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PubMed1988

Conceptual analysis of validation therapy.

The present article examines the conceptual aspects of Validation Therapy. Validation Therapy is a humanistic approach used to give disoriented old-old people, eighty years and older, an opportunity to resolve their life's unfinished conflicts by encouraging them to express their feelings. This approach emphasizes the relationship between the old-old person and the caregiver by focusing on empathy, acceptance, and acknowledgment. Four stages of disorientation, ranging from mild to severe, are described on the basis of emotional and physical characteristics. The theoretical assumptions and underlying principals of Validation Therapy are discussed. Finally, research studies are outlined to evaluate the effectiveness of Validation Therapy. It is concluded that although Validation Therapy is a well-formulated, alternative approach to helping disoriented individuals, further research is needed to determine its validity.

Aged↗

PubMed2000

Development and validation of a questionnaire to evaluate patient satisfaction with diabetes disease management.

OBJECTIVE: To develop a reliable and valid questionnaire to measure patient satisfaction with diabetes disease management programs. RESEARCH DESIGN AND METHODS: Questions related to structure, process, and outcomes were categorized into 14 domains defining the essential elements of diabetes disease management. Health professionals confirmed the content validity. Face validity was established by a patient focus group. The questionnaire was mailed to 711 patients with diabetes who participated in a disease management program. To reduce the number of questionnaire items, a principal components analysis was performed using a varimax rotation. The Scree test was used to select significant components. To further assess reliability and validity; Cronbach's alpha and product-moment correlations were calculated for components having > or =3 items with loadings >0.50. RESULTS: The validated 73-item mailed satisfaction survey had a 34.1% response rate. Principal components analysis yielded 13 components with eigenvalues > 1.0. The Scree test proposed a 6-component solution (39 items), which explained 59% of the total variation. Internal consistency reliabilities computed for the first 6 components (alpha = 0.79-0.95) were acceptable. CONCLUSIONS: The final questionnaire, the Diabetes Management Evaluation Tool (DMET), was designed to assess patient satisfaction with diabetes disease management programs. Although more extensive testing of the questionnaire is appropriate, preliminary reliability and validity of the DMET has been demonstrated.

Adolescent↗

PubMed1996

Test development and validation of a back education posttest.

Assessment of physiotherapeutic treatment efficacy is dependent on valid outcome assessment. This study examined the validity of an existing back education knowledge posttest through a series of validation tests, generated a revised test. Methods included test-item analysis, content and construct validity, expert panel review, and a series of field trials. Purposive samples and subgroups, with varying levels of knowledge of back care concepts, participated in the study. Results of the study found the existing test possessed content validity. The final version of the alternate posttest was able to detect statistically significant differences among subgroups with varying knowledge levels by one-way analysis of variance (F = 116, p < .000). This research is an initial evaluation of a new instrument, and future research is required to fully validate this instrument.

Adolescent↗

PubMed1998

Reliability and validity of rigid lift and pelvic leveling device method in assessing functional leg length inequality.

Clinicians commonly include an assessment of leg length inequality (LLI) as a component of a musculoskeletal examination. Little research is available, however, documenting reliability and validity of clinical methods for assessing LLI. The purpose of this study was to determine the reliability and validity of assessing functional LLI using a pelvic leveling device. Subjects were 19 women and 13 men between the ages of 18 and 55 who reported having a diagnosed or suspected LLI. Clinical determination of LLI was made by placing rigid lifts under the suspected shorter lower extremity until the leveling device indicated that the iliac crests were level. This measurement was made twice by one investigator and once by a second investigator. Standing radiographic measurements of LLI using rigid lifts were used to establish validity of the clinical method. Intraclass correlation coefficients [ICC(2,1)] and absolute difference values were computed to assess reliability and validity. The mean absolute difference between the two clinical measurements of LLI by the same investigator was 0.29 cm (+/- 0.52), with an ICC = 0.84. The mean absolute difference between clinical measurements of LLI by the two investigators was 0.49 cm (+/- 0.46), with an ICC = 0.77. The ICC and mean absolute difference reflecting agreement between radiographic measurements and clinical measurements of LLI was 0.64 and 0.58 cm (+/- 0.58), respectively, for one investigator and 0.76 and 0.55 cm (+/- 0.37), respectively, for the second investigator. The intratester reliability, intertester reliability, and validity assessments included instances in which paired observations disagreed regarding which lower extremity was the shorter lower extremity. Factors that may be associated with the unacceptable reliability and validity of the clinical assessment method include asymmetric positioning of the ilia, body composition of the patient, and design of the clinical instrument. The authors discuss clinical implications related to assessment of LLI.

