N-of-1 Clinical Trials: Removing the Hay to Find the Needle

Selection of a proper sample size is an important concept in statistics. Typically, the larger the number of included subjects, the better the ability to make an accurate inference about the population. Numerous methods exist for determining the proper sample size to help balance the desired statistical power with the need to be realistic in how many subjects can be recruited. But the recognition of individual variability, with the well-known limitations of classic clinical trials to predict patient outcomes, has shed light on the growing need to refocus on single-person studies.N -of-1 or single-subject clinical trials use observations from a single patient to establish efficacy or side-effect profiles (1). The renewed interest in N -of-1 clinical trials stems from an observed …