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Results for “validation study”

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PubMed1991

Siriraj stroke score and validation study to distinguish supratentorial intracerebral haemorrhage from infarction.

OBJECTIVES: To develop a simple, reliable, and safe diagnostic tool for acute stroke syndromes in a setting where computerised brain scanning was not readily available and to validate its accuracy with regard to pathological types of stroke. DESIGN: 13 clinical variables that potentially might differentiate supratentorial cerebral haemorrhage from infarction were recorded and tested by multivariate analysis in a prospective study of 174 patients with acute stroke. In developing the Siriraj stroke score stepwise discriminant analysis of the variables was followed by a linear discriminant equation to differentiate between supratentorial haemorrhage and infarction. The score obtained was validated against scores in 206 other patients with stroke, computerised brain scans being used for definitive diagnosis. SETTING: Siriraj Hospital Medical School, Mahidol University, Bangkok. SUBJECTS: Prospective study: 174 consecutive patients with acute supratentorial stroke syndrome (not subarachnoid haemorrhage) admitted to Siriraj Hospital during 1984-5; validation study: 206 patients admitted to Siriraj Hospital or another hospital for supratentorial intracerebral haemorrhage or infarction. RESULTS: The Siriraj stroke score was developed and calculated as (2.5 x level of consciousness) + (2 x vomiting) + (2 x headache) + (0.1 x diastolic blood pressure) - (3 x atheroma markers) - 12. A score above 1 indicates supratentorial intracerebral haemorrhage, while a score below -1 indicates infarction. The score between 1 and -1 represents an equivocal result needing a computerised brain scan or probability curve to verify the diagnosis. In the validation study of the Siriraj stroke score the diagnostic sensitivities of the score for cerebral haemorrhage and cerebral infarction were 89.3% and 93.2% respectively, with an overall predictive accuracy of 90.3%. CONCLUSION: The Siriraj stroke score is widely accepted and applied in hospitals throughout Thailand as a simple and reliable bedside method for diagnosing acute stroke.

Acute Disease↗

PubMed1990

Validation studies from the Western Australian Congenital Malformations Registry.

A series of studies was undertaken in 1989 to validate the data held by the Western Australian Congenital Malformations Registry. Comparison with hospital discharge data identified 1585 children six years of age or younger with malformations discharged from hospitals in Western Australia in 1986, 226 of whom were not already recorded on the Congenital Malformations Register. When the records of a special register for cleft lip and palate were examined, all cases of facial cleft known to the special register were also recorded on the Malformations Register. Comparison of the Western Australian data for major groups of malformations with data from the South Australian Birth Defects Register raised the possibility of under ascertainment in Western Australia of cases of congenital heart disease. Multiple sources of ascertainment and evaluation of the ways in which such sources are tapped are important factors in striving for complete and accurate information on congenital malformations for research and public health purposes.

Child, Preschool↗

PubMed1987

A validation study of three anxiety and depression self-assessment scales.

All measuring instruments require further validation both in the setting for which they were designed and in other fields. The Hospital Anxiety and Depression Scale was designed for detection and assessment of those mood disorders in the setting of hospital medical and surgical clinics. Reasons are given for supposing it has advantages over other similar scales. The present study undertakes a further validation of the scale in a general hospital setting. The opportunity is taken to assess the usefulness, in this setting of the Irritability Depression and Anxiety Scale and also of two subscales of the General Health Questionnaire, the one relating to the concept of depression and the other to the concept of anxiety. Score ranges of the latter two subscales are suggested and will require replication for confirmation of their usefulness.

Ambulatory Care Facilities↗

PubMed1986

A validity study of a new rating scale for psychiatric patients.

