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PubMed2002

[Linguistic validation of Japanese version of International Prostate Symptom Score and BPH impact index].

PURPOSE: To evaluate linguistic validity of the Japanese version of International Prostate Symptom Score (IPSS) and BPH Impact Index (BII). METHODS: The translation was performed through multi-step procedure. Forward translation was created through the discussion by 5 urologists, 2 Japanese translators and 1 nurse on independent translations of the discussants and the translation published in the Guideline in Japan. Back translation was made by 2 native speakers of American English, and negotiated with the original developers. A person-to-person in-depth interview was carried out on 20 patients with benign prostatic hyperplasia. RESULTS: The developers generally approved our translation, but had 2 major concerns in the Japanese version; 1) "how often" in every sentence of English version was not translated into Japanese, and 2) the Japanese expression in the response choices of QOL index should be more emotional. The former concern was compromised by placing a sentence at the beginning of the questionnaire explaining that the response should be considered in frequency. The latter concern was examined in a pre-test involving additional 88 patients and compromised by making the translation of some response choices more emotional. CONCLUSION: We evaluated linguistic validity of Japanese translations of IPSS and BII, and proposed a valid Japanese version of these questionnaires.

Health Status Indicators↗

PubMed2000

The Southampton Needs Assessment Questionnaire (SNAQ): a valid tool for assessing the rehabilitation needs of disabled people.

OBJECTIVE: To validate the Southampton Needs Assessment Questionnaire (SNAQ) for use with disabled people during face-to-face interviews. DESIGN: The SNAQ was designed to be used in a cross-sectional survey of disabled people with a physical disability with a follow-up study one year later. Content and criterion validity was examined using 32 disabled people who took part in the pilot study. Construct validity and internal reliability was examined using data from 93 disabled people who took part in the main survey. Responsiveness of the questionnaire was evaluated using the data gathered during a follow-up study of 77 people had taken part in the original study. OUTCOME MEASURES: The OPCS Disability Severity Scales (OPCS) and the Functional Independence Measure (FIM) were used to measure level of disability of participants, the Nottingham Health Profile (NHP) and the UK version of the SF-36 to examine perceived health status. PARTICIPANTS: People with a primary physical disability, aged 16-65, randomly selected from two disability registers in southern England. MAIN RESULTS: Content and criterion validity were established. Construct validity and internal reliability of the SNAQ was good. Inter-rater reliability was not tested since only one researcher conducted the interviews. Test-retest reliability was not formally tested because of the probability that participants would learn from the first needs assessment questionnaire and that different results on a retest occasion could arise from this. The SNAQ was sensitive in picking up changes over time. CONCLUSION: The SNAQ has shown good validity (content, coverage and construct), internal reliability, sensitivity and responsiveness. Further studies are needed to define the consequences of meeting or not meeting the rehabilitation needs of disabled people. Inter-rater reliability remains to be established.

Adolescent↗

PubMed2005

Creating a reliable and valid blueprint for the internal medicine clerkship evaluation.

The objective of this study was to design an examination blueprint for the Internal Medicine clerkship rotation that is congruent with both the learning objectives and delivered learning experiences and reflects the perceived importance of clinical presentations from both the students' and clinicians' perspectives. In this cross-sectional study 11 specialists in General Internal Medicine (GIM) and 11 clinical clerks at the University of Calgary were asked to score each of the 47 clinical presentations in the Internal Medicine clerkship rotation for 'impact' and 'frequency'. These attributes were used to provide an estimate of the relative importance of each clinical presentation. Statistical tests used were the Pearson's correlation coefficient and the Kappa statistic. Multi-attribute utility theory was applied to assess the best way of combining the variables of 'impact' and 'frequency'. The correlation between clerks and GIM specialists was 0.85 for the impact score and 0.86 for the frequency score (p < 0.001 for both). Corresponding Kappa values were 0.71 and 0.82, respectively (p < 0.001 for both). Combining impact and frequency as a multiplicative function produced a distribution that was positively skewed towards common, high impact presentations such as chest pain. We have created an examination blueprint that provides a realistic and objective measure of the relative importance of clinical presentations. Such a blueprint provides both face validity and content validity to the evaluation process.

Alberta↗

PubMed2006

P-drive: assessment of driving performance after stroke.

