"During the years 1948 through 1953, some 120 children were seen in private practice. Of this number, 16 were adopted." A recent communication began with these sentences. What do they mean? Perhaps the writer personally adopted 16 of the 120 children he examined between 1948 and 1953. Of course, other interpretations exist. Further reading of the published article reveals that its author meant this: Between 1948 and 1953, he examined 120 children from his private practice. Sixteen of these children were not the offspring of their present parents, who had adopted them.
This example illustrates one of the commonest problems afflicting medical writing, one which you should learn to recognize, and avoid: the passive voice. What is the passive voice? Grammatically, it consists of some form of the verb "to be" plus a past participle, and shows whether a subject performs or receives the action expressed by the verb. In
Roland CG. The Passive Voice. JAMA. 1967;201(8):616-617. doi:10.1001/jama.1967.03130080058014