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PubMed2000

Development and validation of the Validity Indicator Profile.

The Validity Indicator Profile (VIP; Frederick, 1997) is a two-alternative forced choice (2AFC) procedure intended to identify when the results of cognitive and neuropsychological testing may be invalid because of malingering or other problematic response styles. The test consists of 100 problems that assess nonverbal abstraction capacity and 78 word-definition problems. The VIP attempts to establish whether an individual's performance in an assessment battery should be considered representative of his or her true overall capacities (valid or invalid). Performances classified as valid are classified as "compliant" and reflect a high effort to respond correctly. Performances classified as invalid are subclassified as "careless" (low effort to respond correctly), "irrelevant" (low effort to respond incorrectly), or "malingering" (high effort to respond incorrectly). The VIP development sample included 944 nonclinical participants and 104 adults undergoing neuropsychological evaluation. The cross-validation sample consisted of 152 nonclinical participants, 61 brain-injured adults, 49 individuals considered to be at risk for malingering, and 100 randomly generated VIP protocols. The nonverbal subtest of the VIP demonstrated an overall classification rate of 79.8%, with 73.5% sensitivity and 85.7% specificity. The verbal subtest of the VIP demonstrated an overall classification rate of 75.5%, with 67.3% sensitivity and 83.1% specificity.

Adolescent↗

PubMed2000

Comparing the predictive validity of DUI risk screening instruments: development of validation standards.

AIMS: This study compares the predictive efficacy of driving under the influence (DUI) screening instruments validated in previous studies, illustrates how variations in base rates of failure and selection ratios affect conclusions concerning the efficacy of different instruments, and develops evaluation standards to ensure valid comparisons of risk prediction instruments. DESIGN: The study: (1) examines a sample of 4815 DUI offenders to illustrate how variations in base rates of failure and selection ratios affect traditional measures of predictive efficacy, (2) uses such measures to compare the predictive efficacy of 10 instruments validated in previous studies, and (3) demonstrates the use of a measure of predictive efficacy which is relatively insensitive to the aforementioned variations. FINDINGS: While three instruments examined at specific cut-points consistently ranked highest on several measures of predictive efficacy, use of different evaluation standards produced substantively different conclusions regarding the efficacy of different instruments. Based on the analyses, standards for validation of risk prediction instruments were developed. CONCLUSIONS: The findings illustrate how failure to use equivalent standards have led to erroneous conclusions concerning the relative predictive efficacy of different risk prediction instruments. The standards developed in this study should facilitate equivalent comparisons of the predictive efficacy of risk prediction instruments.

Alcohol Drinking↗

PubMed1995

Valid arguments? a consideration of the concept of validity in establishing the credibility of research findings.

Validity is an important concept in establishing the credibility of research findings. However, the current debate about the criteria used to substantiate claims for the validity of research evidence is largely based on a set of distinctions between qualitative and quantitative methodology which are outdated and misleading. This paper argues that validity is an epistemological concept, whose application depends upon some fundamental positions taken about the nature of truth, representation and scientific methodology. There remain important, unresolved questions about the meaning and application of the concept of validity which have a crucial bearing on what criteria are used to establish the credibility of research evidence.

Philosophy↗

PubMed1994

Validation of professional licensure examinations. Professions theory, test design, and construct validity.

Although the unitary view of test validity has gained support recently, it has real limitations where professional licensing examinations are concerned. A strategy for validation of professional licensure tests requires modifying conventional approaches in three ways. First, a theory of professions must be incorporated into the test development process so as to acknowledge the social character of professions. Second, the importance of test design in the validation of licensing tests should be enhanced. Third, the concept of construct validation must be expanded to accommodate the special features of content that inhere to professional licensure testing. Methods for accomplishing these three things are described and the implications of these and other views discussed.

Cognition↗

PubMed1990

Concurrent validity of the MacAndrew Alcoholism Scale: mixed-group validation.