A criterion validation of a new scale, REHAB (Rehabilitation Evaluation Hall And Baker) (1) is described. Forty-three long-stay psychiatric patients from two wards were observed by a psychologist over a 2-week period using a time sampling procedure. The observed behaviour was coded into predetermined categories based on Blunden & Kushlick's (2) concept of engagement. Also during this period the ward nurses rated the 43 patients using the REHAB assessment. The time sampled observations were correlated with REHAB factors and items. Five hypotheses about the relationship between the two measures were tested. Four of the five hypotheses were supported by the data. Overall, despite certain limitations of the study, it is concluded that evidence is provided for the criterion validity of REHAB.

Activities of Daily Living↗

PubMed1992

Bioelectrical impedance estimation of fat-free body mass in children and youth: a cross-validation study.

The purposes of this study were to develop and cross-validate the "best" prediction equations for estimating fat-free body mass (FFB) from bioelectrical impedance in children and youth. Predictor variables included height2/resistance (RI) and RI with anthropometric data. FFB was determined from body density (underwater weighing) and body water (deuterium dilution) (FFB-DW) and from age-corrected density equations, which account for variations in FFB water and bone content. Prediction equations were developed using multiple regression analyses in the validation sample (n = 94) and cross-validated in three other samples (n = 131). R2 and standard error of the estimate (SEE) values ranged from 0.80 to 0.95 and 1.3 to 3.7 kg, respectively. The four samples were then combined to develop a recommended equation for estimating FFB from three regression models. R2 and SEE values and coefficients of variation from these regression equations ranged from 0.91 to 0.95, 2.1 to 2.9 kg, and 5.1 to 7.0%, respectively. As a result of all cross-validation analyses, we recommend the equation FFB-DW = 0.61 RI + 0.25 body weight + 1.31, with a SEE of 2.1 kg and adjusted R2 of 0.95. This study demonstrated that RI with body weight can predict FFB with good accuracy in Whites 10-19 yr old.

Adipose Tissue↗

PubMed1989

Emotional indicators in the human figure drawings of hearing-impaired children: a small sample validation study.

The use of human figure drawings as projective personality assessment techniques is a well-established practice among psychological service providers to hearing-impaired children yet few studies have shown these techniques to be valid indicators of emotional functioning in any population. The purpose of the present work is to establish concurrent validity for the Koppitz scoring technique in a sample of 7- to 12-year old hearing-impaired students. Results indicate that the Koppitz technique shows a positive correlation with emotional status as measured on the Stress Response Scale. The Koppitz technique is especially sensitive to impulsive and passive-aggressive types of response modes.

Child↗

PubMed2026

Predicting 5-Year Mortality in Non-Small-Cell Lung Cancer Using the Korean Central Cancer Registry: Model Development and Validation Study.

BACKGROUND: Non-small-cell lung cancer (NSCLC) is one of the most common cancers and a leading cause of cancer-related mortality, making prognostic prediction clinically essential. Machine learning models are increasingly used to assess prognosis; however, developing systems that combine high discrimination with clear, clinically interpretable reasoning remains challenging. OBJECTIVE: This study aimed to develop deep learning models that predict 5-year mortality in NSCLC using data from the Korea Central Cancer Registry and quantify feature importance through permutation testing. METHODS: We identified 3144 patients diagnosed between 2014 and 2017 who had complete clinical data, pulmonary function test results, histological information, genomic data, and staging details. After preprocessing, the cohort was divided into stratified training, validation, and test sets in a 70%-15%-15% ratio. Five models were tuned using Hyperband across 10 predefined feature groups. The primary evaluation metric was the area under the receiver operating characteristic curve (AUC); additional metrics included accuracy, F1-score, precision, and recall. Groupwise permutation importance was calculated for each model, and the concordance of importance rankings was assessed using the Friedman test. RESULTS: All 5 models yielded comparable discrimination values on the test set (AUC=0.875-0.879). Model A was selected as the primary model and achieved an AUC of 0.879, an accuracy of 0.806, an F1-score of 0.824, and a Brier score of 0.142. Permuting the stage resulted in the largest decrease in AUC (0.217), followed by the pulmonary function test (0.016). Gene mutation had a modest overall impact but became more influential within the adenocarcinoma subset. The Friedman test showed no statistically significant differences in importance rankings across the models (P=.93). CONCLUSIONS: A grouped-input deep learning framework achieved discrimination comparable to a conventional Cox proportional hazards model using the same routine clinical variables for 5-year mortality prediction in NSCLC. Group-level permutation importance provided stable and reproducible insights into the clinical factors influencing risk, which may guide future model refinement and clinical decision-making.

