The phrase "a demonstrable effect of" is correct and usable in written English.
It can be used when discussing evidence or proof of a specific impact or outcome resulting from a particular cause or action.
Example: "The study provided a demonstrable effect of the new policy on employee productivity."
Alternatives: "a measurable impact of" or "a clear result of".
Vitamin Intervention for Stroke Prevention (VISP) is designed to determine whether the utilization of folic acid, vitamins B6 and B12, in addition to other risk factor reducing measures, have a demonstrable effect on prevention of recurrent stroke.
The change in the lateral constraint of the test system had a demonstrable effect on many aspects or attributes of plastic flow: the yield stress and strain-hardening behavior, the intermittency of strain bursts, the spatial distribution of slip bands, and the development of internal crystal rotations.
Furthermore, the lack of a demonstrable effect on daunorubicin binding to the plasma membrane by modulators points to transport mechanisms which do not utilise specific drug binding to the plasma membrane.
This practice has a demonstrable effect on the emergence and prevalence of potentially clinically relevant resistant microorganisms in food animals.
Although we would expect rosiglitazone to have a demonstrable effect on hs-CRP reduction, its lack of any statistically significant effect in our study probably lies in the small number of patients on rosiglitazone when compared to the either metformin or sulfonylurea group.
Importantly, WT p85α decreased the binding of PTEN to WWP2 without a demonstrable effect on NEDD4 binding.
Both of these observations are evidence that chemotherapy is having an effective in these patients and has had a demonstrable effect on their disease.
Impact – having a demonstrable effect on other people's lives – can happen directly through the actions of the philanthropreneur and his or her organisation, or indirectly through a multiplier effect of others' actions.
And although the lives of individuals have improved, loans to the poor have not yet had a demonstrable effect on aggregate poverty levels.
Adopting those measures has a demonstrable effect on robberies, the police official said.