OBJECTIVE: To investigate aspects of validity and stability of Performance Analysis of Driving Ability (P-Drive), for people with stroke when used in a driving simulator. DESIGN: A cross-sectional observational study. SUBJECTS: The study included a consecutive series of 101 participants with stroke referred for evaluation or selected from a stroke registry. METHODS: P-Drive was used to observe driving performance in order to assess driving ability. P-Drive comprises 20 items assessing the quality of the participant's driving performance. Aspects of validity and reliability in P-Drive were evaluated using Rasch statistics. RESULTS: The items (95%) and participants (97%) demonstrated acceptable goodness-of-fit and met statistical expectations according to the Rasch model. The results support internal scale validity and person response validity. P-Drive could separate the participants with different driving abilities and the standard errors were within reasonable criteria for drivers with a moderate-to-low ability to drive. CONCLUSION: The findings from this study indicated that P-Drive is an assessment tool with properties of internal scale validity, person response validity, and which also contains aspects of reliability in relation to precision of the estimates and separation. P-Drive seems to be a valid and stable assessment tool for assessing the driving ability in a simulator of people with stroke.

Aged↗

PubMed2006

Validation of the proposed International Society for Heart and Lung Transplantation grading system for primary graft dysfunction after lung transplantation.

BACKGROUND: A scoring system was recently proposed to grade the severity of primary graft dysfunction (PGD), a frequent early complication of lung transplantation. The purposes of this study are to: (1) validate the PGD grading system with respect to patient outcomes; and (2) compare the performance of criteria employing the arterial oxygenation to fraction of inspired oxygen (P/F) ratio to an alternative grading system employing the oxygenation index (OI). METHODS: We retrospectively reviewed the medical records of 402 patients having undergone lung transplantation at our institution from 1992 through 2004. The ISHLT PGD grading system was modified and grades were assigned up to 48 hours post-transplantation as follows: Grade 1 PGD, P/F > 300; Grade 2, P/F 200 to 300; and Grade 3, P/F < 200. A worst score T(0-48) was also assigned, which reflects the highest grade recorded between T0 and T48. RESULTS: The prevalence of severe PGD (P/F Grade 3) declined after transplant, from 25% at T0 to 15% at T48. Grouping patients by P/F grade at T48 demonstrated the clearest differentiation of 90-day death rates (Grade 1, 7%; Grade 2, 12%; Grade 3, 33%) (p = 0.0001). T48 OI grade also differentiates 90-day death rates. There was no difference in longer-term survival between patients with PGD Grades 1 and 2. OI grade at T0 qualitatively improved differential mortality between Grades 1 and 2; however, the differences did not reach statistical significance. Patients with a worst score T(0-48) of Grade 3 PGD did have significantly decreased long-term survival, as well as longer ICU and hospital stay, when compared with Grades 1 and 2 PGD. Significant risk factors for short- and long-term mortality in our multivariate model were P/F Grade 3 [worst score T(0-48) as well as T0 grade], single-lung transplant, use of cardiopulmonary bypass and high pre-operative mean pulmonary artery pressure. CONCLUSIONS: There is an increased risk of short- and long-term mortality and length of hospital stay associated with severe (Grade 3) PGD. The proposed ISHLT grading system can rapidly identify patients with poor outcomes who may benefit from early, aggressive treatment. Refinement of the scoring system may further improve patient risk stratification.

Adolescent↗

PubMed1998

[Validation of an instrument for identifying styles of the professional practice of the primary care doctor].

OBJECTIVE: To elaborate and validate a questionnaire for identifying common styles of Primary Care doctors' practice. SETTING: Primary Health Care. Public sector in Spain. DESIGN: This was a study to validate a questionnaire administered in two phases with different samples. In the first phase, the items (item-total correlation, using Alpha on eliminating item), validity of construction, empirical validity and internal consistency, were analysed. In the second, discriminatory validity and reliability of the questionnaire (test-retest) were calculated. MEASUREMENTS AND MAIN RESULTS: 81.5% of the doctors replied in the first phase; and 100% in the second. Two factors were isolated with the Principal Components procedure, which confirmed the validity of the questionnaire's construction (52% variance explained). Internal consistency (Alphas ranged between 0.55 and 0.75) and reliability (ranging between 0.50 and 0.95 in function of the time elapsed) were also demonstrated. CONCLUSIONS: This instrument could be used to differentiate two styles in practice, characterised by focusing on the physical illness vs the psycho-social aspects of the disease process. The instrument is also useful because it gives the feeling of control over the task.

Family Practice↗

PubMed2006

Assessment of the validity of a population pharmacokinetic model for epirubicin.

