TY - JOUR T1 - Hemoglobin levels above anemia thresholds are maximally predictive for long-term survival in COPD with chronic respiratory failure JF - Respiratory Care DO - 10.4187/respcare.01961 SP - respcare.01961 AU - Florian Kollert AU - Andrea Tippelt AU - Carolin Müller AU - Rudolf A. Jörres AU - Christine Porzelius AU - Michael Pfeifer AU - Stephan Budweiser Y1 - 2012/12/04 UR - http://rc.rcjournal.com/content/early/2012/12/04/respcare.01961.abstract N2 - Background. In patients with COPD, chronic anemia is known as an unfavorable prognostic factor. Whether the association between hemoglobin (Hb) levels and long-term survival is restricted to anemia, or extends to higher Hb levels has not yet been systematically assessed. Methods. We determined Hb levels in 309 patients with COPD and chronic respiratory failure (CRF) prior to initiation of non-invasive ventilation (NIV), accounting for confounders that might affect Hb. Patients were categorized as anemic (Hb<12g/dl (f); Hb<13g/dl (m)), polycythemic (Hb≥15g/dl (f); Hb≥17g/dl (m)), or normocythemic. In addition, percentiles of Hb values were analyzed with regard to mortality from any cause. Results. Two-hundred-seven patients (67.0%) showed normal Hb levels, 46 (14.9%) anemia, and 56 (18.1%) polycythemia. Polycythemic patients showed a higher survival rate than anemic (p=0.01) and normocythemic patients (p=0.043). In a univariate Cox hazards model, Hb was associated with long-term survival (HR 0.855; 95%-CI 0.783-0.934; p<0.001). The 58th percentiles of Hb (14.3g/dl (f); 15.1g/dl (m)) yielded the highest discriminative value for predicting survival (HR 0.462; 95%-CI 0.324-0.661; p<0.001). In the multivariate analysis this cut-off was an independent predictor for survival (HR 0.627; 95%-CI 0.414-0.949; p=0.027), in addition to age and body mass index. Conclusion. In patients with COPD and CRF undergoing treatment with NIV and LTOT, high Hb levels are associated with better long-term survival. The optimal cut-off level for prediction was above the established threshold defining anemia. Thus, predicting survival only on the basis of anemia does not fully utilize the prognostic potential of Hb values in COPD. ER -