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Biomedical subjects

S B Green

Publications and source records attributed to S B Green.

At least 73 records · Page 4Linked to original sources
PubMed1981

Prognostic variables in mycosis fungoides.

The prognostic importance of various factors was analyzed for 347 patients registered by the Mycosis Fungoides Cooperative Group (MFCG). Extent of skin involvement at the time of registration and number of sites of clinically enlarged lymph nodes were clearly the most important prognostic variables, and were combined into a single variable, TN stage, for adjusted analyses of other factors. Sex, history of tonsillectomy, immunoglobulin E, and telangiectasia did not significantly affect survival. The effects of race and allergic history were questionable and need further study. Age, pruritus, burning, alopecia, ulcers, and erosion were important when studied alone, but their effects were no longer statistically significant after adjustment for TN stage. Chills and malaise, the latter a symptom of debility, retained prognostic significance after such adjustment. This analysis demonstrates the importance of considering the joint effects of multiple prognostic factors rather than analyzing them one at a time.

Adult↗
PubMed1981

Efficacy of intratumorally administered mycobacterial cell walls in the treatment of cattle with ocular carcinoma.

Individual Hereford cows with naturally occurring ocular squamous cell carcinoma were treated by intralesional injections of mycobacterial cell walls in an oil-in-water emulsion. Six of 23 treated animals were alive (5 free of tumor and 1 with arrested disease) at a minimum of 2.5 years after treatment, as compared to 1 of 18 controls. A necropsy, lymph node metastases were found in most animals with progressive disease. The disease progressed to an advanced stage (which required death of the animals) at a faster rate for control animals than for treated animals.

Animals↗
PubMed1980

Randomized comparisons of radiotherapy and nitrosoureas for the treatment of malignant glioma after surgery.

Within three weeks of definitive surgical intervention, 467 patients with histologically proved malignant glioma were randomized to receive one of four treatment regimens: semustine (MeCCNU), radiotherapy, carmustine (BCNU) plus radiotherapy, or semustine plus radiotherapy. We analyzed the data for the total randomized population and for the 358 patients in whom the initial protocol specifications were met (the valid study group). Observed toxicity included acceptable skin reactions secondary to radiotherapy and reversible leukopenia and thrombocytopenia due to chemotherapy. Radiotherapy used alone or in combination with a nitrosourea significantly improved survival in comparison with semustine alone. The group receiving carmustine plus radiotherapy had the best survival, but the difference in survival between the groups receiving carmustine plus radiotherapy and semustine plus radiotherapy was not statistically significant. The combination of carmustine plus radiotherapy produced a modest benefit in long-term (18-month) survival as compared with radiotherapy alone, although the difference between survival curves was not significiant at the 0.05 level. This study suggests that it is best to use radiotherapy in the post-surgical treatment of malignant glioma and to continue the search for an effective chemotherapeutic regimen to use in addition to radiotherapy.

Aged↗
PubMed1980

Overadjustment in case-control studies.

In analyzing data from case-control studies to identify association between an exposure variable and disease status, other variables may be considered as potential confounding variables. Even when a variable has no causal association with disease (we assume that in the underlying population it is not related to disease conditional on the exposure variable) and is not a source of selection bias, apparent confounding may occur by chance. Adjusting on such a variable increases variability in the estimate of relative risk. Furthermore, an approach that selects from such variables those which most decrease the relative risk leads to bias in the risk estimate. These two effects lead to reduced statistical significance of the relative risk estimate and can lead to declaring detectable associations as insignificant. Theoretical approximations for quantitating these effects are derived and the adequacy of these approximation is confirmed by simulation. These results demonstrate the danger of overadjustment.

Epidemiologic Methods↗
PubMed1980

The choice of treatment for cancer patients based on covariate information.

This paper discusses the analysis of data from clinical trials in an effort to determine whether comparisons of treatment in various subsets of patients yield sufficiently different results to justify the idea that there may be an optimal treatment for each patient based on his individual characteristics. This approach belongs more to the field of exploratory data analysis than to classical hypothesis testing. The idea of treatment-covariate interactions is discussed and methods for detecting them are presented using parametric survival models incorporating covariate information. A detailed example using data from a clinical trial of estrogen treatment for prostatic cancer is presented. In this study significant treatment-covariate interactions were detected. Subsidiary analyses indicated that young patients with high grade tumors should have been treated with estrogens, but that older patients with low grade tumors were harmed by estrogen treatment.

