10 research outputs found
Clinical prognostic factors for patients with anterior knee pain in physical therapy
Background: Although many authors have studied the prognostic factors that may contribute to anterior knee pain, synthesis of the existing evidence has not been performed.
Purpose: The purpose of this systematic review is to summarize and examine existing prognostic models in patients with anterior knee pain that first present to physical therapists (primary care setting).
Design: Systematic review
Method: For this review Pubmed, Embase and Cinahl databases were searched and published papers that reported prognostic models for patients with anterior knee pain that first present to physical therapists (primary care setting) were selected. The authors extracted and summarized the univariate and multivariate predictors and evaluated which predictors consistently appeared to be relevant to pain, function, or recovery.
Results: Nine studies were included. The quality scores of these s
Clinical course and prognostic models for the conservative management of cervical radiculopathy: a prospective cohort study
Purpose: To describe the clinical course and develop prognostic models for poor recovery in patients with cervical radiculopathy who are managed conservatively. Methods: Sixty-one consecutive adults with cervical radiculopathy who were referred for conservative management were included in a prospective cohort study, with 6- and 12-month follow-up assessments. Exclusion criteria were the presence of known serious pathology or spinal surgery in the past. Outcome measures were perceived recovery, neck pain intensity and disability level. Multiple imputation analyses were performed for missing values. Prognostic models were developed using multivariable logistic regression analyses, with bootstrapping techniques for internal validation. Results: About 55% of participants reported to be recovered at 6 and 12Â months. All multivariable models contained 2 baseline predictors. Longer symptoms duration increased the risk of poor perceived recovery, whereas the presence of paresthesia decreased this risk. A higher neck pain intensity and a longer duration of symptoms increased the risk of poor relief of neck pain. A higher disability score increased the risk of poor relief of disability, and larger active range of rotation toward the affected side decreased this risk. Following bootstrapping, the explained variance of t
Dynamic prediction model to identify young children at high risk of future overweight: Development and internal validation in a cohort study
Background: Primary prevention of overweight is to be preferred above secondary prevention, which has shown moderate effectiveness. Objective: To develop and internally validate a dynamic prediction model to identify young children in the general population, applicable at every age between birth and age 6, at high risk of future overweight (age 8). Methods: Data were used from the Prevention and Incidence of Asthma and Mite Allergy birth cohort, born in 1996 to 1997, in the Netherlands. Participants for whom data on the outcome overweight at age 8 and at least three body mass index SD scores (BMI SDS) at the age of ≥3 months and ≤6 years were available, were included (N = 2265). The outcome of the prediction model is overweight (yes/no) at age 8 (range 7.4-10.5 years), defined according to the sex- and age-specific BMI cut-offs of the International Obesity Task Force. Results: After backward selection in a Generalized Estimating Equations analysis, the prediction model included the baseline predictors maternal BMI, paternal BMI, paternal education, birthweight, sex, ethnicity and indoor smoke exposure; and the longitudinal predictors BMI SDS, and the linear and quadratic terms of the growth curve describing a child's BMI SDS development over time, as well as the longitudinal predictors' interactions with age. The area under the curve of the model after internal validation was 0.845 and Nagelkerke R2 was 0.351. Conclusions: A dynamic prediction model for overweight was developed with a good predictive ability using easily obtainable predictor information. External validation is needed to confirm that the model has potential for use in practice
Performance of methods to conduct mediation analysis with time-to-event outcomes
Previous studies have discouraged the use of the Cox proportional hazards (PH) model for traditional mediation analysis as it might provide biased results. Accelerated failure time (AFT) models have been proposed as an alternative for Cox PH models. In addition, the use of the potential outcomes framework has been proposed for mediation models with time-to-event outcomes. The aim of this paper is to investigate the performance of traditional mediation analysis and potential outcomes mediation analysis based on both the Cox PH and the AFT model. This is done by means of a Monte Carlo simulation study and the illustration of the methods using an empirical data set. Both the product-of-coefficients method of the traditional mediation analysis and the potential outcomes framework yield unbiased estimates with respect to their own underlying indirect effect value for simple mediation models with a time-to-event outcome and estimated based on Cox PH or AFT
Childhood prediction models for hypertension later in life: a systematic review.
