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Results for “validation study”

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PubMed1977

The measurement of obsessionality: first validation studies of the Lynfield obsessional/compulsive questionnaires.

The difficulties encountered in attempts at the rating and quantification of obsessional behaviour are outlined and some of the reasons for such difficulties are mentioned. The development of the Lynfield Obsessional-Compulsive Questionnaire from the Leyton Obsessional Inventory is discussed together with the advantages and disadvantages attendant upon its administration. The author concludes that the Lynfield Obsessional-Compulsive Questionnaire promises well as a measure for assessing change and that, following further validity and reliability tests, it may be used in multicentre trials of treatment procedures.

Evaluation Studies as Topic↗

PubMed1984

Measuring family functioning with the MMPI: a reliability and concurrent validity study of three MMPI family scales.

Examined the utility of three MMPI family scales. Three MMPI family scales and three criterion family scales were administered to 110 undergraduates. Internal consistency coefficients were calculated for each MMPI family scale. Relationships between the MMPI family scales and the criterion scales are examined by a correlational analysis. Findings suggest that the MMPI family scales are reliable and concurrently valid measures of an individual's perception of interpersonal family relationships. Procedures for scoring and interpreting the MMPI family scales are examined. The findings also indicate which MMPI family scale is the overall best scale.

Adolescent↗

PubMed1980

A validation study of forms A and B of the Whitaker Index of Schizophrenic Thinking.

Hospitalized psychiatric patients (n = 115) completed either Form A or Form B of the Whitaker Index of Schizophrenic Thinking, along with the Beck Depression Inventory, State Anxiety Inventory, and the MMPI. Only error scores on the WIST were calculated in an effort to assess validity of the WIST for use in group testing situations where individual timing and administration is cumbersome. Results supported the convergent and discriminant validity of Form A where significant correlations were found with measures of thought disorder (MMPI F, Pt, Sc and Pa) but not with indices of other symptomatology, such as depression and anxiety. Form B did not show such validity, with only one significant correlation with other measures (MMPI Pd). Both WIST Forms correctly identified nonschizophrenics (76% for Form A and 73% for Form B) more often than schizophrenics (57% for each form). Also, Form A was found to be negatively related to years of education. Suggestions for further research on the influence of intelligence and social class variables on WIST scores were made. Overall, Form A emerged as the most valid WIST form, with suggestions for its clinical use being offered.

Adolescent↗

PubMed1990

Mean transit time for videodensitometric assessment of myocardial perfusion and the concept of maximal flow ratio: a validation study in the intact dog and a pilot study in man.

Over the last decade it has become more and more obvious that besides anatomical information about the severity of coronary artery stenoses, information about coronary and myocardial blood flow is necessary to understand the functional significance of these obstructions and to evaluate the result of an intervention. Several methods have been proposed for this purpose, each of these having their particular limitations. In this study a new method is shortly described which allows the accurate calculation of relative maximal myocardial perfusion by ECG-triggered digital radiography (videodensitometry), using mean transit time (Tmn) as time parameter; this technique is based on the original physiologic principles of indicator dilution theory. This method was validated in 8 instrumented dogs in which an excellent linear relation was present between 1/Tmn and flow (r = 0.96 +/- 0.03). Although this method does not allow assessment of resting flow and therefore coronary flow reserve (CFR), it provides a means for the reliable comparison of maximal myocardial flow in different situations and it is independent of most factors affecting coronary flow reserve. The ratio between maximal flow after and before an intervention is called maximal flow ratio (MFR) and this concept was applied in a pilot study in man to evaluate PTCA results in 10 patients undergoing elective angioplasty. MFR was compared with the result of exercise testing 24 hours before and 10 days after the angioplasty. MFR greater than or equal to 1.5 was always accompanied by reversal of exercise test result from positive to negative. We conclude that the accurate calculation of relative maximal perfusion of the myocardium is possible by videodensitometry and suggest that comparison of maximal flow after and before an intervention can be valuable in man for functional evaluation of the result of the intervention.

Adult↗

PubMed1992

The Hamilton scales and the Hopkins Symptom Checklist (SCL-90). A cross-national validity study in patients with panic disorders.

The HRSD, HRSA, SCL-90 scales were psychometrically investigated in a cross-national sample of patients with varieties of non-psychotic symptoms of anxiety and depression. Across the cultural backgrounds the scores obtained from the original versions of these scales are not sufficient statistics. However, latent structure analysis has identified homogeneous subscales for depression (the HRSD) and for discomfort (an SCL subscale). High concurrent validity was found between the subscales of depression, anxiety and discomfort. In international research, inhomogeneity among scale items can be confounded with group differences which are usually ascribed to drug differences.

Adult↗

PubMed1987

Measurement of regional myocardial perfusion and mass by subselective hydrogen infusion and washout techniques: a validation study.

