signs of dementing disorders, such as Alzheimer disease (AD), is necessary to undertake early interventions and treatments.

Methods: The neuropathological profile of brains donated from The University of Manchester Longitudinal Study of Cognition in Normal Healthy Old Age, including CERAD (Consortium to Establish a Registry for Alzheimer's Disease) and Braak stage, was assessed by immunohistochemistry.

The Health and Occupation Research Network: An Evolving Surveillance System.

Vital to the prevention of work-related ill-health (WRIH) is the availability of good quality data regarding WRIH burden and risks. Physician-based surveillance systems such as The Health and Occupation Research (THOR) network in the UK are often established in response to limitations of statutory, compensation-based systems for addressing certain epidemiological aspects of disease surveillance. However, to fulfil their purpose, THOR and others need to have methodologic rigor in and ascertaining cases.

How serious is bias in effect estimation in randomised trials with survival data given risk heterogeneity and informative censoring?

It is often assumed that randomisation will prevent bias in estimation of treatment effects from clinical trials, but this is not true of the semiparametric Proportional Hazards model for survival data when there is underlying risk heterogeneity. Here, a new formula is proposed for estimation of this bias, improving on a previous formula through ease of use and clarity regarding the role of the mid-study cumulative hazard rate, shown to be an important factor for the bias magnitude. Informative censoring (IC) is recognised as a source of bias.

Changes in selected metabolic parameters in patients over 65 receiving hydrochlorothiazide plus amiloride, atenolol or placebo in the MRC elderly trial.

Background: Treatment of hypertension reduces incidence of stroke, myocardial infarction and heart failure perhaps partly by controlling different metabolic parameters. There is limited information regarding the changes in potassium, sodium, weight, cholesterol and glucose levels in patients using anti-hypertensives. This study aimed to determine changes in potassium, sodium, glucose, cholesterol, weight, urea and urate levels in patients using anti-hypertensives.

Accounting for reporting fatigue is required to accurately estimate incidence in voluntary reporting health schemes.

Objective: Accurate estimation of the true incidence of ill-health is a goal of many surveillance systems. In surveillance schemes including zero reporting to remove ambiguity with nonresponse, reporter fatigue might increase the likelihood of a false zero case report in turn underestimating the true incidence rate and creating a biased downward trend over time.

Study Design And Setting: Multilevel zero-inflated negative binomial models were fitted to incidence case reports of three surveillance schemes running between 1996 and 2012 in the United Kingdom.

Gestational Age and Birth Weight and the Risk of Childhood Type 1 Diabetes: A Population-Based Cohort and Sibling Design Study.

Objective: We investigated the effects of gestational age, birth weight, small for gestational age (SGA), and large for gestational age (LGA) on risk of childhood type 1 diabetes.

Research Design And Methods: We conducted a population-based cohort study of all singleton live births in Sweden between 1973 and 2009 and a sibling control study. Perinatal data were extracted from the Swedish Medical Birth Register.

Trends in incidence of occupational asthma, contact dermatitis, noise-induced hearing loss, carpal tunnel syndrome and upper limb musculoskeletal disorders in European countries from 2000 to 2012.

Objectives: The European Union (EU) strategy for health and safety at work underlines the need to reduce the incidence of occupational diseases (OD), but European statistics to evaluate this common goal are scarce. We aim to estimate and compare changes in incidence over time for occupational asthma, contact dermatitis, noise-induced hearing loss (NIHL), carpal tunnel syndrome (CTS) and upper limb musculoskeletal disorders across 10 European countries.

Methods: OD surveillance systems that potentially reflected nationally representative trends in incidence within Belgium, the Czech Republic, Finland, France, Italy, the Netherlands, Norway, Spain, Switzerland and the UK provided data.

Pesticide exposure and screen-positive neuropsychiatric disease in British sheep farmers.

Background: Epidemiological evidence linking low dose pesticide exposure and chronic ill-health in UK sheep farmers is limited. Our aim was to examine whether neuropsychiatric disorders were associated with low dose chronic and/or more acute pesticide exposure in sheep farmers.

Methods: A cohort of British farmers working in the 1970s was sent a screening questionnaire which asked about their health and work history.

Occupation exposures and sperm morphology: a case-referent analysis of a multi-centre study.

Objective: We examined occupational exposures and sperm morphology to establish whether exposures implicated differed from those affecting motile sperm concentration.

Methods: Computer aided sperm morphometric assessment was undertaken on morphology slides obtained as part of a multi-centre study in 1999-2002 of occupational factors in male infertility. Men attending 14 fertility clinics across the UK were recruited and gave a semen sample.

Air pollution exposure and adverse pregnancy outcomes in a large UK birth cohort: use of a novel spatio-temporal modelling technique.

Objectives: Previous work suggests an association between air pollution exposure and adverse pregnancy outcomes, even at relatively low concentrations. Our aim was to quantify the effect of air pollution having an adverse effect on preterm birth (PTB) and fetal growth in a large UK cohort using a novel exposure estimation technique [spatio-temporal (S-T) model] alongside a traditional nearest stationary monitor technique (NSTAT).

Methods: All available postcodes from a Northwest England birth outcome dataset during 2004-2008 were geocoded (N=203 562 deliveries).

Has the short-term effect of black smoke exposure on pneumonia mortality been underestimated because hospitalisation is ignored: findings from a case-crossover study.

Background: Short-term associations have been demonstrated between air pollution and respiratory mortality including pneumonia. Studies typically estimate exposure based only on place of residence, yet many are in hospital prior to death. This study investigates lag length and tests the hypothesis that the effect of 'black smoke' is greater when restricted to pneumonia deaths in the community - Community Deaths from Pneumonia.

