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Results for “Reproducibility”

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PubMed2006

Test-retest reproducibility of a food frequency questionnaire (FFQ) and estimated effects on disease risk in the Norwegian Women and Cancer Study (NOWAC).

BACKGROUND: The Norwegian Women and Cancer Study (NOWAC) is a national population-based cohort study with 102 443 women enrolled at age 30-70 y from 1991 to 1997. The present study was a methodological sub-study to assess the test-retest reproducibility of the NOWAC food frequency questionnaire (FFQ), and to study how measurement errors in the data can affect estimates of disease risk. METHODS: A random sample of 2000 women aged 46-75 y was drawn from the cohort in 2002. A self-instructive health and lifestyle questionnaire with a FFQ section was mailed to the same subjects twice (test-retest), about three months apart, with a response rate of 75%. The FFQ was designed to assess habitual diet over the past year. We assess the reproducibility of single questions, food groups, energy, and nutrients with several statistical measures. We also demonstrate the method of regression calibration to correct disease risk estimates for measurement error. Alcohol intake (g/day) and high blood pressure (yes/no) is used in the example. RESULTS: For single foods there were some indications of seasonal reporting bias. For food groups and nutrients the reliability coefficients ranged from 0.5-0.8, and Pearson's r, Spearman's rs, and two intraclass correlation coefficients gave similar results. Although alcohol intake had relatively high reproducibility (r = 0.72), odds ratio estimates for the association with blood pressure were attenuated towards the null value compared to estimates corrected by regression calibration. CONCLUSION: The level of reproducibility observed for the FFQ used in the NOWAC study is within the range reported for similar instruments, but may attenuate estimates of disease risk.

Aged↗

PubMed2000

Comparison of young clinical investigators' accuracy and reproducibility when measuring pulmonary and skin surface nodules using a circumferential measurement versus a standard caliper measurement: American Association for Cancer Research/American Society of Clinical Oncology Clinical Trials Workshop.

PURPOSE: The clinical investigator must understand that errors in measuring tumors can greatly affect such clinical-trial end points as tumor response. We performed a prospective, controlled study of tumor measurements that compared circumferential measurements made with a loop planimeter with linear measurements made with a standard caliper. METHODS: Using a cross-over design, 76 clinical oncology fellows/junior oncology faculty members attending a Methods in Clinical Cancer Research Workshop sponsored by the American Association for Cancer Research and the American Society of Clinical Oncology measured five pulmonary nodule phantoms that ranged in size from 1.76 to 13.21 cm(2) and five surface nodule phantoms with sizes ranging from 2.3 to 12.9 cm(2). To perform these measurements, they used both a loop planimeter and a caliper. Forty-two and 40 participants repeated measurements 3 days later on pulmonary and surface nodules. Accuracy, reproducibility, and time efficiency were evaluated. RESULTS: The linear caliper measurements overestimated pulmonary nodule and surface nodule size by a median of 37% and 23%, respectively. Circumferential loop planimeter measurements overestimated pulmonary nodule size and surface nodule size by a median of 8% and 17%, respectively. Interobserver reproducibility for the planimeter was greater than that for the caliper, as evidenced by thinner measurement interquartile ranges. Furthermore, intraobserver reproducibility was higher for the planimeter, with its variability being only 31.4% and 25.5% as large as that of the caliper when measuring the pulmonary and surface nodules, respectively. CONCLUSION: Circumferential measurements provide better accuracy, reproducibility, and speed in measuring both pulmonary and surface nodules than do perpendicular diameters.

Adult↗

PubMed2006

The reproducibility in routine clinical practice of sentinel lymph node identification by pre-operative lymphoscintigraphy in patients with cutaneous melanoma.

Pre-operative lymphoscintigraphy (LS) is an important part of successful sentinel lymph node (SLN) biopsy in most melanoma treatment centers. The test accurately maps lymphatic drainage from cutaneous melanoma sites and has been shown to be reproducible in prospective studies. Its reproducibility has not been tested, however, in routine clinical practice. Occasionally, after LS has been performed to map the location of SLNs, the patient is unable to proceed to SLN biopsy surgery within the time limit imposed by the radioactive decay of the 99mTc label attached to the colloid particles. In this situation, the surgery is rescheduled and LS repeated to relabel the SLNs so that they may be accurately biopsied. This has happened on 21 occasions at the Sydney Melanoma Unit and we have performed a retrospective analysis of the reproducibility of the LS results. In 19 patients, the same SLNs were shown in the same locations on the two studies. Two patients had discrepant results. One showed two extra interval nodes on the back as well as concordant flow to SLNs in each axilla. The other with a leg melanoma showed the same groin SLNs but failed to relabel the two popliteal SLNs on the second study. SLN locations were identical during 95%, and SLNs were identical 94% of the time. These results indicate that in routine clinical practice LS is a highly reproducible procedure to locate and radiolabel the SLNs prior to biopsy in patients with melanoma.

