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H Morgenstern

Publications and source records attributed to H Morgenstern.

At least 127 records · Page 7Linked to original sources
PubMed1985

The use of pediatric medical care: a critical review.

The problems of who uses medical services and why, are important ones for investigators interested in studying chronic diseases, particularly if they wish to avoid systematic error when assembling a study population. These issues are important when studying pediatric diseases due to the uneven use of medical services by children and the tendency of lower socioeconomic groups to use hospital facilities rather than private practitioners. In order to address these problems, we must understand why families seek medical care for young children. Utilization research shows that a number of descriptive factors such as child's age, birth order, parental education, financial resources and perceived symptoms are related to service use. Additionally, psychosocial variables, such as distress, also predict utilization. Neither the descriptive nor psychosocial variables explain much of the variance in utilization. While some of this lack of explanatory power can be attributed to problems in measurement or study design, there are also conceptual and methodological issues that are not addressed in pediatric utilization research. This paper discusses four of these issues. It is our conclusion that two of these problems, the need for a new utilization taxonomy and the ambiguity of cause and effect, can be remedied. While more difficult to address, the inadequate conceptualization of social stress, psychological distress, and social support can be improved. However, measuring health status independently of utilization represents a major methodologic problem for which we currently have no ideal solution.

Birth Order↗
PubMed1985

Estrogen replacement and tardive dyskinesia.

A double-blind randomized clinical trial was conducted among 10 post-menopausal women with tardive dyskinesia (TD) to test the effect of estrogen replacement of the severity of abnormal movements and other outcome variables. After 3 weeks of treatment, the mean Abnormal Involuntary Movement Scale (AIMS) score decreased by 38% in the estrogen group and by 9% in the placebo group; the difference between groups was marginally significant (p less than 0.10). However, the small sample size and the imbalance between groups in baseline AIMS scores do not allow us to rule out the confounding effects of other prognostic factors. There were no significant differences between treatment groups for parkinsonian and psychological symptoms at any visit or for changes in these variables between visits. The findings of this preliminary trial are consistent with the results of other human and animal investigations, and they support the need for future research to understand the role of estrogens in the neuropathology and treatment of TD.

Aged↗
PubMed1985

The impact of social stressors and social networks on pediatric medical care use.

Substantial differences in the use of pediatric medical resources reinforce the need for identifying and understanding factors that influence the use of medical services for children. This research assesses the simultaneous impact of sociodemographic characteristics, health attitudes and beliefs, psychologic distress, social stressors, and social networks on the use of pediatric acute care services during a 12-month period. Using a prospective longitudinal study design, data were obtained on 513 children and their families enrolled in a prepaid group practice. Linear modeling results showed that health attitudes and social networks were important predictors of acute care utilization in addition to child's age, birth order, baseline health status, and ethnic group. The authors were able to show significant effects for network size, dispersion, and tendency to use one's network members. Individuals with large nondispersed networks are more likely to use pediatric health services, apparently due to the transmission of the networks' pro-medical care health beliefs. Also the tendency to call on network members modifies an individual's propensity to seek care for minor pediatric medical problems and can make a difference by as much as 1.6 visits per year per child for acute care episodes.

Adolescent↗
PubMed1984

Tardive dyskinesia. A discontinuation study.

Twenty-one nonschizophrenic and 12 schizophrenic outpatients with tardive dyskinesia (TD) were followed up for a mean of 12.0 and 8.6 months, respectively, following discontinuation of neuroleptic therapy. Of the 33 patients, only one demonstrated complete reversal of TD. Cumulative survival curves of the length of time to first improvement (reduction in movement ratings by 50% of baseline) did not differ between the two groups. The median time to first improvement was seven months. If a patient can be kept off of a neuroleptic regimen for 18 months, the estimated probability of showing a 50% reduction in movement is 87.2%. In the nonschizophrenic group, depressed mood was negatively correlated with severity of abnormal movements.

Antipsychotic Agents↗
PubMed1984

The impact of a psychosocial support program on survival with breast cancer: the importance of selection bias in program evaluation.

A retrospective follow-up study was conducted to assess the impact of a psychosocial support program on survival with breast cancer. One-hundred and two nonparticipants were individually matched to 34 participants on several prognostic factors, and both groups were followed from date of cancer diagnosis (1971-1980) until December, 1981. Preliminary findings suggest a strong beneficial effect of the program on survival, which is statistically significant. However, this observed effect is due largely to a selection bias caused by the failure to match on the duration of the lag period between cancer diagnosis and program entry. Correcting for this bias in the analysis results in a small, nonsignificant program effect. We are not able to rule out a possible effect, however, because of the relative lack of statistical power and because of a modest, though nonsignificant benefit observed for women who entered the program shortly after diagnosis. Furthermore, the program might have other beneficial effects on the quality of life.

Adult↗
PubMed1983

Dimensions of delusional experience.

