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PubMed2004

Cross-cultural adaptation and validation of the Spanish version of the Calgary Depression Scale for Schizophrenia.

BACKGROUND: The Calgary Depression Scale for Schizophrenia (CDSS) is a valid tool to assess depression in schizophrenics and has been translated, adapted, and validated to be used in different non-English languages. Therefore, it may be predicted that a Spanish version of this scale will be also a valid instrument to assess symptoms of depression in patients with schizophrenia. OBJECTIVE: We determined the validity of the Spanish version of the Calgary scale (CDSS-S). METHODS: Outpatients and inpatients (n=93) diagnosed as having schizophrenia by DSM-IV criteria confirmed by SCID-IV interview were included. The Positive and Negative Syndrome Scale (PANSS), Hamilton Depression Rating Scale (HDRS-17 and HDRS-21 items), Montgomery-Asberg Depression Rating Scale (MADRS), Extrapyramidal Symptoms Rating Scale (ESRS), and Barnes Acathisia Rating Scale were administered by a first rater, whereas the CDSS-S was assessed by a second independent rater. RESULTS: The internal consistency (Cronbach's alpha 0.83) and the interrater reliability (>0.73 intraclass correlation coefficient [ICC] for single items and 0.92 for total score) were good. The test-retest reliability was high (ICC of 0.89). The scale showed a good construct validity with statistically significant correlations with HDRS-17, HDRS-21, MADRS, and G6 item (depression) of PANSS. The CDSS showed no correlation with the positive subscale of PANSS and a weak correlation with the negative subscale, general psychopathology subscale, and total score of PANSS. A cut point of five showed 94.7% sensitivity, 86.5% specificity, and 70% and 98% positive and negative predictive values, respectively. CONCLUSIONS: The Spanish version of CDSS is a valid instrument to assess depressive episodes for stabilized and acute patients with schizophrenia.

Adult↗
PubMed1999

Validity and reproducibility of a food frequency interview in a Multi-Cultural Epidemiology Study.

PURPOSE: There is limited support for the validity and reproducibility of dietary assessment in culturally diverse populations. The goal of this study was to evaluate the comparative validity and reproducibility of a Food Frequency Questionnaire (FFQ) used in the observational, multi-cultural Insulin Resistance Atherosclerosis Study (IRAS). METHODS: Women (n = 186) were approximately equally distributed by ethnicity from one urban center (African Americans and non-Hispanic whites) and one rural center (Hispanics and non-Hispanic whites). The IRAS FFQ was modified from the National Cancer Institute Health Habits and History Questionnaire to include ethnic and regional foods. Validity was assessed by comparing dietary values, including supplements, obtained from the FFQ to the average intake estimated from a series of 8 24-hour dietary recalls collected by telephone over the same 1-year period. Reproducibility was assessed among women who reported no change in their usual diet (n = 133) by comparing data from the original IRAS FFQ (in-person) with the FFQ administered for the validity study (two to four years later, by telephone). RESULTS: Correlation coefficients for validity were statistically significant for most nutrients (mean r = 0.62 urban non-Hispanic white, 0.61 rural non-Hispanic whites, 0.50 African American, 0.41 Hispanic) and did not differ among subgroups of obesity or diabetes status. The median correlation coefficient for the total sample was 0.49. Correlations were lower for women with less than 12 years of education (mean r = 0.30; median r = 0.25). The lower correlations among Hispanics was largely explained by the lower educational attainment in that sample. For reproducibility, the mean correlation for nutrients evaluated was r = 0.62 (median r = 0.63) and did not differ for subgroups. CONCLUSIONS: Although educational attainment must be considered, the IRAS FFQ appears to be reasonably valid and reliable in a diverse cohort.

Adult↗
PubMed2005

Design, format, validity and reliability of multiple choice questions for use in nursing research and education.

Multiple choice questions are used extensively in nursing research and education and play a fundamental role in the design of research studies or educational programs. Despite their widespread use, there is a lack of evidence-based guidelines relating to design and use of multiple choice questions. Little is written about their format, structure, validity and reliability of in the context of nursing research and/or education and most of the current literature in this area is based on opinion or consensus. Systematic multiple choice question design and use of valid and reliable multiple choice questions are vital if the results of research or educational testing are to be considered valid. Content and face validity should be established by expert panel review and construct validity should be established using 'key check', item discrimination and item difficulty analyses. Reliability measures include internal consistency and equivalence. Internal consistency should be established by determination of internal consistency using reliability coefficients while equivalence should be established using alternate form correlation. This paper reviews literature related to the use of multiple choice questions, current design recommendations and processes to establish reliability and validity, and discusses implications for their use in nursing research and education.