Adult↗

PubMed2006

Quantitative colorectal cancer perfusion measurement by multidetector-row CT: does greater tumour coverage improve measurement reproducibility?

The purpose of this study was to determine if greater z-axis tumour coverage improves the reproducibility of quantitative colorectal cancer perfusion measurements using CT. A 65 s perfusion study was acquired following intravenous contrast administration in 10 patients with proven colorectal cancer using a four-detector row scanner. This was repeated within 48 h using identical technical parameters to allow reproducibility assessment. Quantitative tumour blood volume, blood flow, mean transit time and permeability measurements were determined using commercially available software (Perfusion 3.0; GE Healthcare, Waukesha, WI) for data obtained from a 5 mm z-axis tumour coverage, and from a 20 mm z-axis tumour coverage. Measurement reproducibility was assessed using Bland-Altman statistics, for a 5 mm z-axis tumour coverage, and 20 mm z-axis tumour coverage, respectively. The mean difference (95% limits of agreement) for blood volume, blood flow, mean transit time and permeability were 0.04 (-2.50 to +2.43) ml/100 g tissue; +8.80 (-50.5 to +68.0) ml/100 g tissue/min; -0.99 (-8.19 to +6.20) seconds; and +1.20 (-5.42 to +7.83) ml/100 g tissue/min, respectively, for a 5 mm coverage, and -0.04 (-2.61 to +2.53) ml/100 g tissue; +7.40 (-50.3 to +65.0) ml/100 g tissue/min; -2.46 (-12.61 to +7.69) seconds; and -0.23 (-8.31 to +7.85) ml/100 g tissue/min, respectively, for a 20 mm coverage, indicating similar levels of agreement. In conclusion, increasing z-axis coverage does not improve reproducibility of quantitative colorectal cancer perfusion measurements.

Adenocarcinoma↗

PubMed1994

Reproducibility of dietary and other data from a self-administered questionnaire.

This study examined the reproducibility of information obtained from a questionnaire covering dietary and other information by comparing the answers to the questionnaires with answers to the same questions one year later. Answers from 191 men and 220 women, aged 40 to 65, in Fukuoka prefecture, Japan were compared. The surveys were conducted in November 1989 and November 1990. In the second survey, 97.2% of the first respondents answered. The concordance between the two responses was high, and the differences between the mean intakes from the two surveys were within 5% for 7 food items and within 15% for 14 food items among the 20 items about which the respondents were asked. The intraclass correlation coefficients varied from 0.30 for eggs to 0.62 for milk, with 16 items greater than 0.4. The differences in reproducibility between the sexes and two age categories were not significant. Close values also were obtained for the estimated consumption of salt. A substantially high reproducibility was observed on items regarding drinking and smoking; most of the kappa statistics and the intraclass correlation coefficients were between 0.5 and 0.9. The above reproducibility on individual food items was comparable to or better than those reported from other studies. The results of the present study thus indicate that the self-administered semiquantitative food intake questionnaire used for our cross-sectional study is useful for epidemiologic studies to assess the association between diet and various diseases. In particular, the present questionnaire is highly dependable regarding the overall group intake of foods.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1997

Quantifying estrogen metabolism: an evaluation of the reproducibility and validity of enzyme immunoassays for 2-hydroxyestrone and 16alpha-hydroxyestrone in urine.

