The paper defined the concept of engineering quality and 4M1E, and proposed the five direct assumptions that 4M1E all significantly affect the quality of engineering as well as the four indirect assumptions that man factors will affect the quality of engineering by impacting other factors.
We first discuss the methodology of each available scoring system, describing how each of these scores make important indirect assumptions in the way they account (or do not account) for calcium density, location of calcium, spatial distribution of calcium, and microcalcification/emerging calcium that might limit their predictive power.
Consequently, microarray experiments allow for rough and mostly indirect assumptions.
Instead, we relied on an indirect measure: the assumption that the trajectory of the stimulus was, to a good approximation, circular.
In the absence of continuous monitoring of energy expenditure with indirect calorimetry, the assumption was made that patients' energy requirements were equal to those of the basal metabolic rate (BMR) for healthy children using the Schofield equations [ 14], with no correction for stress factors [ 15].
This means the assumptions on similarity (comparability of the studies with regard to effect modifiers) and, in case of a combination of direct and indirect evidence, the assumptions on consistency (comparability of the estimated effect from direct and indirect evidence) have to be fulfilled.
Based on a number of statistical assumptions, indirect comparisons are interpreted with caution; among their defects is a greatly reduced statistical power to detect differences among groups [ 3, 13, 20, 21].
To be more precise, in the absence of head-to-head clinical trials between EVE plus EXE and the selected comparators (BEV plus PACL and BEV plus CAPE), indirect methods and assumptions, similar to those considered in the model submitted to the National Institute for Clinical Excellence (NICE) [ 15], were used to obtain estimates for HRs of the comparators against EVE plus EXE.
Notwithstanding the evidence coming from these guidelines and clinical trials, the choice of treatment in common clinical practice is rather arbitrary and seems to partly depend on indirect and direct assumptions of the clinician, style of health service delivery and patient factors (e.g. [ 25]).
Moreover, the results of the assessment of the assumptions can help determine the reliability of the indirect evidence; if the assumptions appear reasonable, the indirect evidence should be valid.
