Is research from databases reliable? No

Excerpt

The findings of clinical research inform clinicians, guideline committee members and policy-makers on how to provide the best care of patients at the lowest possible cost. It is of utmost importance that such research findings are trustworthy. If not, we may harm patients and waste resources by the use of interventions with an unfavourable balance between risk and benefit. The risk of harm is real as indicated in a recent systematic review of all interventions shown to affect mortality in critical care trials [1]. Among the 15 interventions that affected mortality, eight increased mortality. Many of these harmful interventions were in clinical use at the time of testing, including tight glycaemic control, hydroxyethyl starch and high-frequency oscillatory ventilation [2‐4]. Faced with the need to identify and promote interventions that may help patients and with the similar need to identify and avoid interventions that may harm patients, intensivists have used a variety of approaches. One such approach has been based on the use of databases or registries. Such an approach, however, carries important risks. In particular, the reliability of findings from such investigations is open to challenge. …