<prompt> The Relative risk of 0.25 indicates-75 reduction of the incidence rate in the exposed individuals compared with the unexposed25 increase in the incidence rate in the exposed individuals compared with the unexposed2.5 times higher risk in the exposed individuals compared with the unexposed75 risk increase in the exposed individuals compared with the unexposed  <response>: Defined as the ratio between the incidence among exposed persons and incidence among non exposed. A typical case-control study does not provide incidence rates from which relative risks can be calculated directly because there is no appropriate denominator or population at risk to calculate these risks Ref: 25th edition, Parks Textbook of Preventive and Social Medicine, Page no. 86 