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[Application of the multiple vocabulary test to assessing mental disorders].

The multiple vocabulary test has been used to investigate approaches to objectifying general mental deterioration. Compared to methods used to determine the actual level of intelligence, the premorbid levels of intelligence which were determined with the use of the multiple vocabulary test were roughly the same for patients with brain injuries that cannot be detected by means of specialized instruments. In the case of patients where brain injuries were detectable through the use of instruments, the premorbid level of intelligence was significantly higher than the actual intelligence level. Patients with general mental deterioration showed highly significant differences between premorbid and actual levels of intelligence. The results obtained indicate that the multiple vocabulary test is a useful means of diagnosing general mental deterioration due to organic or psychological factors. Also discussed by the authors in their present paper are hitherto unsolved problems that stand in the way of an objective diagnosis of dementia and loss of intelligence.

Humans

Multimodality evoked potentials and neurophysiological tests in multiple sclerosis. Effects of hyperthermia on test results.

Data on critical frequency of photic driving (CFPD), frequency following response (FFR), and visual, somatosensory (peroneal nerve), and brain-stem auditory evoked potentials (EPs) were obtained from 20 patients who had clinically definite multiple sclerosis and ten healthy normal subjects in a controlled, balanced study under normothermic and hyperthermic (+1 degrees C) conditions with a test-retest interval of one week. Normal subjects' test results showed no changes during hyperthermia. Patients' EP and CFPD data correlated well with history, clinical signs, and symptoms during both normothermia and hyperthermia. The FFR test data were equivocal and not fully analyzed. Data from the four other tests showed additional patient abnormalities during hyperthermia. Multimodality testing increased the number of patient abnormalities compared with single tests, and the number increased further during hyperthermia. Test-retest reproducibility was higher during hyperthermia.

Adult

The latent class model for multiple binary screening tests.

Given multiple binary tests, such as repeated application of a blind screening test to each individual in a sample, we attempt to estimate the prevalence, sensitivity and specificity of the test without knowing the true disease status of those tested (gold standard). This problem is equivalent to finding the mixing distribution of a mixture of binomial distributions. We suggest a new method to determine the number of latent classes. Our simulations show that the coverage probabilities of the bootstrap confidence intervals of our estimates are correct. Our methods are illustrated by examples from published medical research.

Algorithms

An exact linkage test for multiple case families.

A test of linkage that is exact even in small samples is developed for multiple case families, together with large-sample theory for estimation and supplementary tests. Hemochromatosis, insulin-dependent diabetes, and celiac disease are compatible with an intermediate model biased toward recessivity on the penetrance scale, whereas multiple sclerosis favors dominance and unlinked modifiers. Alternatives to the model are complex, and comparison of affected sib pairs with larger sets of relatives provides no critical evidence of epistasis. Problems of sampling and inference are discussed.

Epidemiologic Methods

Utilisation of multiple biochemical tests in a large general hospital.

This report gives an account of the patterns of requesting of multiple biochemical tests in a large general hospital and the frequency of abnormal test results in different hospital departments. There are appreciable differences between some areas in the frequency of requests for multiple testing and in the proportions of abnormal results. If it is assumed that clinicians should be aware of abnormal values and their progress, facilities for multiple testing are desirable and economically justifiable.

Chemistry, Clinical

The Multiple Sleep Latency Test: a paradoxical test?

The Multiple Sleep Latency Test (MSLT) has gradually gained acceptance as an objective equivalent of the complaint of sleepiness. The history of this test and questions considering the validity of the MSLT in different situations are discussed.

Arousal

HIV testing behaviors in a population of inner-city women at high risk for HIV infection.

The relationship between HIV testing history. HIV serostatus, and risk behaviors was examined to investigate factors associated with obtaining an HIV test, returning for results, or receiving multiple tests. Seven hundred and five volunteers for an HIV study were questioned about prior HIV testing, drug and sexual practices, and sociodemographic characteristics. Women who reported a prior HIV test were compared with those without a previous test, women who returned for test results were compared with those not returning; and women who reported multiple tests were compared with those having only one test. Seventy-five percent of the women reported a prior test; 12% had not returned for test results; 46% reported multiple tests. Women reporting higher levels of HIV risk behaviors were more likely to have been tested and to return for results. Injection drug use and having four or more sex partners were significantly associated with repeated HIV testing. Over one third of the women with substantial HIV risk practices had not been HIV tested or failed to obtain test results. Women who obtained multiple HIV tests were more likely to report high-risk practices in spite of having received risk counseling with repeated testing.