Rapid and simple enzyme immunoassays (EIAs) were recently developed to measure 2-hydroxyestrone and 16alpha-hydroxyestrone in unextracted urine. The balance between these competing estrogen metabolism pathways may serve as a biomarker of breast cancer risk. Before testing these assays in epidemiologic studies, we evaluated their reproducibility, and validity relative to gas chromatography-mass spectroscopy (GC-MS). Overnight 12-hr urine collections from five midfollicular premenopausal women, five midluteal premenopausal women, and five postmenopausal women were aliquoted and stored at -70 degrees C. Two aliquots from each woman were assayed with the EIAs in a random, blinded order, monthly over 4 months and 1 year later. Reproducibility over 4 months was good for both metabolites in premenopausal women (coefficient of variation = 8-14%) and satisfactory in postmenopausal women (approximately 19%). Reproducibility over 12 months remained good in premenopausal women, but was poor in postmenopausal women, with mean readings increasing 50 to 100%. Wide variation in estrogen metabolite levels enabled a single EIA measurement to characterize individual differences among premenopausal women in midfollicular (intraclass correlation coefficient = 98-99%) and midluteal phase (85-91%). A narrower range in metabolite levels among postmenopausal women reduced discrimination (78-82%). The correlation between EIA and GC-MS measurement was excellent for both metabolites (r>0.9), except for 2-hydroxyestrone in postmenopausal women (r=0.6). Analysis of absolute agreement suggested that both EIAs were less sensitive than GC-MS, and each detected nonspecific background. The low concentration of estrogen metabolites in urine from postmenopausal women may explain the problems with reproducibility and validity in this menstrual group. Accordingly, more sensitive EIAs have been developed and are now being evaluated.

Adult↗

PubMed2004

Human papillomavirus typing with hybrid capture II on archived liquid-based cytologic specimens: is HPV typing always reproducible?

Reproducibility of human papillomavirus (HPV) typing on archived ThinPrep (Cytyc, Boxborough, MA) specimens was evaluated repeating Hybrid Capture II (HCII) (Digene, Gaithersburg, MD) testing after 25 to 40 months (mean, 31.3 months; group 1), 6 to 11 months (mean, 8.4 months; group 2), and 0 to 5 months (mean, 3.5 months; group 3). Another ThinPrep slide was prepared to evaluate cellularity and reproducibility of the cytologic diagnosis. The mean residual relative light units (RLU) calculated for each group showed a strong decrease of RLU values at the second typing (group 1, 21.69%; group 2, 26.47%; and group 3, 32.25% of original values). No residual HPV DNA was shown in group 1 in 8 (13%) of 60 cases or in groups 2 and 3 in 2 (3%) of 60 cases each. These cases were associated mostly with poor cellularity and reproducibility of the initial cytologic diagnosis in the final cytologic examination. Intergroup statistical analysis of mean relative percentages for cases with satisfactory residual cellularity revealed a significant difference only between groups 1 and 3 (P < .05). Although mostly reproducible, HPV typing results by HCII on archived specimens are influenced by material consumption. In addition, results might be affected by some DNA degradation after long-term sample storage.

Animals↗

PubMed1996

Reproducibility of cardiopulmonary exercise parameters in patients with valvular heart disease.

STUDY OBJECTIVES: To determine the degree of reproducibility of exercise parameters in patients with chronic heart failure. Parameters such as treadmill walking time (TWT), oxygen uptake (Vo2), heart rate, oxygen pulse, minute ventilation (VE) ventilatory equivalents for oxygen uptake (VE/Vo2) and carbon dioxide output (Vco2), and respiratory quotient at both anaerobic threshold (AT) and peak exercise (PE) each were assessed. DESIGN: Using the Naughton-Weber protocol, two repeated cardiopulmonary treadmill exercise tests were performed after detailed instructions prior to the first test and on strict adherence to standardized investigational conditions, viz, at the same time of day and at the same ambient temperature, receiving constant medication, and while in a 12-h fasting state. PATIENTS: The studies were carried out in 17 patients with chronic heart failure due to valvular heart disease considered candidates for intervention because of symptoms. According to Weber's classification of functional capacity, 10 patients were in class A (Vo2 max > 20 mL O2/min/kg), 5 patients were in class B (16 to 20 mL O2/min/kg), and the remaining 2 were in class C (10 to 16 mL O2/min/kg). MEASUREMENTS: Parameters assessed were TWT, Vo2, heart rate, oxygen pulse, VE and ventilatory equivalents for oxygen (VE/Vo2) and carbon dioxide (VE/Vco2) both at AT and at PE. To reflect reproducibility, correlation coefficients (r) were calculated. RESULTS: An excellent reproducibility was found for TWT (r = 0.963, p < 0.0001), Vo2 at AT in percent of predicted Vo2max (r = 0.984, p < 0.0001), Vo2 at PE (r = 0.996, p < 0.0001), heart rate at AT (r = 0.943, p < 0.0001) and at PE (r = 0.928, p < 0.0001), oxygen pulse at AT (r = 0.980, p < 0.001) and at PE (r = 0.991, p < 0.0001), VE at AT (r = 0.949, p < 0.0001) and at PE (r = 0.912, p < 0.0001) as well as VE/Vo2 at AT (r = 0.942, p < 0.0001) and at PE (r = 0.781, p < 0.0002) and VE/Vco2 at AT (r = 0.995, p < 0.0001) and at PE (r = 0.943, p < 0.0001), respectively. CONCLUSIONS: On adherence to standardized conditions, an excellent reproducibility existed for TWT, Vo2 (reflecting cardiac output), ventilation, and heart rate as well as derived parameters, rendering cardiopulmonary exercise testing a reliable means of quantification of heart failure as a prerequisite for enabling diagnostic or therapeutic decisions.