Adolescent↗

PubMed1988

Reliability and validity of the quantitative inventory of alcohol disorders (QIAD) and the veracity of self-report by alcoholics.

The purpose of this study was to investigate a recently developed instrument for alcoholism severity: The Quantitative Inventory of Alcohol Disorders (QIAD). The primary intention was to demonstrate the reliability and validity of the QIAD as a diagnostic tool within the field of alcoholism. A secondary intention was to examine the veracity of alcoholics self-report on the QIAD and other alcohol-related instruments. The subjects for the experimental group were 25 inpatient alcoholics and their spouses. The control group consisted of 21 nonalcoholics and their spouses. All subjects were administered the QIAD, Michigan Alcoholism Screening Test (MAST), and the Alcohol Severity Rating Scale (ASRS). The alcoholics and partners were given the same tests 5 to 8 days after initial testing. The primary therapists for the alcoholics were asked to rate alcoholism severity for each subject using the ASRS. Pearson product moment correlation coefficients were used for the test-retest reliability procedure. Alcoholics scores on the QIAD, MAST, and ASRS were compared with their spouses scores using a test-retest procedure. Nonalcoholics scores on these instruments were also compared with their spouses' scores. Construct and concurrent validity for the QIAD were tested through comparison of QIAD scores of the alcoholics with their corresponding scores on the MAST and ASRS. t-Tests were used to determine differences between alcoholics and nonalcoholics on all three scales. The results of this investigation supported the position that the QIAD is a reliable and valid instrument for measuring alcoholism severity. The QIAD correlated highly for both the alcoholics and their spouses. The test-retest procedure revealed a high level of correlation. A significant difference was found between the QIAD scores of the alcoholics and nonalcoholics. Construct validity was demonstrated by significant correlations between the alcoholics QIAD and MAST scores, both measuring the extent of alcoholism. The QIAD demonstrated concurrent validity by significantly correlating with alcoholics ASRS ratings. High correlations between alcoholic and spouse scores on the QIAD supported the hypothesis that inpatient alcoholics can produce valid responses to self-report questionnaires.

Adult↗

PubMed1998

The validity and reliability of an asthma knowledge questionnaire used in the evaluation of a group asthma education self-management program for adults with asthma.

This paper reports aspects of the validity and reliability of an asthma general knowledge questionnaire for adults (AGKQA), developed as one of the outcome measures for a randomized controlled effectiveness trial of an asthma education program for adults with asthma. It also illustrates how study data can provide a valuable, generally neglected opportunity to assess the validity and reliability of a measure where resources are not available for the extensive investigation of these properties prior to administration of the measure in a study. The AGKQA was demonstrated to have good content and face validity. Construct validity assessed using the principal components method for factor analysis suggested the scale was unidimensional. Criterion-related validity, assessed using the contrasted groups method, demonstrated a significant difference (p < 0.0001) in total score and for 68% of item responses for the adults with and without direct experience of asthma. The Kuder-Richardson 20 reliability coefficient for internal consistency calculated using responses at baseline, immediately, and 12 months post-intervention were, respectively, 0.56, 0.80, and 0.75, indicating excellent reliability. The AGKQA is an acceptably valid and reliable measure for the assessment of program content mastery that it was designed to test.

Adolescent↗

PubMed1998

A logical stepwise approach to laser diffraction particle size distribution analysis methods development and validation.

