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PubMed1996

Reproducibility of the response to short-term low salt intake in essential hypertension.

BACKGROUND: The reproducibility of the arterial pressure response to change in salt intake in essential hypertensives has been little investigated. OBJECTIVE: To study the reproducibility of the response to salt in 14 untreated patients with mild essential hypertension. METHODS: After a run-in phase (1 month), each patient ingested, in random order and with cross-over, 1 week of high salt intake (170 mmol/day) and 1 week of low salt intake (40 mmol/day). The identical experimental protocol was then repeated after an average interval of 3.4 months. Arterial pressure was measured (clinic arterial pressure and 24 h ambulatory monitoring) on the seventh day of each diet period. The reproducibility of the arterial pressure response was assessed in terms the intraclass correlation coefficient and the K statistics. RESULTS: There was a good compliance with the dietary prescription because the urinary Na excretion was on average very close to the prescribed intake both during the first and during the second salt intake period. Both clinic and 24 h arterial pressure fell significantly (P < 0.01) and to the same extent in the low-salt phases of the study. Clinic arterial pressure was consistently higher than 24 h ambulatory arterial pressure but the average changes induced by salt depletion were similar. The variability of 24 h ambulatory arterial pressure at constant salt intake was lower than that of clinic arterial pressure. However, the arterial pressure response to salt showed the same variability with the two methods. The reproducibility of the dichotomous classification of patients into salt-sensitive and -resistant was low both in terms of 24 h ambulatory and in terms of clinic blood pressure. CONCLUSION: Although on rechallenging the average arterial pressure response to salt remains unchanged in essential hypertensives, the individual responses are variable and the reproducibility of the dichotomous classification is unsatisfactory. The problem of dichotomizing patients into salt-sensitive and -resistant ones is only in very little part resolved by more precise arterial pressure estimates.

Adult↗

PubMed1990

Reproducibility and action levels for gamma camera uniformity.

Deciding on the action level for gamma camera non-uniformity is difficult because the reproducibilities of quality control measurements and service adjustments are usually unknown. This work evaluated the reproducibilities of integral uniformity (IU), differential uniformity (DU) and the corrected relative standard deviation (CRSD). The latter was calculated by removing from the relative standard deviation of the pixel counts the component due to statistical fluctuations. The reproducibility of each parameter was evaluated by analysing 10 intrinsic flood acquisitions with total counts of 2, 5, 10 and 30 million. All three parameters were less reproducible at the lower count densities, but as expected IU and DU also showed higher mean values. CRSD was consistent and highly reproducible, at all count densities. At 10 million counts CRSD had a coefficient of variation (COV) of 1.3% which was a five-fold improvement over the 6.6% and 6.1% found for IU and DU, respectively. The relative sensitivity of IU, DU and CRSD was compared in monthly measurements on 10 gamma cameras over one year. No significant difference in relative sensitivity was demonstrated: a change in camera performance produced about the same percentage change in each parameter. The precision with which service engineers adjust gamma cameras was also assessed by measuring the uniformity of 10 gamma cameras immediately after service adjustment at monthly intervals over one year. Finally, general action levels were defined for IU, DU and CRSD at 7%, 5% and 2.5% respectively.

Gamma Cameras↗

PubMed1996

Reproducibility of a questionnaire for assessment of physical load during work and leisure time. Stockholm MUSIC I Study Group. MUSculoskeletal Intervention Center.

A self-administered questionnaire on physical load in lifetime occupational work, in present job, and in present leisure activities was tested for reproducibility with the test-retest method in 126 male and 217 female workers from 30 occupations. The questionnaire contained 92 questions and nine different response scales. The results indicated that questions concerning physical activity retrospectively and in the present job, vibrations in the present job, working postures involving the whole body, and questions concerning specific leisure activities (eg ball games, skiing, etc) seem to offer sufficient reproducibility to be worth testing for validity, at least at a 5-point ordinal level. Questions concerning working postures involving parts of the body, including awkward postures, and questions concerning manual materials handling seem to offer too poor reproducibility to be used in studies in which the aim is to quantify duration in proportions of a typical working day and frequencies in times per hour. Questions concerning level of physical activity and exertion in domestic work seem to offer too poor reproducibility to be used at a 5-point ordinal level. Gender, age, and musculoskeletal complaints did not influence the reproducibility to any great extent.