A technique was developed for measuring regional myocardial perfusion by intracoronary infusions of hydrogen (H2)-saturated saline. H2 concentration was detected during washout in the pulmonary artery by means of the voltage response of a platinum-tipped electrode. Regional myocardial perfusion was calculated from the H2 exponential desaturation curve according to the Kety-Schmidt principle. In 16 anesthetized open-chest dogs, validation of this technique was performed at baseline, reduced (stenosis), and hyperemic (dipyridamole) flow states by means of the radionuclide-labeled microsphere reference withdrawal technique. There was an excellent quadratic correlation between microsphere and H2 washout techniques (range 0.11 to 3.15 ml/min/g) (n = 33, r = .92, y = -0.12x2 + 0.89x + 0.20, SEE = 0.20 ml/min/g; p less than .0001). Hyperemic regional myocardial perfusion was underestimated by H2 washout and severely ischemic regional myocardial perfusion was overestimated. When regional myocardial perfusion values greater than twice normal were excluded, a strong linear correlation was present between H2 and microsphere measurements (n = 27, r = .89, y = 0.76x + 0.22, SEE = 0.18 ml/min/g; p less than .0001). The H2 washout method was further tested in 18 additional open chest dogs for calculations of the mass of an arterial perfusion bed according to the principle that the mass of the bed (g) equals coronary blood flow (ml/min) divided by regional myocardial perfusion (ml/min/g).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1988

[Validation study of the Mannheim Peritonitis Index].

113 patients suffering from purulent peritonitis entered this retrospective study for evaluation of the prognostic value of the Mannheim Peritonitis-Index. There was no lethality below an index x = 21, between x = 21 and x = 29, it was 29% and lethality increased to 100% in patients with an index x greater than or equal to 30. Statistical validation showed that prognosis was correct in 93% for the index x = 27, with a sensitivity and specificity of also 93%. Between x = 21 and x = 29 prognosis of the MPI was correct in at least 65%. The MPI is shown as a prognostic index for peritonitis with high accuracy in individual prognosis, that could be easy routinely documented.

Adolescent↗

PubMed1977

Dream reports and the test of emotional styles: a convergent - discriminant validity study.

Thirty-eight undergraduates completed the forced-choice form of the Test of Emotional Styles and participated in a 4-day dream recall study. Correlational analysis was performed with the three dimensions of emotional style and two dream report aspects as variables. The dimensions failed to correlate significantly with any of the dream report variables, although the dimensions intercorrelated significantly among themselves. Doubt is expressed as to the construct validity of the subscales of the Test of Emotional Styles.

Affect↗

PubMed2026

PCSK9 as a Key Gene of Metastasis in Lung Adenocarcinoma: A Multi-omics and Experimental Validation Study.

BACKGROUND: Lung adenocarcinoma (LUAD) is the most common form of lung cancer. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is abnormally expressed in various tumor tissues and is associated with malignant phenotypes. However, the clinical significance, function, and mechanism of LUAD invasion and metastasis remain unclear. METHODS: We retrospectively enrolled 100 patients with LUAD in this study. Initially, qRT-PCR was performed to detect PCSK9 levels in clinical tissues. Subsequently, bioinformatics analysis of scRNA-seq and The Cancer Genome Atlas Program (TCGA) datasets was performed to predict the role of PCSK9 in tumor cell malignancy and its potential downstream pathways. These predictions were validated experimentally using the CCK-8 assay, TUNEL staining, wound healing, transwell invasion assay, and an in vivo lung metastasis model. Finally, Western blotting and an AKT inhibitor (MK2206) were used to verify the underlying mechanism. RESULTS: PCSK9 was significantly upregulated in LUAD tissues compared to paracancerous tissues and was associated with poorer OS and DFS. Bioinformatics analysis of scRNA-seq data and TCGA analysis predicted that PCSK9 is highly enriched in tumor cells and is involved in EMT, and that the PI3K/AKT pathway plays a significant role in LUAD development. Experiments confirmed that PCSK9 markedly promoted LUAD cell proliferation, migration, and invasion in vitro and lung metastasis in vivo. PCSK9 overexpression significantly upregulated p-AKT, p-PI3K, and p-mTOR levels. Furthermore, the AKT inhibitor, MK2206, reversed the promoting effects of PCSK9. CONCLUSIONS: PCSK9 expression is associated with the prognosis and diagnosis of LUAD. This molecule activates the PI3K/AKT signaling pathway, thereby driving invasion, metastasis, and proliferation in LUAD.

Humans↗

PubMed1988

Multicenter validation study of real-time ultrasonography, arteriography, and pathology: pathologic evaluation of carotid endarterectomy specimens.

