The phrase "a decrease in proportion" is correct and usable in written English.
It can be used when discussing a reduction in the relative size or amount of something compared to another quantity.
Example: "There has been a noticeable decrease in proportion of students choosing science majors over the past decade."
Alternatives: "a reduction in ratio" or "a decline in percentage".
Fortified milk supplementation resulted in a decrease in proportion of children with markedly elevated ZnPP levels (>80 µmol/mole of heme; MN vs. Co: 33.5% vs. 72%) and elevated RDW levels (RDW >14%; MN vs. Co: 85.4% vs. 97%).
Both control groups exhibited a decrease in proportion initiating OAT while the eligible AF cohort exhibited an increase (0.268 vs 0.317).
In the case of ohnologues, however, an increase in ω was associated with a decrease in proportion, accompanying the tissue evolutionary rate.
Both studies also noted a decrease in proportion of LC3+/CTSD+ autolysosomes as compared with total autophagosomes, consistent with deficiencies in autophagosome processing (Fig. 5).
However, the total number of cells showed a similar trend for a decrease in proportion (p < 0.1) and thus the overall cell density in the viable areas was unchanged.
It was reported that mice deficient in IgA harbor an increase abundance of Candidatus Savagella [ 139]; furthermore, a decrease in proportion of IgA-coated bacteria in humans was associated with weight loss [ 140].
As can be seen from one example in Figure 5c we observed a decrease in proportions of CD4+CD25-Foxp3+ T cells after the initiation of therapy with cyclophosphamide.
Conversely, a decrease in the proportion of breast density and increase in the proportion of fat are associated with decreased risk of breast cancer.
There was a decrease in the proportion of patients receiving antibiotics and while a large proportion of patients continued to receive bronchodilators, fewer patients received multiple bronchodilators.