In this study, a logical, stepwise, efficient approach was used to develop and validate particle size distribution analysis methods for 58 different pharmaceutical bulk powders in a timely fashion. Image analysis was used to determine particle morphology and laser diffraction particle size distribution analysis was used to evaluate the dispersion medium, dispersion concentration, sonication time, and dispersion stability. Ruggedness validation was performed, by two different analysis, on different days, with different instruments on two preparations each of two different lots of material. It was determined that if the relative standard deviation (RSD) of the median volume diameters (d50) of the four preparations for each lot was below 20%, the method was suitably rugged for use in a quality control setting. Data for methyldopa, metoprolol tartrate, and metronidazole are presented as typical method validation results for three different modes of analysis. Data at three points (d10, d50, and d90) on the distributions were tabulated and evaluated for all 58 methods validated. The median volume diameter (d50) was found to be adequate for method validation. The approach rapidly generated valid, reproducible particle size distribution analysis methodology.

Chemistry, Pharmaceutical↗

PubMed2006

Modified versus producer milk calibration: mid-infrared analyzer performance validation.

Our objective was to determine the validation performance of mid-infrared (MIR) milk analyzers, using the traditional fixed-filter approach, when the instruments were calibrated with producer milk calibration samples vs. modified milk calibration samples. Ten MIR analyzers were calibrated using producer milk calibration sample sets, and 9 MIR milk analyzers were calibrated using modified milk sample sets. Three sets of 12 validation milk samples with all-laboratory mean chemistry reference values were tested during a 3-mo period. Calibration of MIR milk analyzers using modified milk increased the accuracy (i.e., better agreement with chemistry) and improved agreement between laboratories on validation milk samples compared with MIR analyzers calibrated with producer milk samples. Calibration of MIR analyzers using modified milk samples reduced overall mean Euclidian distance for all components for all 3 validation sets by at least 24% compared with MIR analyzers calibrated with producer milk sets. Calibration with modified milk sets reduced the average Euclidian distance from all-laboratory mean reference chemistry on validation samples by 40, 25, 36, and 27%, respectively for fat, anhydrous lactose, true protein, and total solids. Between-laboratory agreement was evaluated using reproducibility standard deviation (s(R)). The number of single Grubbs statistical outliers in the validation data was much higher (53 vs. 7) for the instruments calibrated with producer milk than for instruments calibrated with modified milk sets. The s(R) for instruments calibrated with producer milks (with statistical outliers removed) was similar to data collected in recent proficiency studies, whereas the s(R) for instruments calibrated with modified milks was lower than those calibrated with producer milks by 46, 52, 61, and 55%, respectively for fat, anhydrous lactose, true protein, and total solids.

Animals↗

PubMed2000

Validation and use of a finite element model of C-2 for determination of stress and fracture patterns of anterior odontoid loads.

OBJECT: The finite element (FE) method is a powerful tool for the analysis of stress patterns of anatomical structures. In this study a highly refined FE model of C-2 was created and validated. The model was then used to characterize stress patterns, predicted fracture patterns, and transitions between Type II and Type III odontoid fractures. METHODS: An anatomically accurate three-dimensional model of C-2 was created from computerized tomography data obtained from the Visible Human Project. The C-2 model was broken down into an FE mesh consisting of 32,815 elements and 40,969 nodes. For validation, the FE model was constrained and loaded to simulate that used in previous biomechanical studies. The validated model was then loaded in an iterative fashion, varying the orientation of the load within the validated range. A matrix of stress plots was created for comparative analysis. Results of the validation testing closely correlated with those obtained in previous biomechanical testing. Pure extension loading produced a Type III stress pattern with maximum stress of 134 MPa. Loading at 45 degrees produced a Type II stress distribution with a maximum stress of 123 MPa. These stresses are within 3% and 11%, respectively, of the reported yield stress of cortical bone (138 MPa). In the second portion of the study, systematic variation in the orientation of the load vector revealed that higher stresses were associated with increased lateral angulation and increasing upward inclination of the load vectors. A transition from a Type III to Type II pattern occurred with lateral orientations greater than 15 degrees and with compressive loads of 45 degrees. CONCLUSIONS: The validated C-2 FE model described in this study both qualitatively and quantitatively was able to simulate the behavior of the C-2 vertebra in biomechanical testing. In this study the authors demonstrate the utility of the FE method when used in conjunction with traditional biomechanical testing.

Algorithms↗

PubMed2002

Validity and reliability of the Short Form-36 in cervical spondylotic myelopathy.

