How do you calculate risk ratio?

How do you calculate risk ratio?

Risk Ratio = Incidence in Experimental Group / Incidence in the Control Group. A risk ratio equals to one means that the outcomes of both the groups are identical.

What does a relative risk of 1.0 mean?

A risk ratio of 1.0 indicates identical risk among the two groups. A risk ratio greater than 1.0 indicates an increased risk for the group in the numerator, usually the exposed group.

What does a risk ratio of 0.8 mean?

Examples. RR of 0.8 means an RRR of 20% (meaning a 20% reduction in the relative risk of the specified outcome in the treatment group compared with the control group). RRR is usually constant across a range of absolute risks. But the ARR is higher and the NNT lower in people with higher absolute risks.

What does a risk ratio of 1.5 mean?

A risk ratio greater than 1.0 indicates a positive association, or increased risk for developing the health outcome in the exposed group. A risk ratio of 1.5 indicates that the exposed group has 1.5 times the risk of having the outcome as compared to the unexposed group.

What does a risk ratio of 2.5 mean?

If odds ratio is 2.5, then there is a 2.5 times higher likelihood of having the outcome compared to the comparison group. ... Here the odds ratio would be 0.80. The odds ratio also shows the strength of the association between the variable and the outcome.

What does a relative risk of 2.0 mean?

A relative risk less than 1 means the disease is more likely to occur in the group than in the. group. For example a relative risk of 2 would mean that people would be twice as likely to contract the disease than people from the. group.

Are relative risks of 2.0 and 0.5 the same or different in strength of association?

Relative risk of 2.0 and 0.5 are different in strength of association.

What does a 0.5 odds ratio mean?

An odds ratio of 0.5 would mean that the exposed group has half, or 50%, of the odds of developing disease as the unexposed group. In other words, the exposure is protective against disease.

What does an odds ratio of 0.7 mean?

For e.g. if odds ratio is 0.70, then there is a 30% lower likelihood of having the outcome.

What does a risk ratio of 0 mean?

A relative risk smaller than 2 indicates no association between risk and disease. ... If RR = 0 there aren't cases of disease among the exposed to the factor, so the factor can be considered as protective.