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PubMed1995

On the utility of the West Haven-Yale Multidimensional Pain Inventory.

STUDY DESIGN: Two studies evaluated the West Haven-Yale Multidimensional Pain Inventory. This 52-item inventory contains 12 scales divided into 3 parts: 1) interference, support, pain severity, self-control, and negative mood; 2) punishing responses, solicitous responses, and distracting responses; and 3) household chores, outdoor work, activities away from home, and social activities. OBJECTIVES: The objective of study 1 was to investigate the internal structure of the Multidimensional Pain Inventory and its demographic correlates. The objective of study 2 was to explore its external correlates (construct validity). SUMMARY OF BACKGROUND DATA: The Multidimensional Pain Inventory appears promising because of its brevity, scope, ease of administration, and initial results. Despite this, it has attracted very little attention in the orthopedic literature since its introduction nearly a decade ago. METHOD: The internal structure was examined using oblique multiple group confirmatory factor analysis. Demographic correlates were examined using discriminant analysis. The external correlates were examined using multiple regression and discriminant analysis. RESULTS: The items' proposed structure fit well except that two pairs of scales are poorly separated: 1) activities away from home and social activities, and 2) solicitous responses and distracting responses. Correlations with external criteria are meaningful. CONCLUSIONS: The Multidimensional Pain Inventory meets standards of reliability and convergent validity, and it may be an improvement over current psychometric devices used to this same end.

Black or African American↗
PubMed2004

[Twenty-four months of external control of fluoride levels in the public water supply in Pelotas, Rio Grande do Sul, Brazil].

The aim of the present study was monthly evaluation of fluoride levels in the public water supply in Pelotas, Rio Grande do Sul State, Brazil, and the validity of forming external control groups. Pelotas was divided into 16 geographic regions, including the three public water treatment stations. Water samples were collected from November 1999 to October 2001. Two samples were drawn from each region. Samples were sent to the Fluoride Health Surveillance Laboratory at Universidade do Vale do Itajaí. Fluoride analysis used an electrometric method (Orion 920 A/Electrometer Orion 9609). After 24 months, 764 samples were collected, demonstrating a discontinuity in the fluoride levels. There was an increase in the number of samples with an ideal concentration of fluoride. However, several points with excessive fluoride levels (> 0.9ppmF) also appeared. Based on these results it was concluded that external control is essential for monitoring fluoride levels in the public water supply.

Brazil↗
PubMed2002

Andragogy and medical education: are medical students internally motivated to learn?

Andragogy - the study of adult education - has been endorsed by many medical educators throughout North America. There remains, however, considerable controversy as to the validity and utility of adult education principles as espoused by the field's founder, Malcolm Knowles. Whatever the utility of andragogic doctrine in general education settings, there is reason to doubt its wholesale applicability to the training of medical professionals. Malcolm Knowles' last tenet of andragogy holds that adult learners are more motivated by internal than by external factors. The validity of this hypothesis in medical education is examined, and it is demonstrated that medical students' internal and external motivation are context-dependent, not easily distinguishable, and interrelate with one another in complex ways. Furthermore, the psychological motivation for medical student learning is determined by a variety of factors that range from internal to external, unconscious to conscious, and individual to societal. The andragogic hypothesis of increased internal motivation to learn on the part of adults in general, and medical trainees in particular, is rejected as simplistic, misleading, and counterproductive to developing a greater understanding of the forces that drive medical students to learn.

Adult↗
PubMed2006

Enhancing validity in co-occurring disorders treatment research.

Despite the high prevalence of co-occurring mental health and substance-use disorders, there has been a relative lack of treatment research with this population, and the existing research often has limited validity. This article explores some of the barriers to the conduct of research on promising interventions for substance-abuse treatment for people with co-occurring disorders, using the concepts of external and ecological validity to make recommendations for future investigation. The central recommendation is to move rapidly from efficacy studies to more credible and valid effectiveness studies, in order to facilitate the adoption of evidence-based interventions in routine practice settings.