The authors describe a scale designed to measure five dimensions of delusional experience: conviction, extension, bizarreness, disorganization, and pressure. Reliability was adequate to excellent on four of the dimensions, but only fair on the dimension of bizarreness. In 52 delusional patients, no two dimensions correlated highly with each other, indicating that the dimensions were not redundant. Factor analysis identified two factors from the five dimensions--delusional involvement and delusional construct. On the basis of these results the authors suggest that delusions are a multidimensional phenomenon; the results have implications for the measurement of delusions in clinical research and for the understanding of the structure of psychotic experience.

Adult↗
PubMed1982

A method for using epidemiologic data to estimate the potential impact of an intervention on the health status of a target population.

A general method is proposed for estimating the potential impact of a prevention program involving risk factor modification on the incidence of specific diseases in a target population. An evaluative framework for comparing alternative intervention strategies is also presented. On the basis of results from epidemiologic studies, the user must specify certain parameters regarding the distribution of the risk factor that is to be modified in the population, the magnitude of the association between the risk factor and disease, and the total risk of disease in the population. A quantitative measure, called the potential impact fraction, is derived to estimate the proportion of expected new cases that may be prevented under intervention programs of varying success. Estimates of this measure are then used to assess the potential efficacy, effectiveness, adequacy, and efficiency of planned intervention strategies. The method is illustrated with published data relating relative weight and coronary heart disease among middle-aged U.S. men, comparing different strategies of weight reduction. Key assumptions of the method and interpretation of results are discussed.

Adult↗
PubMed1982

Uses of ecologic analysis in epidemiologic research.

Despite the widespread use of ecologic analysis in epidemiologic research and health planning, little attention has been given by health scientists and practitioners to the methodological aspects of this approach. This paper reviews the major types of ecologic study designs, the analytic methods appropriate for each, the limitations of ecologic data for making causal inferences and what can be done to minimize these problems, and the relative advantages of ecologic analysis. Numerous examples are provided to illustrate the important principles and methods. A careful distinction is made between ecologic studies that generate or test etiologic hypotheses and those that evaluate the impact of intervention programs or policies (given adequate knowledge of disease etiology). Failure to recognize this difference in the conduct of ecologic studies can lead to results that are not very informative or that are misinterpreted by others.

Ecology↗
PubMed1981

Considerations in determining matching criteria and stratum sizes for case-control studies.

Despite considerable research into the statistical properties of matching in case-control studies, much disagreement remains regarding practical guidelines for the employment of the procedure. We critically examine some recent statistical recommendations, and review a number of theoretical and practical considerations that should be employed in designing matched studies. We conclude that determination of matching criteria and stratum sizes should always involve practical as well as theoretical considerations, and that global recommendations regarding matching cannot be justified on the basis of statistical considerations alone.

Epidemiologic Methods↗
PubMed1981

Selection bias in epidemiologic studies.

Consideration of factors involved in the selection of subjects is essential for evaluating the validity of a putative etiologic association. The purpose of this paper is to provide a quantitative conceptual framework for understanding selection bias; this framework integrates both epidemiologic and statistical considerations. Emphasis is given to specifying the conditions under which such bias is likely to occur, identifying the direction and magnitude of the bias, and illustrating how these features differ by type of study design.

Cross-Sectional Studies↗
PubMed1981

Matching in epidemiologic studies: validity and efficiency considerations.

Validity and efficiency issues are considered with regard to the use of matching and random sampling as alternative methods of subject selection in follow-up and case-control studies. We discuss the simple situation involving dichotomous disease and exposure variables and a single dichotomous matching factor, and we consider the influence on efficiency of a possible loss of subjects due to matching constraints. The decision to match or not should be motivated by efficiency considerations. An efficiency criterion based on a comparison of confidence intervals under matching and random sampling for the effect measure of interest (the risk ratio and risk difference in follow-up studies, and the odds ratio in case-control studies) leads to the following conclusions when the sampling method does not influence the size of the comparison group. In follow-up studies, matching on a confounder is expected to lead to a gain in efficiency over random sampling, while matching on a nonconfounder is not expected to result in a loss of efficiency. In case-control studies, the same conclusions hold, except that matching is not as advantageous as in follow-up studies and can lead to a loss of efficiency in some situations (usually of little practical importance). When matching reduces the size of the comparison group, there is likely to be a meaningful gain in efficiency due to random sampling only when the matched comparison group is at most 40-50% the size of the randomly-sampled comparison group is a follow-up study, and at most 50-65% the size in a case-control study.

Follow-Up Studies↗
PubMed1980

Department of Epidemiology and Public Health, School of Medicine, Yale University, New Haven, CT.

This paper distinguishes between 2 concepts for measuring the incidence of disease: risk and rate. Alternative procedures for estimating these measures from epidemiologic data are reviewed and illustrated. An attempt is made to integrate statistical principles with epidemiologic methods while minimizing the use of higher mathematics. Several theoretical and practical criteria are discussed for choosing the appropriate incidence measure in the planning of a study and for selecting the best method of estimation in the analysis.

Epidemiologic Methods↗