Adolescent↗

PubMed1996

Comparative reproducibility of defibrillation threshold and upper limit of vulnerability.

The upper limit of vulnerability (ULV) is the strength at or above which VF is not induced when a stimulus is delivered during the vulnerable phase of the cardiac cycle. Previous studies have demonstrated a statistically significant correlation between the ULV and the defibrillation threshold (DFT) in groups of patients. However, the correlation between ULV and DFT may not be close in individual patients. This imperfect correlation may be due to physiological factors or to limitations of the measurement methods. The reproducibility of either DFT or ULV has not been studied critically. The purpose of this study was to compare the reproducibility of clinically applicable methods for determination of DFT and ULV. We prospectively studied 25 patients with a transvenous implantable cardioverter defibrillator (Medtronic 7219D) at postoperative electrophysiological study. DFT was defined as the lowest energy that defibrillated after 10 seconds of VF. The ULV was defined as the lowest energy that did not induce VF with three shocks at 0, 20, and 40 ms before the peak of the T wave in ventricular paced rhythm at a cycle length of 500 ms. Both the DFT and the ULV were determined twice for biphasic pulses using a three-step, midpoint protocol. There was no significant difference between the two determinations of DFT (10.1 +/- 5.9 J vs 10.4 +/- 5.8 J), the two determinations of ULV (13.4 +/- 6.8 J vs 13.8 +/- 6.6) or the DFT-ULV Pearson correlation coefficients for each determination (0.84, P < 0.001 vs 0.75, P < 0.001). To analyze reproducibility, Lin concordance coefficients for second determination versus first determination were constructed for both ULV and DFT. This coefficient is similar to the Pearson correlation coefficient, but measures closeness to the line of identity rather than the line of regression. The Lin concordance coefficient for ULV was higher than that for DFT (0.93, 95% CI 0.85-0.97 vs 0.64, 95% CI 0.33-0.82; P < 0.01). For paired comparison of defibrillation efficacy under different experimental conditions, the sample sizes required to detect differences of 2 J, 3 J, and 4 J (80% power, P < 0.05) were 52, 24, and 15 for DFT versus 15, 8, and 6 for ULV. We conclude that a simple, clinically applicable method for determination of ULV is more reproducible than the single point DFT. Measured correlations between the ULV and single point are limited by the reproducibility of the DFT measurement.

Defibrillators, Implantable↗

PubMed1991

Reproducibility of tolerance tests that are useful in the identification of campylobacteria.

Twenty type or other reference strains, each representing a different Campylobacter, Helicobacter, or Arcobacter taxon, were used to assess the reproducibility of 25 phenotypic tests that are used in the identification of such organisms. Twenty-two of the tests depended on growth inhibition, and each of these tolerance tests was performed by using three different basal media. Although the overall reproducibility of the tests with each basal medium exceeded 89%, the proportion of strains that were able to grow in a reproducible manner on the basal media varied from 100% for blood agar and 50% for nutrient agar to 5% for brucella agar. In general, test reproducibility was highest with the basal medium that supported the most luxuriant growth. For the majority of tests, the basal medium which gave the optimum reproducibility could be determined.

Animals↗

PubMed1990

Observer reproducibility in grading dysplasia in colorectal adenomas: comparison between two different grading systems.

The two most well known and well defined grading systems for dysplasia in colorectal adenomas were compared with regard to reproducibility. The Konishi-Morson system (KMS) operates with several histological and cytological variables and grades of mild, moderate, and severe dysplasia. The Kozuka system is based on the extent of nuclear pseudostratification and also has three grades of dysplasia (III-V). As the group of severe dysplasia is very large in this system, it was extended with two higher grades, similarly based on individual histological criteria, known hereafter as the extended Kozuka system (EKS). Fifty six adenomas were graded by two observers, each observer grading twice according to the KMS criteria and twice according to EKS criteria. Intraobserver reproducibility was excellent for the KMS and moderate for the EKS, but this was not significant. The overall interobserver reproducibility was similar (moderate) for the KMS and for the EKS. Kappa values for interobserver reproducibility on individual categories were excellent for severe dysplasia according to the KMS, but low for all other categories in both systems. By simplifying both systems into two groups a high reproducibility can be obtained, but this implies that all the original grades (III-V) for the EKS must be grouped together. It is therefore recommended that a simplified KMS is used for further studies on the biological importance of dysplasia and for comparison between histological changes and other markers for colorectal neoplasia.

