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Biomedical subjects

G Lewis

Publications and source records attributed to G Lewis.

At least 307 records · Page 17Linked to original sources

Effect of sterilization method on properties of Palacos R acrylic bone cement.

The focus of this work was a delineation of the effect of the method of sterilization (gamma-irradiation versus exposure to ethylene oxide (EtO) gas) of the powder constituents of Palacos R bone cement on the molecular weight, quasi-static tensile and compressive properties and fatigue performance of the fully polymerized material. It was found that the quasi-static properties are not noticeably affected. However, when the powder constituents were gamma-sterilized, both the molecular weight and the fatigue performance of the cement are significantly lower compared to when the constituents are EtO-sterilized. Explanations are offered for these findings, and recommendations are submitted regarding the preferred method of sterilization of bone cement and reporting of studies in which different formulations of cement are compared.

Bone Cements↗

Substance misuse and psychiatric comorbidity: an overview of the OPCS National Psychiatric Morbidity Survey.

There have been a number of national surveys of psychiatric morbidity which have included questions on drugs, alcohol and tobacco. These surveys have helped delineate the overlap between substance use and dependence and other psychological morbidity. There is a strong association reported between high substance consumption and other measures of psychological problems. This article provides an overview of a national household survey, a survey of institutional residents with psychiatric disorders and a national survey of a homeless population. All three surveys used comprehensive and complex sampling strategies and lay interviewers to conduct structured diagnostic interviews. The household survey included over 10,000 households, the institutional survey interviewed 755 individuals and the homeless survey of hostels, night-shelters, day centres and private-sector leased accommodation interviewed 1,061 individuals. This overview looks at patterns of nicotine, alcohol and other drug use in the different samples and examines interactions with other psychiatric morbidity. The survey reports that substance-related disorders are some of the commonest disorders in the community, with 5% of the household sample alcohol dependent, 7% alcohol dependent in the institutional sample and over 21% in the homeless sample recorded as alcohol dependent. Tobacco, alcohol and other drug use and dependence were dramatically higher in the homeless sample than in either of the other two samples. Substance use was significantly associated with higher rates of psychological morbidity as measured by the Clinical Interview Schedule Revised. Future service planning needs to take account of the striking disparity of prevalence of psychiatric disorders in different subsections of the population.

Alcohol Drinking↗

Tensile properties of human tendo Achillis: effect of donor age and strain rate.

Two sets of tensile tests were conducted on tendo Achillis taken from 16 embalmed cadavers (donor ages, 36 to 100 years). From the stress, sigma-versus-strain, epsilon results, values of the following properties were obtained: linear stiffness, ST (which is defined as the slope of the linear zone of the post-toe region of the load-versus-extension plot), ultimate tensile strength [UTS], the strain at the UTS point (herein called the ultimate tensile strain) [epsilon max], and the tangent modulus of elasticity, [ET] (which is the slope of the linear zone of the post-toe region of the sigma-epsilon curve). In the first set of tests, the loading rate was 10%/sec. The results are thus: linear stiffness: 685 +/- 262 N/mm.; UTS = 59 +/- 18 MPa; epsilon max = 22 +/- 7%; and ET = 375 +/- 102 MPa. It was found that donor age exerts an insignificant effect on linear stiffness, a marked effect on UTS, an insignificant effect on epsilon max, and a moderate effect on ET (Student's t-test; p < 0.05). In the second set of tests, the test tendons were taken from the cadavers of "middle-aged" donors (52 to 67 years), and the strain rate was 100%/sec. By combining the results of the first and second sets of tests for a subset of this group (i.e., those with matched counterparts), it was found that strain rate has a statistically significant effect on ST and ET but not on UTS and epsilon max (paired Student's t-test; p < 0.05). Based on all results and findings, donor age is suggested as one of the considerations when selecting tendo Achillis to be used as allografts for the repair of severely damaged or ruptured tendo Achillis or anterior cruciate ligament.

