The phrase "subset of patients" is correct and can certainly be used in written English.
You can use this phrase when you are referring to a group of patients within a larger population. For example, "We studied a subset of patients with chronic illnesses to compare the effectiveness of two different treatments."
In fact, on these criteria, they beat even the subset of patients who had been diagnosed with psychopathic personality disorders.
Actimmune is "not a miracle drug, but it does appear to prolong life in a subset of patients".
But the F.D.A. is usually reluctant to approve a drug based on its working in only a subset of patients.
Reviewing the data from the old trial, Dr. Cohn and NitroMed found that the drug had been remarkably effective in the subset of patients who were black.
Pharmacogenetics, however, does offer drug makers some advantages that might offset the risk that a particular drug would be limited in its use to a subset of patients.
Like AG-221, it was designed for a distinct subset of patients, in this case those whose cancers carry a mutated form of the Notch gene.
What these cardiologists actually found was that, among the smaller subset of patients with stable disease, thirty-eight per cent of stents placed were ranked as uncertain.
Researchers say the study, based on brain scans of compulsive hoarders, provides the first solid evidence that hoarding defines a distinct subset of patients.
Using a method of analysis that would not be accepted today, he chose the subset of patients who improved with a placebo, and disregarded those who got worse.
The company argues that the vaccine worked in a subset of patients with stronger immune systems, and it will present data on this in Argentina.
A small subset of patients will suffer long-term health problems; in fewer still, cocci will disseminate from the lungs into other tissue — skin, bones, and, often fatally, the meninges of the brain.
