The importance of individualizing clinical practice guidelines to the specific needs of each patient.
Someday, hopefully, we will look back on the clinical practice guidelines of the past decades as well-meaning but misguided efforts to provide mediocre care for many, while providing optimal care for some.
At their worst, practice guidelines are based on the recommendations of experts who extrapolate from their own clinical experiences. At their best, they are based on research that compares the average outcome of one large group managed in one way to the average outcome of another large group managed in a different way. Ideally, the subjects are randomly allocated so that the two groups are not different, on average, from each other. The key word here, however, is average.
Diagnosing and managing patients using clinical practice guidelines is vastly better than much of the care of the past, which was based on anecdotes and tradition handed down from experienced clinicians to the next generation. It's better, for instance, to follow recommendations for antibiotic treatment of otitis media that are based on clinical and microbiologic outcomes of treatment trials than to treat all otitis with penicillin because that worked in the past.
But individual variability involves more than drug absorption, distribution, and metabolism. We all recognize that success in managing illness depends not only on giving the right medication in the right dose, but also on adherence to recommended treatment, on parental involvement in care, on environmental and nutritional factors, on mental health considerations, on inherited factors, and much more.
Perhaps one day we will be better able to adjust management decisions depending on individual variability. Certainly there is reason to believe that, in time, we will be able to detect specific genetic vulnerabilities to chronic illness, susceptibility to specific infections, and variability in the effects of medication. Until then, we have to deal with knowledge about the average, and the hope that wisdom and experience will allow us to adjust clinical treatment guidelines in consideration of individual circumstances.
All these thoughts are better summarized by Dr. Barton Childs in his book Genetic Medicine1: "The physician needs to know the biology, not only of Homo sapiens, but in some significant degree that of individuals with names and social security numbers who are representative of the species. In doing so the doctor's gaze is shifted away from each person's approximation to an abstract stereotype to the reality of one person's expressions of disease."
1. Childs B: Genetic Medicine: A Logic of Disease. Baltimore; Johns Hopkins University Press, 1999