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Biomedical subjects

H C Sox

Publications and source records attributed to H C Sox.

At least 73 records · Page 4Linked to original sources
PubMed1989

Medical evaluation of psychiatric patients. I. Results in a state mental health system.

Thorough medical evaluation of 529 patients drawn from eight program categories in California's public mental health system revealed active, important physical disease in 200 patients who had 291 diseases. Fourteen percent of the patients had diseases known to themselves but not to the mental health system, and 12% of the patients had diseases newly detected by the study team. We estimate that of the more than 300,000 patients treated in the California public mental health system in fiscal year 1983 to 1984, 45% had an active, important physical disease. The mental health system had recognized only 47% of study patients' physical diseases, including 32 of 38 diseases causing a mental disorder and 23 of 51 diseases exacerbating a mental disorder. Patients treated in public sector mental health facilities should receive careful medical evaluations.

Adult↗
PubMed1989

A medical algorithm for detecting physical disease in psychiatric patients.

An algorithm for screening psychiatric patients for physical disease was empirically derived from a comprehensive assessment of 509 patients in California's mental health system. The first 343 patients were used to develop the algorithm, and the remaining 166 were used as a test group. Calculations were made for several versions of the algorithm, and the data were compared with the diagnoses listed in the patients' admission mental health record. The algorithmic procedure was more accurate and more cost-effective than the medical evaluation procedures used by the state mental health system. When applied to the test group, the algorithm detected up to 90 percent of patients who had an active, important physical disease at a cost of $156 per patient. The mental health system had detected 58 percent of test-group patients with a disease at a cost of $230 per patient.

Algorithms↗
PubMed1986

Probability theory in the use of diagnostic tests. An introduction to critical study of the literature.

The purpose of this article is to provide an understanding of methods that are useful in formulating advice about when to use diagnostic tests. If the clinician expresses diagnostic uncertainty as the probability of a disease in a patient, Bayes' theorem may be used to predict the effect of doing various tests and their impact on patient management. To use Bayes' theorem wisely, one must be aware of pitfalls in estimating probability and must understand the limitations of most studies of the sensitivity and specificity of diagnostic tests.

Bayes Theorem↗
PubMed1986

The erythrocyte sedimentation rate. Guidelines for rational use.

The erythrocyte sedimentation rate (ESR) is seldom the sole clue to disease in asymptomatic persons and is not a useful screening test. When the rate is increased, a careful history and physical examination will generally disclose the cause. An unexplained increase in the ESR is generally transitory and seldom due to serious disease. The test is most useful in diagnosing temporal arteritis and monitoring the patient's response to treatment. The test has little diagnostic value in rheumatoid arthritis but may be useful in monitoring disease activity when clinical findings are equivocal. The ESR is often normal in patients with cancer, infection, and connective tissue disease and is therefore of little use in excluding these diseases in patients with vague complaints.

Adult↗
PubMed1986

Standard and computed tomography in the evaluation of neoplasms of the chest. A comparative efficacy assessment.

Although in practice computed tomography (CT) has nearly replaced standard tomography in the evaluation of chest diseases, an analysis of the literature shows that standard tomography may be preferred in some settings. After a detailed review of studies on test performance, we calculated overall sensitivity and specificity values. Using Bayesian analysis, we then developed guidelines for choosing between computed and standard tomography. A test is recommended if its results might obviate the need for an invasive procedure. Standard tomography is recommended in the detection of mediastinal metastases from lung cancer. In the detection of hilar metastases, standard tomography is recommended for patients who have low pretest probabilities of metastases to this site, and computed tomography is recommended for patients who have high pretest probabilities. Computed tomography is recommended for the detection of calcification in solitary pulmonary nodules. Tomographic procedures are not recommended when the pretest probability is intermediate. The discrepancy between current practice and these guidelines highlights the need for carefully designed, multi-institutional comparative studies of radiographic procedures.

Humans↗
PubMed1985

Clinical prediction rules. Applications and methodological standards.

The objective of clinical prediction rules is to reduce the uncertainty inherent in medical practice by defining how to use clinical findings to make predictions. Clinical prediction rules are derived from systematic clinical observations. They can help physicians identify patients who require diagnostic tests, treatment, or hospitalization. Before adopting a prediction rule, clinicians must evaluate its applicability to their patients. We describe methodological standards that can be used to decide whether a prediction rule is suitable for adoption in a clinician's practice. We applied these standards to 33 reports of prediction rules; 42 per cent of the reports contained an adequate description of the prediction rules, the patients, and the clinical setting. The misclassification rate of the rule was measured in only 34 per cent of reports, and the effects of the rule on patient care were described in only 6 per cent of reports. If the objectives of clinical prediction rules are to be fully achieved, authors and readers need to pay close attention to basic principles of study design.