OBJECT: Validity (the extent to which a test measures what it is intended to measure) and reliability (the stability and reproducibility of measures of the same concept over time or across methods of gathering data) are important characteristics of any outcomes instrument. Generic outcomes instruments are designed for use in any population; however, their validity and reliability in particular diseases should be verified to ensure their appropriateness for use in that disease. In this study the authors assessed the validity and reliability of the Medical Outcomes Study Short Form-36 (SF-36), a generic outcomes instrument, in a population of patients with cervical spondylotic myelopathy (CSM). METHODS: The SF-36 was administered to a cohort of patients with CSM on an outpatient basis. Symptom-related data derived from a structured interview and physical examination findings were used to classify cases according to the myelopathy scales of Nurick, Cooper, Harsh, and a Western modification of the Japanese Orthopaedic Association (JOA). Construct validity was assessed by determining whether SF-36 scores varied in accordance with predefined hypotheses relating to the myelopathy scores by using the Cuzick nonparametric test for trend. The reliability of the SF-36 scores was assessed using Cronbach alpha. Eighty-eight patients with CSM completed the SF-36 and interview. Construct validity was demonstrated by confirming the hypothesized relationship between SF-36 scales and the myelopathy scales of Nurick (p < or = 0.003), Cooper leg subscale (p < or = 0.012, except the general health perceptions domain [p = 0.091]), Harsh (p < or = 0.016), and the motor component of the modified JOA (p < or = 0.006). Reliability was demonstrated for all eight SF-36 domain scales and the physical component and mental component summary scales, in which Cronbach alpha satisfied the Nunnally criterion of 0.7. CONCLUSIONS: The SF-36 provides valid and reliable data on patients with CSM.

Activities of Daily Living↗

PubMed2000

Determining the validity of advance directives.

We examine the ethical principles underpinning advance directives (ADs) and the legal duties of doctors in determining their validity. A physician attending an incompetent patient with an acute life-threatening illness, and an AD refusing treatment, should ensure that the AD is legally valid before making the treatment decision. Treatment against a patient's wishes, as expressed in a valid AD, compromises patient autonomy and may constitute battery. Conversely, withholding treatment in accordance with an AD that is not legally valid risks substantial harm to the patient and may constitute breach of the duty of care and negligence. Legally valid directives should be respected. If an AD is not legally valid, the patient should be treated in his or her best interests. If uncertain, the physician should treat according to the patient's best interests while seeking legal advice.

Acute Disease↗

PubMed1999

ACR and EULAR improvement criteria have comparable validity in rheumatoid arthritis trials. American College of Rheumatology European League of Associations for Rheumatology.

We compared the validity of the American College of Rheumatology (ACR) and the European League of Associations for Rheumatology (EULAR) definitions of response in rheumatoid arthritis (RA) clinical trials. US: ACR and EULAR improvement criteria were calculated in 7 large randomized RA clinical trials. The discriminant validity of the response criteria between treatment groups was studied using the Mantel-Haenszel chi-squared value. To compare both sets of criteria the chi-squared ratio was determined for each trial. Europe: In 2 large randomized RA clinical trials, ACR and EULAR criteria were calculated, once with extensive and once with 28 joint counts. The classification of patients with these 4 criteria were compared with each other using cross tables. We further studied the difference in response between treatment groups per trial, the association of response with patient and investigator assessment of improvement, and the association of response with radiological progression. US: The chi-squared ratio for most trials was close to 1. There was no clear pattern suggesting that the discriminant validity of the ACR criteria was stronger than the discriminant validity of the EULAR definition of response or vice versa. Europe: Conflicting results between ACR and EULAR were present in only 3% of patients in both trials. The discriminant validity of all 4 criteria (ACR and EULAR with reduced and extensive joint counts) was comparable. All criteria were related with the overall assessment of improvement by both investigator and patient. The association with radiographic progression was comparable for EULAR and ACR improvement criteria. There is a high level of agreement between ACR and EULAR improvement classification, and their validity is equivalent. The discriminating potential of the criteria between treatment groups is comparable, as is the association with patient's and investigator's overall assessment and with radiographic progression.