The concurrent validity of the MacAndrew Alcoholism Scale (MAC) was assessed using the mixed-group validation procedure described by Dawes and Meehl (1966). Using mixed groups consisting of different proportions of individuals likely to become alcoholic, classified according to their family histories of probable alcohol abuse, the proportions of subjects exceeding various MAC cutting scores were observed. Depending upon the base rates that were assumed, validity coefficients ranging from .82 to 1.02 were obtained when a MAC cutting score of 24 was used. These values are comparable to concurrent validity estimates obtained using known alcoholics.

Adult↗

PubMedDate not supplied

The quest for better validation: a critical comparison of the AAMI and BHS validation protocols for ambulatory blood pressure measurement systems.

Two validation procedures are currently available for the evaluation of ambulatory blood pressure measurement systems--the standard of the Association for the Advancement of Medical Instrumentation (AAMI) and the protocol of the British Hypertension Society (BHS). Both are in the process of revision. Four systems for measuring 24-hour ambulatory blood pressure--SpaceLabs 90207, Novacor DIASYS 200, Del Mar Avionics Pressurometer IV, and Takeda TM-2420--were evaluated according to the BHS protocol, which incorporates many of the features of the AAMI standard, under similar conditions by the same personnel and in the same subjects, so as to examine the relative merits of the two evaluation procedures. Three recorders of each model were subjected to a before-use inter-device variability test, followed by an in-use phase and an after-use inter-device variability test. The main validation test was carried out in 86 subjects with a wide range of pressures, the results being analyzed according to the BHS grading system and the AAMI validation criteria. The SpaceLabs 90207 and the DIASYS 200 achieved B and C grades, respectively, according to the BHS protocol and also satisfied the AAMI criteria for accuracy. The Pressurometer IV achieved a Grade C rating for systolic pressure and a Grade D rating for diastolic pressure and the Takeda TM-2420 achieved Grade D ratings for both systolic pressure and diastolic pressure. Both these devices failed to fulfil the AAMI criteria for accuracy and both failed to function in the main validation test and had to be replaced.(ABSTRACT TRUNCATED AT 250 WORDS)

Ambulatory Care↗

PubMed1993

[Are blood glucose controls performed with portable dosimeters valid? A comparison of the reliability and validity of 3 commonly used models].

OBJECTIVE: To evaluate and compare the reliability and validity for both normal and high glycaemia values of three models of glycaemia self-analysers: Reflolux, Glucocard and One Touch. DESIGN: Descriptive and crossover study. Validation of a measuring appliance through its comparison with a standard appliance. PARTICIPANTS: The sample was composed of 90 blood specimens chosen by suitability sampling. MEASUREMENTS AND MAIN RESULTS: The glycaemia in the specimens was measured simultaneously by each one of the self-analysers and the central laboratory. There was high reliability (reproducibility) among the self-analysers, with correlation coefficients of 0.98, 0.97 and 0.98, with no statistically significant differences. As to intra-instrument reliability (repeatability), tested by analysing the variances of the differences, no statistically significant differences were found, except in the Glucocard self-analyser which lost precision at high glycaemia levels. Validity or accuracy, measured by the method of taking the average of the differences, showed a systematic bias in the Reflolux model, which had a value of 22.3 mg/dl above the reference model, and in the One Touch of -16.3 mg/dl. The Glucocard was the most accurate with a value of -1.78 mg/dl. CONCLUSIONS: Portable glycaemia dosimeters are very useful in following up diabetic patients because of their high reliability, but are not useful in the diagnosis of diabetes because of their lack of accuracy. Before beginning to use a portable dosimeter, its characteristics in terms of reliability and validity must be known, in order to evaluate correctly its findings.

Adult↗

PubMed1997

Internal validity of the disruptive behavior disorder symptoms: implications from parent ratings for a dimensional approach to symptom validity.

