PURPOSE: This study was performed to investigate the intra- and inter-observer variability in linear measurements with axial images obtained by PreXion (PreXion Inc., San Mateo, USA) and i-CAT (Imaging Sciences International, Xoran Technologies Inc., Hatfield, USA) CBCT scanners, with different voxel sizes. MATERIALS AND METHODS: A cylindrical object made from nylon with radiopaque markers (phantom) was scanned by i-CAT and PreXion 3D devices. For each axial image, measurements were taken twice in the horizontal (distance A-B) and vertical (distance C-D) directions, randomly, with a one-week interval between measurements, by four oral radiologists with five years or more experience in the use of these measuring tools. RESULTS: All of the obtained linear measurements had lower values than those of the phantom. The statistical analysis showed high intra- and inter-observer reliability (p=0.297). Compared to the real measurements, the measurements obtained using the i-CAT device and PreXion tomography, on average, revealed absolute errors ranging from 0.22 to 0.59 mm and from 0.23 to 0.63 mm, respectively. CONCLUSION: It can be concluded that both scanners are accurate, although the linear measurements are underestimations, with no significant differences between the evaluators.
Cone-Beam Computed Tomography* ; Dimensional Measurement Accuracy ; Nylons ; Observer Variation ; Reproducibility of Results

BACKGROUND: In daily clinical practice, it is essential to properly evaluate the postoperative sliding distance of various femoral head fixation devices (HFD) for trochanteric fractures. Although it is necessary to develop an accurate and reproducible method that is unaffected by inconsistent postoperative limb position on radiography, few studies have examined which method is optimal. Therefore, the purpose of this study is to prospectively compare the accuracy and reproducibility of our four original methods in the measurement of sliding distance of the HFD. METHODS: Radiographs of plastic simulated bone implanted with Japanese proximal femoral nail antirotation were taken in five limb postures: neutral, flexion, minute internal rotation, greater external rotation, and flexion with external rotation. Orthopedic surgeons performed five measurements of the sliding distance of the HFD in each of the flowing four methods: nail axis reference (NAR), modified NAR, inner edge reference, and nail tip reference. We also assessed two clinical cases by using these methods and evaluated the intraclass correlation coefficients. RESULTS: The measured values were consistent in the NAR method regardless of limb posture, with an even smaller error when using the modified NAR method. The standard deviation (SD) was high in the nail tip reference method and extremely low in the modified NAR method. In the two clinical cases, the SD was the lowest in the modified NAR method, similar to the results using plastic simulated bone. The intraclass correlation coefficients showed the highest value in the modified NAR method. CONCLUSIONS: We conclude that the modified NAR method should be the most recommended based on its accuracy, reproducibility, and usefulness.
*Bone Nails ; *Dimensional Measurement Accuracy ; Fracture Fixation, Intramedullary/instrumentation/*methods ; Hip Fractures/*surgery ; Prospective Studies ; Reproducibility of Results

Blind review is one of the most important milestones in clinical trials, which connects data management process to statistical analysis. During blind review, data quality should be reviewed and assessed on both data management and statistical aspects. The primary work of data managers in blind review is to ensure the accuracy of data before it is handed over to biostatistics group. Database auditing, listing data reviewing and reconciliation should become a good clinical data management practice. Statisticians, on the other hand, will focus on quality findings related to protocol deviations or protocol violations. To investigate the protocol deviations and/or violations and relevant impacts on data outcomes, it is important to provide the essential basis of data quality through the blind review, and to assess the reliability of study outcomes.
Biostatistics ; Clinical Trials as Topic ; Data Accuracy ; Databases, Factual ; Reproducibility of Results

The quality and integrity of clinical trials and associated data are not only derived from accuracy of trial data analyses, but also closely embodied to the authenticity and integrity of those data and data documents as well as the compliant procedures obtaining those data and relevant files in the life cycle of clinical trials. The compliances of good clinical practices and standards suggest the reliability, complete and accuracy of data and data documents, which is constructing the convincible foundation of drug efficacy and safety validated via clinical trials. Therefore, the monitoring and auditing on clinical trials and associated data quality keep eyes on not only verifications of reliability and correctness on the data analytic outcomes, but also validation of science and compliance of the trial management procedure and documentations in the process of data collections.
Clinical Trials as Topic ; standards ; Data Accuracy ; Reproducibility of Results

OBJECTIVE: To determine the reliability and validity of hand-held dynamometer (HHD) depending on its fixation in measuring isometric knee extensor strength by comparing the results with an isokinetic dynamometer. METHODS: Twenty-seven healthy female volunteers participated in this study. The subjects were tested in seated and supine position using three measurement methods: isometric knee extension by isokinetic dynamometer, non-fixed HHD, and fixed HHD. During the measurement, the knee joints of subjects were fixed at a 35degrees angle from the extended position. The fixed HHD measurement was conducted with the HHD fixed to distal tibia with a Velcro strap; non-fixed HHD was performed with a hand-held method without Velcro fixation. All the measurements were repeated three times and among them, the maximum values of peak torque were used for the analysis. RESULTS: The data from the fixed HHD method showed higher validity than the non-fixed method compared with the results of the isokinetic dynamometer. Pearson correlation coefficients (r) between fixed HHD and isokinetic dynamometer method were statistically significant (supine-right: r=0.806, p<0.05; seating-right: r=0.473, p<0.05; supine-left: r=0.524, p<0.05), whereas Pearson correlation coefficients between non-fixed dynamometer and isokinetic dynamometer methods were not statistically significant, except for the result of the supine position of the left leg (r=0.384, p<0.05). Both fixed and non-fixed HHD methods showed excellent inter-rater reliability. However, the fixed HHD method showed a higher reliability than the non-fixed HHD method by considering the intraclass correlation coefficient (fixed HHD, 0.952-0.984; non-fixed HHD, 0.940-0.963). CONCLUSION: Fixation of HHD during measurement in the supine position increases the reliability and validity in measuring the quadriceps strength.
Dimensional Measurement Accuracy ; Female ; Humans ; Isometric Contraction ; Knee Joint ; Knee* ; Leg ; Methods ; Muscle Strength Dynamometer ; Pilot Projects* ; Reproducibility of Results* ; Restraint, Physical ; Supine Position ; Tibia ; Torque ; Volunteers