Abstract
BACKGROUND:
Hypertension, even during childhood, increases the risk of developing atherosclerosis and cardiovascular disease. Therefore, starting prevention of hypertension early in the life course could be beneficial. Prediction models might be useful for identifying children at increased risk of developing hypertension, which may enable targeted primordial prevention of cardiovascular disease.
OBJECTIVE:
To provide an overview of childhood prediction models for future hypertension.
METHODS:
Embase and Medline were systematically searched. Studies were included that were performed in the general population, and that reported on development or validation of a multivariable model for children to predict future high blood pressure, prehypertension or hypertension. Data were extracted using the CHARMS checklist for prediction modelling studies.
RESULTS:
Out of 12 780 reviewed records, six studies were included in which 18 models were presented. Five studies predicted adulthood hypertension, and one predicted adolescent prehypertension/hypertension. BMI and current blood pressure were most commonly included as predictors in the final models. Considerable heterogeneity existed in timing of prediction (from early childhood to late adolescence) and outcome measurement. Important methodological information was often missing, and in four studies information to apply the model in new individuals was insufficient. Reported area under the ROC curves ranged from 0.51 to 0.74. As none of the models were validated, generalizability could not be confirmed.
CONCLUSION:
Several childhood prediction models for future hypertension were identified, but their value for practice remains unclear because of suboptimal methods, limited information on performance, or the lack of external validation. Further validation studies are indicated
Dynamic prediction of childhood high blood pressure in a population-based birth cohort: a model development study
OBJECTIVES: To develop a dynamic prediction model for high blood pressure at the age of 9-10 years that could be applied at any age between birth and the age of 6 years in community-based child healthcare. DESIGN, SETTING AND PARTICIPANTS: Data were used from 5359 children in a population-based prospective cohort study in Rotterdam, the Netherlands. OUTCOME MEASURE: High blood pressure was defined as systolic and/or diastolic blood pressure ≥95th percentile for gender, age and height. Using multivariable pooled logistic regression, the predictive value of characteristics at birth, and of longitudinal information on the body mass index (BMI) of the child until the age of 6 years, was assessed. Internal validation was performed using bootstrapping. RESULTS: 227 children (4.2%) had high blood pressure at the age of 9-10 years. Final predictors were maternal hypertensive disease during pregnancy, maternal educational level, maternal prepregnancy BMI, child ethnicity, birth weight SD score (SDS) and the most recent BMI SDS. After internal validation, the area under the receiver operating characteristic curve ranged from 0.65 (prediction at age 3 years) to 0.73 (prediction at age 5-6 years). CONCLUSIONS: This prediction model may help to monitor the risk of developing high blood pressure in childhood which may allow for early targeted primordial prevention of cardiovascular disease
Influence of corresponding parameters on the pressure and derivative. (A) preferential flow path length <i>L<sub>D</sub></i>, (B) equivalent radius <i>r<sub>pD</sub></i>, (C) conductivity <i>C<sub>dD</sub></i>, (D) vertical elevation <i>z<sub>pD</sub></i>,, (E) flow rate constant <i>q<sub>DND</sub></i> and (F) storage effect <i>C<sub>D</sub></i>.