Antirheumatic Agents↗

PubMed1976

Health status: types of validity and the index of well-being.

The concept of validity as it applies to measures of health and health status is examined in the context of a set of standard, widely accepted definitions of validity. Criterion validity is shown to be irrelevant to health status measures because of the lack of a single specific, directly observable measure of health for use as a criterion. To overcome this problem, the Index of Well-being has been constructed to fulfill the definition of content validity by including all levels of function and symptom/problem complexes, a clearly defined relation to the death state, and consumer ratings of the relative desirability of the function levels. Data from a two-wave household interview survey provide convergent evidence of construct validity by demonstrating an expected positive correlation of the Index of Well-being with self-rated well-being and expected negative correlations with age, number of chronic medical conditions, number of reported symptoms or problems, number of physician contacts, and dysfunctional status. Discriminant evidence of construct validity is demonstrated by predicted differences in correlation between concurrent Index of Well-being scores and self-assessed overall health status, and between the Index of Well-being scores and self-rated well-being on different days. A simple method of estimating a currently usable comprehensive population index of health status, the Weighted Life Expectancy, is described.

Activities of Daily Living↗

PubMed1998

Validation of analytical methods and laboratory procedures for chemical measurements.

Method validation is a key element in the establishment of reference methods and in the assessment of a laboratory's competence in producing reliable analytical data. Hence, the scope of the term "method validation" is wide, especially if one bears in mind the role of Quality Assurance/Quality Control (QA/QC). The paper puts validation in the context of the process generating chemical information, introduces basic performance parameters included in the validation processes, and evaluates current approaches to the problem. Two cases are presented in more detail: the development of European standard for chlorophenols and its validation by a full scale collaborative trial and the intralaboratory validation of a method for ethylenethiourea by using alternative analytical techniques.

Chemistry Techniques, Analytical↗

PubMed1999

[Reliability and validity of the French version of the first part of the Appropriateness Evaluation Protocol (AEPf): pertinent criteria of hospitalization stay].

BACKGROUND: The Appropriateness Evaluation Protocol (AEP) is a tool used to identify hospitalization days that are appropriate with respect to simple technical criteria, and the reasons for hospitalization days that do not meet these criteria. The goal of the study was to validate the clinical criteria of AEPf, required for identifying the reasons which explain these inappropriate hospital days. METHODS: The validity of a French version of criteria of appropriateness (AEPf) was assessed in a sample of 502 hospital days in medical and surgical wards of six French teaching hospitals. The reliability of the AEPf-based conclusions was studied by the measure of the concordance between two independent measures of AEPf for the same hospital day. Validity of AEPf was studied by the measure of the concordance between AEPf-based conclusions and the judgments of physicians using implicit criteria to assess the necessity of the hospital day studied. The degree of concordance was estimated by the Kappa coefficient. RESULTS: AEPf reproducibility was high (Kappa coefficient: 0.81; 95% confidence interval (95% CI): 0.76-0.87). Validity was also high (Kappa coefficient: 0.61; 95% CI: 0.53-0.68). CONCLUSION: The French version of the AEP was thus shown to be both reliable and valid to identify hospitalisation days appropriate with respect to hospital's technical equipment and specific resources. However, the reproducibility of the assessment of reasons for hospital days that did not meet AEP criteria will require a validation.

Chi-Square Distribution↗

PubMed1999

[Development of a scale for quality of care management process. A Delphi survey and studies on reliability and validity].

The purpose of this study was to develop a measurement tool for assessing quality in care management and to test its reliability and validity. A Delphi survey was initially administered on 96 experienced community health nurses, to improve the content validity of a questionnaire that was developed after three repeated rounds of data collection and content analysis. A total of 353 community health nurses, from 121 cities and towns across Japan, completed the mailed questionnaire. Cronbach's alpha value was more than 0.8, respectively, for all items in questionnaires, and for each factor, indicating internal consistency in reliability. Five factors were identified through factor analysis using a principal factor method with varimax rotation. These factors were good reflections of components classified by some researchers, indicating construct validity. In addition, care managers were grouped according to such criteria as their age and work experience. The QCM-P (Quality of Care Management-Process Measurement) score of each group was compared, as theoretically differences are expected. The questionnaire's validity was evidenced by significant differences in the QCM-P score among each group. Further studies on criterion-related validity and stability which relates to reliability are required. Thus, although further work is needed, QCM-P was found to have both reliability and validity at a permissible level as a scale for measuring the quality of care management process.