Adenoma↗

PubMed1994

Accuracy, reproducibility, and variability of hand-held dynamometry in motor neuron disease.

A spring-loaded device that "breaks" at preset forces was used to assess readings obtained by hand-held dynamometry by three raters with varying experience in the method. Overall accuracy (3%), but not reproducibility or variability, was improved by greater experience. Readings obtained jointly by three raters had 53% greater variability than those obtained by a single rater. Nine muscle groups in 19 patients with motor neuron disease were assessed at 10 sessions (three replications per session) over six days by the experienced rater. Muscle force was expressed relative to that of 22 matched normal controls. The reproducibility was good with a mean % difference of 13.2 and repeatability coefficient of 2.17 kg-force for readings six days apart; the overall correlation coefficient was 0.98. The mean coefficient of variation (CV) of 10 readings was 9.9%. The poorer reproducibility and greater variability seen in clinically weaker muscles may account for differences in patients with bulbar palsy and classical amyotrophic lateral sclerosis; the degree of spasticity had no effect. The rater was estimated to contribute 37% of the total variability when testing patients. The use of a composite score by combining normalised dynamometry readings of eight limb muscles improved mean % difference to 6.7 and mean CV to 5.8%. The reproducibility and variability of hand-held dynamometry readings obtained by a single rater compare well with those of fixed devices. Readings from single raters, irrespective of experience, have similar reproducibility and variability. If, however, multiple raters are used in longitudinal assessments of individual patients, as occurs in clinical trials, the variability of their combined readings should be estimated when calculating the same size required.

Adult↗

PubMed1997

Size quantification of liver metastases in patients undergoing cancer treatment: reproducibility of one-, two-, and three-dimensional measurements determined with spiral CT.

PURPOSE: To assess the reproducibility of one-, two-, and three-dimensional measurements of the size of liver metastases. MATERIALS AND METHODS: The sizes of 10 liver metastases were determined 200 times: Ten observers measured each lesion by using images obtained at two different CT studies and with five different measurement techniques (maximum diameter, product of diameters, area, volume, and product of three diameters). They repeated each measurement in a separate session. The influence of measurement technique and lesion type (size and morphologic appearance) on measurement reproducibility was assessed. RESULTS: Three-dimensional measurements proved to be as reproducible as one- and two-dimensional measurements. Measurement reproducibility was influenced mainly by the size (P < .0001) and morphologic appearance (P < .01) of the lesions. CONCLUSION: Three-dimensional size measurements obtained with spiral CT are reproducible and could therefore replace the two-dimensional measurements of tumor size currently obtained with follow-up CT studies.

Humans↗

PubMed1992

Reproducibility of measurements of coronary narrowings by videodensitometry and by digital calipers.

Computer-assisted videodensitometry has been shown to be a reliable and reproducible method of measuring absolute and relative coronary narrowings. Using a commercially available analyzer (Vanguard XR70) we confirmed intra- and interobserver reproducibilities in 34 narrowings in 9 patients. Analyses were performed on normal area and diameter, stenotic area and diameter, percent area stenosis and percent diameter stenosis. For all 6 analyses, excellent intra- and interobserver correlations were found (r = 0.93-0.98), with slopes close to 1 and intercepts close to zero. Caliper measurements (Mitutoyo Digimatic) of the same lesions by the same observers showed good inter- and intraobserver reproducibility for percent diameter stenosis (r = 0.90 and 0.86), with mean interobserver difference of 1.67 +/- (SD) 6.4% and intraobserver difference of 2.97 +/- (SD) 7.9%. However, less good correlations were found between caliper and videodensitometric measurements of percent diameter stenosis; r = 0.61 and 0.76 for the two observers. These data suggest that videodensitometry is a highly reproducible quantitative angiographic method, suitable for documenting changes in the severity of coronary artery lesions, both spontaneous or related to interventions. Caliper measurements do not provide the same degree of accuracy, but they have acceptable reproducibility in measuring diameter stenosis. As such, they are also suitable for assessing changes in severity of coronary artery lesions in individual patients.

