All is true regarding case fatality rate except ?
Ans. is 'c' i.e., Very useful for chronic disease CFR is typically used in acute infectious disease e.g. food poisoning, cholera, measles. o Its usefulness in chronic disease is limited, because the period from onset to death is long and variable. CFR is closely related to virulence of agent. o Limitation of CFR is that time period is not specified. o The case fatality rate for the same disease may vary in different epidemics because of changes in host, agent and environment factors. o Case fatality rate is the complement of survival rate. CFR =1 - survival rate CRF will be more if survival rate is less more patients are dying due to disease (i.CFR) or in other words less patients are surviving survival rate).
Represents killing power of disease
Closely related to viruleance
Very useful for chronic diseases
May vary in different epidemic for same disease