Clinical instruments and scales

CLINICAL INSTRUMENTS AND SCALES 413 TABLE 32.3 Commercial and Other Sources for Scales and Other Instruments... 

Analyses are performed in accordance with standardized methods issued under the responsibility of a Technical Committee within the Health Ministry. Usually such measurements rely on a comparison of the measured quantity in the unknown sample with the same quantity in a standard , i.e. an RM, according to a specific measurement equation [6], after calibrating the instrument. Calibration of a photometric system for clinical analyses usually means the set of operations that establish, under specific conditions, the relationship, within a specified range, between values indicated by the instrument and the corresponding values assigned to the RMs at the stated uncertainty. Calibration of the photometer itself implies the calibration of wavelength and absorbance scale by means of proper wavelength and absorbance RMs [5], traceable to national standards. A calibration of the instrument is still needed in concentration units to check the indicated provided value. The measurement result is then verified by application of that method of measurement to a certified reference material (CRM). Both the comparator - a photometric device with narrow or wide bandwidth, and the RMs should thus be validated. 

A commonly used profile instrument is the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). This instrument includes nine health concepts or scales (Table 2-3). The SF-36 can be self-administered or administered by a trained interviewer (face to face or via telephone). This instrument has several advantages. For example, it is brief (it takes about 5-10 minutes to complete), and its reliability and validity have been documented in many clinical situations and disease states. " A means of aggregating the items into physical (PCS) and mental (MCS) component summary scores is available." In addition, an abbreviated version of the SF-36 containing only 12 items (SF-12) has been introduced." However, the scale scores and mental and physical component summary scores derived from the SF-12 are based on fewer items and fewer defined levels of health and, as a result, are estimated with less precision and less reliability. The loss of precision and reliability in measurement can be a problem in small samples and/or with small expected effect sizes for an intervention. 

These scales provide objective clinical data on the existence of and changes in a client s depression. Social workers should become familiar in the use of such instruments and utilize them as pretests during the assessment phase and as posttests during different treatment intervals. 

Patient selection based on symptom severity. This can be defined directly by a minimal acceptable severity score as measured by a rating instrument (e.g. the Hamilton Rating Scale for Depression, the Positive and Negative Symptom Scale or other established assessment instruments see Section 5.6). An indirect definition of symptom severity may be a consequence of the status of a patient population a clinical trial designed for inpatients generally implies a more severe symptom profile than a study with... 

These are instruments developed to identify specific psychiatric disorders. Most of these scales are based on a structured or semi-structured interview lasting some 60 90 min. Structured interviews contain a mix of open-ended and closed questions. Open-ended questions are essential for the validity of a diagnostic procedure closed questions support the reliability and the standardization of diagnostic tools. The primary goal for the use of diagnostic scales is to reduce the variance within samples caused by diagnostic differences, i.e. to create homogeneous patient populations included in clinical trials. 

The 1 ale Brown Obsessive Compulsive Scale (YBOCS) is an OCD-specific instrument in which ratings are based mainly on patients self-report in a semi-structured interview. Five items are addressed to rate the severity of obsessive symptoms and five items to assess the compulsive symptoms (Goodmann et al., 1989). The YBOCS is the best-established and standard instrument to diagnose OCD it has been used in most of the clinical trials in this area. 

The Krawiecka Goldberg Scale (or Manchester Scale) is a brief ten-item scale for assessment of changes in the clinical status of patients suffering from psychosis. The items include depression, anxiety, delusions and hallucinations, incoherence, flattened affect, poverty of speech and psychomotor retardation. The absence of items typical of schizoaffective and manic psychoses limits the use of this instrument. It is, however, useful for follow-up of inpatients and outpatients for longer periods of time (Krawiecka et al.y 1977). 

The Clinical Institute Withdrawal Assessment for Alcohol Scale (CIWA-Ar) is a short and practical ten-item instrument for clinical quantitation of the severity of an alcohol withdrawal syndrome. It can be incorporated into the usual clinical care of patients undergoing alcohol withdrawal and into clinical drug trials of alcohol withdrawal ( Sullivan et al.. 1989). 

In a double-blind, parallel-group study, Bondareff et id. (2000) compared the SSRI sertraline and the tricyclic compound nortriptyline with regard to their efficacy and safety in a group of 210 outpatients 60 years and older. The patients met the DSM-DI-R criteria for major depressive episode and had a minimum score of 18 on the Hamilton Rating Scale for Depression. Their mean age was about 68 years, most patients were white and about 60% were female the severity of depression was rated as moderate in more than 70% and as severe in more than 20% of the cases. The daily doses of sertraline were between 50 and 150 mg, and those of nortriptyline were 25 100 mg the treatment lasted 12 weeks. In addition to clinical rating scales and self-assessment instruments, patients took the following tests of cognitive performance ... 

The 17-item HDRS is the most commonly used scale in antidepressant clinical trials. This version of the HDRS is heavily weighted toward melancholic symptoms. There are also 21-item, 24-item, and 28-item versions with the additional items assessing nonmelancholic symptoms. The Montgomery-Asberg Depression Scale (MADRS) is another instrument that is frequently used in antidepressant clinical trials. 

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