AIMS: The aim of this study was to evaluate a population model for epirubicin clearance using internal and external validation techniques. METHODS: Jackknife samples were used to identify outliers in the population dataset and individuals influencing covariate selection. Sensitivity analyses were performed in which serum aspartate transaminase (AST) values (a covariate in the population model) or epirubicin concentrations were randomly changed by +/-10%. Cross-validation was performed five times, on each occasion using 80% of the data for model development and 20% to assess the performance of the model. External validation was conducted by assessing the ability of the population model to predict concentrations and clearances in a separate group of 79 patients. RESULTS: Structural parameter estimates from all jackknife samples were within 7.5% of the final population estimates and examination of log likelihood values indicated that the selection of AST in the final model was not due to the presence of outliers. Alteration of AST or epirubicin concentrations by +/-10% had a negligible effect on population parameter estimates and their precision. In the cross-validation analysis, the precision of clearance estimates was better in patients with AST concentrations>150 U l-1. In the external validation, epirubicin concentrations were over-predicted by 81.4% using the population model and clearance values were also poorly predicted (imprecision 43%). CONCLUSIONS: The results of internal validation of population pharmacokinetic models should be interpreted with caution, especially when the dataset is relatively small.

Adult↗

PubMed2005

Psychometric properties of the Mini-Mental State Examination in patients with acquired brain injury in Turkey.

OBJECTIVE: To evaluate the psychometric properties of Mini-Mental State Examination (MMSE) in patients with acquired brain injury in Turkey. METHODS: A total of 207 patients with acquired brain injury were assessed. Reliability was tested by internal consistency and the person separation index; internal construct validity by Rasch analysis; external construct validity by correlation with cognitive disability; and cross-cultural validity by differential item functioning analysis compared with Italian MMSE data. RESULTS: Reliability was adequate with a Cronbach's alpha of 0.75 and person separation index of 0.76. After collapsing some categories, and adjustment for differential item functioning, internal construct validity was supported by fit of the data to Rasch model. Differential item functioning for culture was found in 2 items and after adjustment, data could be pooled between Turkey and Italy. External construct validity was supported by expected associations. CONCLUSION: The Turkish version of the Mini-Mental State Examination can be used as a cognitive screening tool in acquired brain injury. Cross-cultural validity between Italy and Turkey is supported, given appropriate adjustment for differential item functioning. However, shortfalls in reliability at the individual level, as well as the presence of differential item functioning suggest that a better instrument should be developed to screen for cognitive deficits following acquired brain injury.

Adult↗

PubMed2001

Validation of the Turkish version of the Roland-Morris Disability Questionnaire for use in low back pain.

STUDY DESIGN: A reliability and validity study of a previously translated version of the Roland-Morris Disability Questionnaire (RMDQ). OBJECTIVES: To validate the Turkish version of the RMDQ for use in low back pain. SUMMARY OF BACKGROUND DATA: Clinical and epidemiologic research related to low back pain in the Turkish population would be facilitated by the availability of well-established outcome measures. METHODS: A total of 81 outpatients with low back pain, 64 of whom were followed up on a second occasion, were assessed by the RMDQ. Reliability was assessed using internal consistency and the intraclass correlation coefficient. Internal construct validity was assessed by Rasch analysis; external construct validity was assessed by association with pain and spinal movement. Responsiveness was tested by both the nonparametric and parametric effect sizes. RESULTS: Internal consistency of the RMDQ is found to be adequate (>0.85) at both times, with high intraclass correlation coefficient also at both time points. Internal construct validity of the scale is good, indicating a single underlying construct. Expected associations with pain confirm external construct validity. There is little evidence of differential item functioning. The scale is at the ordinal level. Responsiveness of the RMDQ is good and greater than observed change in spinal movement. CONCLUSIONS: The RMDQ is a robust unidimensional ordinal measure, largely free of differential item functioning, which works well in the Turkish population. Nonparametric effect sizes of ordinal scales are found to overestimate or underestimate the true effect size depending on the nature of the scale and the distribution of patients at baseline.

Adult↗

PubMed2002

Validation of Italian version of the Women's Health Questionnaire: assessment of quality of life of women from the general population and those attending menopause centers.

