Effects of a novel differential diagnosis aid for managing patients with unexplained fatigue in the primary care setting. A prospective randomized, controlled and multicentre pilot study in primary care

Abstract Objective Unexplained fatigue is a common reason for encounter in the primary care setting, with currently no structured tool available to support diagnosis. This study evaluated the effects of the novel Fatigue Differential Diagnostic Aid (FDDA) in clinical practice. Design This was a prospective, randomized, controlled, multicentre study comparing use of the FDDA vs usual care in patients with unexplained fatigue as the main reason for encounter. Setting and Participants The study included 93 patients seen in the primary care setting (FDDA n=40, usual care n=53) in Switzerland. Outcomes Patient Global Impression of Change (PGIC), patient satisfaction with treatment and fatigue improvement, treatment patterns, number of examinations, number of visits. Results There was no statistically significant group difference for the primary endpoint of PGIC. However, five predefined endpoints met statistical significance: (1) More patients were very satisfied with treatment management in the FDDA group at both 1 month (FDDA 56.8% vs usual care 25.6%, p=0.004) and 3 months (FDDA 64.9% vs usual care 31%, p=0.003); (2) patients underwent more examinations at baseline in the FDDA group (median 11.0 for FDDA vs 7.0 for usual care, p=0.002); (3) The FDDA group received a wider range of, and more treatments at 1 month, but less iron replacement therapy (p=0.0233); the FDDA was also associated with (4) a higher total number of visits (median 4.0 vs 3.0, p <0.001), and (5) more patients reporting reduced fatigue after 3 or 6 months (FDDA 97.4% vs usual care 78.4%, p=0.011). Conclusions The FDDA has the potential to improve the management of fatigue. The findings of this study may be relevant to clinical practice because physicians using the FDDA investigated the causes of fatigue more extensively, and more patients reported reduced fatigue. Further studies on diagnostic tools for unexplained fatigue are warranted.