I'm a statistician and I read medical studies and experimental studies pretty much daily. My advice on a simple rule of thumb that is likely to separate out quality research: are the data and statistical code made available? Another, are if the study hypotheses and design are pre-registered. The Cox model is VERY popular, but you have to ask two things: is the hazard reasonably proportional? If you thought learning to code meant you had to be careful about mistakes and typos, statistics is another layer of a similar size.