The phrase "a decrease in the level" is correct and usable in written English.
It can be used when discussing a reduction in a specific measurement or standard, such as in scientific, economic, or environmental contexts.
Example: "The study showed a decrease in the level of pollutants in the river after the new regulations were implemented."
Alternatives: "a reduction in the amount" or "a decline in the standard".
We have observed a decrease in the level of knowledge of the population, as well as healthcare professionals.
Finally, a decrease in the level of personality functioning predicted impaired global functioning.
At home, a decrease in the level of credible threats led the government to lower the terrorism alert by one level, to yellow.
"There has been a decrease in the level of violence -- it hasn't gone to zero, but there's been a decrease -- so these people feel more comfortable coming out".
A decrease in the level of compensation for malpractice victims' non-economic harms therefore will not make it cheaper for doctors to purchase liability insurance.
Obtained data showed a decrease in the level of proteins involved in lipid metabolism in psoriatic patients' plasma.
The operation aimed to release pressure from swelling inside his brain and the statement explained that he had "undergone a decompressive craniectomy after suffering from a decrease in the level of consciousness due to a cerebral edema".
The combination of an increase in the blood level of cholesterol and a decrease in the level of iodine bound to protein indicates hypothyroidism (underactive thyroid gland).
If a number of countries in a region pursue prosecutions, nearby countries also show a decrease in the level of repression, even if they have not held trials.
A decrease in the level of certain proteins in the blood, without these levels being restored to their pre-flight levels 7 days after the flight, can clearly be interpreted as the impact of space flight on the human body.
"Such a significant drop in funding can only mean more repeats and a decrease in the level of new original productions," he said during a speech at Bafta in London last night.
