The phrase "as a linear effect" is correct and usable in written English.
It can be used in contexts where you are discussing the relationship between variables in a linear manner, often in scientific or statistical discussions.
Example: "The data showed a clear increase in performance as a linear effect of the training program."
Alternatives: "in a linear manner" or "as a linear relationship".
Age was modeled as a linear effect.
In previous work [ 6] the aeration type was modeled as a linear effect with both additive and multiplicative components.
We used the likelihood ratio test to estimate if seniority could be fitted as a linear effect.
Age in years was included as a linear effect, rather than as specific age categories, because HbA1c was found to change in a smooth linear fashion with age.
The likelihood ratio test showed that the effect of baggage handler seniority could be fitted as a linear effect for all regions except for the hips, and hence baggage handler seniority was included continuously in the final model (model 3).
We see that the full model without age as a linear effect turns out to be the best; η i = β 0 + β sex (i ) + β year (i ) + β island (i ) + u i. (12 Our further analyses for bill depth are based on this model.
All continuous variables were modelled as having a linear effect on the log odds.
Age, Glasgow Coma Score and number of organ system failures were modelled as having a linear effect on the log odds.
Most previous studies used the case-crossover design with relatively inflexible models to investigate the effects of temperature on mortality, such as assuming a linear effect for temperature in each season, with a single lag model, or moving average lag model (Basu et al. 2008; Green et al. 2010).
As discussed in the section considering genes as instruments, should risk alleles enter these estimating equations as a count assuming a linear effect or as a series of indicator variables?
The latter results should, however, be taken with a grain of salt as they assume a linear effect of program coverage on the risk of miscarriage.
