Uncovering psychiatric test information with graphical techniques of Exploratory Data Analysis.

This article illustrates how Exploratory Data Analysis (EDA) can complement conventional statistical methods in evaluating psychiatric tests. Using one recent EDA computer program, we evaluated the ability of repeated psychiatric screening tests (the General Health Questionnaire [GHQ]) to predict medical and psychiatric service use in a Health Maintenance Organization (HMO), the Harvard Community Health Plan (HCHP). Using a stratified random sample of 244 new HCHP enrollees and viewing three-dimensional graphs of their data from multiple perspectives, we found two subpopulations: low GHQ scorers, for whom the tests did not predict service use; and high scorers, for whom they did. Surprisingly, improving scores forecast increased use and chronically high scores predicted diminished use. Using another stratified random sample of 213 new HCHP enrollees, and with scatterplot matrices from another interactive computer program, we found that high and unchanging GHQ scores forecast HMO dropout. We examine possible interpretations--for example, that chronically distressed patients may become immobilized, diminish service use, and ultimately leave the HMO. We also explain how EDA methods may help uncover elusive results in other data (e.g., mental health outcomes).

An Intelligent Display System for psychiatric education in primary care.

We have shown how new concepts for displaying knowledge and data may overcome some of the limitations of existing decisionmaking and educational aids and how they may improve psychiatric diagnosis and education. Elsewhere, we illustrated how these concepts can also be applied in redesigning ordinary textbooks in many other areas of medicine. Using such ideas to simplify decisionmaking without oversimplifying and without reducing physician participation may help us to cope with the enormous growth of information and knowledge. This is a problem common to many areas of medicine, one that demands new ways of thinking about how to simplify educational methods.

Medical education for a changing future: new concepts for revising texts.

Recent psychological research suggests how to simplify texts and translate quantitative concepts into the language of clinical medicine.

Heuristics, normative models, and the value of serial test patterns.

This paper deals with living systems at the level of the human organism, including all subsystems. It argues that, in medicine, conclusions about the adequacy of clinical heuristics, vis-à-vis normative models, may be suspect until the models are more adequately designed and the heuristics better defined. Through a theoretical analysis, it shows that dynamic information, ordinarily ignored in normative models yet often present in biological systems, can have a profound impact on the cost-effectiveness of test use. Empirically, it also shows that explicit clinical policies ignoring dynamic test patterns can lead to substantial loss in diagnostic information. These results motivate research on clinical strategies for using dynamic information. They also suggest unmet needs in evaluating tests, providing decision support, and educating physicians in cost-effective test use.

How to make laboratory information more informative.

I review psychological literature relevant to the design of medical laboratory data reports and computer display systems, illustrate how to improve such systems, and discuss needs for further research.

A new method for reporting the sources of abnormal activities of lactate dehydrogenase in serum.

We have developed and tested a new method to increase the diagnostic usefulness of measurements of lactate dehydrogenase (LDH; EC 1.1.1.27) isoenzymes. The method estimates the separate contributions from enzymatically distinct organ clusters (e.g., heart/kidney/erythrocyte, liver/muscle, lung) to the total activity of LDH in serum. To test this method, we monitored serum LDH isoenzymes over the entire hospital course of 73 patients admitted to the intensive-care unit with chest pain, myocardial infarction, or serious hemodynamic disturbances. The organ-specific estimates provided useful information beyond measurements of the original isoenzymes. The sensitivity and specificity of this new method in detecting acute myocardial infarction, as well as concomitant disorders involving the liver or lung, are significantly greater than those of other diagnostic indices or pathologists' judgments. Serial plots of the organ-specific estimates may provide additional insight into evolving pathophysiological processes.

A structural method to guide test evaluation.

This paper describes a conceptual framework to guide the evaluation of diagnostic tests in medicine. The framework systematically generates questions about possible test uses and factors that can modify their value.

Radionuclide detection of biliary atresia. Illustration of a structural method to guide test evaluation.

This paper illustrates the conceptual framework for test evaluation developed in the preceding paper. Reanalysis of published data, guided by this framework, contradicts preliminary conclusions about the limited statistical discrimination of a radionuclide scan to discriminate neonatal hepatitis from biliary atresia. It also clarifies the need in future evaluations to consider a number of factors not mentioned in many previous studies.

Social climates in community groups: toward a taxonomy.

While community groups have often helped people cope with stress, little empirical research has been available to guide their use in prevention or treatment. To partly fill this gap, an empirical taxonomy of community groups was derived from ratings of 41 randomly selected groups on 35 dimensions of Group Structure, Function, and Membership Characteristics. Cluster analysis defined five types. By comparison with other associations, Self-Interest (e.g., liberation and minority) groups rated lower in regulations and had members who were newer to the community. Self-Help groups were highly regulated settings providing support, integration, and developmental aids. Their members had few social relations apart from the family. Social Communion groups rated high on the provision of support for members often living without family. Civic Development groups rated highest on dimensions emphasizing personal development for persons with external sources of support and status. Finally, Recreation groups were casual and briefly attended groups. Their members were younger and less often married than those in other associations. Strategies for group referrals may be implied.