Humans↗

PubMed1990

Psychosocial vulnerability, life stress, and suicide ideation in a jail population: a cross-validation study.

The purpose of this present investigation was to cross-validate a stress-psychosocial vulnerability model of suicidal ideation and behavior in a jail population. Measures of social alienation, cognitive distortions, adaptive resources, situational (jail environment) stress, depression, hopelessness, and suicide ideation were administered to 146 male inmates at a county jail facility. It was predicted that each of the vulnerability factors, in addition to jail stress, would be significantly related to suicide ideation among inmates. Furthermore, it was hypothesized that psychosocial vulnerability among inmates would interact with jail stress to best explain suicide intent. The result of a multiple-regression analysis, stepwise forward-inclusion algorithm, indicated that 51% of the variation in suicide ideation could be accounted for by the linear combination of low reasons for living, irrational beliefs, jail stress, and loneliness. In addition, when the variables were entered into a hierarchical multiple-regression model, interactions between select psychosocial vulnerability factors and jail stress were found to best explain suicide intent. Results of the study are discussed in terms of the proposed model, and implications for future research and prevention efforts in jail suicide are noted.

Adaptation, Psychological↗

PubMed1987

Minuchin's psychosomatic family model revised: a concept-validation study using a multitrait-multimethod approach.

The convergent and discriminant validity of three operationalizations of the psychosomatic family features--enmeshment, rigidity, overprotectiveness, and lack of conflict resolution, as described by Minuchin and colleagues--are tested in families that include patients with eating disorders, especially anorexia nervosa and bulimia. We redefined the family features as dimensions and measured them with two behavioral methods (direct observation and behavioral product) and a self-report method. The two behavioral methods showed convergent as well as discriminant validity for the intensity of intrafamilial boundaries, the degree of the family's adaptability, and the family's way of handling conflicts. The self-report method showed only convergent validity for the latter dimension and discriminant validity for none of them. Besides intrafamilial conflict, the self-report method seemed to measure other constructs. A factor analysis of the family questionnaire indeed yielded three more evaluative constructs: conflict, cohesion, and disorganization. We interpreted these findings according to two usually interwoven mechanisms: the different research context (insider/outsider evaluation) in self-report and behavioral observation, and the different level of specification (micro/global evaluation) of certain operationalizations. We draw some conclusions about the psychosomatic family model and discuss the clinical implications of our findings.

Adaptation, Psychological↗

PubMed1992

Arousability and stress-related physical symptoms: a validation study of Coren's arousal predisposition scale.

Coren's Arousal Predisposition Scale was validated against 249 college students' self-ratings of stress-related physical symptoms and an item that assessed general level of health. As we predicted, the 126 high-arousability subjects were substantially higher in mean stress-related symptoms score and lower in general health than the 123 peers low in arousability. These data suggest that the Arousal Predisposition Scale may be a useful instrument in the study of human stress.

Adult↗

PubMed1988

Validation studies for brain blood flow assessment by radioxenon tomography.

A tomographic technique has been used recently for cerebral blood flow measurements with inhaled radioxenon. Based on experiments in a specially developed dynamic phantom and on studies in primates in vivo, we have analyzed the validity of this method for measurements of both regional and total blood flow in the brain. We have also examined the errors introduced into flow computations as a function of changes in such parameters as: rate of xenon input, size of region of interest, magnitude of regional flow rates, and inter-regional flow differences. Our findings indicate a reasonable degree of accuracy for flow measurements in gray matter regions that are 3 cm in diameter or larger, while white matter blood flow is generally overestimated. The accuracy for regional flow assessments degrades as a function of: diminishing region size, increasing inter-regional flow differences, and flow rates in excess of 100 ml/100 g/min. Measurements for brain regions 2 cm or smaller in diameter can be in error by 25-50% as a result of partial volume averaging. Although the technique is not ideal for accurate flow measurements in small regions of the brain, it nevertheless provides a convenient means of assessing perfusion in major vascular territories of the brain in routine clinical applications.