Comorbidity↗
PubMed1987

Factorial dimensions of the Revised Behavior Problem Checklist: replication and validation within a kindergarten sample.

The factor structure of the Revised Behavior Problem Checklist (RBPC) was examined in a large sample of suburban kindergarten children. Teacher-rated dimensions of Conduct Disorder, Attention Problems-Immaturity, Anxiety-Withdrawal, and Psychotic Behavior were closely replicated, and a new factor labeled Unmotivated-Isolated was also revealed. These principal components were consistent across gender and across subsamples of children differing as to risk status for learning failure. Evidence was found for the divergent validity of the externalizing dimensions of Conduct Disorder and Attention Problems-Immaturity with respect to criterion measures of alternative behavior ratings, cognitive functioning, and academic achievement. Parent-rated components of Conduct Disorder, Attention Problems-Immaturity, Hyperactive-Impatient, Tense-Withdrawn, Anxiety, and Passive-Conforming were less clearly validated, and parent-teacher agreement was modest. It was concluded that the RBPC shows promise for the assessment of preschool-aged children and that narrow-band externalizing dimensions of inattentive versus conduct-disordered behavior are reasonably distinct at this age.

Anxiety Disorders↗
PubMed1999

Identification of responders to a therapy: an example of validation of a predictive model.

The general objective of randomized clinical trials is to assess if the treatment effect on a given population is clinically meaningful. In this way, one obtains an average estimate of the treatment effect over the trial population. However, a growing need for medical practitioners is to be able to predict with sufficient precision the efficiency of a given treatment for a given patient. There is little information in the literature about this issue. We have previously proposed a treatment-startified Cox model including interaction between treatment and patient's covariates, to identify and predict the responders to a therapy. In this paper, we focus on the assessment of the predictive power of the model. The performance of the predictive model for a population and for an individual was statistically validated internally and externally from several aspects. The prediction correlates well with the observation. Thus, we suggest that this approach would be useful in identifying and predicting the responders to a therapy, subject to an appropriate and more extensive validation process in real setting.

Female↗
PubMed1991

Internal and external fixation in complex diaphyseal and metaphyseal fractures of the humerus.

The treatment of diaphyseal and metaphyseal fractures of the humerus is often controversial, especially when these fractures are complex and/or unstable (i.e. comminuted, segmental, or with a butterfly fragment). The authors review the indications, advantages, and disadvantages of various open and closed procedures, concluding that a combination of internal and external fixation is a valid treatment for these fractures. The purpose of the external fixation is immediate stabilization of the fracture, which is difficult if not impossible with intramedullary internal fixation alone. Internal fixation devices (Rush rods or "anchor" nails introduced by closed means) make it possible to align the fracture, facilitating application of the external fixator, and at the same time promote rapid healing. Fractures treated by this method healed in an average of 2 1/2 months, without residual functional limitations of the shoulder or elbow.

External Fixators↗
PubMed2006

Comparison between external and internal standard calibration in the validation of an analytical method for 1-hydroxypyrene in human urine by high-performance liquid chromatography/tandem mass spectrometry.

1-Hydroxypyrene is a metabolite of pyrene, a member of the class of polycyclic aromatic hydrocarbons (PAHs) whose toxic properties in some cases include carcinogenicity. The determination of 1-hydroxypyrene in human urine is used as a biological indicator for exposure to PAHs, which is related to the combustion of organic materials, like smoking, living in urban environments, and eating grilled or smoked food. The determination of 1-hydroxypyrene by high-performance liquid chromatography (HPLC) with fluorescence detection has very good sensitivity but it is not highly specific: this can reduce accuracy in the quantitative determination of low levels of analyte in a complex matrix like urine. An HPLC method that uses triple quadrupole mass detection has been validated with the objective both to improve the signal-to-noise (S/N) ratio and to achieve the maximum specificity for the analyte in those urine samples that are richer in possible inteferents. The calibration range for 1-hydroxypyrene is from 0.005-0.1 microg/L in the urine of non-smoking healthy volunteers. After solid-phase extraction, samples were analyzed by HPLC/tandem mass spectrometry (MS/MS) in the multiple reaction monitoring (MRM) mode. In order to obtain reliable results quantitative analysis must be performed by means of the internal standard method (we used deuterium-labelled 1-hydroxypyrene): the method accuracy is not less than 85%. The S/N ratio at a concentration of 0.1 microg/L is about 10, and therefore this can be considered the lowest limit of quantitation. The method performance does not change if urine samples are measured using a calibration curve prepared in methanol, thus reducing the time of analysis and costs.

