The phrase "as a useful variable" is correct and usable in written English.
It can be used when discussing the role or significance of a variable in a particular context, such as in mathematics, statistics, or programming.
Example: "In our analysis, we identified temperature as a useful variable that influences the outcome of the experiment."
Alternatives: "as an important factor" or "as a significant parameter".
Still, we think it is a useful variable and it performs as expected in our analyses.
Although physician-rated health is emerging as a potentially useful variable in research, with implications in practice, it has not been analyzed.
The water vapour and CO2 transmission rates of the sachet and plastic sheet containing Na2CO3 were used as a useful design variable to control the CO2 absorption rate.
The findings also suggest that diet quality, as opposed to individual foods or food groups, may act as a useful explanatory variable in the complex myriad of factors associated with the development of obesity.
This study provided a novel examination of GA as a useful tool for variable selection in the context of questionnaire data.
Fourth, it must remain speculative for now whether concomitant DCIS will emerge as a useful independent prognostic variable, as the degree of biological overlap between size-matched IDC-DCIS and pure IDC may preclude this.
Our data corroborate these earlier notions since several citrullinated peptides emerged as useful variables, as well as MCP-1 demonstrating a near-significant trend of being elevated in responders.
In this paper we describe a novel use of the RICC as a useful tool to screen variables for clustering in multicenter studies.
Wu et al. [ 2009] have suggested calculating a leave-one-out index for each coefficient (based on likelihood ratio tests, leaving one variable out of the final model at a time), as a useful tool for comparing variables in the model.
Planning analyses using causal acyclic diagrams has been advocated by Greenland and others as a useful strategy for identifying variables that may mediate or moderate the relationship between an exposure of main interest and primary health outcome/s [ 55, 56]. Figure 2 illustrates the complexity of possible causal pathways and relationships between obstetric risk factors for maternal morbidity.