A dimensional approach was used to evaluate the internal validity of the DSM-III-R ADHD-inattention, ADHD-hyperactivity/impulsivity, oppositional defiant disorder (ODD), and conduct disorder (CD) symptoms (i.e., whether a symptom has a stronger correlation with its own dimension that the other three). Parents rated 4,019 children between the ages of 2 and 19 on these symptoms. The results showed that 5 of the 6 inattention symptoms, 3 of the 4 hyperactivity symptoms, 1 of the 4 impulsivity symptoms, 6 of the 9 oppositional defiant disorder symptoms, and 8 of the 11 CD symptoms had significant internal validity. Confirmatory factor analysis (CFA) found support for inattention, hyperactivity/impulsivity, oppositional defiant, and conduct disorder dimensions. Multiple-group CFA also found support for factor pattern and loading invariance across gender. The implications of these results as well as the merits of the dimensional approach to symptom validity are discussed in the context of the DSM-IV changes in ADHD, ODD, and CD.

Adolescent↗

PubMed1994

Smoking outcome expectancies: factor structure, predictive validity, and discriminant validity.

Recent models of addiction posit that drug outcome expectancies are influential determinants of drug use. The current research examines the dimensional structure, predictive validity, and discriminant validity of expectancies for cigarette smoking in a prospective study. There was a good fit between the factor structure of the Smoking Consequences Questionnaire and the observed data. In addition, the internal consistency of each scale was satisfactory. Moreover, there was considerable evidence for the predictive and discriminant validity of expectancies. Expectancies of positive outcomes (positive reinforcement, negative reinforcement, and appetite-weight control) predicted withdrawal severity. Negative reinforcement expectancies and expectancies of negative consequences predicted cessation success. Predictive relations remained significant after controlling for related constructs: negative affect, stress, and dependence measures.

Adult↗

PubMed1988

Retaining qualitative validity while gaining quantitative reliability and validity: development of the Transition to Parenthood Concerns Scale.

This article raises issues about the retention of qualitative validity while establishing psychometric estimates of reliability and validity for a scale that was developed from inductively generated concepts to assess and evaluate the learning needs and concerns of expectant parents in the trimester before their baby's birth. A set of practical procedures for pilot testing qualitatively based scales is described. The three procedures, which provide estimates of clarity, apparent internal consistency, and content validity, preserve the assumptions underlying qualitative methods. The ratings from these procedures have provided a base for item and scale revisions and formal quantitative testing.

Adult↗

PubMed1996

MCMI-III diagnostic validity: bad test or bad validity study.

Operating characteristics describe the validity of tests that attempt to dichotomously predict a diagnosis. These statistics are not fully published in the Millon Clinical Multiaxial Inventory-III Manual (MCMI-III manual; Millon, 1994). When calculated from available statistics, the positive predictive powers of the MCMI-III scales are poor both in absolute terms and relative to the MCMI-II (Millon, 1987). There were a number of problems, however, with the initial MCMI-III validity study both inherently and in execution. Although it is doubtful that the MCMI-III is weaker than the MCMI-II, a new validity study is needed.

Diagnosis, Differential↗

PubMed1995

Competency-Based Certification Project. Phase III: content validity, standard setting and criterion-related validity.

This is the final article in a three-part series explaining the CAMRT's Competency-Based Certification Project--an effort to make the Association's certification process more job-relevant. The first article (Journal, August 1994) explained the job analysis process used to specify and validate the list of duties and tasks required of entry-level medical radiation technologists, the imaging and treatment procedures they perform, and the equipment they use. The second article (Journal, October 1994) explained the process for developing an examination blueprint by reviewing the CAMRT's examinations and summaries of clinical experience in the context of competency-based evaluation and the job analysis validation in each discipline. This article examines the development of assessment standards for certification examinations and summaries of clinical experience. It provides an overview of the steps necessary to develop a valid and defensible licensure/certification process after development of the examination content is complete.

Canada↗

PubMed1998

Validation of the Omron F3 blood pressure measuring device for use in the finger through simultaneous invasive comparative measurements according to the German Institute for Validation (DIN) 58130 protocol.

