I like the message behind the quote, but surely in the case given a massive natural control exists in all patients prior to the introduction of the new surgery?
Patient groups and techniques change over time, assuming the data was even recorded in the first place. (eg. a lot of data from the past would not be useful today as a direct comparison or control group, simply because diets have changed so much.)
I like the message behind the quote, but surely in the case given a massive natural control exists in all patients prior to the introduction of the new surgery?
Patient groups and techniques change over time, assuming the data was even recorded in the first place. (eg. a lot of data from the past would not be useful today as a direct comparison or control group, simply because diets have changed so much.)