Grutsch et al. BMC Cancer 2011, 11:193 http://www.biomedcentral.com/1471-2407/11/193 Page 10 of 13 Figure 3 The relationships among two measures of quality of life and circadian rhythm stability. The greater the circadian rhythm in activity/rest, the greater the PF Health and Functioning; the lower the EORTC Fatigue Score (A) and the greater the EORTC Global Health Score (C) in the group as a whole. These relationships are especially clear among outpatients (B, D). *Significant r, p < 0.05. †Marginal r, p=0.08. Among outpatients, whose daytime activity levels were expectedly higher than inpatients, there were many clinically relevant and statistically significant associations between most parameters of circadian organization and cancer associated daytime fatigue that were masked, weakened or lost among inpatients. We conclude that all future studies of cancer-related quality of life and cir- cadian organization should best be done in the patient’s home, not in the hospital. All Ferrans-Powers QLI domains, except Family, which had one statistically significant relationship, had multiple strong statistically significant relationships with cosinor and actigraphy parameters of circadian organiza- tion. Because of this sensitivity and relevance, we believe that future work should employ the Powers and Ferrans scales in addition to any other quality of life scales. Superficially, advanced lung cancer patients appear to be suffering from non-resolving jet lag; disturbed as well as diminished non-restorative sleep; and excessive day- time sleepiness and nighttime wakefulness, daytime fati- gue, problems with concentration and memory during the day, and loss of appetite, especially during the sec- ond half of the waking hours. We found many strong correlations between all Ferrans-Powers QLI domains of each individual and most parameters of that individual’s circadian organization. Apparently a decaying circadian organization affects a patient’s perception of their health and emotional/psychological well being before it actually reduces his/her capacity to fulfill these activities of nor- mal life. This finding of the possible premonitory value of circadian status deserves careful additional quality of life study. There are several limitations in this study. Our sample size may not be large enough to accommodate the num- ber of comparisons made within this study. We una- voidably lacked, by virtue of the nature of our oncology