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Biomedical subjects

S C Newman

Publications and source records attributed to S C Newman.

At least 55 records · Page 3Linked to original sources
PubMed1989

Estimating the morbidity risk of illness from survey data.

A method is proposed for using survey data to estimate lower and upper bounds for the lifetime risk of an illness (morbidity risk). The mathematical model used, which is based on a three-state Markov process, assumes that the illness is irreversible, but allows differential mortality. The data required include information on age at onset collected from prevalent cases, and an estimate of the magnitude of differential mortality, which ordinarily must come from published research. The method is illustrated using data from a community survey of psychiatric illness conducted in Edmonton, Alberta, Canada.

Adolescent↗
PubMed1989

Design of two-phase prevalence surveys of rare disorders.

Two-phase medical surveys, in which a large sample is assessed with an inexpensive screening instrument and a subsample is selected for a more thorough diagnostic evaluation, appear to have great merit in the epidemiologic study of certain rare disorders. We present the optimal design of two-phase surveys when resources are fixed and when 100% of those screened positive in the first phase must be included in the second-phase evaluation. We go on to examine the relative efficiency of this two-phase design compared to a single-phase design in which all resources are used in a survey that employs the diagnostic evaluation. Given information on the accuracy of the screen and the prevalence of the disorder, the utility of the two-phase design depends on the relative cost of the screening to the diagnostic assessments.

Biometry↗
PubMed1988

A Markov process interpretation of Sullivan's index of morbidity and mortality.

Using intuitive arguments Sullivan described a method of combining morbidity data and certain ordinary life table to produce an estimate of illness-free life expectancy. In this paper we use an increment-decrement life table specified in terms of a Markov process to characterize illness-free life expectancy. We show that when the illness under consideration satisfies certain properties Sullivan's approach provides a convenient method of approximation. We illustrate theoretical results with hospital morbidity data on Canadian males for 1981.

Actuarial Analysis↗
PubMed1988

Odds ratio estimation in a steady-state population.

A three-state Markov process is used to model a steady-state population. The classical P = ID equation is derived, as well as a number of identities originally reported by Miettinen (Am J Epidemiol 1976; 103: 226-235) and Freeman and Hutchison (Am J Epidemiol 1980; 112: 707-723. Ibid. 1986; 124: 134-149). Using theoretical and empirical methods it is demonstrated that the odds ratio derived from a prevalence-prevalence case-control study conducted in a steady-state population will generally be a biased estimate of the incidence density ratio. However the bias will not likely be of practical importance unless the incidence density ratio is at least 10 or more.

Actuarial Analysis↗
PubMed1988

On the age-period-cohort analysis of suicide rates.

Cohort analysis has become a popular method of examining national trends in suicide rates. Most of the studies investigating this phenomenon have reported a cohort effect to be present. Using a graphical approach, this paper places cohort analysis within the broader framework of age-period-cohort analysis. It is shown that published reports may have failed to identify cohort effects due to using only portions of the available data. With a simple mathematical model it is demonstrated that what appears to be a cohort effect may be a period effect, and conversely. It is recommended that suicide rates be examined for both period and cohort effects before conclusions are drawn regarding trends, and that the complete data set be used for this purpose.

Adolescent↗
PubMed1988

Suicide trends in Canada, 1956-1981.

Using official suicide statistics, this study examined suicide rates in Canada over a 25-year span (1956 to 1981) as a function of age, gender, and geographical region. The analysis revealed that, for both sexes, the risk of suicide among the 15-24 year-olds increased at a faster rate than in any other age group. Male and female age-standardized suicide rates demonstrated an overall increase between 1956 and 1981. The trend for males was one of continuous increase, whereas female rates reached a maximum in 1976 and then decreased. Regional differences in suicide rates were also apparent. Although not strictly observed, a trend toward increasing risk of suicide in males as one proceeds westward across Canada was found. For females, a pattern of increasing suicide with more westerly location was also found, except that Ontario and the Prairie Provinces were in reverse order. Several possible explanations for these findings are presented.

