Search results for "Regression"
showing 10 items of 2619 documents
Predictor variables for a 100-km race time in male ultra-marathoners.
2010
In 169 male 100-km ultra-marathoners, the variables of anthropometry, training, and prerace experience, in order to predict race time, were investigated. In the bivariate analysis, age ( r = .24), body mass ( r = .20), Body Mass Index ( r = .29), circumference of upper arm ( r = .26), percent body fat (r = .45), mean weekly running hours ( r = –.21), mean weekly running kilometers ( r = –.43), mean speed in training ( r = –.56), personal best time in a marathon ( r = .65), the number of finished 100-km ultra-runs ( r = .24), and the personal best time in a 100-km ultra-run ( r = .72) were associated with race time. Stepwise multiple regression showed that training speed ( p < .0001), me…
Analgesics use in competitive triathletes: its relationship to doping and on predicting its usage
2016
The two major objectives of this study were (i) to assess variables that predict the use of analgesics in competitive athletes and (ii) to test whether the use of analgesics is associated with the use of doping. A questionnaire primarily addressing the use of analgesics and doping was distributed among 2,997 triathletes. Binary logistic regression analysis was performed to predict the use of analgesics. Moreover, the randomised response technique (RRT) was used to estimate the prevalence of doping in order to assess whether users of analgesics have a higher potential risk for doping than non-users. Statistical power analyses were performed to determine sample size. The bootstrap method was …
Evaluation of texture analysis for the differential diagnosis of focal nodular hyperplasia from hepatocellular adenoma on contrast-enhanced CT images
2018
PurposeTo explore the value of CT texture analysis (CTTA) for differentiation of focal nodular hyperplasia (FNH) from hepatocellular adenoma (HCA) on contrast-enhanced CT (CECT).MethodsThis is a retrospective, IRB-approved study conducted in a single institution. A search of the medical records between 2008 and 2017 revealed 48 patients with 70 HCA and 50 patients with 62 FNH. All lesions were histologically proven and with available pre-operative CECT imaging. Hepatic arterial phase (HAP) and portal venous phase (PVP) were used for CTTA. Textural features were extracted using a commercially available research software (TexRAD). The differences between textural parameters of FNH and HCA wer…
Explaining the parental stress of fathers and mothers caring for a child with intellectual disability: a Double ABCX Model.
2003
Background Twenty variables based on the Double ABCX Model of adaptation and selected on the basis of previous research were chosen to explain the parental stress of the mothers (n = 116) and fathers (n = 120) of children with an intellectual disability (age range = 1– 10 years). Methods Principal component analysis, rotated into varimax-criterion, was done separately for mothers and fathers. The solution containing eight factors was considered best for both groups. They accounted for more than 70% of the total variance of the original variables. These eight orthogonal components were then entered into a stepwise regression analysis that was done separately for mothers and fathers. Result…
Expanded gentamicin volume of distribution in critically ill adult patients receiving total parenteral nutrition
1995
Aminoglycoside antibiotics distribute into the extracellular fluid compartment and are eliminated by the kidney via glomerular filtration. Malnutrition and total parenteral nutrition influence the fluid and electrolyte status of the patient, and cause organ changes. The purpose of this clinical study was to characterize the kinetic behaviour of gentamicin in the parenterally fed critically ill adult patient. Eighty-six critically ill adult patients treated with gentamicin for severe Gram-negative infections were enrolled in the study (mean +/- SD): age, 60 +/- 14 years; weight, 69.4 +/- 10.2 kg; height, 163 +/- 10 cm; 22 females and 64 males. Four study groups were defined (2 x 2): total pa…
Relationship between sedentary behavior and depression: a mediation analysis of influential factors across the lifespan among 42,469 people in low- a…
2018
Abstract Background Sedentary behavior (SB) is associated with diabetes, cardiovascular disease and low mood. There is a paucity of multi-national research investigating SB and depression, particularly among low- and middle-income countries. This study investigated the association between SB and depression, and factors which influence this. Methods Cross-sectional data were analyzed from the World Health Organization's Study on Global Ageing and Adult Health. Depression was based on the Composite International Diagnostic Interview. The association between depression and SB (self-report) was estimated by multivariable linear and logistic regression analyses. Mediation analysis was used to id…
Determination of Bolton tooth-size ratios by digitization, and comparison with the traditional method.
2005
The Bolton Index is one of the most useful calculations for precise orthodontic diagnosis as it shows if there is a correct ratio between dental proportions. However, at times, this calculation is not applied because it is a long and time-consuming procedure compared with digital methods. A new digital method for measuring tooth sizes and for calculating the Anterior (ABI) and the Overall (OBI) Bolton Index was tested on 100 sets of study dental casts of the permanent dentition in a Spanish sample and compared with the traditional method. The reproducibility of this digital method versus the traditional one was analysed to determine intra- and inter-examiner measurement errors by calculatin…
Prediction of arch length based on intercanine width.
2008
Arch length (AL), intercanine width (ICW), and intermolar width (IMW) are essential for diagnosis and treatment planning and are closely related factors in orthodontics. The aim of the present study was to determine correlations between these measurements and to predict some of these measurements based on others. The dental casts of 197 Spanish patients (119 females and 78 males) with a mean age of 18 years (11-26 years) in the permanent dentition attending the Orthodontic Department of the University of Valencia, Spain, were selected. ICW, IMW, and AL on each dental cast were measured using a previously tested digital method. Correlation between variables was determined using Pearson's cor…
Optical factors influencing the amplitude of accommodation
2017
AbstractThe purpose of this work was to find plausible predictors among optical parameters that may explain the inter-individual differences in subjective amplitude of accommodation not explained by age. An exploratory multivariable regression analysis was carried out retrospectively on a dataset with 180 eyes from 97 subjects (ages ranged from 20 to 58years). Subjective amplitudes of accommodation were recorded with the use of a custom-made Badal system. A commercial aberrometer was used to obtain each eye’s wavefront during the full range of accommodation. The plausible predictors under study were pupil diameter in the unaccommodated eye, its reduction with accommodation; fourth- and six-…
Modelling the non-linear multiple-lag effects of ambient temperature on mortality in Santiago and Palermo: a constrained segmented distributed lag ap…
2008
Objectives: Exposure to ambient temperature can affect mortality levels for days or weeks following exposure, making modelling such effects in regression analysis of daily time-series data complex. Methods: We propose a new approach involving a multi-lag segmented approximation to account for the non-linear effect of temperature and the use of two different penalised spline bases to model the distributed lag of both heat and cold exposure. Compared with standard splines, the novel penalised framework is more flexible at short lags where change in coefficients is greatest, and selection of the maximum lag appears substantially less important in determining the overall pattern of the effect. …