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PubMed2005

Validation of the AGILIS ambulatory blood pressure monitor according to the European Society of Hypertension International Protocol for validation of blood pressure measuring devices in adults.

BACKGROUND: We evaluated the clinical validity of the AGILIS ambulatory blood pressure monitor according to the European Society of Hypertension International Protocol. METHODS: The blood pressure (BP) was measured at the same arm by two certified observers using two mercury columns and a double stethoscope, then by the volunteer with the automatic device, these measurements were done seven times sequentially using 33 volunteers. For the randomization of the patient, one ABPM measure was compared to the mean of three manual measures. Then, we had three ABPM measures and four manual measures. Each ABPM measure, being compared to two manual measures. Blood pressure readings and recordings were blinded. Position of the subjects was standardized. RESULTS: Phase 1: To pass phase 1, the device had to have at least 25 of the 45 measurements within 5 mmHg, 35 within 10 mmHg or 40 within 15 mmHg of the comparative observer measurements. The AGILIS monitor had 35 measurements lying within 5 mmHg, 42 within 10 mmHg and 45 within 15 mmHg for systolic BP (SBP), 35 within 5 mmHg, 44 within 10 mmHg and 45 within 15 mmHg for diastolic BP (DBP). It passed the criteria for SBP and DBP. Phase 2: To pass phase 2.1, a device must have at least 60 of 99 measurements within 5 mmHg, 75 within 10 mmHg and 90 within 15 mmHg of the comparative observer measurements, and in addition must also have either 65 within 5 mmHg and 80 within 10 mmHg, or 65 within 5 mmHg and 95 within 15 mmHg, or 80 within 10 mmHg and 95 within 15 mmHg. The AGILIS monitor had 78 measurements within 5 mmHg, 91 within 10 mmHg and 96 within 15 mmHg for SBP; and 70 measurements within 5 mmHg, 92 within 10 mmHg and 96 within 15 mmHg for DBP. It passed the criteria for SBP and DBP. For phase 2.2 using the AGILIS monitor, 27 subjects had at least two of the differences within 5 mmHg and none had any differences within 5 mmHg for SBP; 27 subjects had at least two of the differences within 5 mmHg and three subjects had no differences within 5 mmHg for DBP. The results are in concordance with the requested criteria for phase 2.2. CONCLUSION: Thus the AGILIS device fulfils the validation criteria of the international protocol.

Adult↗

PubMed2004

Are caregivers' reports of motivation valid? Reliability and validity of the Reiss Profile MR/DD.

BACKGROUND: Sensitivity theory proposes that there are wide individual differences in what motivates people with intellectual disability. The Reiss Profile MR/DD is a rating scale that measures 15 fundamental motives. This study examined the internal consistency and interrater reliability of the 15 subscales as well as the validity of motivational profiles. METHOD: The study consisted of two distinct but related steps. First, the interrater reliability of the rating scale was established by having pairs of raters evaluate 48 individuals. Second, raters were presented with three different motivational profiles and asked to identify which one corresponded to the individual they had rated 4 weeks earlier. RESULTS: Results indicated good internal consistency (average alpha=0.84), significant variability in the interrater reliability (average intraclass correlation coefficient=0.52), and excellent validity (95% of the correct profiles were chosen). Average discrepancies between pairs of raters are presented. CONCLUSIONS: Interrater reliability is an important topic for professionals working in the field of intellectual disability and results are discussed in terms of the factors that affect it. This is the first published study to report on the interrater reliability of the Reiss Profile MR/DD.

Adaptation, Psychological↗

PubMed2004

Validation of the rat limb bud micromass test in the international ECVAM validation study on three in vitro embryotoxicity tests.

A detailed report is presented on the performance of the rat limb bud micromass (MM) test in a European Centre for the Evaluation of Alternative Methods (ECVAM)-sponsored formal validation study on three in vitro tests for embryotoxicity. Twenty coded test chemicals, classified as non-embryotoxic, weakly embryotoxic or strongly embryotoxic on the basis of their in vivo effects on animals and/or humans, were tested in four laboratories. The outcome showed that the MM test is an experimentally validated test, which holds promise for use for identifying strongly embryotoxic chemicals, but which needs to be improved before it can be recommended for use for regulatory purposes.

Animal Testing Alternatives↗

PubMed2005

Analog validation of German-language symptom validity tests and the influence of coaching.