Adolescent↗
PubMed1988

Design and field methods of the Edmonton survey of psychiatric disorders.

This paper describes aspects of the study design and field methods used in a survey of psychiatric disorders carried out in Edmonton, Alberta, Canada. Between January 1983 and May 1986, information was gathered on 3,258 community residents using the Diagnostic Interview Schedule and the General Health Questionnaire - 30 item version. The survey had a response rate of 71.6%. The nature of the sampling strategy used, features of the study instruments chosen, the selection and training of interviewers, and the approach to data analysis are briefly described.

Alberta↗
PubMed1988

Lifetime prevalence of psychiatric disorders in Edmonton.

3,258 randomly selected adult household residents of Edmonton were interviewed by trained lay interviewers using the Diagnostic Interview Schedule (DIS). Lifetime prevalence for 16 DIS/DSM III diagnoses are given. Overall 33.8% of the population had one or more diagnoses and, excluding substance use disorders, one fifth of the population had a diagnosis. The most common lifetime diagnosis was alcohol abuse/dependence, followed by phobia and major depressive episode. Men were more likely to have had substance use disorders and antisocial personality disorder and women more likely to have had major depressive episode, dysthymia, agoraphobia and simple phobia. Those who were married had generally lower lifetime prevalences. Those over age 65 had the lowest prevalence of any age groups.

Adolescent↗
PubMed1988

Period prevalence of psychiatric disorders in Edmonton.

3,258 randomly selected adult household residents of Edmonton were interviewed by trained lay interviewers using the Diagnostic Interview Schedule (DIS). Six-month prevalence figures for DIS/DSM III diagnoses are given, and selected figures for the one-month and one-year prevalence, and the one-year symptom-free rates. The six-month prevalence for any diagnosis is 17.1%, comparable to findings from other population studies using DSM III derived diagnoses, but lower than studies using the PSE. The prevalence rates for most disorders tended to be lowest in the elderly, but this was not as marked as the drop in lifetime prevalence. Men had higher prevalence for substance use disorders than women, but women had higher rates for affective disorders and anxiety/somatoform disorders. Prevalences for all disorders were either similar or lower in those who were married or living as though married, than in those who were not cohabiting. One-year symptom-free rates were highest for those with substance use disorders and lowest for those with anxiety/somatoform disorders - largely due to the persistence of phobias.

Adolescent↗
PubMed1988

Age of onset of psychiatric disorders.

Age of onset of psychiatric disorders was determined from a random sample of 3,258 household residents who were administered the DIS by trained lay interviewers. Onset was determined by the subject's recall of the age of the first symptom in those who met lifetime criteria for a diagnosis (DSM III without exclusions). The peak age of risk for most disorders was from the teens to 30 years, however a number of schizophrenics showed first symptoms before age 10. Few cases of any disorder had an onset in old age. The ages of onset are generally lower than those usually given from series of treated or hospitalized cases.

Adolescent↗
PubMed1988

Morbidity risk of psychiatric disorders.

Lifetime morbidity risks and percentiles of the age of onset distribution are given for a series of psychiatric disorders based on data collected as part of a community survey in Edmonton, Canada. The Diagnostic Interview Schedule (DIS) was used to gather information from 3,258 community residents between January 1983 and May 1986. Using a recently developed method of estimating morbidity risks from survey data, the lifetime morbidity risks for depression (male 16.4%, female 22.3%), schizophrenia (male 1.2%, female, 1.0%), and other disorders were calculated. These results are consistent with previously published reports.

Adolescent↗
PubMed1988

Prevalence of psychiatric disorders in the elderly in Edmonton.

Prevalence rates (six month and lifetime) for a random sample (N = 358) of the elderly living at home, are compared to the rates for a sample (N = 3,258) of the whole adult population of Edmonton and found to be generally lower in the elderly, except for cognitive impairment. These household resident results are similar to those reported from the United States using similar methods. A sample (N = 199) of the elderly living in institutions was found to have a very high overall prevalence of illness, mostly consisting of cognitive impairment (69%). It is estimated that over half of all cases of cognitive impairment live in institutions. This has considerable implications for the programs in institutions for the elderly, and also the need for institutions in the future, unless alternate means of care can be developed.

