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Biomedical subjects

M Meisner

Publications and source records attributed to M Meisner.

30 records · Page 2Linked to original sources

Haloperidol blood levels and effects in schizophrenia and schizoaffective disorder: a progress report.

To test the hypothesis of a "therapeutic window," we have randomly assigned acutely exacerbating schizophrenic or schizoaffective patients to one of three plasma levels of haloperidol (HAL): 2-13, 13.1-24, or 24.1-35 ng/ml. Patients who did not improve after 6 weeks of this treatment were randomly assigned to one of the three haloperidol levels for another 6 weeks. The improvement was defined as at least 50 percent reduction of the Brief Psychiatric Rating Scale (BPRS) total score. The results obtained in 111 patients do not support any consistent relationship between plasma level of haloperidol and clinical improvement. Patients in the high haloperidol plasma range tended to have more side effects. These results suggest that the haloperidol doses used in clinical practice may be higher than necessary.

Adult

Predicting assaultiveness in psychiatric inpatients: a pilot study.

A sample of 87 psychiatric inpatients known to have been assaultive while in the hospital was contrasted with a matched group of nonviolent patients to identify the personal risk factors that distinguished the two groups. Data were collected using a personal history interview, a neurological examination, and an electroencephalogram. The four risk factors identified--neurological abnormality, history of violent crime, history of violent suicide attempts, and deviant family environment in childhood--were used to develop a statistical model predicting which subjects in a sample of newly admitted patients would become assaultive during the first three months after admission. The predicted classification of patients was found to be significantly related to subsequent assaultive behavior.

Adolescent

Combining multivariate bioassays.

Linear multivariate theory is applied to the problem of combining several multivariate bioassays. Results are an asymptotic test of the hypothesis of a common log relative potency; the maximum likelihood estimator of the common log relative potency; and an exact and asymptotic confidence interval estimator for log relative potency.

Analysis of Variance

Optimal crossover designs in the presence of carryover effects.

Under either the random patient-effect model with sequence effects or the fixed patient-effect model, the usual two-period, two-treatment crossover design, AB,BA, cannot be used to estimate the contrast between direct treatment effects when unequal carryover effects are present. If baseline observations are available, the design AB,BA can validly be used to estimate a treatment contrast. However, the design AB,BA,AA,BB with baseline observations is more efficient. In fact, we show that this design is optimal whether or not baseline observations are available. For experiments with more than two periods, universally optimal designs are found for both models, with and without carryover effects. It is shown that uncertainty about the presence of carryover effects is of little or no consequence, and the addition of baseline observations is of little or no added value for designs with three or more periods; however, if the experiment is limited to only two periods the investigator pays a heavy penalty.

Clinical Trials as Topic

Matched-pairs study of reserpine use and breast cancer.

This paper reports on an analysis of psychiatric population. 55 female patients with breast cancer were matched with non-cancer patients on age, year of admission, psychiatric diagnosis, race, and religion. Reserpine use was examined for yearly use by each year preceding the diagnosis of breast cancer, by cumulative yearly use, and by other defined time periods. Regardless of the definition of reserpine user, there were no significant increased relative risks of breast cancer for those women on reserpine. There was a fairly low proportion of patients from each group who were on the drug in any given year, and a fairly wide range of total dosage received. Over half of the women used reserpine at some time during their hospital stay.

Aged

Statistical inference for cost-effectiveness ratios.

Methods for statistical inference for cost-effectiveness (C/E) ratios for individual treatment and for incremental cost-effectiveness (delta C/ delta E) ratios when two treatments are compared are presented. In a lemma, we relate the relative magnitude of two C/E ratios to the delta C/ delta E ratio. We describe a statistical procedure to test for dominance, or admissibility, that can be used to eliminate an inferior treatment. The one-sided Bonferroni's confidence interval procedure is generalized to the two-sided case. The method requires only that two confidence intervals be available, one for cost and one for effectiveness. We describe Fieller-based confidence intervals and show them to be shorter than Bonferroni intervals. When distribution assumptions hold and variance and covariance estimates are available, Fieller intervals are preferable. However, Bonferroni intervals can be applied in more diverse situations and are easier to calculate. A simple Bonferroni based technique, and a likelihood ratio statistic given by Siegel, Laska and Meisner, for testing the null hypothesis that the C/E ratios of two treatments are equal is presented. The approaches are applied to the data from a phase II clinical trial of a new treatment for sepsis considered previously by others.

Confidence Intervals

The usefulness of average cost-effective ratios.

We demonstrate that average cost-effectiveness ratios (CERs) play an important role in the evaluation of the cost-effectiveness of treatments. Criticisms of the usefulness of CERs derive mostly from the context of resource allocation under a constrained budget in which some decisions are based on incremental CERs. However, we show that in many cases, these decision rules are equivalent to decision rules on CERs. This follows for mutually exclusive treatments first, because a treatment is eliminated by extended dominance if and only if there is a mixed treatment with a smaller CER, where the mixing parameter lies in a certain interval. Second, after elimination of treatments by dominance and by extended dominance, resources can be allocated in order of increasing CERs. Moreover, the CER is a parameter that characterizes clinical and economical properties of a treatment independent of its comparators.

Confidence Intervals

An analytic approach to quantifying pain scores.

Statistical problems in clinical trials frequently involve fitting regression lines when the underlying data are categorical or ordinal response variables. Usually an ad hoc a priori quantification is used to assign values to these ordinal responses. For pain intensity data collected in analgesic trials, the usual approach is to set none equal to 0, mild equal to 1, moderate equal to 2, and severe equal to 3. While this scheme has been generally accepted, on the basis that for similar clinical trials reasonably similar results are obtained by different investigators, concern exists that the distances between pain scores are probably not equal. A method is presented for quantifying categorical responses so that the resulting scores maximize the simultaneous fit of the dose-response regression lines. The optimal scores derived by this technique may then be used in a bioassay analysis to estimate the relative potency of 2 compounds. As illustrative examples, this method was applied to data from 2 clinical trials and the results were compared to the usual method.

Analysis of Variance