OBJECTIVES AND DESIGN: Simultaneous invasive comparative measurements in order to validate the blood pressure measuring device Omron F3 for use in the finger, in accordance with the German Institute for Validation (DIN) 58130 protocol. METHODS: A total of five consecutive simultaneous blood pressure comparative measurements were carried out in each of 15 patients (n = 75). Blood pressure was measured in the left index finger using the blood pressure measuring device Omron F3, and at the same time invasively using a pigtail catheter situated in the aortic arch. The measuring arrangements, validation of the unit of invasive measurement and evaluation were all carried out in accordance with the DIN 58130 protocol. RESULTS: The blood pressure measuring device Omron F3 for use in the finger fulfils the criteria of the European Standard prEn 1060-3. Systolic blood pressure decreased by 2.9+/- 6.6 mmHg and diastolic blood pressure decreased by 2.6+/- 5.9 mmHg. CONCLUSION: The blood pressure measuring device Omron F3 measures blood pressure reliably and accurately if used correctly in appropriate patients. Before using the device for the first time, comparative blood pressure measurements in the upper arm, using the standard auscultatory blood pressure measurement technique according to Riva-Rocci and Korotkoff, should be carried out, in order to check the accuracy of measurement.

Adult↗

PubMed1997

Validation of the OMRON R3 blood pressure self-measuring device through simultaneous comparative invasive measurements according to protocol 58130 of the German Institute for Validation.

OBJECTIVES: To perform simultaneous invasive comparative measurements in order to validate the blood pressure self-measuring device OMRON R3 for use on the wrist, in accordance with protocol 58130 of the German Institute for Validation. METHODS: Five consecutive comparative blood pressure measurements were carried out for each of 15 patients (n = 75 measurements). The blood pressure was measured simultaneously non-invasively using the blood pressure self-measuring device OMRON R3 around the left wrist and at the same time invasively using a pigtail catheter situated in the aortic arch. The pressure curves were drawn continuously. The measuring arrangements, validation of the invasive-measurement unit and evaluation were all carried out in accordance with protocol 58130. RESULTS: The blood pressure self-measuring device OMRON R3 for use on the wrist satisfied the criteria of the European Standard prEn 1060-3. The OMRON systolic values were 2.2 +/- 3.9 mmHg higher and the diastolic values were 0.2 +/- 2.7 mmHg lower than the invasive ones. However, for higher blood pressure levels (> 150 mmHg), the device tested displayed an increasing tendency to underestimate the systolic blood pressure in one-third of the patients by 5-15 mmHg, compared with the invasive measurements. No faulty measurements occurred with the patient group examined. CONCLUSION: The blood pressure self-measuring device OMRON R3 for use on the wrist can be recommended for blood pressure self-measurement. When it is used correctly, it measures the blood pressure reliably and accurately.

Journal Article↗

PubMed2000

Bias and Sampling Error of the Estimated Proportion of Genotypic Variance Explained by Quantitative Trait Loci Determined From Experimental Data in Maize Using Cross Validation and Validation With Independent Samples.

Cross validation (CV) was used to analyze the effects of different environments and different genotypic samples on estimates of the proportion of genotypic variance explained by QTL (p). Testcrosses of 344 F(3) maize lines grown in four environments were evaluated for a number of agronomic traits. In each of 200 replicated CV runs, this data set was subdivided into an estimation set (ES) and various test sets (TS). ES were used to map QTL and estimate p for each run (p(ES)) and its median (p(ES)) across all runs. The bias of these estimates was assessed by comparison with the median (p(TS.ES)) obtained from TS. We also used two independent validation samples derived from the same cross for further comparison. The median p(ES) showed a large upward bias compared to p(TS.ES). Environmental sampling generally had a smaller effect on the bias of p(ES) than genotypic sampling or both factors simultaneously. In independent validation, p(TS.ES) was on average only 50% of p(ES). A wide range among p(ES) reflected a large sampling error of these estimates. QTL frequency distributions and comparison of estimated QTL effects indicated a low precision of QTL localization and an upward bias in the absolute values of estimated QTL effects from ES. CV with data from three QTL studies reported in the literature yielded similar results as those obtained with maize testcrosses. We therefore recommend CV for obtaining asymptotically unbiased estimates of p and consequently a realistic assessment of the prospects of MAS.

