🥸Trials Often Aren't Representative of Real Patients
Phase III clinical trials are often designed to exclude a vast majority of the population of interest.
Last updated
Phase III clinical trials are often designed to exclude a vast majority of the population of interest.
Last updated
External validity is the extent to which the results can be generalized to a population of interest. The population of interest is usually defined as the people the intervention is intended to help.
Phase III clinical trials are often designed to exclude a vast majority of the population of interest. In these cases, the subjects of the drug trials are not representative of the prescribed recipients, once said drugs are approved. One investigation found that only 14.5% of patients with major depressive disorder fulfilled eligibility requirements for enrollment in an antidepressant efficacy trial.
As a result, the results of these trials are not necessarily generalizable to patients matching any of these criteria:
Suffer from multiple mental health conditions (e.g., post-traumatic stress disorder, generalized anxiety disorder, bipolar disorder, etc.)
Engage in drug or alcohol abuse
Suffer from mild depression (Hamilton Rating Scale for Depression (HAM-D) score below the specified minimum)
Use other psychotropic medications
These facts call into question the external validity of standard efficacy trials.
Furthermore, patient sample sizes are very small. The number of subjects per trial on average:
275 patients are sought per cardiovascular trial
20 patients per cancer trial
70 patients per depression trial
100 per diabetes trial
In the example in the graphic above, a drug is prescribed to millions of patients based on a study with only 36 subjects, where a representation of the general public is questionable.
In the real world, no patient can be excluded. Even people with a history of drug or alcohol abuse, people on multiple medications, and people with multiple conditions must be treated. Only through the crowdsourcing of this research, would physicians have access to the true effectiveness rates and risks for their real-world patients.
The results of crowdsourced studies would exhibit complete and utter external validity, since the test subjects are identical to the population of interest.
Furthermore, self-trackers represent a massive pool of potential subjects, dwarfing any traditional trial cohort. Diet tracking is the most arduous form of self-tracking. Yet, just one of the many available diet tracking apps, MyFitnessPal, has 30 million users.
Tracking any variable in isolation is nearly useless in that it cannot provide the causal which can be derived from combining data streams. Hence, this 30 million user cohort is a small fraction of the total possible stratifiable base.