Maternal residential proximity to major roads in north west England and adverse pregnancy outcomes.

Objective: To investigate the effects of maternal residential proximity to major roads on adverse pregnancy outcomes.

Methods: Major road networks in North West England were linked to the maternal residence of 190,909 births (2004 to 2008). Distance between the residence and the nearest major road was calculated and dichotomized at 200 m.

A comparison of population air pollution exposure estimation techniques with personal exposure estimates in a pregnant cohort.

There is increasing evidence of the harmful effects for mother and fetus of maternal exposure to air pollutants. Most studies use large retrospective birth outcome datasets and make a best estimate of personal exposure (PE) during pregnancy periods. We compared estimates of personal NOx and NO2 exposure of pregnant women in the North West of England with exposure estimates derived using different modelling techniques.

Advanced maternal age and adverse pregnancy outcome: evidence from a large contemporary cohort.

Background: Recent decades have witnessed an increase in mean maternal age at childbirth in most high-resourced countries. Advanced maternal age has been associated with several adverse maternal and perinatal outcomes. Although there are many studies on this topic, data from large contemporary population-based cohorts that controls for demographic variables known to influence perinatal outcomes is limited.

Time trends in the incidence of work-related mental ill-health and musculoskeletal disorders in the UK.

Objectives: To determine UK trends (from 1996 to 2009) in incidence of work-related mental ill-health and musculoskeletal disorders, for all industry as well as for health and social care employees. Second, to investigate whether there may have been a recent shift from a physical to psychological perspective in how patients present their illness by comparing reporting trends for back pain and 'other work stress'.

Methods: Multilevel models were used to investigate changes in incidence of work-related illness, as diagnosed by specialist physicians.

Evaluating interventions aimed at reducing occupational exposure to latex and rubber glove allergens.

Objective: Concerns over occupational exposures to blood-borne viruses resulted in increased protective glove use; consequentially latex allergy became a hazard for some occupational groups. Interventions aimed at managing this problem included substitution measures (eg, non-powdered/non-latex gloves), but such changes may not occur simultaneously across occupational sectors. This study evaluated whether the incidence of occupational dermatoses fell after interventions aiming to reduce exposure to 'latex and rubber glove allergens' ('latex') were introduced, and whether these interventions were more effective for healthcare workers (HCWs), compared with non-HCWs.

Applying optimal model selection in principal stratification for causal inference.

Noncompliance to treatment allocation is a key source of complication for causal inference. Efficacy estimation is likely to be compounded by the presence of noncompliance in both treatment arms of clinical trials where the intention-to-treat estimate provides a biased estimator for the true causal estimate even under homogeneous treatment effects assumption. Principal stratification method has been developed to address such posttreatment complications.

The predictive ability of blood pressure in elderly trial patients.

Objectives: To assess the impact of the blood pressure (BP) profile on cardiovascular risk in the Medical Research Council (UK) elderly trial; investigate whether the effects of hypertensive drugs in reducing event rates are solely a product of systolic pressure reduction.

Methods: Using longitudinal BP data from 4396 hypertensive patients, the general trend over time was estimated using a first-stage multilevel model. We then investigated how BP acted alongside other BP-related covariates in a second-stage 'time-to-event' statistical model, assessing risk for stroke events and coronary heart disease (CHD).

Performance of bias-correction methods for exposure measurement error using repeated measurements with and without missing data.

It is known that measurement error leads to bias in assessing exposure effects, which can however, be corrected if independent replicates are available. For expensive replicates, two-stage (2S) studies that produce data 'missing by design', may be preferred over a single-stage (1S) study, because in the second stage, measurement of replicates is restricted to a sample of first-stage subjects. Motivated by an occupational study on the acute effect of carbon black exposure on respiratory morbidity, we compare the performance of several bias-correction methods for both designs in a simulation study: an instrumental variable method (EVROS IV) based on grouping strategies, which had been recommended especially when measurement error is large, the regression calibration and the simulation extrapolation methods.

Work-related asthma in France: recent trends for the period 2001-2009.

Objective: Knowledge on the time-course (trends) of work-related asthma (WRA) remains sparse. The aim of this study was to describe WRA trends in terms of industrial activities and the main causal agents in France over the period 2001-2009.

Method: Data were collected from the French national network of occupational health surveillance and prevention (Réseau National de Vigilance et de Prévention des Pathologies Professionnelles (RNV3P)).

Increased risk of miscarriage and ectopic pregnancy among women with irritable bowel syndrome.

Background & Aims: Irritable bowel syndrome (IBS) is the most commonly diagnosed gastrointestinal condition and is most prevalent in women of reproductive age. We investigated the effects of IBS on risk for adverse outcomes from pregnancy.

Methods: We conducted a cohort study by using the United Kingdom General Practice Research Database.

Risk of affective disorders following prenatal exposure to severe life events: a Danish population-based cohort study.

Objective: To examine the effect of prenatal exposure to severe life events on risk of affective disorders in the offspring.

Methods: In a cohort of 1.1 million Danish births from May 1978 until December 1997, mothers were considered exposed if one (or more) of their close relatives died or was diagnosed with serious illness up to 6 months before conception or during pregnancy.

Performance of statistical methods for analysing survival data in the presence of non-random compliance.

Noncompliance often complicates estimation of treatment efficacy from randomized trials. Under random noncompliance, per protocol analyses or even simple regression adjustments for noncompliance, could be adequate for causal inference, but special methods are needed when noncompliance is related to risk. For survival data, Robins and Tsiatis introduced the semi-parametric structural Causal Accelerated Life Model (CALM) which allows time-dependent departures from randomized treatment in either arm and relates each observed event time to a potential event time that would have been observed if the control treatment had been given throughout the trial.