What is the difference between risk and probability

Risk is essentially the level of possibility that an action or activity will lead to lead to a loss or to an undesired outcome. The risk may even pay off and not lead to a loss, it may lead to a gain. There are many difference kinds of risk. Wikipedia lists six different ways that risk can be defined:.

A probability, on the other hand, is a measure or estimation of how likely is it that an event will come to pass, or that a statement is true. When we assess the probability a risk may occur, we are technically assessing a conditional probability; that is,. The following table provides a guide for assessing risk event probabilities. A risk event that is certain not to occur has, by definition, probability equal to zero. Remember that we used a log transformation to compute the confidence interval, because the odds ratio is not normally distributed.

Therefore, the confidence interval is asymmetric, because we used the log transformation to compute Ln OR and then took the antilog to compute the lower and upper limits of the confidence interval for the odds ratio. Remember that in a true case-control study one can calculate an odds ratio, but not a risk ratio. However, one can calculate a risk difference RD , a risk ratio RR , or an odds ratio OR in cohort studies and randomized clinical trials.

Consider again the data in the table below from the randomized trial assessing the effectiveness of a newly developed pain reliever as compared to the standard of care. Remember that a previous quiz question in this module asked you to calculate a point estimate for the difference in proportions of patients reporting a clinically meaningful reduction in pain between pain relievers as 0.

Because this confidence interval did not include 1, we concluded once again that this difference was statistically significant. When the study design allows for the calculation of a relative risk, it is the preferred measure as it is far more interpretable than an odds ratio. The odds ratio is extremely important, however, as it is the only measure of effect that can be computed in a case-control study design. In such a case, investigators often interpret the odds ratio as if it were a relative risk i.

All Rights Reserved. Date last modified: October 27, In healthcare we must embrace both risk and probability by being prepared. Not only for our practices and organizations, but most importantly our patients. Maria S. Please contact at info mltconsultants. Join Global Risk Community. Exactly Enrique! The fact that we live in this very variable world ensures that we must accept some level of risk. Even though it was a movie I thought it was a brilliant example of how to not only accept risk as a part of life but also how he thrived professionally in spite of risk.

Although he did crash, and thank God survived, he returned to racing at become a Champion again.