ABSTRACT
CONTEXT: Older adults with advanced cancer face uncertainty related to their disease and treatment. OBJECTIVES: To evaluate the associations of uncertainty with psychological health and quality of life (QoL) in older adults with advanced cancer. METHODS: Secondary cross-sectional analysis of baseline data from a national clustered geriatric assessment trial. Patients 70 years and older with advanced cancer considering a new line of chemotherapy were recruited. We measured uncertainty using the modified nine-item Mishel Uncertainty in Illness Scale. Dependent variables included anxiety (Generalized Anxiety Disorder-7), depression (Generalized Depression Scale-15), distress (distress thermometer), QoL (Functional Assessment of Cancer Therapy-General), and emotional well-being (Functional Assessment of Cancer Therapy-General subscale). We used multivariate linear regression analyses to evaluate the association of uncertainty with each dependent variable. We conducted a partial least squares analysis with a variable importance in projection (VIP) plot to assess the contribution of individual variables to the model. Variables with a VIP <0.8 were considered less influential. RESULTS: We included 527 patients (median age 76 years; range 70-96). In multivariate analyses, higher levels of uncertainty were significantly associated with greater anxiety (ß = 0.11; SE = 0.04), depression (ß = 0.09; SE = 0.02), distress (ß = 0.12; SE = 0.02), as well as lower QoL (ß = -1.08; SE = 0.11) and emotional well-being (ß = -0.29; SE = 0.03); the effect sizes were considered small. Uncertainty items related to disease and treatment were most strongly associated with psychological health and QoL scores (all VIP >0.8). CONCLUSION: Uncertainty among older patients with advanced cancer is associated with worse psychological health and QoL. Tailored uncertainty management strategies are warranted.