Introduction: PV is associated with an increased risk of thrombosis, which contributes to morbidity and mortality of patients. Limited data exist on patients with PV among the Veterans Health Administration (VHA) population. The objective of this study is to describe the demographic and clinical characteristics of patients with PV in the VHA population.
Methods: A retrospective, observational analysis was conducted using longitudinal data from the VHA database. The analysis included adult patients who had ≥ 2 claims for PV (ICD-9 238.4) ≥ 30 days apart between 01/01/2007 and 12/31/2009 and ≥ 12 months of continuous enrollment before the first PV claim (index date). Patients were followed from the index date until the earliest date of death, disenrollment, or end of study (9/30/2012). Demographics and comorbid conditions during the pre-index period, and cytoreductive treatments, select laboratory values, thrombotic event (TE) rate, and mortality rate during the follow-up period are reported.
Results: The analysis included 7718 patients with PV; most patients were ≥ 60 years of age (70.7%), male (97.9%), and white (63.9%). The 3 most common comorbid conditions reported during the pre-index period were hypertension (71.7%), dyslipidemia (54.2%), and diabetes (24.0%). Additionally, 8.8% had arterial thrombosis, 4.5% had venous thrombosis, and 8.7% had bleeding. During the follow-up period (median 4.8 years), 23.2% of patients received cytoreductive pharmacotherapy (86.7% hydroxyurea), 32.8% had phlebotomy, and 53.0% had neither cytoreductive therapy nor phlebotomy. 86.4% and 63.3% of patients were using antihypertensive agents and anti-lipid medications, respectively. 86.7% of patients had ≥ 2 elevated HCT levels (≥ 45%) and 37.3% had ≥ 2 elevated WBC counts ( ≥ 11*109/L). 22.9% of patients had ≥ 1 TE (16.5% arterial thrombosis and 8.78% venous thrombosis). The TE rate was 60.5 per 1,000 patient years. Deaths due to any cause were reported for 23.0% of patients during follow-up.
Conclusion: The TE burden is significant among patients with PV in the VHA population. A large proportion of patients had elevated blood values, which may indicate uncontrolled PV, and may predispose patients to greater risk of clinical complications and consequences of PV.