Aged↗
PubMed1979

Measurement of assertive behavior: construct and predictive validity of self-report, role-playing, and in-vivo measures.

Examined the predictive validity and construct equivalence of the three major procedures used to measure assertive behavior: Self-report, behavioral role-playing, and in-vivo assessment. Seventy-five Ss, who spanned the range of assertiveness, completed two self-report measures of assertiveness, the Rathus Assertiveness Scale (RAS) and the College Self-Expression Scale (CSES); two scales from the Endler S-R Inventory of General Trait Anxiousness, the interpersonal and general anxiety scales; eight role-playing situations that involved the expression of positive and negative assertiveness; and a telephone in-vivo task. In general, the study revealed the following: (1) assertiveness measures are task-dependent in that there was more overlap within task than between tasks; (2) there is a moderate degree of correspondence between self-report and role-playing measures, although this was true only for negative assertion; (3) positive and negative assertion do not appear to have the same topography of responding; and (4) there appears to be no consistent relationship between the in-vivo measure and any other type of assertiveness measure.

Anxiety↗
PubMed1979

Status report of 376 mycosis fungoides patients at 4 years: Mycosis Fungoides Cooperative Group.

The frequency and prognostic importance of various characteristics of patients registered by the Mycosis Fungoides Cooperative Group between November 1974 and December 1977 are reported. Variables which were considered include demographic and historical factors, symptoms, extent of disease, and other physical findings. A staging system which is based on the extent of skin involvement and the number of nodal sites clinically involved is described. Finally, a description of therapeutic results to date for patients randomized into Mycosis Fungoides Cooperative Group protocols is presented.

Adult↗
PubMed1977

A population-based study of referral, diagnostic and treatment patterns for childhood acute lymphocytic leukemia.

In order to make decisions about cancer control programs, information is needed on the current management of cancer as actually practiced in the United States. A study to address this issue for acute lymphocytic leukemia in children (age 15 years and under) has been performed. The 101 patients represent all reported incident cases during 1972 in five regions which have population-based registries. Data on patient characteristics, referral patterns, treatment regimens, remission/relapse status, and survival are presented. It is concluded that the treatment strategies developed in leukemia research are reaching the general patient population. The present study can be considered a model for future studies of other forms of malignancy.

Adolescent↗
PubMed1977

Applications of the Mantel-Haenszel statistic to the comparison of survival distributions.

In comparing two survival distributions, a Mantel-Haenszel statistic can be computed after each death as a non-linear two-sample rank statistic. The distributions of both the maximum and terminal statistics in such a sequence are studied numerically, in the absence of censoring, and appropriate critical values are determined. The maximum statistic is applied to simultaneous inference, and both the maximum and terminal statistics are used as the basis for early stopping procedures (especially in the pseudo-sequential context). Procedures based on the two statistics are compared for power and for early decision properties such as stopping index and (for exponential distributions) stopping time.

Biometry↗
PubMed1976

A generalization of the one-sided two-sample Kolmogorov-Smirnov statistic for evaluating diagnostic tests.

Suppose a continuous diagnostic measurement is used to classify patients, and suppose E1 false negative errors and E2 false positive errors result. The quantities E1 and E2, and the total number of misclassifications, L = E1 + E2, depend on the choice of cut-off value. We have determined the null distribution of min L, where minimization is over all possible cut-off values. The statistic, min L, can be used as a quick one-sided two-sample test, and min L is also useful for evaluating publications which present only a 2 X 2 table of false positives, false negatives, true positives and true negatives. In such cases, one can use min L to assess the usefulness of the diagnostic measurement, even if one suspects that the authors chose that particular cut-off value which minimized L after looking at the data. We extend these results to a more general weighted loss L = vE1 + MUE2 where v and mu are positive integers, and we show that min L is a generalization of the one-sided two-sample Kolmogorov-Smirnov statistic, and, indeed, exactly equivalent to that statistic for appropriate choices of v and mu.

Biometry↗