Wouter Leclercq

Chapter 10 166 RESULTS Between Aug 24, 2015, and Aug 12, 2016, 896 potential participants were assessed for study participation. Of these, 344 (38%) gave their consent to participate (Figure 10.2). A comparison of participants and nonparticipants according to age, sex, and type of surgical procedure revealed no clinically relevant or significant differences between both groups (data not shown). 173 participants were randomly allocated to the intervention group and 171 to the control group. One participant allocated to the intervention did not receive an account for the intervention website, because of logistical problems. 138 participants used the intervention as intended (i.e., they at least generated a convalescence plan on the website) and were included in per-protocol analyses. Follow-up ended on March 14, 2017. Median length of follow-up was 26 weeks (IQR 26–26). 344 (100%) participants completed the baseline questionnaire (T0), and questionnaires at 1 week (T1), 3 weeks (T2), 6 weeks (T3), 3 months (T4), and 6 months (T5) after surgery were completed by, respectively, 327 (95%), 323 (94%), 310 (90%), 304 (88%), and 300 (87%) study participants. Data for the primary outcome measure (return to normal activities after surgery) were available for 330 (96%) study participants (Figure 10.2). For four participants, the date for return to normal activities after surgery was based on seven instead of eight activities (n=1 in the intervention group and n=3 in the control group). Baseline characteristics of study participants are groups, except participants in the control group expected to return to work earlier than did participants in the intervention group. The mean difficulty scores of the short forms (personalised by participants) were comparable between the intervention and the control group, which means that the activities selected by participants were comparable in item difficulty. Complications during and after surgery were low in both groups (Table 10.1). Median time until return to normal activities was 21 days (IQR 17-25) for participants in the intervention group and 26 days (20-32) for participants in the control group (adjusted HR 1·38, 95% CI 1.09-1.73; P=0.007; Table 10.2, Figure 10.3). Comparable results were noted in sensitivity analyses when adjustments were made for factors that might affect the length of the recovery period (adjusted HR 1·36, 95% CI 1.08-1.72; P=0.008; Table 10.2), and when return to normal activities was measured from the moment of randomisation instead of from the moment of surgery (median 32 days [IQR 22-52] in the intervention group and 40 days [24-69] in the control group; HR 1.38, 95% CI 1.10-1.73; P=0.006). Perprotocol analyses had no substantial effect on the results (Table 10.2).