I am not sure I want to know what the health care community was doing before the 90s.

On the bright side, some of it was just evidence-based medicine without the branding.

For example, the UK Medical Research Council put randomized trials on the map in 1948 with its randomized trial of streptomycin, which had been discovered only a few years before. The massive 1954 trials of the famous Salk polio vaccine also included a randomized trial comprising over 700,000 children. (That said, the non-randomized trial was even larger; the origin of this odd, hybrid study design is an interesting bit of history.)