Angioplasty, Balloon, Coronary↗

PubMed1990

Reproducibility studies with the Zeiss SLC system and animal cataract models.

Scheimpflug photography has become the basic method for documentation of lens transparency changes in clinical and experimental ophthalmology, due to its high reproducibility. In animal cataract studies, the reproducibility is strongly influenced by the handling characteristics of the camera used, due to limited cooperation of the animal. The reproducibility of the Zeiss SLC system, which offers a direct quality control of the image on the video screen, was tested with 2 animal cataract models, the ultraviolet B (UVB)-induced cataract and the true diabetic cataract in the Brown-Norway rat. 10 rats each of the 2 cataract models and of an untreated control group were photographed in a random order on 3 occasions on the same day by the same photographer. Quality control and densitometry were performed by the same system operator, the measurement window was positioned standardly, coincident with the optical axis of the eye. Statistical comparison was carried out in the capsular layer, that is the area of initial cataract development in both models, and in the cortical layer, into which the diabetic cataract progresses during its later stages of development. The nuclear layer was also evaluated, but has no direct relation to one of the models employed. The results clearly indicate that the reproducibility is predominantly influenced by the homogeneity or inhomogeneity of the cataract model employed. The system operator and the photographer provided that they are well trained, have minor influence on the reproducibility of the Zeiss SLC system.

Animals↗

PubMed1989

A protocol for performing reproducible methacholine inhalation tests in children with moderate to severe asthma.

Reproducibility of methacholine inhalation tests (MIT) over a 2-wk period has been established in adult populations, but similar studies demonstrating reproducibility in children are lacking. We set out to establish the reproducibility of MIT in children as a prerequisite for a study of the natural history of airway hyperreactivity in asthmatic children. Most inhalation testing is done in persons with mild asthma because the recommended time interval for the withholding of medications prior to bronchial challenge is poorly tolerated by more labile asthmatics. In order to evaluate asthmatics with more severe disease, we modified a standardized method of methacholine inhalation to include a three-tier pretest medication regimen and investigated the reproducibility of this MIT protocol in 11 children as young as 6 yr of age. The three tiers were designed to keep baseline FEV1 greater than or equal to 70% predicted since diminished baseline airway caliber may affect MIT results. Eight of the 11 children were bronchodilator-dependent, and two of the eight also required inhaled steroids. Eleven children (6 to 13 yr of age) underwent MIT, between December and March, 1 day, 1 wk, and 1 month after an initial test. The PD20FEV1 using cumulative breath units (BU) were compared. The range of PD20FEV1 in the 11 children was 0.27 to 14.4 BU, with nine subjects classified as severe (PD20FEV1 less than 2.5 BU). We found a high degree of reproducibility of MIT. The interest correlation coefficient (r) was 0.98 after 1 day, 0.95 after 1 wk, and 0.96 after 1 month.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

[Reproducibility of a self-administered questionnaire for dietary habits, smoking, and drinking].