Although symptom validity testing is an integral part of the repertory of neuropsychologists in a number of countries, this is not yet true for Germany. The German adaptations of two effort tests, the Medical Symptom Validity Test (MSVT) by Green and the Amsterdam Short-Term Memory Test (ASTM) by Schmand et al., were investigated with a German-language sample. An analog study was performed with 18 healthy experimental malingerers and 18 controls with a mean age of 25.4 years. The scenario contained detailed information about mild post-traumatic cognitive impairment, as well as an explicit warning against symptom exaggeration. In addition to MSVT and ASTM, the Trail Making Test (TMT), the Complex Figure Test (CFT), and Digit Span were performed. Half of the sample were also given Rey's 15-Item-Test (FIT). Both groups were significantly different in all effort and performance measures, with the exception of the ratio TMT-B:TMT-A. With MSVT and ASTM, correct classification of group membership was between 97 and 100%. For the ratio TMT-B:TMT-A, there was a considerable overlap in the test scores for the two groups and the sensitivity of the FIT was too low. Although the ASTM and the MSVT were identified by a number of subjects as possible effort measures, both tests obtained very good results within this analog design.

Adult↗

PubMed2005

Leisure Time Physical Activity Instrument and Physical Activity at Home and Work Instrument. Development, face validity, construct validity and test-retest reliability for subjects with fibromyalgia.

PURPOSE: A new instrument measuring leisure time physical activity (LTPAI) in populations predominately engaging in low intensity activities and a new instrument measuring the Physical Activity at Home and Work (PAHWI) were designed. METHODS: Patients with long-lasting pain and expert physiotherapists participated in the development of the two instruments. Test-retest reliability was evaluated for the LTPAI and the PAHWI. Construct validity was evaluated for the LTPAI by comparing it with an instrument measuring physical activities for older people, six-minute walk test and aerobic capacity. POPULATION: 37 women with FM, with the mean age of 46 years (SD 8.4) and mean symptom duration of 11 years (SD 5.9) were recruited to the study. RESULTS: The mean time that the study population spent in physical activities during leisure time was 5.2 hours (SD 4.0) a week. Satisfactory test-retest reliability was found for the total score of LTPAI (ICC 0.86, CI 0.79 - 0.93) and for the PAHWI (ICC 0.91, CI 0.82 - 9.96). A significant association between the LTPAI and the six-minute walk test (rs 0.40, p = 0.02) and another physical activity instrument (rs 0.39, p = 0.02) was found. As expected, LTPAI did not have any association with aerobic capacity. CONCLUSIONS: Face validity of the instruments was ensured during the development process. Satisfactory test-retest reliability was found for the LTPAI and the PAHWI. Significant but low associations were found between the LTPAI and the six-minute walk test and an instrument designed for older people, respectively, while no association was found between the LTPAI and aerobic capacity.

Adult↗

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↗

PubMed1989

On the measurement of tobacco use by adolescents. Validity of self-reports of smokeless tobacco use and validity of cotinine as an indicator of cigarette smoking.

This study assessed the validity of self-reports of smokeless tobacco use by adolescents and the validity of cotinine as a measure of adolescent cigarette smoking. For a sample of 1,854 persons aged 12-14 years living in the southeastern United States in 1985, a combination of three biochemical measures (salivary cotinine, salivary thiocyanate, and alveolar carbon monoxide) and self-reports of cigarette smoking were used to identify subjects who used only smokeless tobacco and subjects who did not use smokeless tobacco. The sensitivity and specificity of self-reports of smokeless tobacco use were 40.8% and 97.9%, respectively. It was determined that of the 175 subjects who ordinarily would be considered smokers because they had salivary cotinine levels greater than or equal to 10 ng/ml, 43.4% used only smokeless tobacco.

Adolescent↗

PubMedDate not supplied

Cross-validation of a model predicting discharge home after stroke rehabilitation. Validating stroke discharge predictors.

A new sample of 116 stroke patients was collected in order to validate a logistic regression model, predicting the chances of severely affected stroke patients being discharged home to independent living. The model was found to be accurate in the new sample, especially for those patients who had a high estimated probability of being discharged home. When the dividing line for the predicted probability for discharge home was set at a value of >/=0.5, the positive and negative predictive values were 74 and 73%, respectively. Further modelling resulted in a new extended model including the variables postural stability on admission, cohabiting, age and perceptual impairment on admission that formed the basis for an index predicting discharge home. This index was then validated in the sample of 93 patients that the first developed model was derived from and showed positive and negative predictive values of 85 and 77%, respectively.

