Having taught EBHC for 25 years one of the things I see is that medical graduates don’t understand what confidence intervals mean and do not mean - I think more importantly than being able to calculate a CI they need to understand the context and what it means
to research findings.
The way I understand confidence intervals is
1) IT MEANS in a very large number of repetitions of the study, 95% of all CIs obtained will contain the “true” value of the treatment effect in the population studied (assuming random sampling)
2) IT DOES NOT MEAN the probability that the “true” magnitude of the effect lies within the range observed in a given study
3) IT DOES represent a plausible range of values for the effect – not a probability of its magnitude
Happy to hear if I am misinterpreting the concept
We recently wrote an article showing how authors confuse the meaning of confidence intervals. This group may find it of value as we provide a number of examples (statins and mortality in primary prevention) where authors misinterpret their results
because they misinterpret what a confidence interval means and does not mean.
James McCormack
Hello
As a medical statistician, I have strong support for the use of confidence intervals in the reporting of clinical research findings. However, I am also conscious that medical graduates may lose their
access to licensed software previously used in their undergraduate learning to support such activities. For example, both Minitab and Confidence Interval Analysis are possible choices for non-specialists and often supported by University licenses. However,
do medical graduates have an incentive to obtain their own licenses for such software on entering the workplace? I would be interested to learn from medical graduates as to their personal choices in the above context and indeed, as to whether or not such persons
have found freeware sufficiently reliable and easy to use to adopt in their own working practices specifically for obtaining confidence intervals (not for statistics more generally). This query is also of relevance to the management of courses for distance
learners, not all of whom may have access to a licensed statistical package for calculating confidence intervals but still need to perform the calculations to meet programme requirements.
Many thanks in advance
Best wishes
Margaret