Adult↗

PubMed1997

Reproducibility of nasal peak inspiratory flow among healthy adults: assessment of epidemiologic utility.

STUDY OBJECTIVE: To assess the reproducibility of nasal peak inspiratory flow (PIFn). PARTICIPANTS: Twelve healthy nonsmoking volunteers were studied. METHODS: Repeated measurements of PIFn and oral (PIFm) peak inspiratory flow were performed for 5 consecutive days. Two methods of inhalation were compared. In the residual volume (RV) method, the forced maximal inspiratory maneuver was initiated from the end of a maximal expiration, while in the functional residual capacity (FRC) method, the maneuver was from the end of a tidal breath. Reproducibility was assessed by the intraclass correlation coefficient. Time trend for the 5 days was assessed by random effect models adjusting for different baseline for each subject. RESULTS: The intraclass correlation coefficient (ICC) of PIFn was 0.89 (lower limit of one-sided 95% confidence interval is 0.80) by the RV method and 0.78 (95% lower limit is 0.63) by the FRC method, suggesting that both methods have good reproducibility. These were similar to the ICCs of PIFm by each method. The FRC method did not show a significant time trend for PIFn. The RV method had a small, but significant, decreasing time trend of a magnitude considered inconsequential for the purpose of epidemiologic study. CONCLUSION: PIFn, measured from either RV or from FRC, showed good reproducibility and can be employed in epidemiologic studies investigating the upper airways' response to air pollutant exposure. Further studies of the relationships between PIFn and signs and symptoms of rhinitis are needed to evaluate the utility of this test for clinical and epidemiologic use.

Adult↗

PubMed1998

Respiratory resistance in the emergency department: a reproducible and responsive measure of asthma severity.

OBJECTIVES: To determine, in preschool children with an acute asthma exacerbation, the responsiveness to change of respiratory resistance measurements obtained by the forced oscillation (Rfo) technique, and to identify the magnitude of change indicative of airway obstruction reversibility. DESIGN/SETTING: A prospective observational study of 114 children, aged 3 to 17 years, untrained in the Rfo technique and treated for acute asthma in a tertiary-care pediatric emergency department (ED). MEASUREMENTS: A physical examination followed by three measurements of respiratory resistance by forced oscillation were obtained at 8 Hz (Rfo8) and at 16 Hz (Rfo16). In cooperative children, routine spirometry that included FEV1 was also performed on the Custo Vit R (Custo Med; Munich, Germany). All measurements were obtained twice during the course of the ED treatment, before and after treatment with nebulized bronchodilators. RESULTS: The Rfo8 and Rfo16 measurements were highly reproducible (reproducibility coefficients >0.85). Both the Rfo8 and Rfo16 were at least as responsive to change (responsiveness coefficients of 2.3 and 1.2, respectively) as was FEV1 (2.0) and the four clinical signs most sensitive to change (0.6 to 1.0). A 19% change in Rfo8 was suggestive of significant reversibility. CONCLUSIONS: In the assessment of children aged > or =3 years with acute asthma exacerbation, the respiratory resistance measurements are highly reproducible and responsive to change, particularly when obtained at 8 Hz. A 19% change from baseline Rfo8 is suggestive of reversibility. This technique appears to be an attractive alternative in the evaluation of children who are too young or too sick to perform spirometry reproducibly.

Acute Disease↗

PubMed2006

Repeatability and reproducibility of distraction indices in PennHIP examinations of the hip joint in dogs.

