277 research outputs found
UK survey of non-medical use of prescription drugs (NMURx) as a valuable source of general population illicit drug use data.
PURPOSE OF STUDY: The aim of the study is to describe the prevalence of illicit drug use in England and Wales using data from the UK Survey of Non-Medical Use of Prescription Drugs (NMURx) programme and to compare against the well-established Crime Survey England and Wales (CSEW). The rationale is that recreational and illicit drug use is common, but the prevalence is difficult to estimate with personal interviewing methods. STUDY DESIGN: We compared two cross-sectional population surveys (NMURx, n=8903 and CSEW, n=20 685) with data regarding self-reported recreational drug use and demographics. NMURx is an online survey using non-probability sampling methodology with preset demographical quotas based on census data. CSEW surveys drug use via computer-assisted self-interviewing as part of a computer-assisted personal-interviewing crime survey. RESULTS: Cannabis was the most frequently used drug regardless of demographics. Prevalence of drug use for specific substances was generally higher for males, younger ages and students. The relationship between income and drug misuse is less clear. Self-reported prevalence of drug use in the NMURx survey is consistently higher than CSEW (absolute difference 1%-3 % across substances and timescales) and persists after stratification for gender, age, student status and household income. CONCLUSIONS: The NMURx survey has a broad reach of participants, and a sampling scheme that achieves external validity, compared with general population demographics. NMURx's online format allows flexibility in items surveyed and in response to emerging trends. The self-reported drug use in the NMURx cohort is comparable, although slightly higher, than the CSEW estimates
Lifetime physical activity and risk of breast cancer
We conducted a case–control study of 394 women with breast cancer and 788 control women (91% response) to investigate the association of lifetime physical activity with mainly menopausal breast cancer risk. After controlling for potential confounders, the odds ratios (95% confidence intervals) for increasing quartiles of lifetime physical activity were 1.00 (referent), 0.91 (0.60–1.37), 0.91 (0.60–1.39), and 1.10 (0.73–1.67), respectively;P, trend = 0.47. We also separately examined physical activity at ages 12–18, 19–34, 35–49 and ≥50 years; no significant trends were observed in any age group. These data do not support a role of physical activity in preventing breast cancer. © 2001 Cancer Research Campaignhttp://www.bjcancer.co
Estimating uncertainty of alcohol-attributable fractions for infectious and chronic diseases
Background: Alcohol is a major risk factor for burden of disease and injuries globally. This paper presents a systematic method to compute the 95% confidence intervals of alcohol-attributable fractions (AAFs) with exposure and risk relations stemming from different sources.Methods: The computation was based on previous work done on modelling drinking prevalence using the gamma distribution and the inherent properties of this distribution. The Monte Carlo approach was applied to derive the variance for each AAF by generating random sets of all the parameters. A large number of random samples were thus created for each AAF to estimate variances. The derivation of the distributions of the different parameters is presented as well as sensitivity analyses which give an estimation of the number of samples required to determine the variance with predetermined precision, and to determine which parameter had the most impact on the variance of the AAFs.Results: The analysis of the five Asian regions showed that 150 000 samples gave a sufficiently accurate estimation of the 95% confidence intervals for each disease. The relative risk functions accounted for most of the variance in the majority of cases.Conclusions: Within reasonable computation time, the method yielded very accurate values for variances of AAFs
Risk and protective factors for falls on stairs in young children: multicentre case–control study
Aim: To investigate risk and protective factors for stair falls in children aged <5 years.
Methods: Multicentre case–control study at hospitals, minor injury units and general practices in and around four UK study centres. Cases were children with medically attended stair fall injuries. Controls were matched on age, sex, calendar time and study centre. A total of 610 cases and 2658 controls participated.
Results: Cases’ most common injuries were bangs on the head (66%), cuts/grazes not requiring stitches (14%) and fractures (12%). Parents of cases were significantly more likely not to have stair gates (adjusted OR (AOR) 2.50, 95% CI 1.90 to 3.29; population attributable fraction (PAF) 21%) or to leave stair gates open (AOR 3.09, 95% CI 2.39 to 4.00; PAF 24%) both compared with having closed stair gates. They were more likely not to have carpeted stairs (AOR 1.52, 95% CI 1.09 to 2.10; PAF 5%) and not to have a landing part-way up their stairs (AOR 1.34, 95% CI 1.08 to 1.65; PAF 18%). They were more likely to consider their stairs unsafe to use (AOR 1.46, 95% CI 1.07 to 1.99; PAF 5%) or to be in need of repair (AOR 1.71, 95% CI 1.16 to 2.50; PAF 5%).
