The phrase 'demonstrates a positive effect' is correct and usable in written English.
You can use it when you want to describe a situation in which something has improved the outcome of a situation. For example, "The introduction of the new policy demonstrates a positive effect on the company's profits."
The hydrothermal carbon composite is further activated by KOH, and graphene in the activated carbon composite demonstrates a positive effect of increasing specific surface area, pore volume and electrical conductivity, resulting in superior electrochemical performance.
A before-and-after assessment that demonstrates a positive effect on both the students' knowledge of evolution and their attitudes towards its relevance.
In fact the best current data about metabolism and hormone replacement therapy in menopause demonstrates a positive effect for women taking HRT.
The fact that an RCT demonstrates a positive effect of an intervention does not guarantee adoption of an intervention.
Researchers cannot assume that an intervention which demonstrates a positive effect and has been described in a high impact journal will be translated in practice [ 2].
A review of 13 cases of post-partum hemorrhage by Boehlen and colleagues [ 39] also demonstrates a positive effect on bleeding for doses from as low as 17.5 μg/kg to 120 μg/kg.
Studies which had some risk of conflict of interest demonstrated a positive effect of the intervention (cost-effective to very cost-effective outcome) about 70percentt of the time, whereas 80percentt of the studies deemed to be without a conflict of interest showed a positive effect of the intervention.
Second, research into VE for safety learning and training has demonstrated a positive effect on the ability of participants to identify hazards and provided an effective way for engaging learners.
Only one trial of nefazodone in adolescents with MDD demonstrated a positive effect of medication over placebo and that was on a secondary outcome (Emslie et al, 2002a), while another nefazodone trial was negative (Table 1).
