Author + information
- Richard Conti, MD∗ ()
- ↵∗Cardiology, University of Florida, 1600 SW Archer Road, Gainesville, Florida 32610
In 2015, authors are beginning to use the term precision medicine as if whatever it is they are testing will result in a favorable response to therapy based on a single diagnostic test. In this instance, Sanchez-de-la-Torre et al. (1) measured plasma micro ribonucleic acids (miRNAs) and reported that this substance will predict blood pressure responses to continuous positive airway pressure treatments in patients with refractory hypertension and obstructive sleep apnea (OSA). My interpretation of this article is that miRNAs will predict that response in many but not all patients with OSA and refractory hypertension. Thus, this measurement can have statistical significance for a favorable response in populations, but the individual patient may or may not respond in a similar fashion.
The word precision can be defined simply as reproducibility and does not necessarily mean that the diagnosis or outcome is accurate. Accuracy is defined as being near to the true or desired value. Consider a target on a rifle range; if the shots have a tight grouping anywhere on the target, they are precise, but they are only precise and accurate if that tight grouping is in the bull’s-eye.
Most clinicians must make clinical decisions for an individual patient based on multiple pieces of information. To make the right clinical decision for the right patient at the right time, judgment is required. miRNAs can be part of those multiple pieces of information that influence judgment, similar to other pieces of clinical information. These other pieces of clinical information can include risk profiles such as Framingham risk assessment, clinical trials data, family history, chronic kidney disease, obesity, diabetes, as well as imaging studies, blood tests, functional studies, genetics, and common sense, often related to experience. However, despite this reasonable approach, even genetic profiles do not guarantee that the genotype will become the phenotype in an individual patient. I believe that an individual’s genetic data are powerful factors (and miRNAs may be as well), but they do not always result in the expected clinical outcome, just like other clinical factors.
When all of these factors are evaluated for the individual (including miRNAs), they may come close to being accurate for that person. However, as far as I can tell, prognostication of outcome is easily determined for populations, but prognostication of an individual’s response to therapy is an educated guess.
I am all for being as precise and accurate as possible when making decisions about individual patients. Unfortunately, so far, clinical decisions are not as precise and accurate as one would like.
If medicine ever becomes “precise and accurate,” there will be no need for judgment by physicians. In fact, there may not be any need for physicians. In my opinion, clinical judgment is still necessary to make clinical decisions in the individual patient, and it will stay that way for a long time.
Please note: Dr. Conti has reported that he has no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation