Recruitment rates and strategies in exercise trials in cancer survivorship: a systematic review

Purpose Despite clear evidence-based supporting a benefit to exercise on physical and psychological metrics in patients with cancer, recruitment to exercise trials amongst cancer survivors is suboptimal. We explore current recruitment rates, strategies, and common barriers to participation in exercise oncology trials in cancer survivorship. Methods A systematic review was conducted using a pre-defined search strategy in EMBASE, CINAHL, Medline, Cochrane Library, and Web of Science. The search was performed up to 28/02/2022. Screening of titles and abstracts, full-text review, and data extraction was completed in duplicate. Results Of the 3204 identified studies, 87 papers corresponding to 86 trials were included. Recruitment rates were highly variable with a median rate of 38% (range 0.52–100%). Trials recruiting prostate cancer patients only had the highest median recruitment rate (45.9%) vs trials recruiting colorectal cancer patients only which had the lowest (31.25%). Active recruitment strategies such as direct recruitment via a healthcare professional were associated with higher recruitment rates (rho = 0.201, p = 0.064). Common reasons for non-participation included lack of interest (46.51%, n (number of studies) = 40); distance and transport (45.3%, n = 39); and failure to contact (44.2%, n = 38). Conclusions Recruitment of cancer survivors to exercise interventions is suboptimal with barriers being predominantly patient-oriented. This paper provides the benchmark for current recruitment rates to exercise oncology trials, providing data for trialists planning future trial design and implementation, optimise future recruitment strategies, and evaluate their own recruitment success against current practice. Implications for Cancer Survivors Enhanced recruitment to cancer survivorship exercise trials is necessary in facilitating the publication of definitive exercise guidelines, generalisable to varying cancer cohorts. PROSPERO registration number CRD42020185968.