Repeatability and reproducibility of Distraction Index (DI) measurements in the PennHIP method were evaluated in 100 dogs. The PennHIP distraction views sent to the PennHIP Analysis Center (PAC) were duplicated, digitalised, and identified with a code, and an adequate computer software was used for DI measurements. One examiner performed two DI measurement sessions, evaluating individually 200 hip joints. The scoring repeatability and reproducibility were estimated calculating the Intraclass Correlation Coefficient (ICC) between the two DI measurement sessions and between the second DI measurement session and the DI in PAC reports, respectively. The ICC for repeatability was 0.97 [95% confidence interval (CI), 0.96 to 0.98], and the ICC for reproducibility was 0.95 (95% CI, 0.93 to 0.96). The results suggest that the DI measurement method described is repeatable and can reproduce the PAC reports with confidence. Distraction indices measured in different PennHIP studies, using this DI measurement method and performed by trained researchers, can be considered interchangeable.

Animals↗

PubMed2005

[Intraobserver reproducibility in anterior segment morphometry of normal eyes using ultrasound biomicroscopy (UBM)].

PURPOSE: To systematically study the anterior segment morphometric measurements by ultrasound biomicroscopy (UBM) in a large population of normal eyes, to evaluate their intra-observer reproducibility. Two new measurements are proposed and also tested concerning their intra-observer reproducibility. METHODS: One hundred ninety eyes of 101 patients with normal ophthalmic examination were studied by UBM. Anterior chamber depth (ACD) along with 11 different morphometric parameters that characterize the anterior segment morphometry were measured in the superior, nasal, inferior and temporal meridians. All measurements were performed twice with a minimum interval of four weeks between them. RESULTS: There were no statistical significant differences between the first (M1) and second (M2) measurements and regarding each studied parameter except for 2 variables in 2 meridians in the right eyes (OD) and 2 variables of one meridian in the left eyes (OS). Even in these cases, the largest difference between M1 and M2 was less than 0.006 mm, which was not clinically significant. The new tested parameters also presented a good intra-observer reproducibility. CONCLUSION: This study confirmed the good intra-observer reproducibility of the variables that characterize anterior segment morphometry by UBM.

Adult↗

PubMed2002

[Reproducibility and validity of a food frequency questionnaire].

OBJECTIVE: Methods to evaluate food consumption still need improvement. A study was conducted to verify the reproducibility and validity of a food frequency questionnaire (FFQ) among overweight adults. METHODS: The study was carried out in a private university in São Paulo, Brazil. The study sample consisted of 146 individuals of both sex with body mass index =25 kg/m2 and age between 18 and 60 years old. For reproducibility the FFQ was applied by trained interviewers at two different instances with a mean interval time of 47 days. For validity, data collected from the FFQ were compared with those obtained from the average of 3 different daily records of a 24-hour dietary recall (mean interval time: 15 days). Validity and reproducibility of data on calories and macronutrients consumption was assessed using pondered kappa statistics and intraclass correlation coefficient. RESULTS: A higher variability in the reporting of regular food consumption was seen among obese than overweight individuals. Concerning reproducibility, kappa statistical values varied from 0.23 (carbohydrates and fats) to 0.40 (calories), and intraclass correlation coefficients ranged from 0.28 (protein) to 0.54 (total calories). For FFQ validity, the highest kappa value was 0.25 (calories), and the intraclass correlation coefficient was 0.21 (protein). CONCLUSIONS: Food consumption reports of overweight individuals tend to be underestimated. Despite its limitations, FFQ could be used in epidemiological studies to assess the regular food consumption of overweight individuals.

Adolescent↗

PubMedDate not supplied

Validity and reproducibility of a food frequency questionnaire to assess dietary intake of women living in Mexico City.