OBJECTIVES: The Women's Health Questionnaire has been developed and validated in Anglo-Saxon and Swedish populations. The purpose of this study was to evaluate the Italian version of the questionnaire to determine whether cross-cultural differences exist in the perception of quality of life, and to use it to compare the quality of life in women attending menopause centers with that of women in the general population. METHODS: An Italian version of the Women's Health Questionnaire (WHQ) was produced, using the forward-backward translation method to ensure conceptual equivalence, and approved by the originator. Women were recruited by random selection from the general population and from menopause centers, those taking hormone replacement therapy being ineligible. The questionnaire was completed anonymously at home and mailed to the co-ordinating center. Psychometric evaluation included tests of item convergent and discriminant validity, internal-consistency reliability, test-retest reliability, construct validity and the discriminative properties of the questionnaire. RESULTS: The completeness of the data was good, with missing-value rates consistently low for most items. Item-scale correlations, used to evaluate internal consistency, were also good and the scaling success rate, used to measure item discriminant validity, was high for all scales. Scale scores were reliable for seven out of nine scales and test-retest reliability was excellent. There were few significant differences between the two populations of women in most of the WHQ areas. A comparison of Italian data with published data on English women showed great similarity. CONCLUSION: The Italian version of the WHO is valid and reproducible. The subjective perception of the menopause and its related problems is similar in geographically and culturally different populations.

Affect↗

PubMed1999

Internal consistency and discriminant validity of the Luria Nebraska Neuropsychological Battery-III.

This research presents data pertaining to the development of the recently revised Luria Nebraska Neuropsychological Battery-III. The final version of this test battery consists of 31 clinical scales yielding 35 scores. The battery was given to 109 non brain-injured controls and 119 brain-injured subjects. High internal consistency was demonstrated for each clinical scale. Results further indicated that the test battery was very effective at discriminating between normal and brain-injured subjects, as significant between-group differences on 33 of 35 scores were observed. Significant between-group differences were also observed on 25 of the 35 scores when age and education were covaried out of the analyses; those scales not displaying significant between-group differences generally measured very basic over-learned skills.

Adolescent↗

PubMed2001

Validity of the five-item WHO Well-Being Index (WHO-5) in an elderly population.

BACKGROUND: Depression has a high prevalence in the elderly population; however it often remains undetected. The WHO 5-item Well-Being Index (WHO-5) is a short screening instrument for the detection of depression in the general population, which has not yet been evaluated. The goals of the present study were: 1) to assess the internal and external validity of WHO-5 and 2) to compare the two recent versions of WHO-5. STUDY POPULATION AND METHODS: 367 subjects above 50 years of age were examined with the WHO-5. ICD-10 diagnoses were made using a structured interview (CIDI). The internal validity of the well-being index was evaluated by calculating Loevinger's and Mokken's homogeneity coefficients. External validity for detection of depression was evaluated by ROC analysis. RESULTS: The scale was sufficiently homogeneous (Loevinger's coefficient: version 1 = 0.38, version 2 = 0.47; Mokken coefficient > 0.3 in nearly all items). ROC analysis showed that both versions adequately detected depression. Version 1 additionally detected anxiety disorders, version 2 being more specific for detection of depression. CONCLUSION: The WHO-5 showed a good internal and external validity. The second version is a stronger scale and was more specific for the detection of depression. The WHO-5 is an useful instrument for identifying elderly subjects with depression.

Aged↗

PubMed2003

Application of the CFU-GM assay to predict acute drug-induced neutropenia: an international blind trial to validate a prediction model for the maximum tolerated dose (MTD) of myelosuppressive xenobiotics.