For pharmaceutical industries, clinical data is one of the most valuable deliverables. It is also the basis of analysis, submission, approval, labeling and marketing of a drug product. To ensure the integrity and reliability of clinical data, a scientific standardized quality control (QC) has to be established at each step of a clinical trial. Data validation is conducted to ensure the reasonability and compliance of clinical data by checking data quality before the data is statistically analyzed. This paper focuses on purpose of data validation, creation of data validation plan, rationale of data validation, types of data validation and performance of user acceptance testing on clinical database.
Clinical Trials as Topic ; standards ; Data Accuracy ; Data Collection ; standards ; Databases, Factual ; Quality Control ; Reproducibility of Results

No abstract available.
Reproducibility of Results*

OBJECTIVE: To evaluate the psychometric properties of the Fatigue Severity Scale (FSS), the Fatigue Impact Scale (FIS), and the Multidimensional Fatigue Inventory (MFI-20) in persons with late effects of polio (LEoP). More specifically, we explored the data completeness, scaling assumptions, targeting, reliability, and convergent validity. METHODS: A postal survey including FSS, FIS, and MFI-20 was administered to 77 persons with LEoP. Responders received a second survey after 3 weeks to enable test-retest reliability analyses. RESULTS: Sixty-one persons (mean age, 68 years; 54% women) responded to the survey (response rate 79%). Data quality of the rating scales was high (with 0%–0.5% missing item responses), the corrected item-total correlations exceeded 0.4 and the scales showed very little floor or ceiling effects (0%–6.6%). All scales had an acceptable reliability (Cronbach’s α≥0.95) and test-retest reliability (intraclass correlation coefficient, ≥0.80). The standard error of measurement and the smallest detectable difference were 7%–10% and 20%–28% of the possible scoring range. All three scales were highly correlated (Spearman’s correlation coefficient r(s)=0.79–0.80; p < 0.001). CONCLUSION: The FSS, FIS, and MFI-20 exhibit sound psychometric properties in terms of data completeness, scaling assumptions, targeting, reliability, and convergent validity, suggesting that these three rating scales can be used to assess fatigue in persons with LEoP. As FSS has fewer items and therefore is less time consuming it may be the preferred scale. However, the choice of scale depends on the research question and the study design.
Data Accuracy ; Fatigue* ; Humans ; Poliomyelitis* ; Postpoliomyelitis Syndrome ; Psychometrics* ; Rehabilitation ; Reproducibility of Results ; Weights and Measures*

PURPOSE: To evaluate the psychometric properties of the Korean short form-36 health survey version 2 for assessing the general population and to provide normative data on the general population. METHODS: Six hundred members of the general Korean population were recruited using a multistage quota sampling method. Data quality was evaluated in terms of the completeness of the data and the response consistency index. Each psychometric property was evaluated using descriptive statistics, item internal consistency, item discriminant validity, known-group validity, internal consistency reliability, and exploratory factor analysis. RESULTS: The rate of missing data was low, and the rate of consistent responses was similar to conventional criteria. Item internal consistency was acceptable across all scales, whilst item discriminant validity was satisfactory for five of the eight scales. Social functioning was the least acceptable in terms of not only item discriminant validity but also item consistency reliability (Cronbach's alpha = .64). Test-retest Pearson correlation coefficients ranged from .54 to .80. In known group comparison, male sex, age <60 years, high educational status, and the absence of any comorbidities were associated with higher scores than their counterparts. Item factor analysis yields the presence of six factors, accounting for 68.8% of the variance. CONCLUSION: The findings of this study generally support the use of the Korean short form-36 version 2 for evaluating the general population, although caution is recommended when interpreting the vitality, social functioning, and mental health scales. Further research is needed in Korea.
Accounting ; Comorbidity ; Educational Status ; Health Surveys ; Humans ; Korea ; Male ; Mental Health ; Psychometrics ; Quality of Life ; Reproducibility of Results ; Data Accuracy ; Weights and Measures

This study is related to analysis the validity and reliability of double major data for admission in college of medicine yonsei university. The 69 applicants and 37 of those who had been admitted were sampled and then the GPAs of previous major, the interview scores and the GPAs of medical college were used as sources of analysis. This study is estiamted descriptive statistics, concurrent-related evidence of validity between GPAs previous college and interview scores, predictive-related evidence of validity of GPAs of previous college and interview scores, inter-scorer reliability of interview scores. The results of this study are like this: First, all of 69 students applied and 37(53.6%) applicants were admitted. Eleven students who were admitted graduated bio-chemical department of the college of science. The percentile rank of learning achievement of successful candidates show 64.5~98.2(1995), 43.6~86.6(1996), 22.8~96.9(1997). Second, the result of the estimation of the concurrence-related evidence of validity appear 0.729(1994), 0.673(1995), 0.562(1996), 0.876(1997). Therefore the candidates who got high GPAs also took high interview scores. Third, the predictive-related evidence of validity show insignificant. Forth, generalizability of inter-scorer reliability about intervew scores appear 0.972(1994), 0.983(1995). To improve the validity and relibility double major data, interview skills and educational programs has to be reoriented.
Humans ; Learning ; Reproducibility of Results*