Table 1.

Research questions, interventions, and measurements in two feasibility REACT trials initiated within the GPRD

RETRO-PRO: the effectiveness of simvastatin compared to atorvastatin—a feasibility study (ISRCTN33113202)
Research questions	Feasibility of REACT trials; pilot for comparative effectiveness of simvastatin and atorvastatin in patients with primary hypercholesterolemia and high cardiovascular disease risk
Intervention	Randomisation between simvastatin and atorvastatin in 300 patients; non-blinded
Outcome measures	Recruitment rates and technical challenges; changes in lipid levels at three months; duration of statin treatment over time; long term incidence of myocardial infarction, stroke, and death (as measured in the GPRD, linked hospital data, disease registry data, or death certificates)
eLUNG: the effectiveness of antibiotics compared to no antibiotics for exacerbations of chronic obstructive pulmonary disease: a feasibility study (ISRCTN72035428)
Research questions	Feasibility of REACT trials; pilot for comparative effectiveness of antibiotics in patients with an exacerbation of chronic obstructive pulmonary disease and non-purulent sputum
Intervention	Randomisation between antibiotic (whichever the general practitioner uses as first line) or usual care in 150 patients; non-blinded
Outcome measures	Recruitment rates and technical challenges; patient diary over four weeks of the exacerbations of chronic pulmonary disease tool (EXACT-PRO) as completed on an electronic device; hospital admission over three months (as measured in GPRD and linked hospital data); long term incidence of mortality (as measured in GPRD or linked death certificates)