Innovative use of quality-of-life data: Correlating physiologic parameters with patient-centered symptoms - The example of anemia on the vitality of surgical oncology patients

Background: It has been difficult to correlate quality of life with physiologic parameters. This may be because of the multitude of factors that lead to a symptom. An example of a cause of fatigue, lassitude, and lack of vitality is anemia. This study explores whether a generic quality-of-life instrument's measure of vitality is correlated with anemia. Methods: Surgical oncology patients were asked to complete the SF-36. One of the domains is vitality (VT), which is a measure of fatigue (best possible score 100, worst possible score 0). Hemoglobin (Hb, gm/dL) and hematocrit (Hct, %) levels from the same period were recorded. Results: A total of 319 patients were assessed, 114 postoperative patients with no evidence of disease (NED) and 205 patients with active disease, There were no differences in Hb or Hct levels, but VT was slightly higher in NED patients. Linear regression analysis demonstrated that for overall VT, VT in patients with active malignant disease, and VT in NED patients the regression slopes were statistically significantly different from 0, although the regression coefficients (r) were all less than .5. Conclusions: There are direct correlations between Hb and Hct levels and the VT domain of the SF-36. This correlation was stronger in NED patients. The low r(2) values reflect that anemia is one of many factors affecting VT.