Discussion
PROM, fatigue
Overall, this randomized clinical trial demonstrated small, statistically significant health benefits in HRQOL and fatigue using the remote PROM monitoring intervention compared with the standard of care for patients with hip replacement and patients with knee replacement; for example, patients with hip replacement had a mean 2.10 between-group difference and 1.66 EE on the EQ-VAS, and a −0.69 between-group difference and −0.65 EE on the PROMIS-fatigue. The intention-to-treat analyses and compliance-corrected analyses confirm these results. In addition, among patients with hip replacement, a small but significant difference in the PROMIS-depression score was observed, with a −0.57 between-group difference and −0.60 EE.With regard to the clinical significance of the results, to our knowledge, there is currently no established standard for evaluating meaningful PROM score change differences between groups for all selected PROMs for patients with hip replacement or knee replacement. Considering current generic minimal important change (MIC) recommendations for PROMIS measures,Although the mean change in physical functioning (HOOS-PS and KOOS-PS) was significantly different between the intervention and control groups before adjustment, the significant difference disappeared after adjustment. This could reflect the change in this health dimension being driven by variables for which the randomization might not have completely accounted (eg, presurgery PROM scores). However, a significant difference was observed in the compliance-corrected population, with a difference of −1.85 and an EE of –0.89 for the HOOS-PS among the hip replacement group and a difference of −1.14 and an EE of –0.94 for the KOOS-PS among the knee replacement group, warranting further analysis into the relationship between compliance, alert reactions, and functional health outcomes.Due to the multistep nature of the intervention, it is unclear which aspect of the intervention caused the positive health changes. Whereas filling out the PROMs and, thus, patients reflecting more on their own health status might already have initiated change (step 1), change could have also been initiated by the reassuring idea that, if scores were critical, a health care professional would get in touch (step 2: alert to study nurses). The health changes might also have been triggered by calls or data transfers to patients by study nurses after the alerts (step 3), or by the actions based on the data transfer to physicians (step 4). Although around 70% of patients were informed about their critical values via a telephone call, around 20% received their values also or only per post or email (step 3). Given the low percentage of patients who were called and initiated PROM data transfers to physicians (hip replacement: 8.1%-21.1%; knee replacement: 7.9%-25.2%) (step 4), one could argue that earlier steps (monitoring, alerts, and calls) were more likely than the data transfer to physicians to drive the positive health changes. Considering the affected health dimensions, the results could point toward a “caring effect” through follow-up communication, rather than a “physical recovery effect” through in-person interventions. Virtual monitoring and telephone communication might have been especially relevant because the trial ran during the COVID-19 pandemic. Moreover, literature suggests that the completion of PROMs in itself can change the way in which patients think about their condition.Based on the presented information, some aspects should be considered when implementing the intervention into routine care. First, a high response rate of around 85% was achieved, in comparison with registry-based PROM collection, showing a mean response rate of 42% for digital PROMs without a reminder.