Table 1. The design of RWE studies
Element of RWE studyDesign of an RWE observational study
  • Includes those eligible for care from the health system

  • Clinical topics where case finding and outcomes are measured using routine data

  • Large number of cases

  • Case definition will be that of usual practice

  • Wide range of other therapies and co-morbidities

  • Few inclusion/exclusion criteria

  • Routine care

  • Range of treatment pathways

  • Comprehensive use of computerised medical records, across the care pathway

  • Need to infer meaning from ‘messy’ routine data

  • Prospective (including pragmatic RCTs) and retrospective studies are possible

  • Open label/neither clinician nor patient will be blinded

  • May be over a long period of time

  • That delivered as part of usual care/generally no additional visits

  • Standard patterns of adherence, no attempts to change beyond those that are part of routine care

Outcome measure
  • Defined from routine data

  • Loss to follow-up of those who move out of area/out of system

  • Avoids recall bias

  • Can include health economic impact

Comparator group
  • Differences in exposure

  • From different localities

  • Before and after

  • Stepped introduction of programme