A total of 22,264 patients from 86 hospitals were entered into the registry. Patients from 27 hospitals that had participated in the registry <1 year (n = 2,230) and from nine hospitals that contributed fewer than 50 patients with stroke or TIA (n = 413) were excluded. Of the remaining 19,621 patients, 12,263 (62.5%) were diagnosed at discharge with ischemic stroke, 4,038 (20.6%) with TIA, 1,717 (8.7%) with intracerebral hemorrhage, 414 (2.1%) with subarachnoid hemorrhage, and 1,189 (6.1%) with conditions other than stroke. Thus, 50 eligible hospitals contributed 16,301 patients, of whom 12,263 (75.2%) were diagnosed with ischemic stroke and 4038 (24.8%) with TIA. Of these patients, 774 (4.7%) died before discharge from the hospital and were excluded from analyses for which receipt of antithrombotic medication at discharge was the outcome. For receipt of DVT prophylaxis and antithrombotics within 48 hours, no differences were observed between analyses that were inclusive or exclusive of patients who died in hospital. Results are therefore presented for analyses including all patients. The median duration of participation in the registry for these hospitals was 23 months (IQR 16–30). Age, gender, and discharge disposition were similar across years of registry participation. Although academic medical centers contributed more patients in later years (Table ), there was no significant difference in the median time spent in registry between the two groups (22 months for non-academic hospitals compared to 24 months for academic hospitals, p = 0.47).
Demographic Characteristics by Hospital Years in Registry
Receipt of antithrombotic medication within 48 hours of arrival
Overall, 15,181 patients (93.1%) were optimally treated with antithrombotic medications within 48 h of hospital admission. The majority of these (91.8% of all patients) received antithrombotic medication or thrombolysis. Valid contraindications (primarily related to risk of bleeding or terminal illness) were cited for an additional 1.4%, and 6.8% neither received nor had a documented contraindication to antithrombotic treatment. In the first quartile of participation 92.5% were optimally treated. Longer time spent in registry was associated with increased rates of in-hospital antithrombotic use (Figure ; Table ). Time in registry continued to be significantly associated with rates of treatment even when adjusted for calendar year (p = 0.0005, results not shown). In an analysis ignoring contraindications, actual treatment also improved with duration of participation (Table ).
Figure 2 Percentage of patients optimally treated with antithrombotic medications within 48 h (gray hashed line), DVT prophylaxis (black hashed line), or antithrombotic medications at discharge (black solid line) by quarter of participation in the registry. Adherence (more ...)
Duration of Registry Participation as a Predictor of Care
DVT prophylaxis within 48 hours of arrival
Because DVT prophylaxis is generally not necessary in patients diagnosed with TIA, only the 12,263 patients diagnosed with ischemic stroke were included in analyses using optimal treatment for DVT as an outcome. During the period of observation, 10,067 (82.1%) were optimally treated: 5,623 patients (45.9% of all 12,263 patients) who received DVT prophylaxis, and 4,444 (36.2% of all patients) who were documented as not requiring treatment. Thus, 2196 (17.9%) were not treated and had no documented reason for this. In the first three months of registry participation, only 77.1% were optimally treated. Increased duration of participation in registry was associated with higher rates of optimal treatment (Figure ; Table ). In a separate multivariable model including calendar year, duration in registry was marginally significantly associated with increased optimal treatment rates (p = 0.06, results not shown). There was no change in actual receipt of DVT prophylaxis (Table ), so improvement was likely related to either increased early ambulation or improved documentation.
Antithrombotic use at discharge
Overall, 14,151 patients (91.1% of the 15,527 patients who survived to discharge) were optimally treated with antithrombotic medications at discharge, either receiving them (86.8% of 15,527 patients) or having a valid contraindication (4.4%). A total of 1,376 patients (8.9%) did not receive any antithrombotic medication, and had no documented reason for non-treatment. Duration of registry participation was associated with the increased use, increasing steadily from 84.6% in the first three months of participation (Figure ; Table ). This association even persisted in multivariable analysis that adjusted for calendar year (p = 0.01). Ignoring contraindications, actual treatment also increased with duration of participation (Table ).
Because the hospitals that remained in the registry the longest period of time were predominantly academic and this could bias trends, additional analyses were performed excluding academic hospitals. No significant changes in the results were observed (data not shown).