AIDS Serodiagnosis

Ambulatory blood pressure monitoring and cardiovascular function tests in multiple system atrophy.

Cardiovascular tests (CT) of autonomic function and non-invasive ambulatory blood pressure (BP) and heart rate (HR) monitoring were performed in 17 patients with multiple system atrophy (MSA) (mean age 61 +/- 9 years) and in 12 healthy subjects matched for sex and age. CT showed severe autonomic dysfunction with orthostatic hypertension (OH) in eight patients with MSA (47%) (Group I). The remaining nine out of the 17 patients didn't show BP abnormalities during CT but an impaired HR reflex response was found (Group II). BP monitoring showed a reversed circadian BP rhythm in Group I with higher night-time than day-time values, a blunted circadian BP pattern in Group II and a normal day-night BP reduction in controls. Day-night HR reduction was poor in Group II and absent in Group I. Post-prandial hypotension was evaluated after a standard meal. In Group I systolic/diastolic BP fell within 30 minutes after meal (from 135 +/- 16/89 +/- 13 to 118 +/- 17/73 +/- 12 mmHg; p < 0.05) and after two hours had not returned to basal levels. In Group II a reduction of only systolic BP was found within 45 minutes after meal and persisted for one hour. OH clinically identifies a subgroup of MSA patients with a more severe BP dysregulation characterized by severe post-prandial hypotension and reversed circadian BP rhythm. CT and ambulatory BP monitoring are useful tools in identifying early stage of cardiovascular autonomic impairment.

Adult

More powerful procedures for multiple significance testing.

The problem of multiple comparisons is discussed in the context of medical research. The need for more powerful procedures than classical multiple comparison procedures is indicated. To this end some new, general and simple procedures are discussed and demonstrated by two examples from the medical literature: the neuropsychologic effects of unidentified childhood exposure to lead, and the sleep patterns of sober chronic alcoholics.

Alcoholism

The linoleic acid depression (LAD) test for multiple sclerosis using the macrophage electrophoretic mobility (MEM) test.

With the macrophage electrophoretic mobility (MEM) test of Field & Caspary, lymphocyte sensitization to thyroid antigen (F1-fraction) is demonstrable in all subjects--multiple sclerosis (MS) patients, those with other (destructive) neurological diseases (OND) and normals. The MEM-LAD test enables a further differentiation to be made in neurological patients compared ot normals: Linoleic acid inhibits the positive result by about 95 per cent in the case of MS, 58 per cent in normals and 45 per cent in OND. The high reduction appears to be a characteristic of MS. It is seen at all stages and in all forms of the disease and is not materially influenced by moderate immunosuppressive therapy. The mothers of MS patients show an intermediate result of about 78 per cent, suggesting a familial (genetic) background to the metabolic phenomenon described here; there is, however, evidence of an added exogenic factor for the development of the disease. The theoretical basis of the LAD test suggests further therapeutic trials of linoleic acid in treatment of MS.

Adolescent

[The advantages of multiple choice tests in undergraduate teaching of pharmacology (author's transl)].

Multiple-choice tests in pharmacology were carried out with students who had no previous experience in this kind of examination. The curriculum in pharmacology was divided into four parts. Each part was followed by a test consisting of 90 questions. A special arrangement was made for those students who voluntarily participated in all four tests during academic year. Pass marks in all four completed tests were considered equivalent to a successful outcome in the one oral examination which is, at present, obligatory. In order to encourage a high level of participation amongst the students, failure in one or more of the tests had no adverse consequences. As a result, a markedly increased attendance at lectures, as well as a positive feed back of information for the faculty, were ascertained and assessment of the efficiency of the teaching methods facilitated. Application of multiple choice tests to the teaching of Pharmacology to undergraduate students proved to be recommendable, both as a test procedure and of advantage in the actual learning process.

Austria

Isomorphic patient management problems: a method of creating equivalent problem-solving tests.

Multiple choice format pre- and post-tests have a high likelihood of being equivalent (i.e. parallel) if well-known guidelines are followed. In the absence of such guidelines for pre- and post-tests of problem-solving, the authors devised a simple method of creating problems that are likely to be equivalent. The method was employed with patient management problems (PMPs) and focuses on maintaining the same form or structure of the problems while making the problems appear different to the examinee. Such problems are 'isomorphic'. The equivalence or parallelism of 10 PMPs with their isomorphic counterparts was demonstrated. The method for creating isomorphic PMPs appears to be applicable for creating equivalent pre- and post-tests composed of problems other than PMPs.