In a previous study of prevalidation, a standard operating procedure (SOP) for two independent in vitro tests (human and mouse) had been developed, to evaluate the potential hematotoxicity of xenobiotics from their direct and the adverse effects on granulocyte-macrophages (CFU-GM). A predictive model to calculate the human maximum tolerated dose (MTD) was set up, by adjusting a mouse-derived MTD for the differential interspecies sensitivity. In this paper, we describe an international blind trial designed to apply this model to the clinical neutropenia, by testing 20 drugs, including 14 antineoplastics (Cytosar-U, 5-Fluorouracil, Myleran, Thioguanine, Fludarabine, Bleomycin, Methotrexate, Gemcitabine, Carmustine, Etoposide, Teniposide, Cytoxan, Taxol, Adriamycin); two antivirals (Retrovir, Zovirax,); three drugs for other therapeutic indications (Cyclosporin, Thorazine, Indocin); and one pesticide (Lindane). The results confirmed that the SOP developed generates reproducible IC90 values with both human and murine GM-CFU. For 10 drugs (Adriamycin, Bleomycin, Etoposide, Fludarabine, 5-Fluorouracil, Myleran, Taxol, Teniposide, Thioguanine, and Thorazine), IC90 values were found within the range of the actual drug doses tested (defined as the actual IC90). For the other 10 drugs (Carmustine, Cyclosporin, Cytosar-U, Cytoxan, Gemcitabine, Indocin, Lindane, Methotrexate, Retrovir, and Zovirax) extrapolation on the regression curve out of the range of the actual doses tested was required to derive IC90 values (extrapolated IC90). The model correctly predicted the human MTD for 10 drugs out of 10 that had "actual IC90 values" and 7 drugs out of 10 for those having only an extrapolated IC90. Two of the incorrect predictions (Gemcitabine and Zovirax) were within 6-fold of the correct MTD, instead of the 4-fold range required by the model, whereas the prediction with Cytosar-U was approximately 10-fold in error. A possible explanation for the failure in the prediction of these three drugs, which are pyrimidine analogs, is discussed. We concluded that our model correctly predicted the human MTD for 20 drugs out of 23, since the other three drugs (Topotecan, PZA, and Flavopiridol) were tested in the prevalidation study. The high percentage of predicitivity (87%), as well as the reproducibility of the SOP testing, confirm that the model can be considered scientifically validated in this study, suggesting promising applications to other areas of research in developing validated hematotoxicological in vitro methods.

Acute Disease↗

PubMed2005

Simultaneous determination of niacin, niacinamide and nicotinuric acid in human plasma.

A sensitive, specific, accurate, and reproducible HPLC/MS-method for the simultaneous quantitative determination of niacin (NA) and its main metabolites niacinamide (NAM) and nicotinuric acid (NUR) in human plasma using chinolin-3-carboxylic acid as an internal standard was developed and validated according to international guidelines for method validation. All analytes and the internal standard were separated from acidified plasma by solid phase extraction. Afterwards the extracted samples were analyzed by HPLC/MS in the positive electrospray ionization mode (ESI) and selected ion monitoring (SIM). The total run time was 7 min between injections. The assay had a lower limit of quantification of 50.0 ng/mL for each analyte using 1 mL of plasma. The calibration curves were linear in the measured range between 50.0 and 750 ng/mL plasma. The overall precision and accuracy for all concentrations of quality controls and standards was better than 15%. No indications were found for possible instabilities of niacin, niacinamide and nicotinuric acid in plasma at -20 degrees C, in the extraction solvent or after repeated thawing/freezing cycles. In stabilities were observed in whole blood and in plasma at room temperature. The recovery of the extraction method ranged from 86 to 89% for the three analytes.

Humans↗

PubMed1998

Testing internal consistency and construct validity during evaluation of performance in a patient simulator.

UNLABELLED: The primary goal of this study was to test the items in a rating system developed to evaluate anesthesiologists' performance in a simulated patient environment. A secondary goal was to determine whether the test scores could discriminate between resident and staff anesthesiologists. Two 5-item clinical scenarios included patient evaluation and induction and maintenance of anesthesia. Rating scales were no response to the problem (score = 0), compensating intervention (score = 1), and corrective treatment (score = 2). Internal consistency was estimated using Cronbach's coefficient alpha. Scores between groups were compared using the Cochran-Mantel-Haenszel test. Subjects consisted of 8 anesthesiology residents and 17 university clinical faculty. The Cronbach's coefficient alpha was 0.27 for Scenario A and 0.28 for Scenario B. Two items in each scenario markedly decreased internal consistency. When these four items were eliminated, Cronbach's coefficient alpha for the remaining six items was 0.66. Faculty anesthesiologists scored higher than residents on all six items (P < 0.001). A patient simulator-based evaluation process with acceptable reliability was developed. IMPLICATIONS: The reliability of anesthesia clinical performance in a patient simulation environment was assessed in this study. Of 10 items, 4 were poor in the evaluation process. When these items were removed, the reliability of the instrument improved to a level consistent with other studies. Because faculty scored higher than resident anesthesiologists, the instrument also showed discriminant validity.

Adult↗

PubMed2005

Development of a reliable and valid nutritional knowledge questionnaire for urban South African adolescents.

