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PubMed1991

[Concomitant and discriminatory validity of the Adolescents' Fear of Dental Treatment Cognitive Inventory].

The revised edition of the Inventaire cognitif de la peur des traitements dentaire pour adolescent(e)s [Adolescents' Fear of Dental Treatment Cognitive Inventory] (ICPTD-A) was administered to 38 subjects chosen at random and to nine subjects chosen with an obvious dental phobia problem. Its concomitant validity was established by relating the ICPTD-A scores to those of a behavioral test. The Pearson correlation coefficients that were thus obtained were -0.66 for the general population and -0.87 for the population suffering from dental phobia. The discriminatory validity was then established with a repeated measurement variance analysis based on the scores of the dental phobics after the administration of a recognized psychological treatment program intended to reduce their phobia. The results have shown a statistically significant difference between the experimental and control groups as well as a significant difference between pre- and posttreatments. The authors have therefore concluded that the ICPTD-A is a valid tool for the assessment of dental phobia in 12-15-year-old adolescents.

Adolescent↗
PubMed1997

[Intra-observer variability of measurement of posture with three-dimensional digitization].

A new system based on 3D digitization with magnetic fields has been developed by our research team. The focus of this study was to evaluate the intratester reproducibility of this technique of measurement. Twenty key morphological parameters were used twice to digitize the fourty five female subjects aged 7 to 23 years. The results of variance analysis (ANOVA) for repeated measures showed no statistically significant difference between the two series of measurements for the twenty angles studied. In 56% of the measurements, the difference of the means was less than 1 degree, the greatest being 1.82 degrees. These results confirm the reliability of this new technique of postural evaluation when the measurements are taken by the same tester. Therefore, 3D digitization with magnetic fields could be an interesting alternative to X-Rays for the evaluation of scoliosis.

Adolescent↗
PubMed1975

Standardization of housedust allergen in human skin test trials.

Standardization was carried out by comparison of Bencard and our own ('Human') housedust allergens in human skin test trials. The dose response curves on hypersensitive patients were parallel, linear, and there was no difference between preparations according to the variance analysis. The relative potency was 1.33 compared to the Bencard allergen. 95% confidence limits were 0.29-2.37. The correlation coefficient evaluated from all data was 0.90. Our experience suggests that human skin test trials seem to be a simple and convenient method for the standardization of housedust allergens. According to the results of analysis of factorials, data suitable for standardization can be obtained if the area of both the wheal and flare as different parameters are recorded 10 and/or 20 minutes after the intradermal injections.

Allergens↗
PubMed2004

Risk factors for Toxoplasma gondii infection in women of childbearing age.

OBJECTIVES: Determine the risk factors involved in toxoplasmosis transmission and determine whether pregnancy is a risk factor for toxoplasmosis infection. STUDY DESIGN: Cross-sectional study carried out on 2,242 women at childbearing age. An indirect immunofluorescence reaction was used to identify immunity to Toxoplasma gondii. Previous gestations were also analyzed as a possible risk factor. The results were analyzed by chi2 and OR tests, and by variance analysis. The sample was statistically balanced according to social-economic risk factors. RESULTS: Previously pregnant women were 1.74 times more frequently infected with toxoplasmosis, regardless of environmental conditions. Pregnant women living under unfavorable environmental conditions had an approximately two times increased risk of being infected for each risk factor (contact with host animals, presence of vehicles of oocyst transmission). Previous pregnancy was the risk factor that had the strongest influence on acquiring toxoplasmosis (variance analysis and statistical balancing). DISCUSSION: The prevalence of this zoonosis is high in Goiânia-GO, Brazil (65.8%). Inadequate environmental sanitation was not significantly correlated with toxoplasmosis infection, except when associated with previous pregnancy, showing that the fundamental cause for infection is not environmental. CONCLUSION: The finding that pregnancy makes women more vulnerable to this protozoan, makes it important to implement prophylactic control of at-risk pregnant women.