Achilles Tendon↗

Epidemiology in community psychiatric research: common uses and methodological issues.

OBJECTIVE: Epidemiological principles underpin much medical research particularly that concerned with the planning and evaluation of health services, including research in community and social psychiatry. The aim of this paper is to review some of the common uses of epidemiology in community psychiatric research and to discuss some methodological issues that arise frequently in epidemiological research in community settings. METHODS: This is a review of the relevant literature and of the work currently in progress in the department of psychological medicine of the university of Wales College of Medicine. RESULTS: Among the many uses of epidemiology in health care, four are especially relevant in community psychiatric settings: the assessment of the mental health needs of the population (four approaches are described: the collection of routine data, surveys of existing patients, surveys of the general population and statistical modelling), the identification of risk factors of disease, the contribution to prevention and the assessment of the clinical effectiveness of health care interventions. The most important methodological issues include causal inference which in epidemiology takes the form of explaining the association between an exposure and disease (chance, bias, confounding, reverse causality and causality), the issue of confounding and how to adjust for it and issues arising in the context of specific study designs. CONCLUSION: Epidemiology has become a set of methods used to investigate a wide range of clinical questions. Population based research is an essential part of clinical research but epidemiological knowledge is also needed by clinicians in order to critically appraise and interpret the scientific literature.

Bias↗

The National Psychiatric Morbidity Surveys of Great Britain--strategy and methods.

This paper describes the rationale and methodology of the first National Psychiatric Morbidity Surveys to be carried out in Great Britain. The objectives of the surveys were to estimate the prevalence of psychiatric morbidity among adults aged 16-64 living in Great Britain; to identify the nature and extent of social disabilities associated with psychiatric morbidity; to describe the use of health and social services by people with psychiatric morbidity and to investigate the association between mental illness and potential environmental risk factors in a household sample. Four separate surveys were carried out in order to meet the objectives; a private household sample (n = 10,108), a sample of institutions caring for the mentally ill (n = 1191), a sample of homeless people (n = 1166), and a supplementary sample of patients with psychosis living in private households (n = 350). A two-stage assessment procedure was used, in which all subjects were given the Revised Clinical Interview Schedule (CIS-R) administered by lay interviewers to assess neurotic symptoms and disorders and a psychosis screen, including the Psychosis Screening Questionnaire. Those who were positive on the psychosis screen were then interviewed by psychiatrists using the SCAN (incorporating the tenth edition of the Present State Examination). Large scale national surveys such as this augment the inadequate data on psychiatric morbidity that are routinely available and are, therefore, an important source of information upon which to base policy and generate aetiological hypotheses. These surveys provide a possible model for similar surveys in other countries.

Adolescent↗

The National Psychiatric Morbidity Surveys of Great Britain--initial findings from the household survey.

This paper describes the Household Survey from the National Survey of Psychiatric Morbidity. This covered a sample drawn at random from the population of Britain, with the exception of the Highlands and Islands of Scotland. The Postcode Address File was used as the sampling frame. Nearly 13,000 adults aged 16-65 were selected for interview, of which 10,108 (79.4%) were successfully interviewed. Eight percent could not be contacted and 13% refused interview. Psychiatric assessment was carried out by lay interviewers using the CIS-R. Subjects were also screened for psychosis, and screen-positive individuals were examined by psychiatrists using SCAN. Sixteen per cent of subjects scored above the standard cut-off of 12 on the CIS-R. The overall one-week prevalence of neurotic disorder was 12.3% in males and 19.5% in females. Unmarried and post-marital groups had high rates of disorder, as did single parents and people living on their own. Respondents in Social Class I had notably lower rates of neurotic disorder than the remainder of the sample. Unemployment was strongly associated with disorder. Subjects living in urban areas had a higher overall prevalence, but there was no significant variation by region. Black respondents had higher rates of disorders that were entirely explained by their age, family type, and social class. Individual neurotic disorders were all significantly commoner in women, with the exception of panic disorder. The one-year prevalence of functional psychoses was four per 1000, with no sex difference. Alcohol and drug dependence was considerably more prevalent in men. For the first time, the survey provides data on the prevalence and correlates of psychiatric disorder on a nationwide sample that can be used to inform equitable and effective national psychiatric services.

