Defining the value of observational studies in trauma

The randomized placebo controlled trial (RCT) is considered the gold standard for clinical research. In an RCT patients are randomized between a treatment and a control group while both the patient and the physician are blinded for the treatment choice. This results in two similar and comparable groups and consequently observed differences in outcome between both groups can be ascribed to the treatment. In observational studies on treatment effect of medical interventions, there is no randomization and blinding of the patient and physician for the treatment choice is not possible. Therefore, an observational study is considered to be subject to bias and results of this type of study are considered less credible for decision making.

Observational studies have an important role in reporting of adverse events, long term outcomes, and the effects of new surgical techniques. To study treatment effect, results from observational studies as compared to RCTs, are often better generalizable because of less strict inclusion criteria, have more possibilities such as subgroup analysis, and an observational study is easier, faster and less expensive to perform. These advantages make observational studies an interesting alternative for RCTs, especially in a world with fast technological advancements, continuous implementation of new techniques and limited financial possibilities.

In this thesis, three types of comparisons of interventions are identified in trauma surgery with different associated types of bias influencing the observed treatment effect. Evidence is presented and substantiated which shows observational studies to produce similar treatment effects compared to RCTs. This implies research in trauma surgery can be performed more efficient, faster and with less financial funds with better generelizable results. Finally, a prospective observational study protocol is presented which aims to be a framework for future research in trauma surgery.