Adolescent↗
PubMed2001

[Factors that influence the quality of life of Sichuan population].

OBJECTIVE: To investigate the risk factors influencing quality of life with the aim of providing evidence for valid health promotion measures. METHODS: The authors used the short form 36 to assess the quality of life of 2249 residents in Sichuan Province. The data of potential risk factors including social economic status, culture, chronic condition and personal characteristics were collected. The Student t test, variance analysis, and stepwise multivariate regression methods were used to test the impacts of different risk factors on quality of life. RESULTS: Chronic condition, age, sex, educational level, marital status, occupation, personal income, number of family members, number of generation in a family, inhabitant places (urban or rural), and way of payment of medical expenditure were correlated with all or most of the domains of the short form 36 in t-test or one-way variance analysis. When the effect of interaction between factors were excluded by use of multivariate regression, the chronic condition, personal income, inhabitant places, age, and educational level remained to be significant risk factors. Marital status also had impacts on a few domains. CONCLUSION: The key steps of promoting the quality of life should include the prevention and control of chronic conditions, the development of economy, and the improvement of people's income and educational level. It is necessary to provide norms of the short form 36 stratified by inhabitant's place and age. Further research would be needed to provide evidence for the necessity of norms stratified by sex.

Adolescent↗
PubMed2002

Longitudinal cephalometric changes in incisor position, overjet, and overbite between 10 and 14 years of age.

The purpose of this study was to evaluate the longitudinal growth changes in the incisor position, overjet, and overbite between 10 and 14 years of age. Serial cephalometric radiographs of 63 subjects (31 boys and 32 girls) were taken at the ages of 10, 11, 12, and 14. The effects of age and gender on the incisor positions, overjet, and overbite were investigated by means of variance analysis and least square difference (LSD) tests. The results show that the measurements of overbite, upper incisor-NA (mm), lower incisor-NB (mm), upper incisor-NA (angle), and the interincisal angle were affected by age. The results also show that the measurements of overbite, upper incisor-NA (mm), upper incisor-NA (angle) and upper incisor-SN (angle) were affected by gender.

Adolescent↗
PubMed1995

[Abnormal autonomic cardiovascular responses in patients with sickle cell anemia].

PURPOSE: To evaluate the presence of anomalies of the autonomic reflex cardiovascular response in patients with chronic sickle-cell anaemia. PATIENTS AND METHODS: The study was extended to 30 patients with sickle-cell anaemia, 10 patients with iron-lack anaemia and 30 healthy subjects. Age and sex distribution was similar in each group. To be included in the study, patients should have had no painful crisis or blood transfusion in the 6 months previous to the assay. Clinico-laboratory survey, chest x-ray and EKG were performed in every case. Blood cell count and abnormal haemoglobin study on cellulose acetate were carried out as well. The evaluation of reflex autonomic responses was performed by means of active orthostatism, cold pressor test, Valsalva maneuver and urine catecholamine output. The statistical analysis was performed with the variance analysis (ANOVA) for multiple groups. RESULTS: The following abnormalities were found: 12 patients had haemoglobin SS, 8 had haemoglobin SS and F, 3 had haemoglobin SC, 2 had haemoglobin S and beta-thalassaemia, and 5 had combined haemoglobin SS,F and A2. Systolic pressure and heart frequency in the supine position were similar in all groups. Diastolic pressure was lower in the sickle-cell anaemia group with respect to the normals. Patients with sickle-cell disease had lower heart frequency in the active orthostatism test with regard to the other groups, along with paradoxal changes in systolic pressure and lesser increase of the diastolic pressure. Significantly lower response to the cold pressor test was seen in the sickle-cell patients as compared with the iron-lack cases and the normal controls. Reduced sympathetic tachycardia was seen with the Valsalva maneuver, whereas the bradycardia was similar to the other groups. The urine noradrenaline in output was significantly lower in the sickle-cell patients, it was normal in the other groups (p < 0.01). CONCLUSION: These results suggest a defective sympathetic activity of heart and arteries in patients with sickle-cell anaemia.