Biomarkers↗
PubMedDate not supplied

The Bournemouth Questionnaire: a short-form comprehensive outcome measure. II. Psychometric properties in neck pain patients.

OBJECTIVE: To modify an existing outcome measure (Bournemouth Questionnaire [BQ]) for use in patients with nonspecific neck pain and test its psychometric properties. DESIGN: Prospective longitudinal study in which the questionnaire was administered on 3 occasions (pretreatment, retest, and posttreatment). SETTING: Anglo-European College of Chiropractic outpatient clinic and 8 field chiropractic practices. METHOD: Seven core items relating to the biopsychosocial model of pain were included in the original questionnaire (back BQ). The wording of one of these items (disability in activities of daily living) was modified to include activities likely to be affected by neck pain. Testing of the neck BQ was carried out in 102 patients with nonspecific neck pain. RESULTS: The instrument demonstrated high internal consistency on 3 administrations (Cronbach's alpha = 0.87, 0.91, 0.92). All 7 items were retained on the basis that they each significantly contributed to the total score (item-corrected total score correlations >0.43) and to the instrument's responsiveness to clinical change (item change-corrected total change score correlations >0.42). The instrument was reliable in test-retest administrations in stable subjects (ICC = 0.65). The instrument demonstrated acceptable construct validity and longitudinal construct validity with established external measures. The treatment effect size of the instrument was found to be high (1.67). CONCLUSION: The neck BQ covers the salient dimensions of the biopsychosocial model of pain, is quick and easy to complete, and has been shown to be reliable, valid, and responsive to clinically significant change in patients with nonspecific neck pain. Its use as an outcome measure in clinical trials and outcomes research is recommended.

Activities of Daily Living↗
PubMedDate not supplied

Atom-type-based AI topological descriptors: application in structure-boiling point correlations of oxo organic compounds.

Structure-boiling point relationships are studied for a series of oxo organic compounds by means of multiple linear regression (MLR) analysis. Excellent MLR models based on the recently introduced Xu index and the atom-type-based AI indices are obtained for the two subsets containing respectively 77 ethers and 107 carbonyl compounds and a combined set of 184 oxo compounds. The best models are tested using the leave-one-out cross-validation and an external test set, respectively. The MLR model produces a correlation coefficient of r = 0.9977 and a standard error of s = 3.99 degrees C for the training set of 184 compounds, and r(cv) = 0.9974 and s(cv) = 4.16 degrees C for the cross-validation set, and r(pred) = 0.9949 and s(pred) = 4.38 degrees C for the prediction set of 21 compounds. For the two subsets containing respectively 77 ethers and 107 carbonyl compounds, the quality of the models is further improved. The standard errors are reduced to 3.30 and 3.02 degrees C, respectively. Furthermore, the results obtained from this study indicate that the boiling points of the studied oxo compound dominantly depend on molecular size and also depend on individual atom types, especially oxygen heteroatoms in molecules due to strong polar interactions between molecules. These excellent structure-boiling point models not only provide profound insights into the role of structural features in a molecule but also illustrate the usefulness of these indices in QSPR/QSAR modeling of complex compounds.

Journal Article↗
PubMed2002

A formula for predicting optimal dosage of nedaplatin based on renal function in adult cancer patients.

