Tag Archives: Biostatistics

New Biostatistical Guidance Document Available: Small-Sample Robust Variance Correction for GEE

Tools for ResearchThe NIH Collaboratory’s Biostatistics and Study Design Core has just published a new guidance document by Andrea Cook, PhD, of the Group Health Research Institute, on using small-sample robust variance correction for generalized estimating equations (GEE) for use in cluster-randomized trials. The document, which includes guidance on methods available in the SAS and Stata statistical analysis packages, is available directly from the NIH Collaboratory Knowledge Repository here (opens as PDF), or via the Biostatistical Guidance Documents page in the Living Textbook.

This guidance document is one in a series of research tools focused on detailed aspects of statistical design for conducting pragmatic clinical trials. Each document in this series provides a synthesis of current developments, discusses possible future directions, and, where appropriate, makes recommendations for application to pragmatic clinical research.


New Biostatistical Guidance Document Available – “Frailty Models in Cluster-Randomized Trials”


Tools for ResearchThe NIH Collaboratory Biostatistics/Study Design Core has released a new guidance document concerning the use of frailty models in the setting of cluster-randomized trials (CRTs). This guidance, the fifth in a series from the Core, outlines considerations affecting power calculations in frailty models, as well as issues raised by the use of logistic regression models for time-to-event versus dichotomous outcomes in CRTs .

The guidance document can be found under Biostatistical Guidance Documents on the Tools for Research page on the Living Textbook, or accessed directly here (PDF).


Collaboratory Biostatistics and Study Design Core Releases Guidance Documents


The NIH Collaboratory’s Biostatistics and Study Design Core has released the first in a series of guidance documents focusing on statistical design issues for pragmatic clinical trials. Each of the four guidance documents are intended to help researchers by providing a synthesis of current developments in the field, discuss possible future directions, and, where appropriate, make recommendations for application to pragmatic clinical research.

The guidance documents are available through the Living Textbook and can be accessed on the “Tools for Research” tab or directly here.