Use of fitness trackers in patient-centred healthcare research: a systematic review (Preprint)

BACKGROUND Fitness trackers are increasingly popular consumer electronic devices which provide a rich source of precise individual health data, and are increasingly used in healthcare research. OBJECTIVE This systematic review aims to provide an overview of all patient-centred research studies that used fitness trackers. METHODS MEDLINE and Web of Science databases (up to May 2019) were searched for manuscripts reporting the results of original research using fitness trackers and recruiting patients with any/all medical conditions are included: a total of 63 studies using 41 different models of fitness trackers. Search results were reviewed by two appraisers independently in accordance with the PRISMA statement. Relevant risk-of-bias assessments were performed in all prospective studies. RESULTS Study sizes varied, with a median recruitment of 45 patients (IQR 29-147). Twenty-three randomised controlled trials (RCTs) were identified, of which nine recruited patients with metabolic syndrome or associated conditions with the aim of lifestyle modification. The RCTs did not agree in their conclusions regarding the benefit of using fitness trackers for lifestyle modification. In the remaining 40 studies, 6 were prospective case-control studies, and the remainder were a mix of cohort (21), cross-sectional (8), qualitative (3) and retrospective (2) studies. Fitbit was the commonest device manufacturer, with 27 (42.9%) studies using their products. CONCLUSIONS This review demonstrates the exponential rise of fitness trackers being used in healthcare studies over the last five years, which is likely to continue as fitness trackers and smart-watches offer new healthcare features. Studies reported in this review are of variable quality, and more robust studies to examine the place of fitness trackers in healthcare are necessary – and urgently needed – as their potential to provide objective clinical context is undeniable. CLINICALTRIAL PROSPERO REGISTRATION: CRD42018098993