Reproducibility of results from a self-administered questionnaire on dietary habits (the frequency of taking various foods and eating habits), smoking and drinking was examined to study the reliability of the questionnaire, stability of lifestyle, and the validity of the questionnaire in assessing lifestyle as a risk factor in chronic diseases. The study sample included 120 males and 173 females in a rural town in Kyoto Prefecture, who participated in a series of three health examinations in 1988, 1989, and 1992. A survey using the same questionnaire was performed before each health examination. Reproducibility was assessed by correlation (Spearman's rank correlation coefficient or kappa coefficient), exact agreement of category answered, and comparison of mean frequency. An attempt was made to separate reliability and stability from reproducibility using the data from the questionnaire obtained in the three years. Good reproducibility for one-year and four-year intervals was found for foods taken habitually or often (boiled rice, cooked rice gruel with tea, milk, coffee, fruits and bread), and habits (eating breakfast, some eating habits, smoking and drinking). The same was also found for cigarette or alcohol consumption among current consumers except that cigarette consumption over a four-year interval was more likely to change. The reliability of the questionnaire and stability of these items were considered satisfactory, suggesting that the questionnaire was a valid method of assessing long-term lifestyle. Poor reproducibility of results regarding consumption of green-yellow and other vegetables indicated both poor reliability and a change in consumption over four years, and suggested poor validity. However, disagreement in more than one category of vegetables was not large and misclassification in assessing them as risk factors and changes in frequency of consumption may not be large either. Although correlation coefficients for the items of dairy food and eating snacks were fair, disagreement in more than one category was relatively large which may have caused misclassification. The mean frequency of consumption of pickles and fishpaste, ham or sausage significantly decreased over the four year interval. This may reflect the influence of health education on reducing salt intake.

Adult↗

PubMed1994

Effect of injectate temperature and thermistor position on reproducibility of thermodilution cardiac output determinations.

STUDY OBJECTIVE: The purpose of this study was to evaluate the effect of thermistor position with varying injectate temperatures on the reproducibility of thermodilution cardiac output determination. The key hypothesis to be tested was that the positioning of the proximal thermistor at the right atrial port would improve the reproducibility of thermodilution cardiac output determination, independent of injectate temperature. DESIGN: Prospective randomized trial. SETTING: The study was performed in the cardiac catheterization laboratory of the West Haven Veterans Affairs Medical Center. PARTICIPANTS: Twenty consecutive patients undergoing right and left heart catheterizations were enrolled in the study. INTERVENTIONS: Each patient underwent triplicate determination of thermodilution cardiac output measurements under four experimental conditions: (1) ambient or room temperature injectate using an external thermistor in the injectate reservoir; (2) iced injectate using an external thermistor; (3) room temperature injectate using an internal right atrium (RA) thermistor; and (4) iced injectate using an RA thermistor. Reproducibility was assessed by the coefficient of variation (CV) and standard error of the mean percent (SEM%), of the triplicate measurements. MEASUREMENTS AND RESULTS: Using an internal RA thermistor improved the reproducibility of cardiac output determinations independent of injectate temperature. Using room temperature injectate, the CV was 12.8 percent using an external thermistor and 7.9 percent using an internal RA thermistor (p < 0.05). Using iced injectate, the CV was 10.2 percent using an external thermistor and 5.5 percent using an internal RA thermistor (p < 0.05). CONCLUSIONS: Reproducibility of thermodilution cardiac output determinations is improved when injectate temperature is measured internally, at the RA, as opposed to externally in the reservoir. This has clinical implications for determining significant changes in serial cardiac output determinations.

Analysis of Variance↗

PubMed1990

Long-term reproducibility of respiratory gas exchange measurements during exercise in patients with stable cardiac failure.

Present-day technology has greatly facilitated the monitoring of respiratory gas exchange in the clinical exercise laboratory. Despite the growing use of these techniques to assess the severity and progression of disease or therapeutic response in patients with heart failure, the long-term reproducibility of oxygen uptake (VO2), carbon dioxide production, minute ventilation, heart rate (HR), and blood pressure at rest and during incremental exercise in such patients, to our knowledge, has not been evaluated. Therefore, the purpose of this study was to quantify the reproducibility of these variables along with exercise duration, maximum VO2 (VO2max) and anaerobic threshold in a group of 16 patients (61 +/- 7 years, 14 male) with chronic, stable cardiac failure of varying severity and etiology who had five or more incremental treadmill exercise tests over a period of time that ranged from 3 to 22 months. For each variable, reproducibility was represented by the coefficient of variation (CVAR). Except for exercise duration, CVAR was not a function of the severity of heart failure and, for all variables, patient-to-patient variation in CVAR was approximately 9 percent. The maximum CVAR for HR, systolic blood pressure, VO2, and VO2max was generally below 10.5 percent and for exercise duration and anaerobic threshold it was less than 12.5 percent. Based on this retrospective analysis, it is concluded that reproducible respiratory gas exchange and HR exercise responses are obtainable over extended periods of time in patients with stable, chronic cardiac failure. Exercise duration, however, is less reproducible in patients with moderate to severe failure.