Animals↗

PubMed1992

Separation-individuation, family functioning, and psychological adjustment in college students: a construct validity study of the Separation-Individuation Test of Adolescence.

We evaluated the construct validity of the Separation-Individuation Test of Adolescence (SITA; Levine, Green, & Millon, 1986). Based on a review of the theoretical literature on separation-individuation issues during late adolescence, predictions were made as to how SITA scores would correlate with aspects of family functioning and psychological adjustment. The SITA and a battery of self-report family and adjustment measures were administered to 454 college students (272 females and 182 males; 74% White, 16% African American, and 10% Asian American or Hispanic). Correlational analyses offered partial support for the construct validity of the SITA. Cluster analyses revealed four distinct groups of subjects (anxious deniers, healthy separators, peaceful detachers, and succorance seekers), each with its own coherent set of scores on the SITA and instruments measuring family relations and positive and negative psychological adjustment. Criticisms concerning the labels and composition of the SITA scales are also discussed.

Adaptation, Psychological↗

PubMed2026

Simultaneous determination of imiquimod and terbinafine in skin permeation studies: Validation of a liquid chromatography method with fluorescence detection.

Chromoblastomycosis is a chronic, neglected subcutaneous mycosis posing significant therapeutic challenges. A topical strategy combining terbinafine (TBF), an antifungal, with imiquimod (IMQ), a TLR-7/8 agonist immunomodulator, has emerged a promising alternative. However, no validated analytical method is currently available to simultaneously quantify both drugs in skin, which is crucial for novel formulation development. This study reports the development and validation of a simple HPLC method with fluorescence detection (excitation 236 nm, emission 340 nm) for the simultaneous determination of TBF and IMQ extracted from porcine skin. Separation was achieved on a C8 reversed-phase column (125 × 4.0 mm, 5 μm) using a mobile phase of methanol and water (60,40, v/v), both containing 0.1% formic acid at a flow rate of 0.8 mL/min. The method showed excellent linearity (r > 0.999) over 0.01-1.0 μg/mL for IMQ and 0.1-2.0 μg/mL for TBF. Intra- and inter-day precision demonstrated coefficients of variation below 5%, and recovery rates from skin (79-105%) confirmed accuracy. Limits of detection were 0.001 μg/mL for IMQ and 0.004 μg/mL for TBF, with quantification limits of 0.02 μg/mL and 0.16 μg/mL, respectively. This selective, sensitive, and reproducible method represents a valuable analytical tool for supporting the development and quality control of topical formulations for chromoblastomycosis and other fungal skin diseases.

Animals↗

PubMed1989

[The use of the impedance measurement technic for calculating body fat mass. A validity study].

The body composition of water and fat may be calculated on the basis of measurements of its impedance. Calculations are based on algorithms developed by all measurements of the body compositions of a reference material, by means of standard methods (eg hydrodensiometry, total body water by isotope dilutimetry). A commencial impedance analyser with built-in algorithm for calculation of total body water and body fat mass was evaluated and compared with measurements of the total body water in 42 young men and women. Very good agreement was found (mean values for total water were 34.2 and 33.5, respectively, for women and 46.8 and 47.0, respectively, for men). These calculations of total body water correlated better with the reference values than calculations from four other algorithms published in the literature. Simple anthropometric measurements (skin-fold thickness, BMI) resulted in significantly higher calculations of body fat mass than calculations based on impedance measurement. This study has shown that the technique of impedance measurement has good reliable validity for calculation of the body fat mass and that, on account of its simplicity, the method is suitable for field studies and also individual measurements.