Adolescent↗
PubMed1999

Contribution of single-channel properties to the time course and amplitude variance of quantal glycine currents recorded in rat motoneurons.

The amplitude of spontaneous, glycinergic miniature inhibitory postsynaptic currents (mIPSCs) recorded in hypoglossal motoneurons (HMs) in an in vitro brain stem slice preparation increased over the first 3 postnatal weeks, from 42 +/- 6 pA in neonate (P0-3) to 77 +/- 11 pA in juvenile (P11-18) HMs. Additionally, mIPSC amplitude distributions were highly variable: CV 0.68 +/- 0.05 (means +/- SE) for neonates and 0.83 +/- 0.06 for juveniles. We wished to ascertain the contribution of glycine receptor (GlyR)-channel properties to this change in quantal amplitude and to the amplitude variability and time course of mIPSCs. To determine whether a postnatal increase in GlyR-channel conductance accounted for the postnatal change in quantal amplitude, the conductance of synaptic GlyR channels was determined by nonstationary variance analysis of mIPSCs. It was 48 +/- 8 pS in neonate and 46 +/- 10 pS in juvenile HMs, suggesting that developmental changes in mIPSC amplitude do not result from a postnatal alteration of GlyR-channel conductance. Next we determined the open probability (Popen) of GlyR channels in outside-out patches excised from HMs to estimate the contribution of stochastic channel behavior to quantal amplitude variability. Brief (1 ms) pulses of glycine (1 mM) elicited patch currents that closely resembled mIPSCs. The GlyR channels' Popen, calculated by nonstationary variance analysis of these currents, was approximately 0.70 (0.66 +/- 0.09 in neonates and 0.72 +/- 0.05 in juveniles). The decay rate of patch currents elicited by brief application of saturating concentrations of glycine (10 mM) increased postnatally, mimicking previously documented changes in mIPSC time course. Paired pulses of glycine (10 mM) were used to determine if rapid GlyR-channel desensitization contributed to either patch current time course or quantal amplitude variability. Because we did not observe any fast desensitization of patch currents, we believe that fast desensitization of GlyRs underlies neither phenomenon. From our analysis of glycinergic patch currents and mIPSCs, we draw three conclusions. First, channel deactivation is the primary determinant of glycinergic mIPSC time course, and postnatal changes in channel deactivation rate account for observed developmental changes in mIPSC decay rate. Second, because GlyR-channel Popen is high, differences in receptor number between synapses rather than stochastic channel behavior are likely to underlie the majority of quantal variability seen at glycinergic synapses throughout postnatal development. We estimate the number of GlyRs available at a synapse to be on average 27 in neonate neurons and 39 in juvenile neurons. Third, this change in the calculated number of GlyRs at each synapse may account for the postnatal increase in mIPSC amplitude.

Age Factors↗
PubMed2003

Reliability of a standardized reading chart system: variance component analysis, test-retest and inter-chart reliability.

BACKGROUND: The purpose of this study was to analyze statistically the test-retest and inter-chart reliability of three standardized Radner Reading Charts with respect to reading acuity, maximum reading speed, critical print size and LogRAD/LogMAR ratio and to quantitatively identify the sources of variability. METHODS: At two testing sessions (3 to 4 weeks apart), 36 volunteers read monocularly all three Radner Reading Charts in randomized order (orthogonal Latin square design). The subjects were grouped according to their distance LogMAR visual acuity (group 1, 0.1 or better; group 2, 0.12-0.4; group 3, 0.42-0.8). Based on these 216 reading tests, crude correlations were calculated between the two testing sessions and between the three charts, and "variance component analyses" were performed for all variables. RESULTS: For all visual acuity groups and variables, the test-retest and the inter-chart reliability was high. The variance component analyses showed that the differences between individuals predominantly influenced the variance, whereas the effect of the test replication was low. The three charts caused minimal variability, indicating equality for clinical examinations. CONCLUSION: The standardized Radner Reading Charts provide clinically reliable and reproducible results for individuals with normal eyesight and for patients with visual impairment. These findings indicate that reading test systems, which consider the current international standards for visual acuity measurements (EN ISO 8596, NAS-NRC) and the psychophysical requirements for controlling optical item interactions, can provide reliable measures for clinical and scientific analyses of reading performance.

