Vitality Measured as Self-reported Energy Level and Clinical Outcomes in Hemodialysis Patients: The Japanese Dialysis Outcomes and Practice Pattern Study (J-DOPPS)

Abstract

Rationale & Objective: The infrequent assessment of vitality in clinical practice may be partially due to an inadequate understanding of vitality and the lack of a concise method of assessing it. This study aimed to examine the association of a simple 1-item “vitality” question measuring self-reported energy level with clinical outcomes. Study Design: Prospective cohort study. Setting & Participants: 3,667 hemodialysis patients participating in the Japanese Dialysis Outcomes and Practice Pattern Study (J-DOPPS), phases 3 to 4 (2005-2011). Predictor: Responses to a single question from the 12-item Medical Outcomes Study Short Form survey, version 2.0: “How much time during the past 4 weeks did you have a lot of energy?,” recorded using a 5-level Likert scale. Outcomes: All-cause mortality and a composite of cardiovascular hospitalizations and all-cause mortality. Analytical Approach: A pooled ordered logit model was fit to examine correlates of self-reported energy level. Cox and mixed-effects negative binomial regression models were fit for mortality and the composite outcome. Results: Lower self-reported energy level was associated with tachycardia and use of benzodiazepines, hypnotics, and antidepressants. In contrast, higher energy was associated with higher single-pool Kt/V, serum albumin concentration, and body mass index. Compared to the lowest energy level, the second-highest and middle levels were associated with lower all-cause mortality (adjusted HRs [aHRs] of 0.66 [95% CI, 0.47-0.93] and 0.75 [95% CI, 0.59-0.96], respectively). Each 1-level higher self-reported energy was associated with lower mortality (aHR, 0.86; 95% CI, 0.78-0.96). Associations between self-reported energy level and multiple cardiovascular hospitalizations and mortality were similar to those between self-reported energy and mortality. Limitations: No psychometric assessments were done for the Short Form survey. Conclusions: The response to a single “vitality” question addressing self-reported energy level is associated with adverse clinical outcomes and correlated with potentially modifiable factors.