Aims: Patient-reported outcomes (PROs) are valuable for effectiveness evaluation, but it is unknown whether the patient views obtained represent the actual case mix. We studied the representativeness of the responses obtained to a routinely administered health-related quality of life (HRQoL) questionnaire in a cardiology unit.
Methods and results: Elective coronary artery bypass grafting (CABG; n = 404) and percutaneous coronary intervention (PCI; n = 738) patients operated during June 2012 to August 2014 in the Heart Center, Kuopio University Hospital. The characteristics of the patients with a baseline (n = 260 and 290 for CABG and PCI, respectively) or both baseline and follow-up HRQoL measurements (n = 203 and 189 for CABG and PCI, respectively) were compared with those who did not respond (n = 144 and 448 for CABG and PCI). Baseline questionnaires were less likely obtained from older CABG patients (odds ratio 0.51, 95% confidence interval 0.28-0.91) and those with more severe disease (0.20, 0.05-0.79). Among PCI patients, women (0.64, 0.45-0.91), smokers (0.74, 0.53-1.04), and those with more severe disease (0.26, 0.13-0.52) or more hospital days were underrepresented.
Conclusion: Routinely collected PROs in cardiac patients may be biased towards younger and healthier patients. This needs to be recognized when evaluating the representativeness of such data. The routine collection of these data should be adequately resourced.