Education, Nursing↗
PubMedDate not supplied

Reliability and validity of nutrition knowledge, social-psychological factors, and food label use scales from the 1995 Diet and Health Knowledge Survey.

OBJECTIVE: To test the reliability and validity of scales on nutrition knowledge, social-psychological factors, and use of food labels developed from the 1995 Diet and Health Knowledge Survey (DHKS) questions. DESIGN: The 1995 DHKS questions within a section were pooled together as a scale and their reliability and validity were examined. PARTICIPANTS: US adults (> or =20 years) in the 1995 DHKS who responded to questions selected for this study (n = 1196). VARIABLES: Nutrition knowledge about the diet-disease relationship and nutrient content of products, perceived barriers and benefits of food labels, perceived ease of understanding food labels, food label use, and importance of healthful eating. ANALYSIS: Scales validity, Cronbach alpha, item total correlation, alpha if the item was deleted, and discriminant, convergence, and correspondence validity. RESULTS: Scales on perceived ease of understanding the food label, benefits of using food labels, food label use, and importance of healthful eating were reliable (Cronbach alpha =.78,.82,.91, and.82, respectively) and valid. CONCLUSION AND IMPLICATIONS: Accurate findings and interpretation of survey data depend on the use of reliable and valid instruments. This study identified the scales in the DHKS that can substantiate the conclusion on which effective nutrition education strategies should be established.

Adult↗
PubMed2005

[Internal consistency and validity of the Spanish version of the St. George's respiratory questionnaire for use in patients with clinically stable bronchiectasis].

OBJECTIVE: To analyze the reliability and validity of the St. George's Respiratory Questionnaire (SGRQ) for use in patients with clinically stable bronchiectasis. MATERIAL AND METHODS: The SGRQ (50 items on 3 scales--symptoms, activity, and impact) was administered to 102 patients (mean [SD] age, 69.5 [8.7] years; 63% men) with clinically stable bronchiectasis. Disease severity was classified according parameters such as airflow obstruction (forced expiratory volume in 1 second), colonization by Pseudomonas aeruginosa, extent of bronchiectasis, symptoms, daily quantity of sputum, and number of exacerbations. Internal consistency (Cronbach's alpha and correlation between items and between item and scale), concurrent validity (correlation between items and clinical variables), predictive validity (correlation between items and severity), and construct validity (factorial analysis of main components) were assessed. RESULTS: The internal consistency of the SGRQ was excellent (Cronbach's alpha between 0.81 and 0.87 for the different scales, and 0.90 for the overall score). Concurrent validity was high, as correlations between items and clinical variables were significant and followed the expected distribution. The SGRQ differentiated between degrees of disease severity, regardless of the clinical variable used. The factorial analysis showed a construct of 4 factors that were only moderately similar to the original structure of the questionnaire, due mainly to inclusion of a small number of questions with conditioned response and others with low discriminatory capacity. CONCLUSIONS: The SGRQ shows excellent concurrent and predictive internal consistency and validity, though restructuring of the original construct would be advisable before use in patients with stable bronchiectasis.

Aged↗
PubMed1998

Reliability and validity of a new measure of severity of delirium.

The objective of this study was to assess the psychometric properties of a new instrument, the Delirium Index (DI), to measure changes in the severity of the symptoms of delirium among patients previously diagnosed with delirium. Subjects were medical inpatients aged 65 and over diagnosed with delirium by the Confusion Assessment Method. Interrater reliability of the DI was .78 between research assistants (concordance coefficient) and was .88 between research assistants and geriatric psychiatrists. Criterion validity, assessed by the correlation between DI and Delirium Rating Scale scores (Spearman's correlation coefficient, r), was .84. Construct validity was assessed using correlations of the DI with two measures of current function for convergent validity (r = -.60, -.70) and two measures of function before admission for discriminant validity (r = .26,-.42). We conclude that the DI has acceptable levels of interrater reliability, criterion validity, and construct validity.

Aged↗
PubMed2001

Complete cross-validation and R-factor calculation of a solid-state NMR derived structure.

