the overall plan was to assess the surveillance and control activities in hospitals in the united states in 1970 and 1976 , to measure the change in the nosocomial infection rates from 1970 to 1976 as determined from a carefully conducted retrospective chart review , and to assess the influence of changes in these programs on infection rates after controlling for other important changes that occurred during the interval .
C0205721
nosocomial infection
C0009450
infection