Search results for "Regression toward the mean"
showing 3 items of 3 documents
Segmented relationships to model erosion of regression effect in Cox regression
2010
In this article we propose a parsimonious parameterisation to model the so-called erosion of the covariate effect in the Cox model, namely a covariate effect approaching to zero as the follow-up time increases. The proposed parameterisation is based on the segmented relationship where proper constraints are set to accomodate for the erosion. Relevant hypothesis testing is discussed. The approach is illustrated on two historical datasets in the survival analysis literature, and some simulation studies are presented to show how the proposed framework leads to a test for a global effect with good power as compared with alternative procedures. Finally, possible generalisations are also present…
Evidenz-basierte Überprüfung der Therapieempfehlungen bei Epicondylopathia humeri lateralis (Tennisellenbogen) - eine Übersicht
2004
The guidelines of the German Orthopaedic Societies regarding the treatment of lateral elbow epicondylitis were analysed on the ground of recently published reviews or randomised placebo-controlled trials (RCT). For the acute phase, reviews or RCTs failed to show a clinical effect beyond placebo if follow-up was extended over 6 weeks. For the chronic phase a current Cochrane review failed to identify any controlled trial regarding surgical procedures during the last decades. Without an adequate control group, it is not possible to draw any meaningful conclusions about the value of this modality of treatment. Therefore surgery is not indicated before repetitive low-energy extracorporeal shock…
Changes in blood pressure in a large cohort of elderly individuals: Study 3C
2009
Summary Objective Analysis of changes in blood pressure with a two-year interval, and of factors associated with this change, in a large cohort of elderly individuals. Methods Follow-up of a cohort of 9294 individuals aged 65 years and over recruited from the general population for Study 3C. Changes in blood pressure are defined as the difference in its averages between the inclusion visit and the follow-up visit at 2 years. The factors associated with changes in systolic blood pressure were identified by univariate and multivariate analyses. Results Systolic and diastolic blood pressure decreased on average by 7.60 mmHg and 4.45 mmHg respectively in 7659 individuals included in the study b…