Cross-validation of a solid-state NMR-derived membrane polypeptide structure is demonstrated. An initial structure has been achieved directly from solid-state NMR derived orientational restraints based on a variety of anisotropic nuclear spin interactions. Refining the molecular structure involves setting up a penalty function that incorporates all available solid-state NMR experimental data and an energy function. A validation method is required to choose the optimal weighting factor for the total penalty function to balance the contribution from the experimental restraints and the energy function. Complete cross-validation has been used to avoid over-fitting the orientational restraints. Such cross-validation involves partitioning of the experimental data into a test set and a working set followed by checking the free R-value during the refinement process. This approach is similar to the method used in crystallography and solution NMR. Optimizing the weighting factor on the penalty function by cross-validation will increase the quality of the refined structure from solid-state NMR data. The complete cross-validation and R-factor calculation is demonstrated using experimental solid-state NMR data from gramicidin A, a monovalent cation channel in lipid bilayers.

Journal Article↗
PubMed2003

Recommendations for the bioanalytical method validation of ligand-binding assays to support pharmacokinetic assessments of macromolecules.

PURPOSE: With this publication a subcommittee of the AAPS Ligand Binding Assay Bioanalytical Focus Group (LBABFG) makes recommendations for the development, validation, and implementation of ligand binding assays (LBAs) that are intended to support pharmacokinetic and toxicokinetic assessments of macromolecules. METHODS: This subcommittee was comprised of 10 members representing Pharmaceutical, Biotechnology, and the contract research organization industries from the United States, Canada, and Europe. Each section of this consensus document addresses a specific analytical performance characteristic or aspect for validation of a LBA. Within each section the topics are organized by an assay's life cycle, the development phase, pre-study validation, and in-study validation. Because unique issues often accompany bioanalytical assays for macromolecules, this document should be viewed as a guide for designing and conducting the validation of ligand binding assays. RESULTS: Values of +/- 20% (25% at the lower limit of quantification [LLOQ]) are recommended as default acceptance criteria for accuracy (% relative error [RE], mean bias) and interbatch precision (%coefficient of variation [CV]). In addition, we propose as secondary criteria for method acceptance that the sum of the interbatch precision (%CV) and the absolute value of the mean bias (%RE) be less than or equal to 30%. This added criterion is recommended to help ensure that in-study runs of test samples will meet the proposed run acceptance criteria of 4-6-30. Exceptions to the proposed process and acceptance criteria are appropriate when accompanied by a sound scientific rationale. CONCLUSIONS: In this consensus document, we attempt to make recommendations that are based on bioanalytical best practices and statistical thinking for development and validation of LBAs.

Carrier Proteins↗
PubMed1989

SAGE II aerosol validation: selected altitude measurements, including particle micromeasurements.

Correlative aerosol measurements taken at a limited number of altitudes during coordinated field experiments are used to test the validity of particulate extinction coefficients derived from limb path solar radiance measurements taken by the Stratospheric Aerosol and Gas Experiment (SAGE) II Sun photometer. In particular, results are presented from correlative measurement missions that were conducted during January 1985, August 1985, and July 1986. Correlative sensors included impactors, laser spectrometers, and filter samplers aboard an U-2-airplane, an upward pointing lidar aboard a P-3 airplane, and balloon-borne optical particle counters (dustsondes). The main body of this paper focuses on the July 29, 1986, validation experiment, which minimized the many difficulties (e.g., spatial and temporal inhomogeneities, imperfect coincidences) that can complicate the validation process. On this day, correlative aerosol measurements taken at an altitude of 20.5 km agreed with each other within their respective uncertainties, and particulate extinction values calculated at SAGE II wavelengths from these measurements validated corresponding SAGE II values. Additional validation efforts on days when measurement and logistical conditions were much less favorable for validation are discussed in an appendix.

Aerosols↗
PubMed2003

Validity of two oral health-related quality of life measures.

