As BMJ and Cochrane discouraged uncontrolled before-after studies, what are the chances of publishing such studies (not related to hematology or oncology) in clinical journals?
I suppose it depends on which field you are in. If its new interventions or something with public interest, observational studies may be thought of as a pilot for later controlled studies. You won't get it published in high ranked journals, but there are a huge amount of journals out there in every field.
See for example this observational study with a couple of articles
Article Quality of life improved following in-patient substance use ...
Article Improved drug-use patterns at 6 months post-discharge from i...
both published in quite decent journals.
Since coerced treatment for substance use has not been evaluated before here in Norway (and it's unethical to do an RCT about it), an observational study was the best option we had.