Adolescent↗

Substance misuse and psychiatric comorbidity: an overview of the OPCS National Psychiatric Morbidity Survey.

There have been a number of national surveys of psychiatric morbidity, which have included questions on drugs, alcohol, and tobacco. These surveys have helped delineate the overlap between substance use and dependence and other psychological morbidity. There is a strong association reported between high substance consumption and other measures of psychological problems. This article provides an overview of a national household survey, a survey of institutional residents with psychiatric disorders, and a national survey of a homeless population. All three surveys used comprehensive and complex sampling strategies and lay interviewers to conduct structured diagnostic interviews. The household survey included over 10,000 households, the institutional survey interviewed 755 individuals, and the homeless survey of hostels, night shelters, day centres, and private sector leased accommodation interviewed 1,061 individuals. This overview looks at patterns of nicotine, alcohol, and other drug use in the different samples and examines interactions with other psychiatric morbidity. The survey reports that substance-related disorders are some of the commonest disorders in the community, with 5% of the household sample alcohol dependent, 7% alcohol dependent in the institutional sample and over 21% in the homeless sample recorded as alcohol dependent. Tobacco, alcohol and other drug use and dependence were dramatically higher in the homeless sample than in either of the other two samples. Substance use was significantly associated with higher rates of psychological morbidity as measured by the Clinical Interview Schedule Revised. Future service planning needs to take account of the striking disparity of prevalence of psychiatric disorders in different subsections of the population.

Alcoholism↗

Nicotine, alcohol and drug dependence, and psychiatric comorbidity--results of a national household survey.

There is a well-recognized relationship between substance use disorders and other psychiatric disorders. This relationship has been well documented in a range of population-based studies. This study aims to report on consumption patterns of and dependence on nicotine, alcohol, and non-prescribed drugs and to report on the levels of psychiatric morbidity in these groups. A national household study of psychiatric morbidity was conducted in England and Wales. Psychiatric assessment was based on the Clinical Interview Schedule-Revised (CIS-R). Measures of nicotine, alcohol and drug use and dependence were obtained. This paper compares the levels of psychiatric morbidity in the non-dependent and the nicotine-, alcohol- and drug-dependent cases. Twelve per cent of the non-dependent population were assessed as having any psychiatric disorder compared with 22% of the nicotine-dependent, 30% of the alcohol-dependent, and 45% of the drug-dependent population. There is a clear relationship between dependence on nicotine, alcohol, and drugs and other psychiatric morbidity.

Adolescent↗

Clarifying the relationship between unexplained chronic fatigue and psychiatric morbidity: results from a community survey in Great Britain.

The study examined the associations between several sociodemographic and psychosocial variables and unexplained chronic fatigue in the community before and after adjustment for psychiatric morbidity and determined the prevalence of fatigue and rate of disability resulting from fatigue in the general population. The study is a secondary analysis of 1993 data from a household survey of psychiatric morbidity conducted by the Office for Population Censuses and Surveys in Great Britain. The survey included 12,730 subjects age 16-64 years. Unexplained chronic fatigue was used as the dependent variable in a logistic regression analysis, with various sociodemographic and psychosocial variables and psychiatric morbidity as the independent variables. Psychiatric morbidity was assessed by using the Revised Clinical Interview Schedule. Fatigue was measured by using the fatigue section of the Revised Clinical Interview Schedule. A total of 10,108 subjects agreed to cooperate (79.4% participation rate). The prevalence of unexplained chronic fatigue was 9%. Subjects with psychiatric morbidity had higher rates of fatigue. Adjustment for psychiatric morbidity had a minor effect on the associations between sociodemographic factors and chronic fatigue. After adjustment, older subjects, women, and couples with children had higher rates of fatigue. Single subjects, widowed subjects, adults living with parents, and economically inactive subjects had lower rates of fatigue. Fatigue was associated with considerable disability, but the association between fatigue and psychiatric morbidity explained most of this disability. Unexplained chronic fatigue is a common condition, strongly associated with psychiatric morbidity. The close relationship between fatigue and psychiatric morbidity should not obscure the possibility of differences as well as similarities in their aetiologies.

