Understanding the experiences of adults with spinal muscular atrophy & their transition to an adult program: A mixed methods study.

Cancer-related fatigue (CRF) is consistently reported as one of the most common and debilitating symptoms of cancer and its treatment (; ). CRF is often present at diagnosis, intensifies during treatment, and persists for years beyond treatment completion (). CRF contributes to increased mortality, poor treatment adherence and efficacy, increased healthcare utilization, financial burdens, and impaired health-related quality of life (; ; ; ). The complex and multifactorial nature of CRF makes it a challenging symptom to assess and diagnose, often resulting in insufficient treatment. Contributing to the complexity of CRF is its multidimensional nature. There is general agreement that CRF consists of at least two dimensions (physical, cognitive), with the exact number of dimensions remaining equivocal (). The multidimensionality of CRF is widely accepted as evidenced by patient self-report and the existence of numerous multidimensional questionnaires (; ). Notably the strongest support for the multidimensionality of CRF stems from the most widely cited definition for CRF stating it is “…a subjective sense of physical, emotional, and/or cognitive tiredness or exhaustion related to cancer or cancer treatment that is not proportional to recent activity and interferes with usual functioning” (; ). Although there is common acceptance of CRF as multidimensional, there is limited evidence exploring the individual dimensions of CRF and unique correlates that may contribute to each dimension. A better understanding of the multidimensionality of CRF can aid in improving its assessment, diagnosis, and management. While several studies have examined mechanisms underlying different dimensions of CRF, the evidence base is still nascent especially for men with prostate cancer. Some studies noted differences in intensities and longitudinal trajectories among different CRF dimensions across disease and/or treatment trajectories, providing initial evidence supporting differences among the dimensions (; ; ; ). Studies also have begun to examine correlates among the various dimensions of CRF, but none were exclusively conducted in men with prostate cancer. The most common correlates are sociodemographic, clinical, and co-occurring physical (e.g., sleep) and psychosocial (e.g., anxiety, depression) symptoms. Fewer studies have examined biological correlates for the different dimensions of CRF. Inflammatory cytokines were the most common biomarker across studies and were often observed to be associated with the physical dimension of CRF. Notably, comparisons among studies are challenging due to heterogeneity in study design including the use of various multidimensional questionnaires, resulting in examination of different CRF dimensions and inconsistencies with chosen correlates. Additionally, most studies were either cross-sectional or had limited follow-up and were conducted in women with breast cancer.