Table 2.
Association of factors with warfarin prescribing
| Category | Factor | Direction of association (at 95% confidence) 0 = none + = positive - = negative |
Association (multivariate adjusted) (OR, 95% CI) | Endpoint | Study Condition | Study |
|---|---|---|---|---|---|---|
| Admission | Admitted from hospital | + | OR = 1.16 (1.02-1.31) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] |
| 0 | OR = 1.12 (0.97-1.29) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Age | 65-74 | 0 | OR = 0.98 (0.61-1.57) |
use of warfarin | AF | Lau et al. (2004) [10] |
| 75-84 | 0 | OR = 0.98 (0.61-1.58) |
use of warfarin | AF | Lau et al. (2004) [10] | |
| 0 | OR = 1.13 (0.98-1.31) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| 0 | OR = 0.99 (0.94-1.04) |
use of warfarin or antiplatelets | Previous stroke | Quilliam et al. (2001) [12] | ||
| 0 | not reported | use of warfarin | AF | Gurwitz et al. (1997) [8] | ||
| 0 | OR = 1.01 (0.86-1.19) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| ≥ 85 | 0 | OR = 1.13 (0.70-1.82) |
use of warfarin | AF | Lau et al. (2004) [10] | |
| 0 | OR = 1.07 (CI not reported) |
use of warfarin or antiplatelets | Previous stroke | Sloane et al. (2004) [13] | ||
| + | OR = 1.23 (1.05-1.43) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| - | OR = 0.46 (0.22-0.94) |
use of warfarin | AF | Gurwitz et al. (1997) [8] | ||
| - | OR = 0.86 (0.82-0.91) |
use of warfarin or antiplatelets | Previous stroke | Quilliam et al. (2001) [12] | ||
| 0 | OR = 0.86 (0.72-1.04) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Bleeding risk | 1 risk factor | 0 | OR = 0.75 (0.41-1.36) |
use of warfarin | AF | McCormick et al. (2001) [11] |
| ≥ 2 risk factors | - | OR = 0.51 (0.29-0.94) |
use of warfarin | AF | McCormick et al. (2001) [11] | |
| High risk | 0 | OR = 0.82 (0.52-1.30) |
use of warfarin | AF | Lau et al. (2004) [10] | |
| Cognitive impairment | Moderate | - | OR = 0.93 (0.88-0.97) |
use of warfarin or antiplatelets | Previous stroke | Quilliam et al. (2001) [12] |
| 0 | OR = 0.93 (0.81-1.08) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| 0 | OR = 0.98 (0.86-1.12) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Severe | 0 | OR = 1.19 (0.99-1.44) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| - | OR = 0.64 (0.52-0.80) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| - | OR = 0.63 (0.60-0.67) |
use of warfarin or antiplatelets | Previous stroke | Quilliam et al. (2001) [12] | ||
| 0 | OR = 1.02 (CI not reported) |
use of warfarin or antiplatelets | Previous stroke | Sloane et al. (2004) [13] | ||
| Conditions | Active malignancy | 0 | OR = 0.93 (0.57-1.51) |
use of warfarin | AF | Lau et al. (2004)[10] |
| Alzheimer's disease | - | OR = 0.77 (0.70-0.85) |
use of warfarin or antiplatelets | Previous stroke | Quilliam et al. (2001) [12] | |
| Anemia | 0 | OR = 0.87 (0.55-1.39) |
use of warfarin | AF | Lau et al. (2004) [10] | |
| Aneurysms | 0 | OR = 0.88 (0.55-1.40) |
use of warfarin | AF | Lau et al. (2004) [10] | |
| Atrial fibrillation | - | OR = 0.73 (0.64-0.83) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] |
|
| + | OR = 1.76 (1.50-2.06) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| + | OR = 2.04 (1.95-2.14) |
use of warfarin or antiplatelets | Previous stroke | Quilliam et al. (2001) [12] | ||
| Congestive heart failure | 0 | OR = 1.13 (0.98-1.30) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 1.04 (0.65-1.65) |
use of warfarin | AF | Lau et al. (2004) [10] | ||
| 0 | not reported | use of warfarin | AF | Abdel-Latif et al. (2005) [7] | ||
| 0 | OR = 1.02 (0.87-1.20) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Coronary artery disease | + | OR = 1.06 (1.02-1.11) |
use of warfarin or antiplatelets | Previous stroke | Quilliam et al. (2001) [12] | |
| 0 | OR = 0.99 (0.62-1.58) |
use of warfarin | AF | Lau et al. (2004) [10] | ||
| Dementia | - | OR = 0.84 (0.80-0.88) |
use of warfarin or antiplatelets | Previous stroke | Quilliam et al. (2001) [12] | |
| - | OR = 0.59 (0.38-0.90) |