Adolescent↗

The influence of age and sex on the prevalence of depressive conditions: report from the National Survey of Psychiatric Morbidity.

Women are consistently reported to have a greater prevalence of depressive disorders than men. The reason for this is unclear, and is as likely to be social as biological. There is some evidence that the excess of depression is greater during women's reproductive lives. Data from the National Survey of Psychiatric Morbidity were used to test the hypothesis that the excess disappeared in the post-menopausal years and that obvious social explanations for this were inadequate. Subjects (n = 9792) from a random sample of the British population provided data for the analysis. Lay interviewers using the CIS-R carried out psychiatric assessment. Subjects with ICD-10 depressive episode or mixed anxiety/depression were compared with the remainder. Social variables that were likely to contribute to a post-menopausal decline in depressive disorders were controlled in logistic regression analyses. There was a clear reversal of the sex difference in prevalence of depression in those over age 55. This could not be explained in terms of differential effects of marital status, childcare, or employment status. This large and representative survey adds considerably to the increasingly held view that the sex difference in prevalence of depression is less apparent in later middle age. This may be linked to the menopause, and our attempts to explain it in terms of obvious conditions among social variables were not successful. More specific studies are required to clarify the finding.

Adolescent↗

Socio-economic status, standard of living, and neurotic disorder.

Evidence on the association between socio-economic status and the prevalence of neurotic disorder is contradictory. We studied the association between three elements of socio-economic status and the prevalence of neurotic psychiatric disorder in a representative sample of adults aged 16-64 living in private households in the UK. A cross-sectional survey of 10,108 adults aged 16-65 resident in private households in the UK was selected by a multi-stage, clustered, random-sampling design. Neurotic disorders were defined using a standardised interview, the revised clinical interview schedule (CIS-R). Data for 9570 people were available for this study. We used housing tenure and access to cars as measures of standard of living; both were associated with the prevalence of neurotic disorder even after adjustment for other socio-economic and demographic variables, including the Registrar General's Social Class and educational attainment. Those people with no access to a car had an odds ratio for neurotic disorder of 1.4 (95% CI 1.1-1.7), compared with those who had access to two or more cars. People who rented their homes were also at increased risk (1.3 [1.1-1.5]). We estimated that about 10% of the neurotic disorder in the UK could be attributed to the increased prevalence of those without cars who rented their homes. There was a complex interaction between the Registrar General's Social Class and sex, and there was no independent association with educational attainment. There is an independent association between low standard of living and the prevalence of neurotic psychiatric disorder. The UK has experienced one of the largest increases in income inequality within western market economies over the past 20 years, and this inequality may have had adverse consequences for the mental health of the population.

Adolescent↗

Neurotic disorders and the receipt of psychiatric treatment.

Access to psychiatric treatment by people with neurotic disorders in the general population is likely to be affected both by the severity of disorder and by sociodemographic differences. In the household component of the National Surveys of Psychiatric Morbidity >10,000 subjects in Great Britain with psychiatric symptoms were interviewed using the CIS-R. They were also asked about difficulties experienced in performing seven types of everyday activity. All subjects classed as having an ICD-10 disorder were questioned about their experience of treatment with antidepressants, hypnotics, and counselling or psychotherapy. Less than 14% of people with current neurotic disorders were receiving treatment for them. Within the previous year, only a third had made contact with their primary care physician for their mental problem: of these <30% were receiving treatment. Overall, 9% of people with disorders were given medication and 8% counselling or psychotherapy. A diagnosis of depressive episode was that most associated with antidepressant medication. Treatment access was affected by employment status, marital status, and age, but the major determinant was symptom severity. Neither sex nor social class influenced which people received treatment. People with psychiatric disorders seldom receive treatment, even when they have consulted their primary care physician about them. In many cases, this must represent unmet needs with a strong claim on health resources. There are also inequalities in the receipt of treatment, although the major influence is the severity of disorder.

