We will talk in more detail about CIs in a later segment, but the important message here is that a point estimate requires a CI before meaningful conclusions affecting patient care may be reached.
Applying Results to Patient Care
Once validity issues have been addressed and results have been processed, the key determinants of whether a study’s results can be applied to your patient are whether the study population was reasonably similar to your patient and whether the study setting was reasonably similar to your own. This need not be exact, but if a study enrolled only men, application of the results to women may not be supported.
On the other hand, if a study excluded individuals younger than 60 and your patient is 59 you may still feel comfortable applying the findings of this study to your patient’s care. The application of study results to individual patients is often not a simple decision. A general recommendation is to carefully determine whether there is a compelling reason to suggest that the study results might not apply to your patient. If not, generalizing the results is likely reasonable.
Additional considerations include the balance between benefits and risks, costs, and, of course, patient and provider values. If a treatment promotes survival but may have a negative impact on quality of life (for a recent example, see the MADIT II trial of AICD implantation in patients with prior MI and heart failure), patients and providers must carefully evaluate their priorities in determining the best course of action. Also, a costly treatment having a small but significant benefit may not be justified in an era of limited resources. These issues are at the heart of medicine and are best addressed by collaborative decision-making among patients, care providers, insurers, policy makers, and all other members of our healthcare system.
The results of a study can be reported in many ways, with different measures fitting different clinical questions. The keys to look for are a point estimate and a measure of the precision of that estimate. Applying results to patient care requires complex decisions that go well beyond the numbers from any study. In the upcoming segments of this series, we will focus more attention on how results are evaluated statistically. This will provide additional depth to the discussion of study results and how they inform our clinical decisions. TH
Dr. West practices in the Division of General Internal Medicine, Mayo Clinic College of Medicine, Rochester, Minn.