PURPOSE: To predict the optimal dosage for nedaplatin ( cis-diammineglycolatoplatinum), an anticancer drug and a platinum derivative like cisplatin and carboplatin, a simple formula was developed based on renal function in Japanese adult cancer patients. PATIENTS AND METHODS: Unbound platinum concentrations in plasma after intravenous infusion of nedaplatin were measured for 187 courses in 145 patients with lung, esophageal, and cervical and ovarian cancer undergoing clinical treatment. The data were divided into two sets, a model development data set of 94 courses and a validation data set of 93 courses. Regression analysis was applied to the relationship between the unbound platinum clearance (CL) of nedaplatin and the patients' renal function. The predictability and usefulness of this formula were assessed by validation using the external data set of 93 courses obtained from 75 patients. RESULTS: A simple formula was obtained for predicting the platinum clearance using the creatinine clearance (CLcr): CL=0.0836xCLcr+3.45. Indices for the predictive performance for CL and the area under the plasma concentration curve (AUC) in the validation data were almost the same as those for the model development data. CONCLUSIONS: A formula for predicting the CL of unbound platinum after nedaplatin administration was developed, and only CLcr was found to be a significant covariate of the CL. This formula was useful for estimating the CL for the second as well as the first treatment with nedaplatin.

Adult↗
PubMed2004

Validation of the postoperative nomogram for 12-year sarcoma-specific mortality.

BACKGROUND: On the basis of a prospectively followed cohort of adult patients with primary soft tissue sarcoma (STS) who were treated at Memorial Sloan-Kettering Cancer Center (MSKCC; New York, NY), a nomogram for predicting sarcoma-specific mortality was developed. Although this nomogram was found to be accurate by internal validation tests, it had not been validated in an external patient cohort, and thus its universal applicability remained unproven. METHODS: Between 1975 and 2002, 1167 adult patients (age > or = 16 years) underwent treatment for primary STS at the University of California-Los Angeles (UCLA; Los Angeles, CA). All patients treated with an ifosfamide-based chemotherapy protocol (n = 238) were excluded from the current analysis. The remaining 929 patients constituted the population on which the validation study was performed. The nomogram validation process comprised two activities. First, the extent of discrimination was quantified using the concordance index. Second, the level of calibration was assessed by grouping patients with respect to their nomogram-predicted mortality probabilities and then comparing group means with observed Kaplan-Meier estimates of disease-specific survival. RESULTS: With median follow-up intervals of 48 months for all patients and 60 months for surviving patients, the 5-year and 10-year disease-specific survival rates were 77% (95% confidence interval [CI], 74-80%) and 71% (95% CI, 67-75%), respectively. Application of the nomogram to the UCLA data set yielded a concordance index of 0.76, and the observed correspondence between predicted and actual outcomes suggested a high level of calibration. CONCLUSIONS: In the current study, the MSKCC Sarcoma Nomogram was found to provide accurate survival predictions when it was applied to an external cohort of patients who were treated at UCLA.

Adolescent↗
PubMedDate not supplied

Cross-cultural validity of the Yale-Brown Obsessive Compulsive Scale.

Some psychometric properties of an adaptation of the Yale-Brown Obsessive Compulsive Scale for use in the Netherlands (Y-BOCS-NL) were examined in 65 psychiatric inpatients. The factorial invariance of two-dimensional systems were determined, namely Severity and Disturbance versus Obsessions and Compulsions, with the latter performing substantially better than the former in different respects. All further analyses were therefore focused on the Obsessions and Compulsions prototype. Inter-rater agreement was established in four inpatients by 39 raters at different institutions and found to be excellent. Internal consistency was also excellent. Concurrent and divergent validity were examined and established by correlating the Y-BOCS-NL with the Padua Inventory, the Burns Perfectionism Scale and state and/or trait measures of, among others, hostility, anxiety, depression, irrational fears and assertiveness. The Obsessions and Compulsions dimensions were lowly intercorrelated and showed evidence of clearly different patterns of correlations with external measures (divergent validity).

Adolescent↗
PubMed2004

A QSAR for baseline toxicity: validation, domain of application, and prediction.