The morphologic description and measurements of endarterectomy specimens are usually believed to be accurate and are used as the gold standard against which the findings of diagnostic procedures are judged. Pathology data on 289 endarterectomy specimens from five participating centers and the corresponding angiography and B-mode ultrasonography data provided a basis for scrutinizing the validity of using the morphologic measurements as a standard. Discrepancies of greater than 1 mm between pathology and angiography measurements of minimum residual lumen occurred in 35% of the cases and between pathology and B-mode ultrasonography measurements in 64% of the cases. Discrepancies of greater than 1 mm between pathology- and angiography-measured lesion width occurred in 81% of the cases and between pathology and B-mode ultrasonography measurements in 64% of the cases. The cases representing mismatches of greater than 1 mm at one participating center were subjected to a rigorous review, with remeasurement of all morphologic features, in an attempt to explain the discrepancies. Various types of artifactual distortion of the specimens, the presence of slit-like and occluded lumens that were likely related to loss of perfusion pressure, and an inability to match planes of interrogation used in angiography and B-mode ultrasonography with pathology planes contributed significantly to the existence of mismatches. On the other hand, fixation and decalcification produced minimal and insignificant distortional changes. We conclude that the acquisition of quantitative data from endarterectomy specimens and the acceptance of morphologic data as a standard are limited by a number of problems that can be defined but have been difficult to resolve.

Carotid Arteries↗

PubMed1988

Screening for depressive symptoms among the elderly in Israel. A reliability and validity study.

The Hadassah Elderly Depression Screening Scale (HEDSS)--a modified version of Zung's Self-Rating Depression Scale and Beck's Depression Index--was developed for use among the elderly in Israel. In a sample of 183 elderly residents of Jerusalem, the scale proved to be highly reliable and able to differentiate between persons diagnosed as depressed and those defined as healthy. Moreover, it was found to be valid among subpopulations grouped by sex, education and ethnicity. Various cutoff points were tested for targeting screening at specific populations.

Aged↗

PubMed1989

Quality of the home environment of toddlers: a validation study of the home inventory.

The Home Observation for Measurement of the Environment (HOME) Inventory is introduced in this study to examine the home environments of children (three to four and a half years) in Singapore. The Inventory comprises eight subscales and a total of 54 items with a higher score indicating an environment which provides more possibilities for development and growth. Various statistical tests were carried out to determine the validity of the Inventory for use in the local context. These showed the Inventory to be internally consistent and to possess construct validity in particular the HOME Inventory had been validated in correlation tests with demographic variables such as social class index (F = 8.01, p less than 0.0001), people to room ratio (r = -0.37, p less than 0.0001) and a measure of IQ (r = 0.0003). Norms for local toddlers were also provided. It was concluded that the Inventory would play a useful role in detecting children who are physically and intellectually less advanced due to a poorer home environment. This finding could possibly be used in an intervention programme in ameliorating these conditions.

Child Care↗

PubMed1979

Signal detection theory pain measures: empirical validation studies and adaptation-level effects.

Proponents of the use of signal detection theory (SDT) in the assessment of pain modulation have generally looked for changes in d' to indicate a reduction of sensory function, and a change in criterion to indicate a modification of the subject's response bias or attitudinal predisposition. In the first experiment, both assumptions failed to receive empirical verification. Discrimination d' was eqivalent before and after two strong levels of electrical current was reduced. The criterion parameter appeared to shift in a more conservative direction after the stimulus diminution. These results are used to question the validity of both detection and discrimination indices in the measurement of pain. An alternative means for describing the experimental results revealed a striking adaptation-level effect with implications for the assessment of both experimentally induced and endogenous pain. The outcome of a second experiment reinforced the adaptation-level theory interpretation of the results and provided additional evidence concerning the difficultuies in evaluating SDT parameters in studies of potential analgesics.

Discrimination, Psychological↗

PubMed1987

Patient-initiated postmarketing surveillance: a validation study.

A new patient-initiated, pharmacy-based postmarketing surveillance system is described. At the time a new prescription for a targeted drug was filled, 2705 outpatients (experimentals) randomly assigned to the new system had a printed notice attached to their medication bags: the information requested them to report any "new or unusual symptoms" during the next 2 weeks by a toll-free telephone number to a trained nonprofessional who conducted a standardized adverse drug reaction (ADR) interview. To help validate the new system, another sample of 1109 patients (controls) did not receive a request for self-monitoring but were interviewed by telephone 2 weeks later. Target drugs were chosen from two classes for which side effect profiles are well identified: oral antibiotics and tricyclic antidepressants. Results show that within both drug classes, all patient-initiated reports closely matched those obtained from controls; the experimental and control groups also reported predictably high relative frequencies for the most commonly expected ADRs. Additional analyses suggest that a patient-initiated monitoring system could prove to be a promising complement to existing physician-based surveillance systems.

Adult↗

PubMed1987

Validation studies of a multifactor cognitive-behavioral Anger Control Inventory.