OBJECTIVE: To assess the reproducibility and validity of a 116 item semi-quantitative food frequency questionnaire (FFQ), designed to assess the relation between dietary intake and chronic diseases. MATERIAL AND METHODS: To test the reproducibility of the FFQ questionnaire, the FFQ was administered twice to 134 women residing in Mexico City at an interval of approximately one year; to assess the validity we compared results obtained by the FFQs with those obtained by four 4-day 24-hour recalls at three month intervals. Validity and reproducibility were evaluated using regression analysis and Pearson and intraclass correlation coefficients of log-e and calorie-adjusted nutrient scores. RESULTS: Mean values for intake of most nutrients assessed by the two food frequency questionnaires were similar. However, means for the 24-hr recall were significantly lower. Intraclass correlation coefficients for nutrient intakes, assessed by questionnaires, administered one year apart, ranged from 0.38 for cholesterol to 0.54 for crude fiber. Correlation coefficients between energy-adjusted nutrient intakes, measured by diet recalls, and the first FFQ ranged from 0.12 for polyunsaturated fatty acids to 0.67 for saturated fatty acids. Regression coefficients between 24-hr recall and FFQ,s were all significant were significant for all nutrients, except for polyunsaturated fat, folic acid, vitamin E and Zinc. CONCLUSIONS: These data indicate that this semi-quantitative FFQ is reproducible and provides a useful estimate by which to categorize individuals by level of past nutrient intake. However, its application outside Mexico City or in different age and gender populations will require additional modifications and validation efforts.

Diet↗

PubMed1996

Reproducibility of attachment level recordings using an electronic and a conventional probe.

This study describes the variations in the reproducibility of attachment level recordings for different subjects at different examinations. Twenty patients with different degrees of periodontal disease were recruited and examined bi-monthly for their attachment levels using an electronic probe in two quadrants and a conventional probe in the other two quadrants. At each of the 7 examinations attachment level recordings were repeated with the appropriate probe after approximately 30 minutes. Results demonstrate that the reproducibility of attachment level recordings was slightly better for the conventional probe than for the electronic probe. Attachment level recording reproducibility varied considerably between subjects and between examinations for the same subject. Aggregation of attachment level recordings in the form of mean tooth values or mean individual values reduced the range of the differences, but considerable between-subject and between-examination variation was still seen. These results indicate that no single uniformly valid estimate of attachment level reproducibility exists which can be used to set diagnostic thresholds such that a minimum number of incorrect diagnoses are made.

Dental Instruments↗

PubMed2005

Examination of the reproducibility of grip force and muscle oxygenation kinetics on maximal repeated rhythmic grip exertion.

The contribution of physiological mechanisms involving force-exertion value during maximal repeated rhythmic muscle contraction work changes over time. The purpose of this study was to examine the reproducibility of grip force and muscle oxygenation kinetics with a decrease of the gripping force during maximal repeated rhythmic grip (RRG). Subjects were 10 males, aged 20-26 years (height 173.9+/-7.3 cm, body weight 71.5+/-11.2 kg). Each subject performed maximal repeated rhythmic grip as a target value with a target frequency of 30 grips.min(-1) for 6 min. The trial-to-trial reproducibility of Oxygenated haemoglobin (Oxy-Hb), Deoxygenated haemoglobin (Deoxy-Hb), Total haemoglobin (Total Hb) and grip force during the RRG (6 min) was very high (r(xy)=0.919-0.966) and the decreasing pattern of the force-time curve was consistent. The cross correlation coefficients of the grip force (r(xy)=0.985) and muscle oxygenation kinetics (Total Hb: 0.996, Oxy-Hb: 0.992, Deoxy-Hb: 0.995) in the pre-inflection phase (marked force decreasing phase) were very high, while these coefficients in the post-inflection phase (almost steady state phase) were low as compared with those in the pre-inflection phase. The trial-to-trial reliabilities of any parameter regarding grip were fair or high (ICC=0.686-0.927). The changing points of muscle oxygenation kinetics appeared before reaching an almost steady state, which showed a high reliability and they were considered to reflect the shift of physiological mechanisms. In particular, the intraclass correlation coefficients (ICC) for the time to reach maximum Deoxy-Hb and Oxy-Hb values and regression coefficient in an increasing phase of Oxy-Hb were very high (ICC=0.894-0.947). It was found that the trial-to-trial reproducibility of grip force and muscle oxygenation kinetics is very high during the whole 6 min in RRG, but is poor during the post-inflection phase. The reproducibility of the grip force and muscle oxygenation kinetics in the phase before reaching an almost steady state during RRG is fair, and the decrease of the grip force in this phase may be influenced by the muscle oxygenation kinetics.

Adult↗

PubMed1996

Measurement of coronary artery calcium with dual-slice helical CT compared with coronary angiography: evaluation of CT scoring methods, interobserver variations, and reproducibility.