The interest in modeling and application of structure-activity relationships has steadily increased in recent decades. It is generally acknowledged that these empirical relationships are valid only within the same domain for which they were developed. However, model validation is sometimes neglected, and the application domain is not always well-defined. The purpose of this paper is to outline how validation and domain definition can facilitate the modeling and prediction of baseline toxicity for a large database. A large number of theoretical descriptors (867) were generated from two-dimensional molecular structures for compounds present in the U.S. EPA's Fathead Minnow Database (611) and the Syracuse Research Corporation's PhysProp Database (25,000+). A quantitative structure-activity relationship model was developed for baseline toxicity (narcosis) toward the fathead minnow (Pimephales promelas) using a projection-based regression technique, PLSR (partial least squares regression). The PLSR model was subsequently validated with an external test set. The main factors of variation were related to size/shape and polar interactions. The prediction error was comparable to, or slightly better than, the ECOSAR procedures. A set of 16,805 compounds, drawn from the PhysProp Database, was projected onto the PLSR model. More than 90% (15,597) of the compounds fall within the valid model domain, defined by the residual standard deviation and the leverage. The predicted baseline toxicity indicates an acute hazard for two-thirds of these compounds, classes I-III in the OECD Globally Harmonized Classification System (LC50 < or = 100 mg L(-1)). Finally, the mode of action assigned in the U.S. EPA Fathead Minnow Database was investigated. Reclassification to narcosis as the mode of action is suggested for 92 compounds, mostly from the groups "unsure" and "mixed". The present classification into specific modes of action seems to be further strengthened by the findings in this investigation.

Animals↗
PubMed2006

p66 Shc and tyrosine-phosphorylated Shc in primary breast tumors identify patients likely to relapse despite tamoxifen therapy.

INTRODUCTION: Shc adapter proteins are secondary messenger proteins involved in various cellular pathways, including those mediating receptor tyrosine kinase signaling and apoptosis in response to stress. We have previously reported that high levels of tyrosine-phosphorylated Shc (PY-Shc) and low levels of its inhibitory p66 Shc isoform are strongly prognostic for identifying both early node-negative and more advanced, node-positive, primary breast cancers with high risk for recurrence. Because aberrant activation of tyrosine kinases upstream of Shc signaling proteins has been implicated in resistance to tamoxifen--the most widely prescribed drug for treatment of estrogen receptor-positive breast cancer--we hypothesized that Shc isoforms may identify patients at increased risk of relapsing despite tamoxifen treatment. METHODS: Immunohistochemical analyses of PY-Shc and p66 Shc were performed on archival primary breast cancer tumors from a population-based cohort (60 patients, 9 relapses) and, for validation, an independent external cohort (31 patients, 13 relapses) in which all patients received tamoxifen as a sole systemic adjuvant prior to relapse. RESULTS: By univariate and multivariate analyses, the Shc proteins were very strong and independent predictors of treatment failure in both the population-based cohort (interquartile hazard ratio = 8.3, 95% confidence interval [CI] 1.8 to 38, P = 0.007) and the validating cohort (interquartile relative risk = 12.1, 95% CI 1.7 to 86, P = 0.013). CONCLUSION: These results suggest that the levels of PY-Shc and p66 Shc proteins in primary tumors identify patients at high risk for relapsing despite treatment with tamoxifen and therefore with further validation may be useful in guiding clinicians to select alternative adjuvant treatment strategies.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Multiinstitutional validation of the UCSF cancer of the prostate risk assessment for prediction of recurrence after radical prostatectomy.