Adolescent↗

Unequal access and unmet need: neurotic disorders and the use of primary care services.

In this paper we use data from the National Survey of Psychiatric Morbidity to examine how many people with neurotic disorders receive professional evaluation, and how this is affected by clinical and sociodemographic differences. We hypothesized that psychiatric symptoms and attendant dysfunctions would both have an effect on contacting, and that key demographic variables would not. The household component of the British National Surveys of Psychiatric Morbidity was based on a random sample of >10,000 subjects. Lay interviewers using the CIS-R established psychiatric symptoms and ICD-10 diagnosis. Social dysfunction was tapped by asking about difficulties in performing seven types of everyday activity. We examined symptom score, ADL deficit score, and demographic variables in relation to contact with primary care physicians for psychiatric symptoms. The major determinant of contacting a primary care physician was severity, mainly due to the level of psychiatric symptoms, but with an independent contribution from social dysfunction. There were also significant contributions from sex, marital status, age, employment status, and whether the subject had a physical condition as well. The major influence on whether people seek the help of their family doctors for mental health problems is the severity of disorder. Although there are some social inequalities in access to family doctors, these are less important. The most salient finding from our study is that even people suffering from high levels of psychiatric symptoms very often do not have contact with professionals who might help them.

Adolescent↗

The reluctance to seek treatment for neurotic disorders.

In previous papers from the National Survey of Psychiatric Morbidity in Great Britain, we have demonstrated that people with neurotic disorders rarely present their symptoms to primary care physicians and when they do, are quite likely not to be given treatment. In this paper, we examined survey respondents' reports of specific instances of reluctance to seek help in relation to sociodemographic, socio-economic and clinical attributes of our subjects. All people in the National Household Survey assessed as having a neurotic disorder were asked if at any time in the previous year they had avoided seeking appropriate treatment. Clinical measures included diagnosis, symptom severity, and deficits in carrying out tasks of daily living. Of nearly 1400 respondents, a quarter said they had not been to see a doctor at some time in the past year when they or their family felt they should have. The major determinant of this reluctance was symptom severity: more severe cases were more likely to report an episode of reluctance. Reasons included those related to ignorance of neurotic disorders and the effectiveness of treatment and to stigma. The attitudes detected in our subjects with neurotic disorder help to explain why people do not always seek effective help for their mental disorders, and are indicators of a worrying public education gap that will be hard to bridge.

Adolescent↗

Promoting awareness and practice of testicular self-examination.

AIM: To evaluate the efficacy of a health promotion initiative on men's knowledge of testicular cancer and self-examination rates. METHOD: A quasi-experimental, pre- and post-test questionnaire study of men at 14 workplace and leisure sites across two primary care trusts was undertaken: ten experimental sites received the intervention and four acted as a control. Men at all 14 sites were given a pre- and post-test questionnaire. RESULTS: Of the 835 pre-test and 835 post-test questionnaires distributed, 518 (62.0 per cent) and 356 (42.6 per cent) were respectively returned for evaluation. In the intervention group, the median total knowledge score increased from three points (interquartile range: 2,4) at baseline to four points (interquartile range: 2,4) at post-test. However, no statistically significant change was observed in the control group. Post-intervention, the percentage of test participants examining their testicles regularly increased from 58.4 per cent to 68.3 per cent, while levels among control peers did not significantly alter. CONCLUSION: This evaluation highlights the potential of using a low-cost initiative which targets innovative venues to improve men's knowledge of testicular cancer and rates of self-examination. Longer-term follow-up may be required to determine whether such increases are sustained.

Adolescent↗