Aged↗

PubMed1996

Reproducibility of the growth hormone response to stimulation with growth hormone-releasing hormone plus arginine during lifespan.

The reliability and reproducibility of provocative stimuli of growth hormone (GH) secretion in the diagnosis of GH deficiency are still controversial both in childhood and in adulthood. The combined administration of GH-releasing hormone (GHRH) and arginine (ARG), which likely acts via inhibition of hypothalamic somatostatin release, is one of the most potent stimuli known so far and has been proposed recently as the best test to explore the maximal somatotrope capacity of somatotrope cells. However, it is well known that, usually, provocative stimuli of GH secretion suffer from poor reproducibility and that of the GHRH + ARG test has still to be verified. We aimed to verify the between- and within-subject variability of the GH response to the GHRH + ARG test in normal subjects during their lifespan as well as in hypopituitaric patients with GH deficiency (GHD). In 10 normal children (C: six male and four female, age 12.3 +/- 0.9 years, body mass index (BMI) = 16.6 +/- 0.7 kg/m2, pubertal stages I-III), 18 normal young adults (Y: ten male and eight female, age 31.1 +/- 1.3 years, BMI = 21.4 +/- 0.4 kg/m2), 12 normal elderly subjects (E: two male and ten female, age 74.4 +/- 1.8 years, BMI= 22.6 +/- 0.6 kg/m2) and 15 panhypopituitaric GH-deficient patients (GHD: nine male and six female, age 40.9 +/- 4.1 years, BMI= 22.7 +/- 1.0 kg/m2), we studied the inter- and intra-individual variability of the GH response to GHRH (1 microg/kg i.v.) + ARG (0.5 g/kg i.v.) in two different sessions at least 3 days apart. The GH responses to GHRH + ARG in C (1st vs 2nd session: 61.6 +/- 8.1 vs 66.5 +/- 9.4 microg/l), Y (70.4 +/- 10.1 vs 76.2 10.7 microg/l) and E (57.9 14.8 vs 52.1 +/- 8.0 microg/l) were similar and reproducible in all groups. The somatotrope responsiveness to GHRH + ARG also showed a limited within-subject variability (r = 0.71, 0.90 and 0.89 and p < 0.02, 0.0005 and 0.0005 for C, Y and E, respectively). Similarly in GHD, the GH response to the GHRH + ARG test showed a good inter- (1st vs 2nd session: 2.3 +/- 0.5 vs 2.2 +/- 0.6 microg/l) and intra-individual reproducibility (r = 0.70, p < 0.005). The GHRH + ARG-induced GH responses in GHD were markedly lower (p < 0.0005) than those in age-matched controls and no overlap was found between GH peak responses in GHD and normal subjects. In normal subjects, the GH response to GHRH + ARG is very marked, independent of age and shows limited inter- and intra-individual variability. The GH response to the GHRH + ARG test is strikingly reduced in panhypopituitaric patients with GHD, in whom the low somatotrope responsiveness is reproducible. Thus, these findings strengthen the hypothesis that GHRH + ARG should be considered the most reliable test to evaluate the maximal secretory capacity of somatotrope cells and to distinguish normal subjects from GHD patients in adulthood.

Adult↗

PubMed1995

Reproducibility of periodontal probing using a conventional manual and an automated force-controlled electronic probe.