Two studies are reported on a new Anger Control Inventory based on a cognitive-behavioral person-situation interaction model. In Study 1, the inventory responses of 118 clinical subjects and 190 normal subjects were correlated with an anger problem criterion based on observable signs. Factor analyses were conducted to clarify the construct base of the inventory. In Study 2, comparisons were made between the inventory responses of 100 spouse batterers and 96 normal subjects. Significant differences between the pretreatment and posttreatment scores of 65 batterers given treatment in anger control were obtained on the inventory scales, which were found to be correlated with the problem criterion and discriminating between the clinical and normal groups. The construct validity and clinical utility of the Anger Control Inventory are discussed.

Adaptation, Psychological↗

PubMed1991

Impedance measurement of absolute blood flow using an angioplasty catheter: a validation study.

An angioplasty catheter was developed to allow measurement of absolute coronary blood flow during interventional procedures. This method uses electrical impedance changes induced by a 0.5 ml bolus of 5% dextrose solution and indicator-dilution principles. The indicator is injected through a port located just proximal to the dilating balloon and the resulting changes in blood impedance are measured by electrodes at the catheter tip. Excellent linear correlations were found between known flow in 2 to 4 mm to diameter plastic tubes and catheter measurements (r = 0.99) and between timed collection canine femoral artery flow and catheter measurements (r = 0.97). Final validation was performed in canine coronary arteries using electromagnetic flowmeter data as the standard (r = 0.94). Thus accurate clinical determination of absolute coronary blood flow can be accomplished using this relatively inexpensive and simple catheter technique.

Angioplasty, Balloon, Coronary↗

PubMed1984

Radioimmunoassay of fragment E-related neoantigen: validation studies and clinical application.

Measurement of fibrinogen-fibrin degradation products (FDP) levels in plasma may provide a direct index of plasmin action, and increased levels of FDP would indicate coagulopathy. We have established an E-neoantigen radioimmunoassay ( Eneo RIA) that can determine normal and pathological plasma levels of E-related FDP. The assay employs rabbit antiserum produced against fragment E derived from a plasmin digest of fibrinogen and subsequently absorbed with fibrinogen. The absorbed antiserum contains antibodies which are equally reactive with fibrinogen derived E (Fg-E) and fibrin derived E (Fb-E) but not with fibrinogen at 1 mg/ml. The Eneo RIA was validated by assay parallelism and by recovery experiments. Plasma Eneo immunoreactivities in 14 normals were 4-22 ng/ml (mean 12.7 ng/ml). Plasma Eneo levels in 23 of 24 patients with neoplastic and haematological diseases were elevated above normal (range 27-2027 ng/ml). Unusually high Eneo values were observed with three patients whose diseases were complicated by either disseminated intravascular coagulation (DIC) or deep vein thrombosis. After heparin therapy, the Eneo level of a patient with chronic DIC declined. A pathological plasma was eluted from a Sephadex G-200 column and Eneo immunoreactivity was determined on the eluates. The gel filtration pattern of Eneo indicates that E-related FDP is a family of plasmic fragments derived from crosslinked fibrin.

Anticoagulants↗

PubMed1981

A radioisotopic method for the simultaneous quantitation of regional cerebral blood flow and glucose utilization in small dissected samples: validation studies and values in the nitrous oxide-anesthetized rat.

A method is described for the simultaneous determination of the rates of regional cerebral blood flow (rCBF) and regional cerebral glucose utilization (rCMRgl) in 6-7 mg brain samples dissected from multiple areas of interest. The method utilizes [131I]iodoantipyrine ([131I]IAP) to measure rCBF by indicator fractionation, and [14C]2-deoxyglucose to measure rCMRgl. [131I]IAP was synthesized with specific activity exceeding 350 Ci/mmol and radiochemical purity greater than 99.5% by the radioiodination of antipyrine with Na131I. A triple-counting strategy was developed to quantitate 14C activity of the dissected brain samples in the presence of 131I. The factors contributing to the propagated error of the double-label separation strategy were defined and optimal assay parameters were determined. The separation strategy was validated by measuring rCBF simultaneously with both [131I]IAP (x) and [14C]IAP (y) in a series of rats. The equation of the regression line was y = 1.025 x -0.065 (correlation coefficient 0.985), denoting excellent agreement. In another series of 5 normocapnic rats anesthetized with nitrous oxide, rCBF and rCMRgl were measured simultaneously. In individual animals, the rates of rCBF within 14-16 brain areas were closely coupled to their respective rates of glucose metabolism. For the group data, the linear regression equation relating rCBF (y) to rCMRgl (x) was y = 1.76 x + 0.13 (correlation coefficient 0.93, P less than 0.001). These studies provide direct evidence, based upon data obtained in the same brain, of a close coupling of regional metabolic rate and blood flow.

Animals↗