Aged↗
PubMed1975

[Morphology versus prognosis in renal cell carcinoma a statistical approach].

In a group of 102 selected cases of renal cell carcinoma which at various periods after nephrectomy terminated fatally, age, sex, and 23 gross and/or histologic tumor characteristics were examined, subclassified, and evaluated. An attempt was made to correlate these parameters statistically to postoperative survival time. A newly developed and programmed statistical method, i.c. "dichotomic variance analysis", proved to be superior to both multiple regression and cluster analysis. Using infiltrative-destructive tumor growth, polymorphy, and chromatin density of tumor cell nuclei, extension of renal vein invasion, age and sex, as the only 6 required out of 25 distinguished tumor parameters, this statistical multivariate method comprised 7 distinctive groups of different mean geometrical postoperative survival time, obviously corresponding to 7 tumor types of increasing degree of malignancy. By step-wise dichotomic splitting of tumor groups it therefore was possible to delinate schematically some of the complex connections between the criteria or variables of prognostic significance. Conceivable sources of errors possibly influencing reproducibility and practical applicability of the presented dichotomic variance analysis in evaluating prognostic criteria in renal cell carcinoma are discussed.

Adult↗
PubMed1990

Monitoring brain function during cardiothoracic surgery in children and adults at two levels of hypothermia.

The EEGs of 9 infants and 9 adults undergoing cardiac surgery were analysed during 2 different temperature ranges. Variance analysis showed that there were very significant interactions between age and temperature effects (P less than 0.01) and between temperature and specific frequency bands (P less than 0.005). These interactions were studied further and the greatest changes were discovered in the infant group when the temperature fell from the upper to the lower hypothermic range: low delta activity increased significantly while those of alpha and theta fell significantly. The significant quantitative differences found in this study agree with qualitative observations from other reports.

Age Factors↗
PubMedDate not supplied

Statistical dependence of clinical data on the chosen treatment of patients with a multivessel coronary artery disease.

BACKGROUND: In this study we tried to check which clinical data are connected with the choice of treatment in patients with a multivessel coronary artery disease. MATERIAL AND METHODS: The data of 137 patients with a multivessel coronary artery disease, were analysed retrospectively. The patients were divided into three groups: treated conservatively, CABG and PTCA. Multivessel coronary artery disease was recognised when there were atherosclerotic changes in more a 2 vessels with a not less a 2 mm in diameter. Patients with previous CABG or a left main coronary artery disease were excluded. The data were analysed by means of several methods, variance analysis, correlation analysis, discriminant functions, chi-square test and T-Student test. RESULTS: For treatment decision making in multivessel coronary artery disease of statistical significance were: the state of the left anterior descendent artery below the first diagonal branch, the state of the first diagonal branch and peripheral parts of the left anterior descendent artery and right coronary artery, the systolic function of the antero-lateral, apical and phrenic segments of the left ventricle, the global left ventricular ejection fraction in angiography and echocardiography, local systolic disturbances of the left ventricular observed in echocardiography, the coexistence of symptoms of heart failure as well as unstable angina. CONCLUSION: Treatment decision making will always depend not only on diagnostic procedures but also on all the clinical data about the patient and the experience of coworking cardiology and surgery centres.

Analysis of Variance↗
PubMed1999

Genetic variance components analysis for binary phenotypes using generalized linear mixed models (GLMMs) and Gibbs sampling.

