In particular, Victora et al. [ 25] specified the parameters of dose-intervention variability and associated each of them with a specific type of efficacy or effectiveness study (i.e., clinical efficacy trial, public health regimen efficacy studies, public health delivery efficacy studies, public health program efficacy studies, and public health program effectiveness studies).
However, a number of difficulties were encountered in assessing hand hygiene studies: the problem of attributing efficacy to an alcohol-based product when used in a multi-component intervention; the variability inherent in the design of such studies; and how to use data from uncontrolled, unblinded studies in the assessment.
An intervention reducing variability in SBP without direct renal effects would have the capacity to demonstrate causation.
Other factors that will determine the effect size include the type of intervention, assay variability and the nature of the marker (being dynamic or static).
GPs appear to be ideally placed for early identification and intervention, but variability in services due to the broad and complex range of individuals seen in primary care, and the different pathways through which individuals enter the CJS means this cannot be the only provision relied upon.
Undertaking reviews in this area is difficult because of the complexity inherent in the interventions, the variability of the methods used, and the difficulty of generalising findings across healthcare settings.
However, if a chronic assessment is to be considered (e.g. pre-post a training intervention), short-term variability and equipment measurement error, but also day-to-day variability, may potentially influence the results.
48 A generic challenge for trials aiming to evaluate the merits of allied health treatment is the lack of expertise among therapists who deliver the trial intervention, creating undesirable variability and insufficient contrast with the control arm.
Descriptive analyses will be used to provide summary estimates of outcome measures, focussing on the dropout rate at each time point, the order of magnitude of the effect of the intervention and the variability of the outcome measure at baseline.
