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Biomedical subjects

S J Finch

Publications and source records attributed to S J Finch.

25 records · Page 2Linked to original sources
PubMed1991

The implementation of community-based crisis services for people with acute psychiatric illness.

This article describes three recently established community-based crisis services for people with acute psychiatric illness. Data were obtained from local information systems developed in the early phase of service operation. Patterns of service were found to vary among the teams in terms of the frequency of contact with the client, the period of contact with the client and the overall numbers of contacts. Such diversification of services reflects, at least in part, the differences in the service networks within which the new services were Such diversification of services is inevitable and creative, and the evaluation of these services must consider not only the short-term impact of crisis services, but also the impact of the network of care services on longer term outcomes for the client.

Acute Disease↗
PubMed1991

The likelihood ratio test for the two-component normal mixture problem: power and sample size analysis.

We find, through simulation and modeling, an approximation to the alternative distribution of the likelihood ratio test for two-component mixtures in which the components have different means but equal variances. We consider the range of mixing proportions from 0.5 through .95. Our simulation results indicate a dependence of power on the mixing proportion when pi less than .2 and pi greater than .80. Our model results indicated that the alternative distribution is approximately noncentral chi-square, possibly with 2 degrees of freedom. Using this model, we estimate a sample of 40 is needed to have 50% power to detect a difference between means equal to 3.0 for mixing proportions between .2 and .8. The sample size increases to 50 when the mixing proportion is .90 (or .1) and 82 when the mixing proportion is .95 (or .05). This paper contains a complete table of sample sizes needed for 50%, 80%, and 90% power.

Alleles↗
PubMed1988

Simulated percentage points for the null distribution of the likelihood ratio test for a mixture of two normals.

We find the percentage points of the likelihood ratio test of the null hypothesis that a sample of n observations is from a normal distribution with unknown mean and variance against the alternative that the sample is from a mixture of two distinct normal distributions, each with unknown mean and unknown (but equal) variance. The mixing proportion pi is also unknown under the alternative hypothesis. For 2,500 samples of sizes n = 15, 20, 25, 40, 50, 70, 75, 80, 100, 150, 250, 500, and 1,000, we calculated the likelihood ratio statistic, and from these values estimated the percentage points of the null distributions. Our algorithm for the calculation of the maximum likelihood estimates of the unknown parameters included precautions against convergence of the maximization algorithm to a local rather than global maximum. Investigations for convergence to an asymptotic distribution indicated that convergence was very slow and that stability was not apparent for samples as large as 1,000. Comparisons of the percentage points to the commonly assumed chi-squared distribution with 2 degrees of freedom indicated that this assumption is too liberal; i.e., one's P-value is greater than that indicated by chi 2(2). We conclude then that one would need what is usually an unfeasibly large sample size (n greater than 1,000) for the use of large-sample approximations to be justified.

Biometry↗
PubMed1984

A factorial analysis of BDI scores.

Undertook a factorial analysis of the BDI on a sample of 214 male cardiac outpatients. The factor structure yielded three psychologically distinct dimensions interpreted as negative self-attitudes, physiological symptoms and sadness. The sample was divided into depressed and nondepressed subgroups in order to investigate whether the BDI factor structure is dependent on the range of BDI scores selected. While the first two factors from the nondepressed group's scores mimicked those for the full sample, in general the subgroups' factor structures provided no clear interpretation.

Adult↗
PubMedDate not supplied

Serving the urban poor: a study of child welfare preventive services.

This summary, for journal publication, of a study whose full details are being published in book form, brings the welfare field up-to-date on what began as a precedent-setting agency. The Lower East Side Family Union, in New York City, has provided many years of service, and has justifiably drawn national attention from its inception, when prevention was more talked about than funded. The lessons to be drawn from its work and the example it has set grow more timely every year.

Adolescent↗
PubMedDate not supplied

Modes of exit from foster family care and adjustment at time of departure of children with unstable life histories.

In a study of the modes of exit and condition at exit of 585 children who left the care of The Casey Family Program, a program devoted to the care of children who were judged not able to be reunited with their families, the research reveals a number of significant relationships between certain conditions, circumstances, and characteristics of the children previous to admission and their condition upon departure from agency care.

Adolescent↗