An extensive Monte Carlo simulation study is carried out to validate the proposed formulas. We find that the proposed formulas have satisfactory performance across a range of cluster size variability, as long as suitable finite-sample corrections are applied to the sandwich variance estimator and the number of clusters is at least 10. Our findings also suggest that the sample size estimate under the exchangeable working correlation is more robust to cluster size variability, and recommend the use of an exchangeable working correlation over an independence working correlation for both design and analysis. The proposed sample size formulas are illustrated using the Stop Colorectal Cancer (STOP CRC) trial.In epidemiology, identifying the effect of exposure variables in relation to a time-to-event outcome is a classical research area of practical importance. click here Incorporating propensity score in the Cox regression model, as a measure to control for confounding, has certain advantages when outcome is rare. However, in situations involving exposure measured with moderate to substantial error, identifying the exposure effect using propensity score in Cox models remains a challenging yet unresolved problem. In this paper, we propose an estimating equation method to correct for the exposure misclassification-caused bias in the estimation of exposure-outcome associations. We also discuss the asymptotic properties and derive the asymptotic variances of the proposed estimators. We conduct a simulation study to evaluate the performance of the proposed estimators in various settings. As an illustration, we apply our method to correct for the misclassification-caused bias in estimating the association of PM2.5 level with lung cancer mortality using a nationwide prospective cohort, the Nurses' Health Study. The proposed methodology can be applied using our user-friendly R program published online.Receiver operating characteristic curves are widely used in medical research to illustrate biomarker performance in binary classification, particularly with respect to disease or health status. Study designs that include related subjects, such as siblings, usually have common environmental or genetic factors giving rise to correlated biomarker data. The design could be used to improve detection of biomarkers informative of increased risk, allowing initiation of treatment to stop or slow disease progression. Available methods for receiver operating characteristic construction do not take advantage of correlation inherent in this design to improve biomarker performance. This paper will briefly review some developed methods for receiver operating characteristic curve estimation in settings with correlated data from case-control designs and will discuss the limitations of current methods for analyzing correlated familial paired data. An alternative approach using conditional receiver operating characteristic curves will be demonstrated. The proposed approach will use information about correlation among biomarker values, producing conditional receiver operating characteristic curves that evaluate the ability of a biomarker to discriminate between affected and unaffected subjects in a familial paired design.Humans often experience wet stimuli using their hands, yet we know little on how sensitive our fingers are to wetness and the mechanisms underlying this sensory function. We therefore aimed to quantify the minimum amount of water required to detect wetness on the human index fingerpad, the wetness detection threshold, and assess its modulation by temperature. Eight blinded participants (24.0 ± 5.2 yr; 23.3 ± 3.5 body mass index) used their index fingerpad to statically touch stimuli varying in volume (0, 10, 20, 30, 40, or 50 mL) and temperature (25, 29, 33, or 37°C). During and after contact, participants rated wetness and thermal sensations using a modified yes/no task and a visual analog scale. The wetness detection threshold at a moisture temperature akin to human skin (33°C) was 24.7 ± 3.48 mL. This threshold shifted depending on moisture temperature (R = 0.746), with cooler temperatures reducing (18.7 ± 3.94 mL at 29°C) and warmer temperatures increasing (27.0 ± 3.04 mL at 37°C) thresholds. When normali time, has quantified the high sensitivity of the human index fingerpad to wetness and its modulation by moisture temperature.
To assess the feasibility of a multi-site randomised controlled trial to evaluate the effect of functional electrical stimulation on bradykinesia in people with Parkinson's disease.
A two-arm assessor blinded randomised controlled trial with an 18 weeks intervention period and 4 weeks post-intervention follow-up.
Two UK hospitals; a therapy outpatient department in a district general hospital and a specialist neuroscience centre.
A total of 64 participants with idiopathic Parkinson's disease and slow gait <1.25 ms
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Functional electrical stimulation delivered to the common peroneal nerve while walking in addition to standard care compared with standard care alone.
Feasibility aims included the determination of sample size, recruitment and retention rates, acceptability of the protocol and confirmation of the primary outcome measure. The outcome measures were 10 m walking speed, Unified Parkinson's Disease Rating Scale (UPDRS), Mini Balance Evaluation Systems Test, Parkinson's Disease Questionnaire-39, EuroQol 5-dimension 5-level, New Freezing of Gait questionnaire, Falls Efficacy Score International and falls diary. Participants opinion on the study design and relevance of outcome measures were evaluated using an embedded qualitative study.
There was a mean difference between groups of 0.14 ms
(CI 0.03, 0.26) at week 18 in favour of the treatment group, which was maintained at week 22, 0.10 ms
(CI -0.05, 0.25). There was a mean difference in UPDRS motor examination score of -3.65 (CI -4.35, 0.54) at week 18 which was lost at week 22 -0.91 (CI -2.19, 2.26).
The study design and intervention were feasible and supportive for a definitive trial. While both the study protocol and intervention were acceptable, recommendations for modifications are made.
The study design and intervention were feasible and supportive for a definitive trial. While both the study protocol and intervention were acceptable, recommendations for modifications are made.click here
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