Adipose Tissue↗

PubMed1985

The "case-control" study: valid selection of subjects.

For valid selection of subjects in "case-control" (case-referent) studies it is critical to understand that these studies do not represent an alternative to cohort studies but, rather, to census-ascertainment of the facts about the study base. Specifically, in these studies, the fact-finding scheme is to obtain a census of the study base with respect to outcome, and then a census of the cases together with a sample of the base to gather information on the determinant(s) as well as modifiers and confounders. If the base is defined a priori (primary base), then the challenge is to devise a scheme to obtain a census of the cases in it and a sample of the base itself ("control" or reference series) that is representative of it, conditional on the covariates that will be controlled in the analysis of the data. On the other hand, if the definition of the base is secondary, a corollary of the way the cases are selected, then the case series is best viewed as the totality of the cases in the base as a matter of definition. The corresponding secondary base is the population experience in which each potential case, had it occurred, would have been included in the case series. Representative sampling of a secondary base tends to call for the use of subjects coming to the source of cases because of other conditions--conditions whose occurrence is known to be unrelated to the determinant under study and whose diagnosis and referral to the source are known to have the same relation to the determinant as those of the illness under study. With both types of base, primary and secondary, the accuracy of the information on the determinant should be comparable between the case and reference series, and this requirement of comparability, just as that of representativeness, can have important implications for the selection of the study subjects.

Epidemiologic Methods↗

PubMed1990

A discriminant validity study of negative symptoms with a special focus on depression and antipsychotic medication.

If the construct validity of the negative symptom syndrome is to be established, the conceptual and operational overlap between negative symptoms and other syndromes such as depression and the effects of medication must be explained. The author assessed 26 patients with schizophrenia and 21 patients without schizophrenia, most of whom had depression, at the end of an average 2-week drug washout period and after approximately 2 months of psychotropic medication administration. Negative symptoms were remarkably consistent in patients with schizophrenia despite pharmacological intervention. In contrast, the patients without schizophrenia manifested significant decreases in negative symptoms.

Adult↗

PubMedDate not supplied

A cross-validation study for predictors of scores on state board examinations.

Regression equations were computed and cross-validated for predicting nurses' scores on each of the five state board examinations (SBEs). Scores on five National League for Nursing (NLN) achievement tests of 101 nurses who graduated from a baccalaureate program between 1968 and 1972 were used as predictor variables. Stepwise regression analysis was used to compute the equations which were, in turn, used to predict the SBE scores for an independent sample of nurses who graduated in 1973. Cross-validation correlations between the predicted and actual obtained scores of the 1973 graduates ranged from .64 to .81. For each equation, the NLN test scores in Nursing of Children and Obstetric Nursing were consistently the best indicators of performance on the SBEs. Additionally, a factor analysis indicated that the SBEs do not measure independent entities, but that all five examinations have high loadings on the same factor. The results suggest that nursing programs should develop and validate prediction equations to assist nurses in preparing for SBEs.

Achievement↗

PubMed1989

A factorial, reliability, and validity study of the Devereux Elementary School Behavior Rating Scale.

This investigation explored the factor structure, reliability, and validity of the Devereux Elementary School Behavior Rating Scale, employing a large (n = 648) sample of children. Factor analysis suggested that the Devereux scale can be described by four factors, which were named Disruptive-Oppositional, Poor Comprehension-Disattention, Cooperative-Initiating, and Performance Anxiety. All four factors showed high internal consistency, and three of the four were stable over a 17-mo. period. Correlations of the four factors with academic achievement, IQ, socioeconomic status, and peer ratings of social competence are presented. All four factors showed significant relations with these variables, with Poor Comprehension-Disattention the strongest of all. Multiple regression analysis indicated that the Poor Comprehension-Disattention factor accounted for significant variance in academic achievement even after IQ was taken into account. Large differences between classroom means on the factor scores suggested that Devereux ratings for individual students may need to be interpreted cautiously.

Achievement↗