use of warfarin | AF | Gurwitz et al. (1997) [8] | ||
| Depression | + | OR = 1.22 (1.02-1.46) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| + | OR = 1.11 (1.05-1.18) |
use of warfarin or antiplatelets | Previous stroke | Quilliam et al. (2001) [12] | ||
| 0 | OR = 1.08 (0.93-1.24) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Diabetes mellitus | 0 | not reported | use of warfarin | AF | Abdel-Latif et al. (2005) [7] | |
| 0 | OR = 1.17 (0.73-1.86) |
use of warfarin | AF | Lau et al. (2004) [10] | ||
| Hypertension | - | OR = 0.87 (0.78-0.97) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| + | OR = 1.23 (1.09-1.39) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| 0 | OR = 1.10 (0.69-1.75) |
use of warfarin | AF | Lau et al. (2004) [10] | ||
| 0 | not reported | use of warfarin | AF | Abdel-Latif et al. (2005) [7] | ||
| + | OR = 1.27 (1.22-1.32) |
use of warfarin or antiplatelets | Previous stroke | Quilliam et al. (2001) [12] | ||
| Left ventricular dysfunction | 0 | OR = 0.83 (0.63-1.09) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 1.07 (0.88-1.30) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Liver disease | 0 | OR = 1.53 (0.95-2.49) |
use of warfarin | AF | Lau et al. (2004) [10] | |
| Major comorbidity burden | 0 | not reported | use of warfarin | AF | Gurwitz et al. (1997) [8] | |
| Moderate comorbidity burden | 0 | not reported | use of warfarin | AF | Gurwitz et al. (1997) [8] | |
| Multiple conditions (4 or more) | 0 | OR = 0.84 (CI not reported) |
use of warfarin or antiplatelets | Previous stroke | Sloane et al. (2004) [13] | |
| Peptic ulcer disease | 0 | OR = 0.90 (0.57-1.43) |
use of warfarin | AF | Lau et al. (2004) [10] | |
| - | OR = 0.64 (0.58-0.71) |
use of warfarin or antiplatelets | Previous stroke | Quilliam et al. (2001) [12] | ||
| Peripheral vascular disease | + | OR = 1.13 (1.05-1.20) |
use of warfarin or antiplatelets | Previous stroke | Quilliam et al. (2001) [12] | |
| Previous bleeding | 0 | not reported | use of warfarin | AF | Gurwitz et al. (1997) [8] | |
| Previous falls | 0 | not reported | use of warfarin | AF | Gurwitz et al. (1997) [8] | |
| Previous GI bleeding | - | OR = 0.57 (0.52-0.62) |
use of warfarin or antiplatelets | Previous stroke | Quilliam et al. (2001) [12] | |
| - | OR = 0.18 (0.03-0.91) |
use of warfarin | AF | Abdel-Latif et al. (2005) [7] | ||
| Previous major bleeding | 0 | OR = 0.73 (0.46-1.15) |
use of warfarin | AF | Lau et al. (2004) [10] | |
| Previous stroke | + | OR = 4.93 (2.11-11.49) |
use of warfarin | AF | Abdel-Latif et al. (2005) [7] | |
| + | OR = 1.87 (1.20-2.91) |
use of warfarin | AF | Gurwitz et al. (1997) [8] | ||
| Previous stroke or TIA | 0 | OR = 1.24 (0.78-1.97) |
use of warfarin | AF | Lau et al. (2004) [10] | |
| Previous systemic embolus | 0 | OR = 1.46 (0.92-2.34) |
use of warfarin | AF | Lau et al. (2004) [10] | |
| Recent surgery | - | OR = 0.59 (0.37-0.94) |
use of warfarin | AF | Lau et al. (2004) [10] | |
| Renal insufficiency | 0 | OR = 0.91 (0.57-1.45) |
use of warfarin | AF | Lau et al. (2004) [10] | |
| Rheumatic mitral valvular | 0 | OR = 0.80 (0.50-1.28) |
use of warfarin | AF | Lau et al. (2004) [10] | |
| Seizure disorder | 0 | OR = 1.05 (0.66-1.67) |
use of warfarin | AF | Lau et al. (2004) [10] | |
| Transient ischemic attack | + | OR = 1.34 (1.09-1.64) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 0.99 (0.84-1.17) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Drug Interaction | Uses meds that increase bleeding risk | 0 | not reported | use of warfarin | AF | Gurwitz et al. (1997) [8] |
| 0 | OR = 1.26 (0.80-1.98) |
use of warfarin | AF | Lau et al. (2004) [10] | ||
| Duration of AF | 12-24 months | 0 | not reported | use of warfarin | AF | Gurwitz et al. (1997) [8] |
| > 24 months | 0 | not reported | use of warfarin | AF | Gurwitz et al. (1997) [8] | |
| Onset of AF after admission | 0 | not reported | use of warfarin | AF | Gurwitz et al. (1997) [8] | |
| Facility | Alzheimer's unit | 0 | OR = 0.78 (0.57-1.05) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] |