Activities of Daily Living↗

PubMed1985

Comment on the validity of Watson et al.'s "Do alcoholics give valid self-reports?".

This is a critique of a study by Watson et al. on the validity of alcoholics' self-reports that suggested that clinical researchers and clinicians abandon the use of such data for now. It is shown, however, through an analysis of the rationale, procedures and data analyses reported by Watson et al., that their conclusions are not warranted. It is argued that the use of a situational and convergent validity approach to the collection and interpretation of self-report data is likely to continue to be a productive research and clinical strategy.

Alcohol Drinking↗

PubMed1999

Temporal variation of validity of self-rating questionnaires: improved validity of repeated use of Zung's Self-Rating Depression Scale among women during the perinatal period.

It has been reported that Zung's Self-Rating Depression Scale (SDS) loses its validity in predicting cases of depression when used repeatedly. The validity of SDS was tested against the subject's Research Diagnostic Criteria (RDC) diagnoses of major/minor depressive disorders in 120 pregnant women four times throughout the perinatal period. Different sets of predictive SDS items were found at different time points. We developed an 'RDC-like' algorithm from SDS items. Though varying in sensitivity, we found that this formula yielded low, but stable, positive predictive values and constantly high negative predictive values. We suggest that the RDC-like algorithm is a better alternative for screening depression among perinatal women.

Adult↗

PubMed2004

Statistical validation of surrogate endpoints: is bone density a valid surrogate for fracture?

In the treatment of osteoporosis using anti-resorptive agents there has been increasing interest in quantifying the relationship between fracture endpoints and surrogates such as bone mineral density (BMD) or bone turnover markers. Statistical methodology constitutes a critical component of assessing surrogate validity. Depending on study designs, data resources, and statistical methods used for analyses, one has to use caution when interpreting results from different analyses, especially when results are disparate. For example, analyses based on individual patient data reported that only a limited proportion of the anti-fracture efficacy was explained by BMD increases for agents such as alendronate, risedronate and raloxifene. Analyses employing meta-regression based on summary statistics, however, indicated that most of the anti-fracture benefits were due to improvements in BMD. In this paper, we review definitions of surrogate endpoints and requirements for their statistical validation. We evaluate whether BMD meets these requirements as a possible surrogate for fracture. Our review indicates that the actual BMD value is correlated with fracture risk and thus BMD is useful in identifying patients that might need treatment. There is limited evidence to support BMD increase with anti-resorptive agents as a reliable substitute for fracture risk reduction. Strengths and limitations for various statistical methods are discussed.

Biomarkers↗

PubMed1990

Development and validation of an index for scoring baseline respiratory disease in the very low birth weight neonate. Severity Index Development and Validation Panels and Newborn Lung Project.

An accurate description of the population at risk for neonatal chronic lung disease is clearly of prime importance for comparative studies and the planning of interventions. Attempts to explain variations in chronic lung disease rates in such studies have been compromised by lack of a way of estimating the severity of the initial pulmonary disease as a risk factor. Therefore, a severity index was developed for use in very low birth weight (less than 1501 g) neonates. Special emphasis was placed on applicability of the index in the multicenter observational setting. Development followed a clinician panel approach, with the resulting index designed to capture clinical judgment of severity. The index was validated prospectively on neonates in a neonatal intensive care unit, and retrospectively using charts from nine hospitals nationwide. Correlations of the index with clinical judgment in the two samples were .95 and .93, respectively. In an additional validation the index combined with birth weight correctly predicted oxygen dependence status at 30 days in 36 of 42 neonates consecutively admitted to five neonatal intensive care units (P = .002). Birth weight and the severity index contributed about equally to the prediction, and therefore they seem to represent partly independent components of baseline propensity for prolonged oxygen dependence.

Apgar Score↗

PubMed1994

Validation of the Box and Block Test as a measure of dexterity of elderly people: reliability, validity, and norms studies.

Manual dexterity is a skill frequently evaluated in rehabilitation to estimate hand function. Several tests have been developed for this purpose, including the Box and Block Test (BBT) that measures gross manual dexterity. The goal of the present study was to verify the test-retest reliability and construct validity of the BBT with subjects aged 60 and over with upper limb impairment. The second objective of this research was to develop normative data based on a random sample of healthy elderly community-living individuals. The results show that the test-retest reliability is high (intraclass correlations coefficients of 0.89 to 0.97) and the validity of the test is shown by significant correlations between the BBT, an upper limb performance measurement and a functional independence measurement. The norms will help rehabilitation clinicians to differentiate better between real difficulties and those that may be attributed to normal aging.