A total of 1,128 sites in 15 periodontal maintenance patients were examined twice, 7 to 10 days apart, to evaluate reproducibility of periodontal probing by a conventional manual and an automated force-controlled electronic probe. Probing depths (PD) and relative attachment levels (AL) were recorded to the nearest 0.5 mm with both instruments. At each visit, all sites were probed first with the conventional and then with the electronic probe. Reproducibility of PD at shallow sites (PD < or = 3 mm) by the manual probe was 59.1% for exact agreement and 98.6% within +/- 1.0 mm variation. For the electronic probe, corresponding values were 41.3% and 91.5%, respectively. Reproducibility of PD measurements at deeper sites (PD > 3 mm), was 33.0% for exact match and 96.4% within +/- 1.0 mm for the manual and, correspondingly, 31.7% and 85.9% for the electronic probe. Reproducibility of AL followed a similar pattern, but was consistently lower than for PD. Reproducibility was consistently higher for anterior than for posterior sites and, for some comparisons, higher in the maxilla than in the mandible. These differences were smaller for the manual than for the electronic probe. Time required to complete the probing was longer for the conventional probe than for the electronic instrument. Under the prevailing study conditions, the automated force-controlled electronic probe failed to offer significant advantages over the conventional manual probe.

Adult↗

PubMed1996

Interobserver reliability and intraobserver reproducibility of the modified Ficat classification system of osteonecrosis of the femoral head.

Anteroposterior and lateral plain radiographs of 116 osteonecrotic femoral heads were reviewed to assess the interobserver reliability and intraobserver reproducibility of the modified Ficat classification system. The radiographs were reviewed initially and then again six months later by three adult reconstructive surgeons, two general orthopaedic surgeons, two orthopaedic residents, and one musculoskeletal radiologist. All eight observers agreed on the classification of twenty hips (17 per cent) at both the first and the second review of the radiographs. Paired comparisons revealed a mean interobserver kappa reliability coefficient of 0.46 (range, 0.30 to 0.67) for the first review and 0.45 (range, 0.30 to 0.66) for the second. For all observers, the mean rate of perfect agreement between the first and the second review was 68 per cent (range, 56 to 80 per cent). The mean kappa value for intraobserver reproducibility was 0.59 (range, 0.44 [one of the residents] to 0.73 [one of the general orthopaedic surgeons]). No observer or pair of observers had excellent reproducibility or reliability (kappa > 0.75). The poor interobserver reliability and fair intraobserver reproducibility diminishes any meaningful comparison of studies in which the modified Ficat classification system has been used and illuminates the need for a more reliable and reproducible classification system.

Femur Head Necrosis↗

PubMed1996

Ambulatory blood pressure reproducibility and application of the method in a healthy Finnish cohort.

The aim of the present study has been to study the reproducibility, validity and normal values of ambulatory blood pressure measurement in a healthy Finnish cohort. The reproducibility of ambulatory blood pressure monitoring was examined in healthy volunteers and normal values were determined in a Finnish cohort of males and women of different ages. In the reproducibility study the recording was repeated at 2-week intervals. In the validity study simultaneous measurements were done manually with a mercury sphygmomanometer and compared with the measurement by the ambulatory blood pressure recording unit, both connected with the cuff by a T-tube; this study included 100 consecutive measurements in a patient group. A relatively small cohort was taken from the normal value study group. In addition to ambulatory blood pressure their left ventricle mass was also determined by echocardiography. The correlation between manual blood pressure measurement and simultaneous measurement by the ambulatory blood pressure unit was 0.98. In the reproducibility study the correlations between the two 24-h measurements 2 weeks apart were also good. Depending on the parameter (daytime, nighttime or 24-h blood pressure mean, systolic or diastolic values) the correlation coefficient varied between 0.81 and 0.91. Thus both systolic and diastolic blood pressures, whether expressed as 24-h averages and daytime or nighttime averages, correlated well between these two recording sessions. The data obtained in the present Finnish cohort were well within the published reference value limits, showing only fairly modest age-dependence appearing at quite an old age. There was no significant correlation between the left ventricle mass and ambulatory blood pressure values in a population having normal blood pressure. The results suggest good intra-individual correlation and reproducibility in ambulatory blood pressure monitoring, suggesting this method to be useful in the monitoring of individual blood pressure levels. The validity of the method is good and the published reference values can be applied with reasonable reliability in different populations. In an adult population with normal blood pressure, no correlation between left ventricle mass and blood pressure values can be found, suggesting this correlation may first appear in cohorts including persons with elevated blood pressure values.

Adolescent↗