To examine the association between an exposure and outcome, for example body mass index as exposure and all-cause mortality as outcome, some of studies reported relative risk as a continuous form. For example, reported relative risk only for 1 unit increment in body mass index. Now, how we can rescale relative risk and estimate it for 2 unit increment? I am trying to conduct a systematic review and meta-analysis but I dont know how we can do this. And what is such solution for case-control studies?
another example,
association between Mediterranean dietary pattern score and all-cause mortality: score range from 0 to 9 / number of participants: 1849 / number of death: 553 / relative risk of all-cause mortality for one unit increment in MED score : 0.95 (95%CI: 0.91, 1) /
know, relative risk for 2 unit increment in MED score?