Background. Understanding points of onset of the frailty syndrome is vital to early identification
of at-risk individuals and to targeting intervention efforts to those components that are first …

The medical syndrome of frailty is widely recognized, yet debate remains over how best to
measure it in clinical and research settings. This study reviewed the frailty-related research …

Background. Frailty assessment provides a means of identifying older adults most vulnerable
to adverse outcomes. Attention to frailty in clinical practice is more likely with better …

Background Frailty in older adults, defined as a constellation of signs and symptoms, is
associated with abnormal levels in individual physiological systems. We tested the hypothesis …

R users can often solve optimization tasks easily using the tools in the optim function in the
stats package provided by default on R installations. However, there are many other …

Frailty in aging marks a state of decreased reserves resulting in increased vulnerability to
adverse outcomes when exposed to stressors. This Perspective synthesizes the evidence on …

The expectation‐maximization (EM) algorithm is a popular approach for obtaining maximum
likelihood estimates in incomplete data problems because of its simplicity and stability (eg …

BACKGROUND: Most randomized controlled trials (RCTs) and meta-analyses of RCTs examine
effect modification (also called a subgroup effect or interaction), in which the effect of an …

Heterogeneity of treatment effect (HTE) refers to the nonrandom variation in the magnitude or
direction of a treatment effect across levels of a covariate, as measured on a selected scale…

We discuss R package BB, in particular, its capabilities for solving a nonlinear system of
equations. The function BBsolve in BB can be used for this purpose. We demonstrate the utility …