OBJECTIVE: This study was performed to evaluate new scoring methods for quantitating coronary artery calcifications with helical CT and to compare the results with those of quantitative coronary angiography in patients with suspected coronary artery disease. SUBJECTS AND METHODS: Unenhanced dual-slice helical CT and coronary angiography were performed within 24 hr of each other in 101 patients with symptoms of coronary artery disease. Coronary artery calcifications with a density above 90 H were identified on each slice and, with the same regions of interest, quantitative scoring was performed at thresholds of 90 H (new) 130 H (old). Two mathematical algorithms (one new and one old) were evaluated for both thresholds (yielding four scoring systems). By CT imaging, we defined disease as a score of greater than zero. By angiography, we defined disease as a 50% or greater reduction in the luminal diameter of any major vessel. Interobserver variations in calcification scoring were evaluated. Seventeen of our patients. also underwent a second, consecutive CT scan to determine reproducibility. RESULTS: With the new threshold and the new algorithm, the sensitivity, specificity, and accuracy of helical CT in predicting disease were 88%, 52%, and 76%, respectively. We found a moderate positive association between the total CT calcification score and the number of stenotic coronary arteries at angiography (Pearson's correlation coefficient, .43; p = .05 [analysis of variance]). The accuracy and the area under the receiver operating characteristic curve were higher with the new threshold and the new algorithm. Interobserver agreement in calcification scoring was high (intraclass correlation coefficient, .99 [n = 85]), as was reproducibility (intraclass correlation coefficient, .94 [n = 17]). Reproducibility was higher when scoring was based on the new threshold and the new algorithm. CONCLUSION: The quantity of coronary artery calcifications as measured by helical CT correlated positively with obstructive coronary artery disease as measured by angiography. Interobserver agreement and reproducibility were excellent. A new scoring method showed promise.

Adult↗

PubMedDate not supplied

[Radiographic signs of scaphoid union after bone grafting: the analysis of inter-observer agreement and intra-observer reproducibility].

INTRODUCTION: The diagnosis of radiological union of scaphoid bone after bone grafting requires clear evidence of bony trabeculae traversing the graft from the proximal to the distal pole on at least two of four standard scaphoid views. This sign is the only objective assessments of union. Radiographs of the scaphoid taken 18 weeks after operation, however, can be difficult to interpret. This fact led us to question whether radiographs of scaphoid at 18 weeks provide reliable and objective indication of union. OBJECTIVE: Our study was, therefore, designed to determine the reliability of the radiographic diagnosis of scaphoid union after bone grafting by testing the degree of inter-observer agreement and reproducibility. METHODS: Out of 30 sets of the scaphoid bone radiographs after bone grafting taken 18 weeks after operation, 15 of good quality were selected. Each set included four views: postero-anterior, lateral, semi- pronated and semi-supinated. Seven observers were tested: three orthopedic consultants, three residents and one consultant in radiology. Each was presented with 15 sets of radiographs designated from 1 to 15 and each was asked to answer the question: "Are there trabeculae crossing the fracture site?" Possible answers were 'yes' or 'no'. Eight weeks later, the same 15 sets of radiographs were marked in alphabetic order from A to K and presented to the same seven observers. Data was then analyzed and expressed in terms of interobserver agreement in pairs and intra-observer reproducibility. Calculation was done by kappa statistics so that the degree of disagreement was taken into account and allowance was made for chance agreement. Kappa values can vary from -1.0 (complete disagreement) through 1 (chance agreement) to +1 (complete agreement). RESULTS: For all 15 sets of radiographs, the degree of agreement between each pair of observers was illustrated in Table 2. It demonstrated the level of agreement between each pairs of seven observers. The overall median kappa coefficient for inter-observer agreement was 0,46. This value corresponded to "moderate" strength of agreement. Median kappa coefficient for consultant was 0.62, but median kappa coefficient for residents was 0.43. The degree of agreement between the opinions of each observer at his first and at his subsequent reviews of the same set of radiograph after 8 weeks was presented in Table 3. The overall median Kappa coefficient for the intraobserver agreement for all seven observers was 0.54. The ability of seven observers to reproduce their own opinion regarding trabeculae crossing the fracture line was poor to use it for assessment of bone union. CONCLUSION: Our conclusion is that radiographs taken 18 weeks after scaphoid grafting cannot be reliable and reproducible for assessment of bone union.

Bone Transplantation↗