Education, Medical

Serial electrophysiologic testing of multiple drugs in patients with atrioventricular nodal reentrant paroxysmal tachycardia.

Serial electrophysiologic testing of multiple drugs was performed in 21 patients with recurrent atrioventricular (AV) nodal reentrant paroxysmal supraventricular tachycardia (PSVT). All patients had reproducible sustained PSVT induced before drug administration. Serial daily PSVT induction was attempted after administration of i.v. ouabain (0.01 mg/kg) (16 patients), i.v. propranolol (0.1 mg/kg (17 patients), i.v. ouabain + propranolol (same dosages) (12 patients), i.v. procainamide (600-1000 mg) (17 patients) and oral quinidine (1600-2400 mg/day) (nine patients). In two of 21 patients (10%), no tested drug prevented induction of sustained PSVT. In 19 of 21 patients (90%), one or more drugs prevented induction of sustained PSVT: ouabain--seven patients, propranolol--seven patients, ouabain + propranolol--seven patients, procainamide--11 patients, quinidine--seven patients. The site of action of ouabain and/or propranolol was either the antegrade limb or the retrograde limb (RL) of the circus movement. The site of action of procainamide or quinidine was always the RL. These 19 patients were treated with oral drugs, based on results of serial testing. Eighteen patients were successfully followed for 6-50 months. In 13 of these 18 patients PSVT did not recur. Two patients (11%) had > 95% reduction in frequency of PSVT recurrences, and three (17%) did not respond to chosen oral drugs. Serial electrophysiologic testing of multiple drugs is feasible in patients with AV nodal reentrant paroxysmal tachycardia. Drug responses are variable. In most but not all patients, serial electrophysiologic testing defines effective prophylactic drug therapy. This method of defining prophylactic drug therapy appears most suitable for patients with poorly tolerated tachycardias that occur only sporadically.

Administration, Oral

Persistent neurological deficit precipitated by hot bath test in multiple sclerosis.

For a half century, the hot bath test has been used as a "diagnostic test" in multiple sclerosis. The appearance of new neurological signs or aggravation of preexisting signs generally is transient, with resolution on return of body temperature to normal. We have observed four patients, however, with considerable and prolonged neurological debilitation after hot bath testing. We suggest caution in the application of such testing.

Adult

Assessing the effect of multiple linkage tests in complex diseases.

The significance of a lod score value of 3 is very difficult to assess in linkage studies between a genetic marker and a complex disease. One reason is that multiple tests may have been performed, voluntarily or otherwise. For the same disease, linkage may be tested by different laboratories with several markers under various genetic models and diagnostic schemes for the disease. In such a case, we show that the probability of getting a lod score value of 3 under independent transmission of the disease and the marker may be not negligible.

Female

Maximum Shannon information content of diagnostic medical testing. Including application to multiple non-independent tests.

The increase in Shannon information available from a diagnostic test associated with grading of the test results into many outcomes, rather than simply positive or negative, was examined to determine its upper limit as the number of test outcomes is increased indefinitely. Numerical methods were employed to find the optimal locations of outcome boundaries when a single normally distributed test variable is classified into 2, 3, 4, 5, 6, 8, 14, or 20 outcome categories. In each case Shannon information was computed for values of prior probability between 0.01 and 0.99 and for distances between the means in diseased and nondiseased populations ranging from 0.5 to 5.0 standard deviations. There is an important improvement in Shannon information as the number of outcomes defined is increased, but the increment in information diminishes rapidly with each additional category. A 20%-30% increment in information may be achieved with three outcomes instead of two. A further important increase in information occurs with four to seven outcomes, but beyond this the increment in inforation is negligible. The findings were similar over a wide range of prior probabilities and distances between the means. The analysis was extended to the case of multiple nonindependent tests by demonstrating their application to a Fisher discriminant function incorporating such tests. It was concluded that for normally distributed test variables: grading of test results significantly improves the information content of both single and multiple tests; the value of information content for 8-20 outcomes represents very nearly the maximum information content of a test; there is little value in using more than five to seven test outcomes; multiple grading should not be neglected for discriminant functions.

Bayes Theorem