Although thought to occur frequently, the actual prevalence of polycythemia among patients with COPD and its effect on outcomes in the current treatment environment is unknown. We characterized polycythemia prevalence and its association with outcomes in COPD.
We retrospectively analyzed data collected prospectively on 683 patients between 1/97 and 6/02 in a VA Pulmonary clinic for BMI, airflow obstruction, dyspnea, and exercise capacity (BODE) index validation1. Polycythemia (P+) was defined as Hb≥17 g/dL in men and ≥15 g/dL in women2. All values are expressed as percentages or mean (SD). P values were derived using a 2-sided Student’s t-test or Chi-square statistic where appropriate.
In this sample of 677 patients with known Hb values, polycythemia was present in 36 (5.3%) patients. The Table below compares P+ to non-polycythemic (P-) patients.
Polycythemia is uncommon in COPD, occurring in ∼5% of patients, and is not associated with greater hypoxemia or any other important clinical expression of the disease.
Additional studies are warranted to evaluate the prevalence and effects on outcomes of polycythemia in COPD patients.1Celli BR et al. N Engl J Med 2004;350:1005-12 2Harrison’s online, accessed 11-12-04 http://www3.accessmedicine.com/content.aspx?aID=58150&searchStr=polycythemia.
P+ (n=36)P- (n=641)p ValueHb (g/dL)17.5 (0.8)14.3 (1.5)<0.0001On supplemental O2 (%)31340.62Age (yrs)68.7 (9.5)70.2 (9.0)0.35F/U time (mos)34.3 (20.4)36.7 (22.2)0.52FEV1%42.7 (18.3)42.2 (17.2)0.88Room air PaO2 (torr)70.4 (11.3)72.0 (12.2)0.446MWD (m)339.1 (131.1)313.5 (125.6)0.24MRC dyspnea2.4 (0.8)2.6 (0.9)0.21Charlson co-morbidity4.8 (2.1)5.1 (2.7)0.56BMI (kg/m2)27.8 (4.6)26.4 (6.0)0.16BODE index4.4 (2.4)4.9 (2.5)0.302-year respiratory mortality (%)31270.822-year all-cause mortality (%)36350.93
Claudia Cote, Grant monies (from industry related sources) These analyses were supported by Ortho Biotech Clinical Affairs, LLC.; Employee Marya Zilberberg, MD and Samir H. Mody, PharmD are employees of Ortho Biotech Clinical Affairs, LLC.