OBJECTIVES: To assess the validity of the Oral Impacts on Daily Performance (OIDP) and the short form of the Oral Health Impact Profile (OHIP 14) in the UK. SETTING: Primary care department at a UK dental hospital. SAMPLE: Consecutive patients. METHOD: Cross-sectional comparison of impacts using OIDP and OHIP 14 against clinical findings, Global Oral Health Ratings and pain. RESULTS: A total of 179 patients participated (83.2% response rate). OIDP had weak face validity because it contained contingency questions. Both instruments were developed from the same theoretical model and appeared to have reasonable content validity. In regression analyses, the number of impacts detected by each measure and the total score using OHIP 14 were related to the presence of oral disease and inversely related to age. No suitable transformation could be found to allow regression analysis of OIDP total scores. OHIP 14 correlated more closely with Global Oral Health Ratings but both measures correlated similarly to the experience of pain (0.43 < r < 0.47). The correlation between OHIP and OIDP scores was +0.78. The use of a simple additive method for calculating the total OHIP 14 score did not compromise its validity. CONCLUSION: Both instruments have some validity as measures of Oral Health-Related Quality of Life (OHRQoL) among dental hospital patients. The superior face, criterion and convergent validity and greater amenability to analysis of OHIP 14 render it more suitable for questionnaire-based research and for comparing groups. The additive method may be used to calculate the total score for OHIP 14.

Activities of Daily Living↗
PubMed1999

The validity of self-reported cocaine use in two groups of cocaine abusers.

To evaluate the validity of 2 self-report methods for estimating cocaine use, Timeline Follow-Back (TLFB) and weekly calendar reports from 65 patients with a cocaine use disorder were compared with urine drug test results. The TLFB showed fair to moderate validity, and the weekly calendar showed moderate to high validity in measuring the frequency of cocaine use. Similar results were obtained when the self-report measures were used to time specific cocaine use episodes. In addition to evidence for superiority of the weekly calendar, the validity of self-reports was inversely related to the percentage of positive urine test results. Furthermore, there was some evidence that validity increased as the time window over which the comparisons were drawn increased. Given the central role of self-reports in the clinical and research evaluation of drug use, factors affecting their validity warrant further investigation.

Adult↗
PubMed2000

On the invalidity of validity scales: evidence from self-reports and observer ratings in volunteer samples.

Because of the potential for bias and error in questionnaire responding, many personality inventories include validity scales intended to correct biased scores or identify invalid protocols. The authors evaluated the utility of several types of validity scales in a volunteer sample of 72 men and 106 women who completed the Revised NEO Personality Inventory (NEO-PI-R; P. T. Costa & R. R. McCrae, 1992) and the Multidimensional Personality Questionnaire (MPQ; A. Tellegen, 1978/1982) and were rated by 2 acquaintances on the observer form of the NEO-PI-R. Analyses indicated that the validity indexes lacked utility in this sample. A partial replication (N = 1,728) also failed to find consistent support for the use of validity scales. The authors illustrate the use of informant ratings in assessing protocol validity and argue that psychological assessors should limit their use of validity scales and seek instead to improve the quality of personality assessments.

Adolescent↗
PubMed1997

Racial subgroup differences in predictive validity perceptions on personality and cognitive ability tests.

The relationships between examinees' racial subgroup membership and their perceptions of the predictive validity of a widely used personality test (NEO Five Factor Inventory; P. T. Costa & R. R. McCrae, 1992) and a widely used cognitive ability test (Wonderlic Personnel Test; E. F. Wonderlic, 1984) were examined. Results from 241 undergraduates showed that Black examinees perceived the cognitive ability test as less valid than White examinees, whereas no significant Black-White difference in predictive validity perceptions was observed on the personality test. Results also indicated a significant but small positive association between performance on the cognitive ability test and predictive validity perceptions of the cognitive ability test. Contrary to predictions, there was little evidence that test performance mediated the relationship between race and predictive validity perceptions on the cognitive ability test. Conversely, predictive validity perceptions did not appear to account for any substantial portion of the racial subgroup differences in test performance.

Adult↗
PubMed2001

Implications of empirical Bayes meta-analysis for test validation.

Empirical Bayes meta-analysis provides a useful framework for examining test validation. The fixed-effects case in which rho has a single value corresponds to the inference that the situational specificity hypothesis can be rejected in a validity generalization study. A Bayesian analysis of such a case provides a simple and powerful test of rho = 0; such a test has practical implications for significance testing in test validation. The random-effects case in which sigma2rho > 0 provides an explicit method with which to assess the relative importance of local validity studies and previous meta-analyses. Simulated data are used to illustrate both cases. Results of published meta-analyses are used to show that local validation becomes increasingly important as sigma2rho increases. The meaning of the term validity generalization is explored, and the problem of what can be inferred about test transportability in the random-effects case is described.