Adult↗

PubMed2000

Development of prediction models for three in vitro embryotoxicity tests in an ECVAM validation study.

Since 1997 the National Center for Documentation and Evaluation of Alternative Methods to Animal Experiments, ZEBET, in Berlin, has been coordinating a validation study aimed at prevalidation and validation of three in vitro embryotoxicity tests, funded by the European Center for the Validation of Alternative Methods (ECVAM) at the Joint Research Center (JRC, Ispra, Italy). The tests use the cultivation of postimplantation rat whole embryos (WEC test), cultures of primary limb bud cells of rat embryos (micromass or, MM, test), and cultures of a pluripotent mouse embryonic stem cell line (embryonic stem cell test or EST). Each of the tests was performed in four laboratories under blind conditions. In the preliminary phase of the validation study 6 out of 20 test chemicals comprising different embryotoxic potential (non, weakly, and strongly embryotoxic) were tested. The results were used to define biostatistically based prediction models (PMs) to identify the embryotoxic potential of test chemicals for the WEC test and the MM test. The PMs developed with the results of the preliminary phase of the validation study (training set) will be evaluated with the results of the remaining 14 test chemicals (definitive phase) by the end of the study. In addition, the existing, improved PM (iPM) for the EST, which had been defined previously, was evaluated using the results of the preliminary phase of this study. Applying the iPM of the EST to the results of this study, in 79% of the experiments, chemicals were classified correctly according to the embryotoxic potential defined by in vivo testing. For the MM and the WEC test, the PMs developed during the preliminary phase of this validation study provided 81% (MM test) and 72% (WEC test) correct classifications. Because the PM of the WEC test took into account only parameters of growth and development, but not cytotoxicity data, a second PM (PM2) was developed for the WEC test by incorporating cytotoxicity data of the differentiated mouse fibroblast cell line 3T3, which was derived from the EST. This approach, which has previously never been used, resulted in an increase to 84% correct classifications in the WEC test.

3T3 Cells↗

PubMed2000

Validity of the MACTAR questionnaire as a functional index in a rheumatoid arthritis clinical trial. The McMaster Toronto Arthritis.

OBJECTIVES: The McMaster Toronto Arthritis patient preference questionnaire (MACTAR) is a functional index that measures change in impaired activities selected by each patient in a baseline interview, and change in rheumatoid arthritis (RA) disease activity. In addition, it contains questions on the state of physical, social and emotional function and overall health, and their relation to RA. We evaluated MACTAR's feasibility and validity (content validity, construct validity, and responsiveness). METHODS: A randomized trial of combined treatment in 155 patients with early RA; patients' mean age at baseline was 50 years and median disease duration since diagnosis was 4 months. RESULTS: Feasibility: MACTAR requires trained interviewers. In the trial, interviews took about 15 min. In longer term followup, activities selected at baseline may become less relevant as the pattern of disability changes. Followup from 153 patients (99%) was available. At least 5 impaired activities were identified and ranked by 147 patients (95%); interviewers could follow 99% of these. The scoring system proved complex and required amendments. Content validity: Although its main focus is physical function, the MACTAR also contains generic questions; 75% of the patients named at least one impaired activity from the category "mobility." Only 48% were covered by Health Assessment Questionnaire (HAQ) items. Construct validity: MACTAR scores correlate highly with other functional indices and with measures of disease activity. Responsiveness: At 16 weeks the standardized response mean for the total MACTAR score in the combined-treatment group was excellent, at 2.2. Items that directly address change were even more responsive. CONCLUSION: The MACTAR interview is a valid and highly responsive instrument to assess change in functional ability of patients with early RA with active disease. It provides insight into problems--mainly of physical function--that really matter to patients. For standard clinical trials and clinical care, feasibility of the MACTAR is limited and the simpler HAQ remains the instrument of choice.

Arthritis, Rheumatoid↗