Jeremy Howick, Ioannidis et al.: "Most healthcare interventions tested are not effective according to high quality evidence: a systematic review and meta-analysis"
In this large sample of 1567 drugs, interventions studied...effects of most interventions (94%) interventions were not supported by high quality evidence.
“Patients, doctors, and policy makers should consider the lack of high-quality evidence supporting the benefits and harms of many interventions in their decision-making.”
SOURCE:
“Of 1567 eligible interventions, 87 (5.6%) had high quality evidence on first-listed primary outcomes, positive, statistically significant results and were rated by review authors as beneficial. Harms were measured for 577 (36.8%) interventions, 127 of which (8.1%) had statistically significant evidence of harm. Our dependence on the reliability of Cochrane author assessments (including their GRADE assessments) was a potential limitation of our study.”

Not surprised by the findings. But trusting Cochrane or any medical " authority" is a real problem for me now also. Such a sad situation for us all. I do know that in US the elderly people put on hospice and removed from most of their prescription drugs end up living longer than people who stay on the drugs until the end.
The study reflects the fraudulent manipulation of statistics to create the endpoint for profit! The woman’s health initiative that was a $30 million study is a prime example. It was designed to discredit estrogen and push osteoporosis drugs by Lilly. Lilly was smart enough to invite George Bush Senior on to their Board of directors so he could get the federal government to fund the $30 million study. Today Alex Azar from Lilly runs NIH.