Conclusion: Structural factors including having landings part-way up the stairs and keeping stairs in good repair were associated with reduced stair fall injury risk. Family factors including having stair gates, not leaving gates open and having stair carpets were associated with reduced injury risk. If these associations are causal, addressing these factors in housing policy and routine child health promotion could reduce stair fall injuries
Mortality attributable to excess adiposity in England and Wales in 2003 and 2015: explorations with a spreadsheet implementation of the Comparative Risk Assessment methodology
Our aim was to estimate the burden of fatal disease attributable to excess adiposity in England and Wales in 2003 and 2015 and to explore the sensitivity of the estimates to the assumptions and methods used
Organotypic Culture of Physiologically Functional Adult Mammalian Retinas
BACKGROUND: The adult mammalian retina is an important model in research on the central nervous system. Many experiments require the combined use of genetic manipulation, imaging, and electrophysiological recording, which make it desirable to use an in vitro preparation. Unfortunately, the tissue culture of the adult mammalian retina is difficult, mainly because of the high energy consumption of photoreceptors. METHODS AND FINDINGS: We describe an interphase culture system for adult mammalian retina that allows for the expression of genes delivered to retinal neurons by particle-mediated transfer. The retinas retain their morphology and function for up to six days— long enough for the expression of many genes of interest—so that effects upon responses to light and receptive fields could be measured by patch recording or multielectrode array recording. We show that a variety of genes encoding pre- and post-synaptic marker proteins are localized correctly in ganglion and amacrine cells. CONCLUSIONS: In this system the effects on neuronal function of one or several introduced exogenous genes can be studied within intact neural circuitry of adult mammalian retina. This system is flexible enough to be compatible with genetic manipulation, imaging, cell transfection, pharmacological assay, and electrophysiological recordings
Age at menarche in Canada: results from the National Longitudinal Survey of Children & Youth
<p>Abstract</p> <p>Background</p> <p>Given the downward trend in age at menarche and its implications for the reproductive health and wellbeing of women, little is known about menarcheal age in Canada. Most Canadian studies are only representative of specific populations. The present study, therefore, aims to assess the distribution of age at menarche for Canadian girls and explore its variation across socio-economic and demographic factors.</p> <p>Methods</p> <p>The analysis of the study was based on all female respondents aged 14 to 17 years during Cycle 4 (2000/2001) of the National Longitudinal Survey of Children & Youth (NLSCY). The main outcome was age at menarche assessed as the month and year of the occurrence of the first menstrual cycle. Kaplan Meier was used to estimate the mean and median of age at menarche. Chi-square test was used to assess the differences in early, average and later maturers across the different levels of socio-economic and demographic variables. Bootstrapping was performed to account for the complex sampling design.</p> <p>Results</p> <p>The total number of girls analyzed in this study was 1,403 weighted to represent 601,911 Canadian girls. The estimated mean and median of age at menarche was 12.72 years (standard deviation = 1.05) and 12.67 years, respectively. The proportions of early (< 11.53 years), average (≥11.53 years and ≤13.91 years) and late maturers (> 13.91 years) were 14.6% (95% confidence interval (CI): 11.92-17.35), 68.0% (95% CI: 63.82-72.17) and 17.4% (95% CI: 14.10-20.63), respectively. Variations across the menarcheal groups were statistically significant for the province of residence, household income and family type.</p> <p>Conclusion</p> <p>The findings of the study pave the way for future Canadian research. More studies are warranted to understand menarcheal age in terms of its variation across the provinces, the secular trend over time and its potential predictors.</p
Association of Intrauterine Exposure to Maternal Diabetes and Obesity With Type 2 Diabetes in Youth: The SEARCH Case-Control Study
OBJECTIVE—Limited data exist on the association between in utero exposure to maternal diabetes and obesity and type 2 diabetes in diverse youth. These associations were explored in African-American, Hispanic, and non-Hispanic white youth participating in the SEARCH Case-Control Study
The impact of workplace risk factors on the occurrence of neck and upper limb pain: a general population study
BACKGROUND: Work-related neck and upper limb pain has mainly been studied in specific occupational groups, and little is known about its impact in the general population. The objectives of this study were to estimate the prevalence and population impact of work-related neck and upper limb pain. METHODS: A cross-sectional survey was conducted of 10 000 adults in North Staffordshire, UK, in which there is a common local manual industry. The primary outcome measure was presence or absence of neck and upper limb pain. Participants were asked to give details of up to five recent jobs, and to report exposure to six work activities involving the neck or upper limbs. Psychosocial measures included job control, demand and support. Odds ratios (ORs) and population attributable fractions were calculated for these risk factors. RESULTS: The age-standardized one-month period prevalence of neck and upper limb pain was 44%. There were significant independent associations between neck and upper limb pain and: repeated lifting of heavy objects (OR = 1.4); prolonged bending of neck (OR = 2.0); working with arms at/above shoulder height (OR = 1.3); little job control (OR = 1.6); and little supervisor support (OR = 1.3). The population attributable fractions were 0.24 (24%) for exposure to work activities and 0.12 (12%) for exposure to psychosocial factors. CONCLUSION: Neck and upper limb pain is associated with both physical and psychosocial factors in the work environment. Inferences of cause-and-effect from cross-sectional studies must be made with caution; nonetheless, our findings suggest that modification of the work environment might prevent up to one in three of cases of neck and upper limb pain in the general population, depending on current exposures to occupational risk
Occupational cancer in Britain: Statistical methodology
An approach using the attributable fraction (AF) has been developed to estimate the current burden of occupational cancer in Britain. The AF combines the relative risk (RR) associated with exposure with the proportion exposed. For each cancer–exposure pairing, the RR is selected from key epidemiological literature such as an industry, or population-based study, meta-analysis or review. The CARcinogen EXposure (CAREX) database provides point estimates for the number of workers exposed to a range of carcinogens; alternative sources are national surveys such as the Labour Force Survey and Census of Employment. The number of workers exposed are split between high and low exposure levels matched to appropriate RRs from the literature. The relevant period for cancer development during which exposure occurred is defined as the risk exposure period (REP). Estimation of the numbers ever exposed over the REP takes into account the changes in the number of people employed in primary and manufacturing industry and service sectors in Britain where appropriate, and adjustment is made for staff turnover over the period and for life expectancy. National estimates of the population ever of working age during the REP are used for the proportion denominator. Strategies have been developed to combine exposure AFs correctly while avoiding double counting and minimising bias. The AFs are applied to national cancer deaths and registrations to obtain occupation-attributable cancer numbers. The methods are adaptable for other diseases and other geographies, and are also adaptable to more sophisticated modelling if better exposure and dose–response data are available
- …