Deep Vein Thrombosis Prophylaxis in Medicare Patients with Ischemic Stroke: Results from the National Stroke Project
Background: Patients with ischemic stroke (IS) often have impaired mobility that can increase their risk of deep vein thrombosis (DVT). Current guidelines recommend prophylactic treatment for DVT in immobile IS patients. As part of HCFA’s National Stroke Project, we examined national patterns of DVT prophylaxis for Medicare patients hospitalized with IS. Methods: Project data were abstracted from a national sample of Medicare inpatient charts (discharge dates 4/98 - 3/99). All U.S. states, the District of Columbia and Puerto Rico were sampled using a systematic random approach. All medical records had a principal diagnosis of one of the following ICD-9-CM codes: 362.34, 433.xx, 434.xx, 435.0, 435.1, 435.3, 435.8, 435.9 or 436. Eligible cases had a confirmed diagnosis of IS and were non-ambulatory on the second hospital day. For DVT prophylaxis, we included the administration of warfarin or heparin (including low molecular weight), or the use of an intermittent pneumatic compression device (IPCD). Results: Of the 36,650 cases reviewed, 3,500 met the inclusion criteria. Nationwide, 694 (unadjusted rate 19.8%) had DVT prophylaxis initiated by the second hospital day. The data show that 75 (10.8%) patients utilized an IPCD, 602 (86.7%) were given warfarin, 36 (5.2%) received heparin and 19 (2.7%) utilized more than one form of DVT prophylaxis. Of the patients receiving warfarin for DVT prophylaxis, 263 (43.7%) were on warfarin prior to arrival. The state-specific rates of DVT prophylaxis utilization ranged from 7.8% to 33.3% (chi-square, p<0.001). Univariate analyses showed that DVT prophylaxis was utilized less frequently (p<0.002) for adults 85 years and over (rate=16.2%, OR=0.72, 95% CI=0.59–0.88) and African-Americans (rate=14.6%, OR=0.65, 95% CI=0.50–0.85). Conclusions: For non-ambulatory Medicare patients with IS, recommended prophylaxis for DVT is not given in the majority of cases. There is a large opportunity to improve this aspect of IS care and to reduce DVT as a complication of IS for non-ambulatory patients.