Exercise interventions for patients with advanced cancer: A systematic review of recruitment, attrition, and exercise adherence rates

Abstract

Patients with advanced cancer can experience debilitating physical symptoms, making participation in exercise programs difficult. This systematic review investigated the recruitment, adherence, and attrition rates of patients with advanced cancer participating in exercise interventions and examined components of exercise programs that may affect these rates. Relevant studies were identified in a systematic search of CINAHL, PubMed, PsycINFO, and EMBASE to December 2017. Two quality assessment tools were used, and levels of evidence were assigned according to the Oxford Centre for Evidence-Based Medicine (CEBM) guidelines. The search identified 18 studies published between 2004 and 2017. Recruitment, adherence, and attrition rates varied widely among the studies reviewed. The mean recruitment rate was 49% (standard deviation [SD] = 17; range 15-74%). Patient-reported barriers to recruitment included time constraints and difficulties in traveling to exercise centers. Levels of adherence ranged from 44% to 95%; however, the definition of adherence varied substantially among trials. The average attrition rate was 24% (SD = 8; range 10-42%), with progression of disease status reported as the main cause for dropout during exercise interventions. Concentrated efforts are needed to increase the numbers of patients with advanced disease recruited to exercise programs. Broadening the eligibility criteria for exercise interventions may improve accrual numbers of patients with advanced cancer to exercise trials and ensure patients recruited are representative of clinical practice.