Activities of Daily Living↗

PubMed2003

The construct validity of the client questionnaire of the Wisconsin Quality of Life Index--a cross-validation study.

The Wisconsin Quality of Life Index (W-QLI, Becker, Diamond and Sainfort, 1993) consists of eight scales: satisfaction with life domains, occupational activities, symptoms, physical health, social relations/support, finances, psychological wellbeing, and activities of daily living. The W-QLI has been modified to fit the characteristics of the Canadian population, the universal Canadian health system, and community and social services in Canada and the modified form was named CaW-QLI (Diaz, Mercier, Hachey, Caron, and Boyer, 1999). This study will verify the empirical basis of these theoretical dimensions by applying a cross-validation procedure on two samples, most of whose subjects have a serious mental illness. Confirmatory factor analyses and exploratory factor analyses using the principal component extraction technique with varimax rotation were applied. With the exception of the occupational activities domain, the remaining scales were correctly identified by the factor analyses on each sample. The occupational activities scale should be developed by additional items for representing this scale, which is too brief, and two other items should be revised in order to improve the quality of the instrument.

Adult↗

PubMed2002

Validation of a near-infrared transmission spectroscopic procedure, part A: validation protocols.

It is possible to devise calibration and validation protocols that enable the ICH guidelines to conform to the specialized requirements of the NIR method of analysis. Some of the required characteristics of evaluation specified by the guidelines, such as accuracy and repeatability, can be applied directly, just as with any other analytical method. Other characteristics are adapted through the novel use of specialized statistics, or through the use of creative methods and procedures to match the recommendations of the guidelines to the unique and specialized requirements of the NIR method.

Algorithms↗

PubMed2005

The validity of the SRS-22 instrument in an adult spinal deformity population compared with the Oswestry and SF-12: a study of response distribution, concurrent validity, internal consistency, and reliability.

STUDY DESIGN: Prospective analysis of a consecutive cohort of adult spinal deformity patients queried over a 12-month period. OBJECTIVES: To assess the SRS-22 instrument compared with the SF-12 and Oswestry. SUMMARY OF BACKGROUND DATA: Very few reports in the literature have applied the SRS-22 to adult spinal deformity patients. METHODS: Consecutive adult spinal deformity patients were applied the SRS-22, SF-12, and Oswestry. Four analyses were done: 1) floor/ceiling effect; 2) Pearson's correlation coefficients between the SRS-22, SF-12, and Oswestry; 3) Cronbach's alpha analysis for internal consistency within the SRS-22; and 4) test/retest. RESULTS: Floor/ceiling range for the SRS-22 compared favorably with the SF-12 and Oswestry. The Pearson's coefficients correlating the two questionnaires relative to the SRS-22 were > 0.7. The Cronbach's alpha within each domain for the SRS-22 were > 0.7, except for pain (0.67). Test/retest correlation coefficients ranged from 0.84 to 0.95 for the subscales. CONCLUSIONS: The SRS-22 is a disease-specific instrument with the capacity to demonstrate change in health status more effectively than the SF-12 and in more domains than the Oswestry. The SRS-22 showed high criterion validity with the SF-12 and Oswestry based on Pearson's coefficients. High Cronbach's alpha scores suggested a high internal consistency within each domain of the SRS-22, except for pain (0.67). Test/retest reliability was excellent.

Adolescent↗

PubMedDate not supplied

Pathways to understanding mind: construct validity and predictive validity of maternal mind-mindedness.

The construct validity of maternal mind-mindedness (MM) was investigated in the context of its relations with children's later understanding of mind. MM measures were obtained from infant-mother (N = 52) interactions at 6 months, and from maternal interviews at 48 months. Children's understanding of mind was assessed using theory of mind (ToM) tasks at 45 and 48 months, and a stream of consciousness (SoC) task at 55 months. One of the early MM measures--mothers' appropriate mind-related comments--was a positive independent predictor of: (a) MM at 48 months, and (b) ToM and SoC performance at 45 to 55 months. Path analyses suggested direct links between mothers' use of appropriate mind-related comments and children's later understanding of mind.

Child↗