Journal Article↗

PubMedDate not supplied

Ethical issues surrounding informed consent. Part II. Components of a morally valid consent and conditions that impair its validity.

To be valid, a consent must be given by a person who has received all relevant information, is competent, has not been coerced into agreement or refusal, and is not emotionally overwhelmed. Persons who have received incomplete information, are incompetent, have been coerced, or are psychodynamically overcome cannot give valid consent or refusal. HCPs who accept consents or refusals from such patients do not act in accordance with the ethical foundations and goals the practice was designed to promote. Nursing plays a crucial role in assuring the validity of informed consent/refusal. This role will be examined in Part III of this series.

Decision Making↗

PubMed1986

Development and validation of personal monitoring methods for low levels of acrylonitrile in workplace atmosphere: II. Thermal desorption and field validation.

Thermal desorption is a more sensitive alternative to solvent desorption for the determination of acrylonitrile in air. A dual-bed collection tube (Tenax GC and Carbosieve B) was developed for collecting and concentrating low levels of acrylonitrile. Two thermal desorption techniques were evaluated for the recovery of acrylonitrile collected on the dual-bed tubes over a concentration range from 0.05 to 5 ppm. A commercially-available system, the Century Programmable Thermal Desorption Unit, was easy to operate, allowed for multiple injections of the sample and had a recovery of 82 +/- 12% (RSD). Samples were stored for up to two months without affecting the recovery and there was not an observable effect from humidity or from the presence of other organic compounds. This system was found to have limitations at acrylonitrile concentrations above 1 ppm. A field validation study tested the sampling and analytical methods developed for monitoring low levels of acrylonitrile in the workplace. Three methods employing Pittsburgh Coconut-Base activated charcoal, Ambersorb XE-348 and Tenax-GC and Carbosieve B sampling mediums were validated for concentrations ranging from 0.05 to 5 ppm and confirmed in the field from 0.02 to 3 ppm in tests conducted at plant sites. These field studies were run over varying humidity and temperature conditions. The overall absolute recoveries and relative standard deviations found for these methods found during the field trials are 90 +/- 18% for charcoal; 85 +/- 11% for Ambersorb XE-348; and 90 +/- 19% for the Century dual-bed sorbent. These values were in quite good agreement with the 91 +/- 10%, 88 +/- 8%, and 82 +/- 12% determined in laboratory studies.

Acrylonitrile↗

PubMed1999

Is there really a heterosexual AIDS epidemic in the United States? Findings from a multisite validation study, 1992-1995. Mode of Transmission Validation Study Group.

The objective of this study was to verify the mode of exposure to the human immunodeficiency virus (HIV) among cases who obtained acquired immunodeficiency syndrome (AIDS) through heterosexual contact and to determine the proportion of cases initially reported with no risk but whose exposure may have been heterosexual. Adults aged > or = 13 years with AIDS, diagnosed from 1992 through 1995 with heterosexual risk or no risk at six US study sites (Alabama, California, Florida, New Jersey, New York City, and Texas), were eligible. Heterosexual risk was validated in 82% (1,610/1,952) of the heterosexual cases. Men were more likely than women to have a risk other than heterosexual (24% vs. 13%, chi2 p < 0.01). An HIV risk was identified for 351 (55%) of those cases with no risk, and men were more likely than women to remain without risk (48% vs. 38%, chi2 P = 0.02). Of the 415 men with no risk, 215 (52%) were reclassified: 94 (44%) were men who had sex with men, 61 (28%) were injection drug users, 48 (22%) had a heterosexual risk, and 12 (6%) had other exposures. Of the 219 women with no risk, 136 (62%) were reclassified: 82 (60%) had a heterosexual risk, 47 (35%) were injection drug users, and 6 (4%) had infection associated with transfusion. In conclusion, most cases reported with heterosexually acquired AIDS had valid heterosexual risk exposures.

Acquired Immunodeficiency Syndrome↗