<p>Influence of corresponding parameters on the pressure and derivative. (A) preferential flow path length <i>L<sub>D</sub></i>, (B) equivalent radius <i>r<sub>pD</sub></i>, (C) conductivity <i>C<sub>dD</sub></i>, (D) vertical elevation <i>z<sub>pD</sub></i>,, (E) flow rate constant <i>q<sub>DND</sub></i> and (F) storage effect <i>C<sub>D</sub></i>.</p
One risk assessment tool for cardiovascular disease, type 2 diabetes, and chronic kidney disease
OBJECTIVE - Individuals at high risk for chronic cardiometabolic disease (cardiovascular disease [CVD], type 2 diabetes, and chronic kidney disease [CKD]) share many risk factors and would benefit from early inte
Additional value of transluminal attenuation gradient in CT angiography to predict hemodynamic significance of coronary artery stenosis
Objectives The current study evaluates the incremental value of transluminal attenuation gradient (TAG), TAG with corrected contrast opacification (CCO), and TAG with exclusion of calcified coronary segments (ExC) over coronary computed tomography angiogram (CTA) alone using fractional flow reserve (FFR) as the gold standard. Background TAG is defined as the contrast opacification gradient along the length of a coronary artery on a coronary CTA. Preliminary data suggest that TAG provides additional functional information. Interpretation of TAG is hampered by multiple heartbeat acquisition algorithms and coronary calcifications. Two correction models have been proposed based on either dephasing of contrast delivery by relating coronary density to corresponding descending aortic opacification (TAG-CCO) or excluding calcified coronary segments (TAG-ExC). Methods Eighty-five patients with intermediate probability of coronary artery disease were prospectively included. All patients underwent step-and-shoot 256-slice coronary CTA. TAG, TAG-CCO, and TAG-ExC analyses were performed followed by invasive coronary angiography in conjunction with FFR measurements of all major coronary branches. Results Thirty-four patients (40%) were diagnosed with hemodynamically-significant coronary artery disease (i.e., FFR ≤0.80). On a per-vessel basis (n = 253), 59 lesions (23%) were graded as hemodynamically significant, and the diagnostic accuracy of coronary CTA (diameter stenosis ≥50%) was 95%, 75%, 98%, and 54% for sensitivity, specificity, negative predictive value, and positive predictive value, respectively. TAG and TAG-ExC did not discriminate between vessels with or without hemodynamically significant lesions (-13.5 ;plusmn& 17.1 HU [Hounsfield units] ;times&10 mm;bsupesup&vs. -11.6 ;plusmn&13.3 HU ;times&10 mm;bsupesup&, p = 0.36; and 13.1 ;plusmn&15.9 HU ;times&10 mm;bsupesup&vs. -11.4 ;plusmn&11.7 HU ;times&10 mm;bsupesup&, p = 0.77, respectively). TAG-CCO was lower in vessels with a hemodynamically-significant lesion (-0.050 ;plusmn&0.051 10 mm;bsupesup&vs. -0.036 ;plusmn&0.034 10 mm;bsupesup&, p = 0.03) and TAG-ExC resulted in a slight improvement of the net reclassification index (0.021, p ≤ 0.05). Conclusions TAG did not provide incremental diagnostic value over 256-slice coronary CTA alone in assessing the hemodynamic consequences of a coronary stenosis. Correction for temporal nonuniformity of contrast delivery or exclusion of calcified coronary segments slightly enhanced the results
Survival prediction model of children with diffuse intrinsic pontine glioma based on clinical and radiological criteria
Background Although diffuse intrinsic pontine glioma (DIPG) carries the worst prognosis of all pediatric brain tumors, studies on prognostic factors in DIPG are sparse. To control for confounding variables in DIPG studies, which generally include relatively small patient numbers, a survival prediction tool is needed. Methods A multicenter retrospective cohort study was performed in the Netherlands, the UK, and Germany with central review of clinical data and MRI scans of children with DIPG. Cox proportional hazards with backward regression was used to select prognostic variables (P <. 05) to predict the accumulated 12-month risk of death. These predictors were transformed into a practical risk score. The model's performance was validated by bootstrapping techniques. Results A total of 316 patients were included. The median overall survival was 10 months. Multivariate Cox analysis yielded 5 prognostic variables of which the coefficients were included in the risk score. Age ≤3 years, longer symptom duration at diagnosis, and use of oral and intravenous chemotherapy were favorable predictors, while ring enhancement on MRI at diagnosis was an unfavorable predictor. With increasing risk score categories, overall survival decreased significant