What can available randomised controlled trials evaluating monitoring strategies tell us about the design and analysis of future trials?

Background Randomised controlled trials (RCTs) of monitoring regimes present unique challenges. Trials of monitoring evaluate a strategy, “a planned and organised system of repeated assessments and subsequent decisions about additional interventions, such as starting, stopping or modifying treatment” [1] all of which should be specified in advance, and ideally supported by previous research. The complexity of the intervention and consequent potential for “interactions between tests, repeated tests, test results and the decisions based on these results” [1] also necessitates large sample sizes in order to detect an effect on important patient outcomes.