Diagnostic Errors↗
PubMed1985

Exercise testing in suspected coronary artery disease.

The interpretation and selection of exercise tests depends on the pretest probability of CAD. Imperfect tests (like exercise tests) provide probability estimates, not definite statements (such as "the patient has CAD" or "the patient does not have CAD"). In patients with a low pretest probability of CAD (asymptomatic persons or men and women with nonanginal chest pain), abnormal exercise test results provide probability estimates that are much too low to conclude that the patient has CAD. In patients with anginal pain and normal exercise tests, the probability of CAD is too high to conclude that the patient has a normal coronary circulation. Exercise tests are not useful for trying to rule out CAD in patients with anginal pain. In patients with an intermediate pretest probability of CAD (men and women with atypical angina and women with typical angina), abnormal exercise tests (particularly the myocardial scintiscan) provide probability estimates that are high enough to justify starting treatment for CAD. Exercise tests are most useful in this group, a conclusion that has been reached by other methods of analysis. The myocardial scintiscan is much more useful than the exercise ECG in women. When CAD is strongly suspected, exercise tests have relatively little diagnostic value but may be useful for prognosis. However, clinical evidence of poor ventricular function may alone suffice to select patients with angina pectoris for coronary arteriography. Conversely, when clinical indicators of congestive heart failure are absent, the prognosis in chronic stable angina is so favorable that any further testing may be unnecessary. Screening asymptomatic persons for CAD is a very low yield practice. Patients who have no cardiac risk factors (hypercholesterolemia, family history of CAD, cigarette smoking, and hypertension) are at especially low risk of a primary cardiac event. Older men with stable typical angina are particularly likely to have left main coronary artery stenosis or three-vessel disease with poor ventricular function. The exercise ECG can identify groups of older men with a relatively high risk of having left main coronary artery stenosis. Physicians should be cautious when applying these recommendations to a primary care practice. The foregoing analysis is based on data obtained from patients who had been selected for coronary arteriography. There are two principal effects of biased selection of study patients: The pretest probability of CAD in clinical subgroups is probably lower than as shown here.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1985

Systematic bias in recording the history in patients with chest pain.

Because of its central importance in medical diagnosis, sources of bias in the patient history must be identified. We report here a study of interobserver agreement in chest pain histories. Histories were obtained by physicians, nurse practitioners, and self-administered questionnaires. We used a discriminant rule to classify the histories as being more or less typical of angina pectoris. A sub-group of the subjects underwent coronary arteriography after the histories were obtained. In subjects with positive coronary arteriograms, physicians consistently obtained histories typical of angina pectoris more often than a self-administered questionnaire. There was no significant systematic bias when comparing physician interviews to the questionnaire among subjects with negative arteriograms nor when comparing two physicians' interviews or a nurse practitioner interview to a questionnaire. When compared to physician interviews, nurse practitioner interviews produced histories less typical of angina pectoris. We conclude that there are systematic differences between the histories obtained by physicians, nurse practitioners, and self-administered questionnaires. Questionnaires can produce biased patient histories and should be carefully validated before being used in patient care activities or health care research.

Aged↗
PubMed1985

Modifying test-ordering behavior in the outpatient medical clinic. A controlled trial of two educational interventions.

Education is an effective tool for modifying physician use of the laboratory. We compared two interventions by assigning 56 medical house officers into four groups: control group; feedback group, which received feedback concerning its use of tests; manual group, which received a manual concerning cost-effective laboratory use; and manual plus feedback group, which received both interventions. All intervention groups experienced significant decreases in test use. When we controlled for diagnosis, the manual plus feedback group had the most profound decrease (42%) in laboratory use, followed by the manual group. The feedback and control groups had no change. Attitudes and knowledge did not change. We conclude that one can, via simple techniques, modify house staff use of the outpatient laboratory. The less-expensive intervention was a cost-oriented manual, which may have a "sensitizing" rather than educational effect.

Ambulatory Care↗
PubMed1984

Tutored videotape-instruction in clinical decision-making.

Tutored videotape-instruction (TVI) is a method for providing high quality instruction in topics for which the supply of expert teachers is limited. A small group of students and a tutor can watch a videotaped lecture that can be interrupted for discussion or questions. The tutor facilitates discussion and directs the students to outside reading. The authors in this report describe the use of tutored videotape-instruction in teaching clinical decision-making. Students were randomly assigned to a tutored videotape-instruction group or to a group that heard identical live lectures. The two groups had the same mean score on a final examination on the course material. The group that heard the live lectures rated the quality of instruction higher than the videotape group; however, the ratings were high for both groups. Tutored videotape-instruction provides expertise in a specialized topic and the advantages of instruction in small groups.

Diagnosis↗