The common complex diseases such as asthma are an important focus of genetic research, and studies based on large numbers of simple pedigrees ascertained from population-based sampling frames are becoming commonplace. Many of the genetic and environmental factors causing these diseases are unknown and there is often a strong residual covariance between relatives even after all known determinants are taken into account. This must be modelled correctly whether scientific interest is focused on fixed effects, as in an association analysis, or on the covariances themselves. Analysis is straightforward for multivariate Normal phenotypes, but difficulties arise with other types of trait. Generalized linear mixed models (GLMMs) offer a potentially unifying approach to analysis for many classes of phenotype including multivariate Normal traits, binary traits, and censored survival times. Markov Chain Monte Carlo methods, including Gibbs sampling, provide a convenient framework within which such models may be fitted. In this paper, Bayesian inference Using Gibbs Sampling (a generic Gibbs sampler; BUGS) is used to fit GLMMs for multivariate Normal and binary phenotypes in nuclear families. BUGS is easy to use and readily available. We motivate a suitable model structure for Normal phenotypes and show how the model extends to binary traits. We discuss parameter interpretation and statistical inference and show how to circumvent a number of important theoretical and practical problems that we encountered. Using simulated data we show that model parameters seem consistent and appear unbiased in smaller data sets. We illustrate our methods using data from an ongoing cohort study.

Binomial Distribution↗
PubMed1996

[The psychophysics of sweet taste. 8. Interindividual variability of differential findings].

Contribution to the psychophysics of sweet taste. Part 8. On the inter-individual variability of the difference sensitivity. The variability of sensitivity of volunteers is a considerable imponderability for the comparison of sensoric results. The paper deals with the quantitative determination of the different sensitivity of sweet taste of 132 persons, 38 men and 94 women at the age of 19 to 64 years, using a statistically defined method. The numbers of errors are estimated for each person by means of one test difference of two saccharose concentrations using 10 pairs of comparisons and 4 runs. The average number of error of 10 comparisons corresponds to the individual measure of sensitivity. The medium value of the total distribution is 1.54 and the standard deviation is 1.19 errors. The value is only less above the binomial calculated number. In random test women show in comparison to men a significant higher variance at the statistical identical mean. A variance analysis based on the cutting of the distribution edges in the range of 0.5 to 4.0 errors can detect high significantly the steady learning effect of the volunteers during the runs. The method is applicable to determine classified subjective characteristics. The calculations of necessary group numbers for such experiments on the base of binomial distribution are discussed.

Adult↗
PubMed1994

Neuropsychological evaluation of children with intracranial tumors: impact of treatment modalities.

Antineoplastic treatment has a deleterious effect on intellectual functions, which is mainly attributable to radiotherapy. With the object of determining the neuropsychological disturbances associated with brain irradiation in the child, and to try to differentiate them from the effects caused by the other types of treatment (surgical and chemotherapy) as well as from the effects of the tumor itself, a cross-sectional study was carried out in 25 survivors of medial edge intracranial tumors. In order to monitor the effect of systemic chemotherapy on the cognitive functions, and the effect of prolonged absence from school, two control groups were formed, one made up of subjects treated with chemotherapy for extracranial tumors, and the other of patients with non-malignant chronic disease. Neuropsychological functions were measured using the Spanish version of the Wechsler scale, as well as the following tests: Spreen-Benton, ITPA and TALE scales, Yuste Memory Test, Thurstone Attention Test, and the Rey Complex Figure. In addition to a progressive decline found in the full scale intelligence quotient in children irradiated for intracranial tumors, variance analysis showed that these patients deteriorate mainly in visual attention and memory, but also significantly in verbal fluency and in the Performance Intelligence Quotient and all its subtests, when compared to the control groups. Visual attention and the Wechsler Picture Arrangement and Block Designs, were the tests whose decline correlated with the total radiation administered. The article relates this specific neuropsychological injury with the total brain irradiation dose but also with the structures located in the cone-down fields of irradiation to boost regions in the middle edge intracranial content.

Adolescent↗