Te weinig aandacht voor bijwerkingen
Information that combines the best evidence on benefits with the best data on risks is also needed for daily clinical practice. Whenever a patient and physician decide on a particular course of treatment, they do so because they expect that the likely benefits will exceed potential harms. For the benefits of drug treatments, they often have authoritative sources to provide information: randomized trials and systematic reviews and meta-analyses of such trials.
For adverse effects, the situation is different. Given the average duration of randomized trials (often months to 1 or 2 years) and the average number of patients in randomized trials (often dozens to a few hundred), such trials are at most able to detect and quantify frequent adverse events that occur only early during treatment. Moreover, the adverse effect has to be known beforehand or anticipated to be recorded systematically in the trials. The study population in trials, which often includes young persons with a single diagnosis and without concurrent disease, is often not representative of those who will eventually use the drug in the community.
En ook klinische studies missen essentiele informatie over mogelijke bijwerkingen en interacties. De auteurs geven een boeiend voorbeeld:
A dramatic example is the interaction between selective serotonin reuptake inhibitors and nonsteroidal anti-inflammatory drugs that was missed in selective serotonin reuptake inhibitor trials but led to an excess of upper gastrointestinal bleeding in combined users.
De auteurs gaan in op oplossingen, waarbij gegevens van klinische studies, meta-analyses en observationele studies gecombineerd worden.
 Vandenbroucke JP, Psaty BM. | Benefits and risks of drug treatments: how to combine the best evidence on benefits with the best data about adverse effects. | JAMA. | 2008 Nov 26;300(20):2417-9. doi: 10.1001/jama.2008.723.