In statistics, it takes smaller and smaller sample sizes to determine a statistical difference between events the greater the difference. There is no way to tell without running power calculations. There's over 300 million people in the United States. A recent study testing apixaban in severe renal disease patients had a total of 146 patients in it. And that study is probably going to lead to a change in clinical practice and allow physicians to start prescribing apixaban over warfarin in renal impairment.
Point being, off the top of your head, you literally have no idea whether or not the sample is able to be applied to the population.
Not to mention, this all has literally nothing to do with my original comment. He said a small sample is not even considered a sample. But, in fact, a small sample is without a doubt, a sample. Which leads me to re-ask my original question to you: Ok? How does that dispute my claim at all?