**3.6 Reasons for not participating in the study**

The reasons for the unreachability of the remaining 118 patients during the first measurement were: wrong phone number = 43 (40% RPP), occupation = 33 (45% RPP), being out of geographical reach = 17 (35% RPP), and exclusion criteria = 14 (57% RPP). Only 11 patients (36% RPP) were excluded due to concomitant disease or death, which is associated with a decrease in HRQOL. One year later, of the missing RPP patients: 6 refused to participate (2 due to disease), 6 couldn't be contacted, and 3 had died. In CT: 5 refused to participate (1 due to disease), 4 couldn't be contacted, and 6 had died.
