Comparing outcomes of percutaneous transluminal coronary angioplasty with coronary artery bypass grafting. Can routine health service data complement and enhance randomized controlled trials?

Aim To compare outcomes of percutaneous transluminal coronary angioplasty (PTCA) with coronary artery bypass graft surgery (CABG) for a population stemming from routinely collected data, in order to assess the merits of such data sources as a complement, and possible enhancement, to randomized controlled trial results. Methods and Results A population of Scottish patients were taken from a routine discharge summary and from this data source patients comparable to those from randomized controlled trial settings were identified. Between 1989 and 1995, 12238 pseudo randomized controlled trial patients were identified from the routine data set, of which 3714 (30·3%) received PTCA and 8524 (69·7%) received CABG. The baseline characteristics of the pseudo randomized controlled trial and randomized controlled trial patients were similar. The evidence from both the randomized controlled trials and routine data indicate that for 1 year follow-up the risk of cardiac death and/or non-fatal myocardial infarction is not significantly different between the two treatment groups. Conclusion The outcomes expected of PTCA and CABG following trial evidence have been realized in the routine data which are representative of a complete, non-selective population. Due to the size of the routine data set it would be possible to set up hypotheses for potential subgroup effects at the outset.