BACKGROUND: The University of California, San Francisco (UCSF) Cancer of the Prostate Risk Assessment (CAPRA) is a novel preoperative index which predicts the risk of biochemical recurrence after radical prostatectomy. The performance of the index is at least as good as the best available instruments based on clinical variables, and the 0 to 10 score is simple to calculate for both clinical and research purposes. This study used a large external dataset to validate CAPRA. METHODS: Data were abstracted from the Shared Equal Access Regional Cancer Hospital (SEARCH) database, a registry of men who underwent radical prostatectomy at 4 Veterans Affairs and 1 active military medical center. Of 2096 men in the database, 1346 (64%) had full data available to calculate the CAPRA score. Performance of the CAPRA score was assessed with proportional hazards regression, survival analysis, and the concordance (c) index. RESULTS: Of the studied patients, 41% were non-Caucasian, and their mean age was 62 years. Twenty-six percent suffered recurrence; median follow-up among patients who did not recur was 34 months. The hazard ratio (HR) for each 1-point increase in CAPRA was 1.39 (95% CI [confidence interval], 1.31-1.46). The 5-year recurrence-free survival rate ranged from 86% for CAPRA 0-1 patients to 21% for CAPRA 7-10 patients. Increasing CAPRA scores were significantly associated with increasing risk of adverse pathologic outcomes. The c-index for CAPRA for the validation set was 0.68, compared with 0.66 for the original development set. CONCLUSIONS: The UCSF-CAPRA accurately predicted both biochemical and pathologic outcomes after radical prostatectomy among a large, diverse, cohort of men. These results validated the effectiveness of this powerful and straightforward instrument.

Adult↗
PubMed2001

Development and validation of the Ontario acute myocardial infarction mortality prediction rules.

OBJECTIVES: To develop and validate simple statistical models that can be used with hospital discharge administrative databases to predict 30-day and one-year mortality after an acute myocardial infarction (AMI). BACKGROUND: There is increasing interest in developing AMI "report cards" using population-based hospital discharge databases. However, there is a lack of simple statistical models that can be used to adjust for regional and interinstitutional differences in patient case-mix. METHODS: We used linked administrative databases on 52,616 patients having an AMI in Ontario, Canada, between 1994 and 1997 to develop logistic regression statistical models to predict 30-day and one-year mortality after an AMI. These models were subsequently validated in two external cohorts of AMI patients derived from administrative datasets from Manitoba, Canada, and California, U.S. RESULTS: The 11-variable Ontario AMI mortality prediction rules accurately predicted mortality with an area under the receiver operating characteristic (ROC) curve of 0.78 for 30-day mortality and 0.79 for one-year mortality in the Ontario dataset from which they were derived. In an independent validation dataset of 4,836 AMI patients from Manitoba, the ROC areas were 0.77 and 0.78, respectively. In a second validation dataset of 112,234 AMI patients from California, the ROC areas were 0.77 and 0.78 respectively. CONCLUSIONS: The Ontario AMI mortality prediction rules predict quite accurately 30-day and one-year mortality after an AMI in linked hospital discharge databases of AMI patients from Ontario, Manitoba and California. These models may also be useful to outcomes and quality measurement researchers in other jurisdictions.

Aged↗
PubMed2001

[Validation of methods assessing the quality of life in patients with stable angina pectoris].

The aim of the study was evaluation of the validity, reliability and sensitivity of the Seattle Angina Questionnaire (SAQ) and Disease Effect Profile (DEP) translated into Russian by the authors in assessment of life quality (LQ) of patients with stable angina of effort (SAE). The examination of 106 SAE (functional class II-IV) patients demonstrated that LQ by SAQ and DEP correlated with the evidence by the Medico-Social Questionnaire of the Cardiological Research Centre. The constructive validity of SAQ and DEP was examined using factor analysis. All the SAQ sections but one and 7 of 11 sections of DEP were valid. Reproducibility was 0.938 and 0.906, respectively (p < 0.05), Cronbach's alpha was 0.56 and 0.94, respectively. According to SAQ, adequate choice of therapy improves LQ in SAE patients with functional class III but not in functional class II or IV. According to DEP LQ remained unchanged irrespective of the therapy. Thus, Russian translation of SAQ and DEP has proved its internal, external and constructive validity, is integral and reproducible. In addition, SAQ is sensitive to changes in LQ in SAE.

Angina Pectoris↗