Aged↗
PubMed1988

Suicide attempts and psychiatric disorders in Edmonton.

The relationship between lifetime histories of attempting suicide, psychiatric disorders and other social problems was assessed by examining data from a random sample of 3,258 household residents of Edmonton who were administered the Diagnostic Interview Schedule (DIS) and the Goldberg General Health Questionnaire (GHQ) by trained lay interviewers. While the overall lifetime rate for suicide attempt was 3.6%, of particular interest was the finding that a lifetime history of a psychiatric disorder was 2.6 times more frequent in those who had made a suicide attempt than in those who had not. Alcoholism, major depressive episode and antisocial personality disorder carried the highest lifetime prevalence rates for male attempters, whereas major depressive episode, alcoholism and phobic disorder were the most common disorders in female attempters. Having thoughts and feelings about wanting to die and committing suicide were strongly associated with having made a suicide attempt in both males and females. GHQ results indicated that in comparison to nonattempters those who attempted suicide were most likely to have high current symptom levels.

Adolescent↗
PubMed1988

Psychiatric disorders and unemployment in Edmonton.

Significant relationships were found between unemployment in the last five years and a lifetime history of psychiatric disorder. These results are based on interviews of 3,258 randomly selected non-institutionalized adult residents of Edmonton, conducted by trained lay interviewers using the Diagnostic Interview Schedule (DIS) and the Goldberg General Health Questionnaire (GHQ, 30-item). Having a lifetime history of a psychiatric disorder increased the odds of being unemployed 2.8 times. Disorders carrying the highest risk for unemployment were anorexia, antisocial personality disorder, schizophrenia, and substance use disorders. GHQ results indicated that those experiencing periods of unemployment are also likely to have higher current symptom and stress levels than those who are employed.

Adolescent↗
PubMed1988

Month of birth and schizophrenia in Alberta.

Numerous studies have demonstrated that a greater than expected number of schizophrenics are born during the winter months. The present investigation examined this phenomenon in Alberta. The study population consisted of 1,101 schizophrenic patients admitted to either of the two provincial mental hospitals during 1976-1983 and who were born in Canada. After controlling for year of birth, no seasonality effect was found.

Adolescent↗
PubMed1988

Occupational injuries due to violence.

Each year in the United States, an estimated 800 to 1,400 people are murdered at work, and an unknown number of nonfatal injuries due to workplace violence occur. Based on Ohio's workers' compensation claims from 1983 through 1985, police officers, gasoline service station employees, employees of the real estate industry, and hotel/motel employees were found to be at the highest risk for occupational violent crime (OVC) injury and death. Grocery store employees, specifically those working in convenience food stores, and employees of the real estate industry had the most reported rapes. Four previously unidentified industries at increased risk of employee victimization were described. Identification of industries and occupations at high risk for crime victimization provides the opportunity to focus preventive strategies to promote employee safety and security in the workplace.

Adolescent↗
PubMed1987

Sexual assault of women at work.

Review of twenty-one workers' compensation claims for sexual assault filed in Ohio for the period 1983-1985 revealed that five (62%) of the rapes by unknown assailants after dark occurred in convenience food stores. The rape rate was 7.0 per 100,000 females employed in convenience food stores per year compared with a rate of 0.3 per 100,000 females employed in Ohio (IRR = 25.6, CI 8.1-132.3). In addition, three rapes occurred among motel maids and housekeepers, and three among residential property managers. Police reports for sexual assault in Memphis, Tennessee for 1985 corroborated the observation of a potential increased risk of rape in female employees of convenience food stores. Strategies for the provision of personal security against assault in the workplace have not previously been addressed in the public health literature. A review of workers' compensation claims has identified an area for which strategies to prevent workplace injuries should be developed.

Adolescent↗