| 0 | OR = 1.14 (0.80-1.62) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Hospital based | 0 | OR = 0.96 (0.72-1.29) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 0.96 (0.75-1.23) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Location rural | 0 | OR = 0.89 (CI not reported) |
use of warfarin or antiplatelets | Previous stroke | Sloane et al. (2004) [13] | |
| Location urban | + | OR = 1.38 (1.16-1.65) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 1.06 (0.87-1.3) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Large new model facility (vs small) | 0 | OR = 0.61 (CI not reported) |
use of warfarin or antiplatelets | Previous stroke | Sloane et al. (2004) [13] | |
| Non-white > 10% (vs > 0% to < 5%) | 0 | OR = 1.09 (0.91-1.32) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| + | OR = 1.22 (1.03-1.43) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Non-white > 5% to < 10% (vs > 0% to < 5%) | 0 | OR = 1.00 (0.81-1.24) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 0.95 (0.78-1.15) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Non-white 0% (vs > 0% to < 5%) | - | OR = 0.74 (0.57-0.96) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 1.17 (0.93-1.46) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Ownership status for profit (vs non-profit) | 0 | OR = 0.90 (0.76-1.07) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 0.90 (0.77-1.05) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Ownership status government (vs non-profit) | 0 | OR = 0.86 (0.64-1.17) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 0.99 (0.76-1.29) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Part of a chain | + | OR = 1.20 (1.01-1.42) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| - | OR = 0.85 (0.73-0.99) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Payment source % Medicaid (per 10 unit increase) | 0 | OR = 0.98 (0.91-1.05) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 0.95 (0.88-1.03) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Payment source % other-pay (per 10 unit increase) | 0 | OR = 0.94 (0.87-1.01) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 0.97 (0.89-1.05) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Presence of a RN/LPN | 0 | OR = 0.74 (CI not reported) |
use of warfarin or antiplatelets | Previous stroke | Sloane et al. (2004) [13] | |
| Size ≤ 80 (vs 81-199) | 0 | OR = 1.01 (0.81-1.26) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 0.92 (0.77-1.11) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Size ≥ 200 (vs 81 to 199) | 0 | OR = 1.17 (0.99-1.39) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 1.08 (0.90-1.30) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Special care unit | 0 | OR = 1.15 (0.83-1.59) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| + | OR = 1.33 (1.02-1.73) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Staff resources any full-time physicians | - | OR = 0.76 (0.63-0.92) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 1.05 (0.89-1.24) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Staff resources (contract) | 0 | OR = 1.04 (0.89-1.20) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 1.02 (0.89-1.17) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Staff resources (physician extenders) | + | OR = 1.21 (1.0-1.47) |
discontinue warfarin or antiplatelets |
Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 1.08 (0.87-1.34) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Traditional facility (vs small) | 0 | OR = 0.78 (CI not reported) |
use of warfarin or antiplatelets | Previous stroke | Sloane et al. (2004) [13] | |
| Weekly physician visits | 0 | OR = 0.94 (CI notreported) |
use of warfarin or antiplatelets | Previous stroke | Sloane et al. (2004) [13] | |
| Gender | Female | 0 | not reported | use of warfarin | AF | Gurwitz et al. (1997) [8] |
| - | OR = 0.94 (0.90-0.98) |
use of warfarin orantiplatelets | Previous stroke | Quilliam et al. (2001) [12] | ||
| 0 | OR = 0.99 (0.87-1.13) |
