Premium
A model‐based approach to sample size estimation in recent onset type 1 diabetes
Author(s) -
Bundy Brian N.,
Krischer Jeffrey P.
Publication year - 2016
Publication title -
diabetes/metabolism research and reviews
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.307
H-Index - 110
eISSN - 1520-7560
pISSN - 1520-7552
DOI - 10.1002/dmrr.2800
Subject(s) - analysis of covariance , statistics , sample size determination , medicine , type 2 diabetes , econometrics , analysis of variance , variance (accounting) , presumption , demography , estimation , diabetes mellitus , mathematics , endocrinology , economics , accounting , management , sociology , political science , law
Background The area under the curve C‐peptide following a 2‐h mixed meal tolerance test from 498 individuals enrolled on five prior TrialNet studies of recent onset type 1 diabetes from baseline to 12 months after enrolment were modelled to produce estimates of its rate of loss and variance. Results Age at diagnosis and baseline C‐peptide were found to be significant predictors, and adjusting for these in an ANCOVA resulted in estimates with lower variance. Conclusions Using these results as planning parameters for new studies results in a nearly 50% reduction in the target sample size. The modelling also produces an expected C‐peptide that can be used in observed versus expected calculations to estimate the presumption of benefit in ongoing trials. Copyright © 2016 John Wiley & Sons, Ltd.