Drip-and-Ship Thrombolytic Treatment Paradigm Among Acute Ischemic Stroke Patients in the United States
Background and Purpose—To provide a national assessment of thrombolytic administration using drip-and-ship treatment paradigm.
Methods—Patients treated with the drip-and-ship paradigm among all acute ischemic stroke patients treated with thrombolytic treatment were identified within the Nationwide Inpatient Sample. Thrombolytic utilization, patterns of referral, comparative in-hospital outcomes, and hospitalization charges related to drip-and-ship paradigm were determined. All the in-hospital outcomes were analyzed after adjusting for potential confounders using multivariate analysis.
Results—Of the 22 243 ischemic stroke patients who received thrombolytic treatment, 4474 patients (17%) were treated using drip-and-ship paradigm. Of these 4474 patients, 81% were referred to urban teaching hospitals for additional care, and 7% of them received follow-up endovascular treatment. States with a higher proportion of patients treated using the drip-and-ship paradigm had higher rates of overall thrombolytic utilization (5.4% versus 3.3%; P<0.001). The rate of home discharge/self-care was significantly higher in patients treated with drip-and-ship paradigm compared with those who received thrombolytics through primary emergency department arrival in the multivariate analysis (OR, 1.198; 95% CI, 1.019–1.409; P=0.0286).
Conclusions—One of every 6 thrombolytic-treated patients in United States is treated using drip-and-ship paradigm. States with the highest proportion of drip-and-ship cases were also the states with the highest thrombolytic utilization.
Drip-and-ship acute ischemic stroke treatment paradigm has been evaluated in multiple single centers and regional studies.1,2,3 The paradigm consists of initiating intravenous recombinant tissue-type plasminogen activator (rt-PA ) infusion at smaller community and rural hospitals and then transporting patients to established stroke centers within 24 hours for postthrombolytic care. A population-based study ascertaining the utilization and impact of a drip-and-ship paradigm that reflects the heterogeneity of implementation by various practices and is derived from various racial/ethnic and socioeconomic population groups is not available.
We used data from the Nationwide Inpatient Sample files from October 2008 to December 2009 (http://www.hcup-us.ahrq.gov). Patients admitted with acute ischemic stroke were identified using the primary International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis codes 434.01, 434.11, and 434.91. Procedure code 99.10 and diagnosis code V45.88 were used to identify patients who received thrombolytic treatment and those treated using drip-and-ship paradigm, respectively. About 3% of all thrombolytic-treated patients (688/22 243) who erroneously received both 99.10 and V45.88 codes were labeled as drip-and-ship patients. Endovascular treatment was identified using the Medicare Severity-Diagnosis Related Group (codes 23 and 24, excluding craniotomy code 01.12). Our analysis focused on the postdiagnosis code V45.88, approved by the Centers for Medicare and Medicaid Services on October 1, 2008.4 Discharge destinations were divided into home discharge/self-care (favorable outcome), home health care, short-term care facility (including inpatient rehabilitation), long-term nursing facility, and in-hospital death. Thrombolytic utilization per state and patterns of referral (final destination of urban teaching hospital) were determined in patients treated using the drip-and-ship paradigm.
SAS 9.1 software (SAS Institute, Inc) was used to provide weighted national estimates. Logistic regression analysis was used to examine the impact of drip-and-ship paradigm on clinical outcome of patients after adjusting for potential confounders.
The overall utilization rate of thrombolytic treatment was 4.3% among 623 958 acute ischemic stroke patients admitted during the 14-month period. Of 22 243 patients who received thrombolytic treatment, 4474 patients (17%) were treated using the drip-and-ship paradigm. Of these 4474 patients, 81% were referred to urban teaching hospitals for additional care, and 7% of them received follow-up endovascular treatment. The rates of thrombolytic treatment for primary emergency department arrival and drip-and-ship paradigm within the United States ranged from 1.07% to 7.13%, and 0% to 3.69%, respectively. States in the upper quartile for high drip-and-ship utilization had higher rates of thrombolytic utilization compared with those in the lower quartile (5.4% versus 3.3%; P<0.001; Figure). Patients treated with drip-and-ship paradigm were more likely to be admitted to teaching hospitals (81.5% versus 61.1%; P<0.0001). Drip-and-ship paradigm was associated with shorter hospital stay (mean [days, 95% CI]: 5.7 [5.4–6.2] versus 7.4 [7.1–7.7]; P<0.001), and lower hospitalization charges (mean total charges [$, 95% CI]: 54 115 [47 808–60 421] versus 80 243 [73 323–87 162]; P<0.001), lower rates of in-hospital complications (pneumonia and urinary tract infection, 2.6% versus 5.1%; P=0.0003, and 10.8% versus 14.1%; P=0.0081, respectively; Table 1). After adjusting for age, sex, presence of hypertension, diabetes mellitus, renal failure, congestive heart failure, and hospital teaching status, the rate of home discharge/self-care was significantly higher in patients treated with the drip-and-ship paradigm compared with those who received thrombolytics through primary emergency department arrival in the multivariate analysis (OR, 1.198; 95% CI, 1.019–1.409; P=0.0286; Table 2).
Drip-and-ship paradigm was used in 17% of all patients treated with intravenous rt-PA for acute ischemic stroke, and 81% of those were transferred to an urban teaching hospital. There was variability in rates of utilization among states,5–8 and states with the highest proportion of drip-and-ship cases were also the states with the highest overall thrombolytic utilization (Figure 1). Whether this association reflects a cause-and-effect relationship or merely a marker of more developed stroke systems needs to be studied. The overall impact of the drip-and-ship paradigm may appear modest, as it was only utilized in 17% of all rt-PA-treated stroke patients.
We observed that patients treated with the drip-and-ship paradigm had significantly higher rates of home discharge/self-care compared with patients treated with intravenous rt-PA through primary emergency department arrival. Whereas baseline stroke severity measures (eg, admission National Institutes of Health Stroke Scale) for adjusted comparison are not available, lower rates of hospital complications (pneumonia and urinary tract infection), and mechanical ventilation (Table 1) suggest that drip-and-ship patients have a lower severity of deficits consistent with findings of Get With the Guidelines-Stroke analysis.8 The exact interpretation of lower hospitalization charges associated with the drip-and-ship paradigm is also confounded by differences in patient characteristics and pharmacy cost of rt-PA.
Although the sensitivity of V45.88 for ascertaining the use of drip-and-ship is high9 in selected centers, the variation in sensitivity rates among numerous sites may impact and underestimate utilization rates.
One issue that we are unable to answer is the impact of the drip-and-ship paradigm on door-to-needle time, and whether reduction in transport time is offset by relatively slower response time within the emergency department of the referring facility.
Higher rates of implementation of the drip-and-ship paradigm were associated with higher rate of overall thrombolytic utilization and final admission to urban teaching hospitals, supporting the role of this paradigm as an important strategy to improve the national rate and postadministration care of intravenous rt-PA utilization.
Sources of Funding
Dr. Qureshi has received funding from the National Institute of Health RO1-NS44976-01A2 (medication provided by ESP Parma), American Heart Associated Established Investigator Award 0840053N, National Institute of Health U01-NS062091-01A2, and the Minnesota Medical Foundation, Minneapolis, MN.
- Received March 16, 2012.
- Accepted April 11, 2012.
- © 2012 American Heart Association, Inc.
- Rymer MM,
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