initiate warfarin orantiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| 0 | OR = 1.00 (0.89-1.13) |
discontinue warfarinor antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| 0 | OR = 0.81 (CI not reported) |
use of warfarin orantiplatelets | Previous stroke | Sloane et al. (2004) [13] | ||
| Physical Function | Substantial mobility | 0 | not reported | use of warfarin | AF | Gurwitz et al. (1997) [8] |
| Mild impairment | 0 | not reported | use of warfarin | AF | Gurwitz et al. (1997) [8] | |
| Intermediate mobility | 0 | not reported | use of warfarin | AF | Gurwitz et al. (1997) [8] | |
| Moderate impairment | 0 | OR = 0.95 (0.75-1.20) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 0.90 (0.70-1.16) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| 0 | not reported | use of warfarin | AF | Gurwitz et al. (1997) [8] |
||
| 0 | OR = 1.03 (0.95-1.11) |
use of warfarin or antiplatelets | Previous stroke | Quilliam et al. (2001) [12] | ||
| Dependent | - | OR = 0.69 (0.64-0.75) |
use of warfarin or antiplatelets | Previous stroke | Quilliam et al. (2001) [12] | |
| - | OR = 0.73 (0.56-0.96) |
initiate warfarin or antiplatelets |
Previous stroke | Hughes et al. (2004) [18] | ||
| 0 | OR = 0.99 (0.79-1.25) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| 0 | OR = 1.21 (CI notreported) |
use of warfarin or antiplatelets | Previous stroke | Sloane et al. (2004) [13] | ||
| Severe impairment | 0 | not reported | use of warfarin | AF | Gurwitz et al. (1997) [8] | |
| Race/ethnicity | American Indian | 0 | OR = 1.00 (0.70-1.43) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] |
| 0 | Difference = -0.8(-8.9 to 7.3) | prevalence difference from non-Hispanic white for receiving warfarin or antiplatelets | Recent ischemic stroke | Christian et al. (2003) [17] | ||
| 0 | OR = 1.47 (0.98-2.20) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Asian/Pacific islander | 0 | Difference = -5.2 (-18.1 to 7.8) |
prevalencedifference from non-Hispanic white for receiving warfarin or antiplatelets | Recentischemicstroke | Christian et al. (2003) [17] | |
| 0 | OR = 0.71 (0.42-1.21) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| - | OR = 0.44 (0.23-0.83) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Black | - | OR = 0.80 (0.75-0.85) |
use of warfarin or antiplatelets | Previous stroke | Quilliam et al. (2001) [12] | |
| Hispanic | 0 | Difference = - 7.6 (-17.6 to 2.2) |
prevalence difference from non-Hispanic white for receiving warfarin or antiplatelets | Recent ischemic stroke |
Christian et al. (2003) [17] | |
| 0 | OR = 0.81 (0.51-1.29) |
initiate warfarin or antiplatelets | Previous stroke |
Hughes et al. (2004) [18] | ||
| 0 | OR = 1.01 (0.62-1.65) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| Non- Hispanic black | - | OR = 0.62 (0.49-0.78) |
initiate warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | |
| 0 | OR = 1.03 (0.86-1.24) |
discontinue warfarin or antiplatelets | Previous stroke | Hughes et al. (2004) [18] | ||
| - | Difference = - 7.6 (-11.2 to -3.9) |
prevalence difference from non-Hispanic white for receiving warfarin or antiplatelets | Recent ischemic stroke | Christian et al. (2003) [17] | ||
| Other | 0 | OR = 0.95 (0.86-1.04) |
use of warfarin or antiplatelets | Previous stroke | Quilliam et al. (2001) [12] | |
| White | 0 | OR = 0.69 (CI not reported) |
use of warfarin or antiplatelets | Previous stroke | Sloane et al. (2004) [13] | |
| Stroke risk | 1 risk factor | 0 | OR = 1.44 (0.52-4.03) |
use of warfarin | AF | McCormick et al. (2001) [11] |
| 2 risk factors | 0 | OR = 2.44 (0.93-6.39) |
use of warfarin | AF | McCormick et al. (2001) [11] | |
| 3 risk factors | 0 | OR = 2.37 (0.90-6.20) |
use of warfarin | AF | McCormick et al. (2001) [11] | |
| ≥ 4 risk factors | 0 | OR = 2.50 (0.90-6.95) |
use of warfarin | AF | McCormick et al. (2001) [11] | |
| High risk | 0 | OR = 1.49 (0.93-2.36) |
use of warfarin | AF | Lau et al. (2004)[10] | |
AF, atrial fibrillation; CI, confidence interval; OR, odds ratio