«The authors of this meta - analysis provide limited evidence to support their contention, and even concede that their own observational findings have not been confirmed in experimental studies and may be influenced by publication bias.» (australianbeverages.org)
Then there was an observational finding that a drug called reserpine produced depression. (discovermagazine.com)
«These observational findings warrant a randomized clinical trial to assess efficacy of therapeutic hypothermia for in - hospital cardiac arrest.» (sciencedaily.com)