Our findings provide preliminary evidence that palliative care consultation for fatigue for advanced cancer patients seen at an outpatient palliative care clinic in a comprehensive cancer center was associated with improvement of fatigue at the time of the first follow-up visit.
Moderate to severe fatigue was common (84%) in the patients we evaluated. Severity of fatigue at the time of consultation significantly correlated with all ESAS items, with pain and appetite having the strongest associations. These findings are consistent with those from previous studies
One of the strengths of this study, despite its retrospective design, is that the fatigue assessment was performed prospectively at both the initial and subsequent follow-up visits using validated tools in a dedicated outpatient palliative care clinic. The fatigue assessment was completed by the patients under the supervision of nurses trained specifically in palliative care, and standardized management was provided by a specialist-led palliative care team in accordance with our institutional protocol based on the findings from previous fatigue assessments
. Moreover, this study differed from earlier studies in its relatively large population sample size of over 1700 patients and its focus on factors associated with improvement in fatigue after an outpatient palliative care consultation. Thus, our findings provide preliminary reference data about the effectiveness of outpatient palliative care when standard palliative care is applied to patients with fatigue.
We found that the severity levels of pain, depression, appetite, nausea, drowsiness, well-being, and shortness of breath and albumin level were predictive of the severity of fatigue at the time of the initial consultation. This information emphasizes the importance of thorough serial assessment of all cancer-related symptoms for optimal management of fatigue. Future prospective trials are needed, and fatigue interventions should incorporate a multimodal interdisciplinary approach with targets including the treatment of fatigue-related symptoms such as pain, low appetite, and depression in addition to specific pharmacological interventions for fatigue. These results are consistent with prior studies by Hwang et al
, who found that shortness of breath, pain, lack of appetite, drowsiness, sadness, and irritability predicted fatigue. However, female gender and low hemoglobin levels, which prior studies have found to be predictive of severity of fatigue
[24–26], were not associated with fatigue in our study. This result could be due to the overwhelmingly high symptom burden in our patient population, which may reduce the role of factors such as anemia
We also found that severe anorexia at the initial visit to the palliative care clinic was associated with improvement of fatigue. This may be due to a strong association of fatigue with anorexia and cachexia, as both of which may be caused by the same pathophysiologic process, namely inflammation
We also found that patients with GU cancers (prostate, renal, and transitional cell cancers) were more likely to improve in fatigue (OR = 1.74 per point, p = 0.045). In patients with prostate cancer, anorexia cachexia is less important contributor to fatigue
. The authors speculate that fatigue as a result of androgen deprivation in prostate cancer patients may be more amenable to palliative interventions such as exercise
[33, 34]. However, further studies are needed to understand this result.
The results of his study suggest that the changes in the fatigue scores were positively associated with the changes in the severity of other ESAS symptoms; these finding would strongly imply a causal relation between symptom load and fatigue.
Though the results of this study show preliminary evidence that palliative care consultation was successful in reducing the severity of fatigue, our model did not capture all the factors associated with improvement of fatigue, as indicated by adjusted r2 of 0.33. Further studies are needed.
The results show that the severity of fatigue and other ESAS symptoms in patients who did not have a follow-up visit (excluded patients) were milder than in those who had at least one follow-up visit (the study sample) (Table
3). This analysis validates that the results are a good representation of the patients seen in outpatient palliative care.
Our study has several limitations, the most important of which was the retrospective design and its lack of patients in the setting other than an outpatient palliative care clinic. Another limitation is the use of single item measure to assess physical and emotional symptoms using ESAS. However prior studies have shown that ESAS items and other single item questionnaires correlate well with multi-item symptom assessment tools
[22, 35–38]. Although in the vast majority cases patient complete the ESAS by themselves in outpatient setting there is a possibility that in the most fatigued patients the nurse or caregiver could have introduced the bias by assisting the patient. More research is necessary to address this possibility. This study also did not assess other well-known factors that may contribute to fatigue such as inflammatory biomarkers, which play an important role in fatigue causation
[32, 39, 40]. Some of the statistically significant associations in this study may be as a result of multiple analysis. Future prospective studies are needed to confirm these findings.