Pharmacoepidemiology – current opportunities and challenges

Abstract

ABSTRACTPharmacoepidemiology is defined as the the study of the use and the effects of drugs in large groups ofpeople. It can be viewed as an epidemiological discipline with particular focus on drugs. The Scandinavianspioneered the developement of methods to study drug utilization. The ATC and DDD methodology is now awidely accepted consensus on how to categorise drugs and compare sales of drugs of different potency. Thehierachy of available designs to study drug effects is described. There is an inverse relationship between thevalidity of a study design and its resource requirements. One of the most pervasive methodological problemsof pharmacoepidemiology is the possibility of confounding by indication. Often, such confounding can onlybe handled by mounting a randomised trial. If a trial is unethical or unfeasible, the research question has thepotential of becoming af standing controversy. The emergence of large population based prescription databasesis an exciting new development in pharmacoepidemiology. The validity of drug exposure data is discussed.It is established that data from a pharmacy based database should be preferred over data from a GPbased database. Whether interview data are preferable to dispensing data can not be established in generalbut may occasionally be inferred from the context of the research question.