Psychometric tests reliability

Psychometric test set (E. Kuntz, h.-D. Kuntz) This test set facilitates psychodiagnostic monitoring of potential liver-diseased patients, identification of SHE and control of therapeutic measures. In some cases, the very simple four basic tests can be evaluated in their overall assessment with even greater reliability by means of supplementary tests, which are likewise easy to implement. (19) (s. tab. 10.7)... 

By means of psychometric tests, neurological/psychi-atric findings and possibly also EEG changes, an accurate assessment can be made regarding the degree of severity of HE - this guarantees a reliable follow-up, in which the efficiency of the therapy can be reviewed. 

Disorders of cerebral functions on the one hand and of the water and electrolyte balance on the other hand are the earliest and most reliable hints of the onset of decompensation in severe liver disease, especially cirrhosis. In clinical terms, they can be easily diagnosed as latent hepatic encephalopathy (by carrying out psychometric tests) and/or latent oedema (by recording the increase in body weight). For this reason, these examination methods are also of fundamental importance in the follow-up of chronic liver disease, (s. fig. 15.3)... 

Impairment of cerebral functions and disturbances of the water and electrolyte balance are the two most important and most common manifestations of decompensated liver cirrhosis. They may be reliably detected at an early stage by means of daily body weight control and simple psychometric tests. A documentation sheet filled in by the patient has proved to be worthwhile latent oedemas or the onset of ascites as well as latent encephalopathy can be detected in this way and thus treated at an early stage. Longterm standing leads to a reduction of natriuresis with subsequent water retention and a deterioration of renal blood flow (like a vicious circle). This is caused by activation of the RAAS and the sympathetic nervous system. Such a dangerous situation (which can arise for example after two hours of standing at a sports event with excessive emotional participation) is often underrated, as we ourselves observed in several patients (s. p. 292) (s. fig. 15.3) (see chapter 16 )... 

Vincamine is an alkaloid extracted from the plant Vinca minor. Ethyl apovincaminate is a related synthetic ethyl ester of vincaminic acid. These drugs have spasmolytic effects similar to those of reserpine, but also have metabolic effects, including, in high doses, inhibition of phosphodiesterase. Although increased cerebral blood flow has been reported after the intravenous administration of vincamine, there have been no reliable studies of blood flow after oral medication. Improvement in scores on some psychometric tests have been obtained in some patients with cerebrovascular disease, but no clear-cut practical benefit has been demonstrated. 

The first part of diis chapter has presented what we call "paper and pencil" tips regarding a variety of issues that can be considered when developing surveys and tests. One step in survey or test design is to compute a reliability statistic, such as Cronbach alpha. Typically, researchers collect data with their instrument and commence their statistical analysis. However, researchers should include a second analysis step that utilizes psychometric theory to guide die development of surveys and tests, to provide techniques Aat allow die functioning of surveys and tests to be monitored and improved, and to prepare data for statistical calculations. In the second part of the chapter, we provide an overview of one psychometric technique (the Rasch model) diat allows researchers to easily carryout this important second analysis step. 

Table 1 summarizes the PbB, other blood chemistry, medical, electrophysiological, psychometric, behavioural and demographic measures collected from participating children and parents. These measures were chosen to provide convergent information from several different perspectives to elaborate more clearly the subtle and complex effects of asymptomatic lead exposure on CNS development. Several tests were selected on the basis of guidelines later adopted at an International Symposium on Neurobehavioral Methodology in Pediatric Lead Research (Cincinnati OH September 1981). These guidelines included (1) use of standardized, age-normed tests with documented validity and reliability when available (2) use of experimental measures to evaluate areas of function for which standardized measures are not available, and (3) use of instruments with cross-cultural comparison data. 

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