OBJECTIVES: We wanted to develop a valid and reliable nutritional knowledge test for urban South African adolescents who were participating in the Birth-to-Twenty cohort study. The questionnaire was intended for use every second year, from ages 13 to 14 y until age 20 y. METHODS: The initial steps involved the development of a conceptual framework and identification of nutritional concepts in collaboration with nutritional experts, and this defined the construct of the questionnaire. The South African national teaching curriculum objectives for nutritional education and other relevant issues were selected as the desired concepts, and most items were phrased in accordance with the recently developed South African Food-Based Dietary Guidelines. Thereafter, 140 items (questions) were developed and in turn assessed by an expert panel, and the result was that only 88 items remained. This was done to ensure content and face validity of the items. The 88 items were constructed into a questionnaire and piloted for appropriateness and understanding by adolescents, ages 13 to 14 y, as a means of assessing face validity by non-experts. The edited preliminary questionnaire (still with 88 items) was administered to a nutrition expert group (n = 71) versus a non-expert group (n = 82), referred to as sample 1, for the purposes of performing item analysis and assessing construct validity of the questionnaire. The result of the analysis, a 63-item questionnaire, was administered to adolescents at three school grade levels, 8 (n = 128), 10 (n = 143), and 12 (n = 98), referred to as sample 2, which was representative of the grades in which the Birth-to-Twenty group will be in when the questionnaire is administered. The questionnaire was administered to the sample to assess its content validity and internal consistency reliability. The final questionnaire had 60 items, and its construct, content, and internal consistency reliability were reassessed. RESULTS: The final 60-item questionnaire displayed a significant difference (P < 0.0001) in the mean scores of the expert and non-expert groups tested. It had internal consistencies (Cronbach's alpha) of 0.71, 0.79, and 0.82 for grades 8, 10, and 12 respectively, and an overall value of 0.77 for all groups combined. However, it was less than 0.7 for most grade 8 pupils and for all grades at a historically disadvantaged school. CONCLUSION: A nutritional knowledge questionnaire with construct, face, and content validities and internal consistency was developed for use in South African adolescents to evaluate their nutritional knowledge. Internal consistency was low in children at a disadvantaged school and those in grade 8 compared with multiracial groups at a multiracial school. It is recommended that pupils at disadvantaged schools be assisted by trained interviewers when taking the test.

Adolescent↗

PubMed2000

Effect of experimental treatment on housekeeping gene expression: validation by real-time, quantitative RT-PCR.

The effects of serum on the expression of four commonly used housekeeping genes were examined in serum-stimulated fibroblasts in order to validate the internal control genes for a quantitative RT-PCR assay. NIH 3T3 fibroblasts transfected with an inducible chimeric gene were serum-starved for 24 h and then induced with 15% serum for 8 h. Serum did not alter the amount of total RNA that was expressed in the cells, however, the amount of mRNA significantly increased over time with serum-stimulation. Both messenger and total RNA from each of the time points were reverse transcribed under two different conditions; one in which the reactions were normalized to contain equal amounts of RNA and another series of reactions that were not normalized to RNA content. The resulting cDNA was amplified by real-time, quantitative PCR using gene-specific primers for beta-actin, beta-2 microglobulin, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and 18S ribosomal RNA. The expression of beta-actin and GAPDH increased up to nine- and three-fold, respectively, under all conditions of reverse transcription (P<0.01). The expression of 18S rRNA increased with serum-stimulation when the cDNA synthesized from non-normalized, total RNA was assayed (P<0. 01) but not when the reverse transcriptions were normalized to RNA content (P>0.05). The expression of beta-2 microglobulin increased up to two-fold when assayed from cDNA synthesized from non-normalized mRNA, but was unaffected by serum when the reverse transcriptions were normalized to mRNA. beta-2 Microglobulin expression was found to be directly proportional to the amount of mRNA that was present in non-normalized reverse transcription reactions. Thus, beta-2 microglobulin and 18S rRNA are suitable internal control genes in quantitative serum-stimulation studies, while beta-actin and GAPDH are not. The internal control gene needs to be properly validated when designing quantitative gene expression studies.

3T3 Cells↗

PubMed1980

Reliability and validity of the Group Embedded Figures Test across the life span.

Data from a previous investigation were reanalyzed to determine the split-half reliability and two forms of validity, i.e., internal consistency and construct, of the Group Embedded Figures Test across the life span. Subjects were 175 females, ranging in age from 17 to 72 yr., who fell into one of seven age groups. The Group Embedded Figures had adequate split-half reliability for the entire sample and for each age group. Significant, consistent differences between performance on Parts II and III of the GEFT were found. Estimates of internal consistency were adequate. Though satisfactory construct validity for the total correct on Parts II and III was obtained as correlations with the Portable-Rod-and-Frame Test for the entire sample, the construct validity of the Group Embedded Figures and separate parts was not adequately demonstrated within all age groups.

Adolescent↗