Bayes Theorem↗
PubMed2004

The concept of validity.

This article advances a simple conception of test validity: A test is valid for measuring an attribute if (a) the attribute exists and (b) variations in the attribute causally produce variation in the measurement outcomes. This conception is shown to diverge from current validity theory in several respects. In particular, the emphasis in the proposed conception is on ontology, reference, and causality, whereas current validity theory focuses on epistemology, meaning, and correlation. It is argued that the proposed conception is not only simpler but also theoretically superior to the position taken in the existing literature. Further, it has clear theoretical and practical implications for validation research. Most important, validation research must not be directed at the relation between the measured attribute and other attributes but at the processes that convey the effect of the measured attribute on the test scores.

Humans↗
PubMed2003

The abbreviated multidimensional acculturation scale: empirical validation with two Latino/Latina samples.

Two studies were conducted to develop and examine internal consistencies and validate the Abbreviated Multidimensional Acculturation Scale. Study 1 participants were 156 Latino/Latina college students. Findings indicated good internal reliabilities for all 3 subscales. Adequate concurrent validity was established with length of residence in the United States. The scale also showed adequate convergent and discriminant validity. Study 2 participants were 90 Latino/Latina community members. The subscales were also reliable and showed adequate concurrent validity with length of residence in the United States. Convergent and discriminant validity were also adequate. Construct validity was further demonstrated through factorial analyses of the combined samples (N = 246). Three separate factors emerged: cultural identity, language competence, and cultural competence.

Acculturation↗
PubMed2003

Development and validation of the Diabetes Bowel Symptom Questionnaire.

BACKGROUND: Although gastrointestinal symptoms occur frequently, there is no validated measure of gastrointestinal symptoms in patients with diabetes mellitus. AIM: To develop the Diabetes Bowel Symptom Questionnaire. METHODS: A questionnaire derived from previously validated symptom measures was compiled to assess all relevant gastrointestinal and diabetes items. Face and content validity were ascertained by expert review. One hundred and sixty-eight patients with diabetes mellitus completed the instrument, and reliability was evaluated by a test-re-test procedure 1 week later. Concurrent validity was evaluated by an independent physician interview (n = 33). Measures of glycaemic control (glycated haemoglobin and plasma glucose) were compared with self-reported glycaemic control on a five-point Likert scale in diabetic out-patients (n = 166). RESULTS: The questionnaire had adequate face and content validity. There was good to excellent test-re-test reliability for the gastrointestinal and diabetes items (median kappa: 0.63 and 0.79, respectively); concurrent validity was good to excellent (median kappa: 0.47 and 0.65, respectively), except for the items assessing the severity of gastrointestinal symptoms. Both glycated haemoglobin (P < 0.0001) and plasma glucose (P = 0.005) correlated significantly with self-reported glycaemic control. CONCLUSION: The Diabetes Bowel Symptom Questionnaire appears to be a useful measure of gastrointestinal symptoms and glycaemic control in diabetes mellitus, and should have applicability in epidemiological and clinical studies.

Adult↗
PubMed2000

Validation of a population pharmacokinetic model for adjunctive lamotrigine therapy in children.

AIMS: This analysis was performed to validate a previously developed population pharmacokinetic model for lamotrigine in order to establish a basis for dosage recommendations for children. METHODS: (a) The importance of the covariates in the final model was confirmed using the model validation dataset. Population and individual (Bayesian estimate) pharmacokinetic parameters were estimated using both the initial model, which included none of the covariates, and the final model. Accuracy and precision of parameter estimation and of concentration prediction were compared between the two models. (b) The performance in predicting the validation concentrations by the final model parameters obtained previously from the model development dataset was assessed. (c) The parameters of the final model were refined using a dataset combining both the development and validation data. RESULTS: Prediction performance of the final pharmacostatistical model was superior to that of the initial model. The results of the validation confirmed that concomitant antiepileptic drugs that increased or reduced lamotrigine clearance in adults had similar effects in children. The validation also verified the linear relationship between weight and clearance. The previously seen small sex effect on clearance was found statistically insignificant. CONCLUSIONS: The current analysis confirmed the previous findings. To achieve the same concentrations, children receiving enzyme-inducing antiepileptic drugs without valproate require higher doses than those receiving valproate; and heavier children require higher doses.

Adolescent↗