Table 2. Multivariate Analysis of Predictors of Avoidable Imaging (AI) for Pulmonary Embolism in Patients With Low Pretest Probability.
| Characteristic | OR (95% CI)a | ||
|---|---|---|---|
|
| |||
| All AI | AI Owing to No D-Dimer Test Done | AI Owing to Negative D-Dimer Test Results | |
| Patients, No. | 1205 | 811 | 394 |
| Age, by decade, y | |||
| <30 | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| 30-40 | 1.15 (0.90-1.48) | 1.16 (0.85-1.58) | 1.09 (0.74-1.61) |
| 41-50 | 1.60 (1.25-2.05) | 1.51 (1.11-2.05)b | 1.54 (1.06-2.24) |
| 51-60 | 1.60 (1.24-2.08)b | 1.56 (1.14-2.16)b | 1.48 (0.99-2.18) |
| 61-70 | 1.54 (1.16-2.04)b | 1.69 (1.20-2.37)b | 1.20 (0.77-1.87) |
| 71-80 | 1.77 (1.31-2.42)b | 2.36 (1.65-3.37)b | 0.77 (0.45-1.35) |
| >80 | 1.54 (1.09-2.17)b | 2.27 (1.54-3.36)b | 0.45 (0.21-0.95) |
| Race/ethnicity | |||
| White | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Black | 0.83 (0.70-0.97) | 0.83 (0.69-1.01) | 0.84 (0.66-1.07) |
| Hispanic | 0.88 (0.67-1.17) | 0.86 (0.62-1.19) | 0.99 (0.63-1.55) |
| Other | 0.69 (0.45-1.06) | 0.73 (0.44-1.21) | 0.68 (0.34-1.36) |
| Immobility | |||
| No immobility | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Generalized | 0.52 (0.37-0.72) | 0.54 (0.37-0.79) | 0.56 (0.31-1.02) |
| Limb | 0.45 (0.24-0.83) | 0.62 (0.32-1.21) | 0.15 (0.02-1.06) |
| Neurological | 0.75 (0.31-1.83) | 1.41 (0.56-3.58) | NP |
| Cancer | |||
| No cancer history | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Active cancerc | 0.67 (0.51-0.89) | 0.86 (0.64-1.16) | 0.33 (0.17-0.65) |
| Inactive cancer | 1.48 (1.13-1.95)b | 1.31 (0.95-1.80) | 1.66 (1.11-2.49)b |
| Surgery | |||
| No surgery | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Abdominal | 0.91 (0.59-1.39) | 1.15 (0.73-1.82) | 0.44 (0.16-1.20) |
| Chest | 0.85 (0.46-1.56) | 0.95 (0.49-1.84) | 0.57 (0.14-2.35) |
| Orthopedic | 1.08 (0.62-1.88) | 1.50 (0.82-2.72) | 0.21 (0.03-1.57) |
| Other | 1.03 (0.29-3.56) | 0.68 (0.08-5.44) | 1.44 (0.32-6.51) |
| Warfarin use | 0.81 (0.59-1.17) | 0.79 (0.55-1.14) | 0.89 (0.52-1.54) |
| Pregnancy | 1.36 (0.94-1.98) | 1.96 (1.29-2.99)b | 0.54 (0.24-1.19) |
| Sickle cell disease | 2.07 (0.84-5.12) | 4.84 (1.81-12.95)b | NP |
| Connective tissue disease | |||
| No CTD | 1 [Reference] | 1 [Reference] | 1 [Reference] |
| Lupus | 1.44 (0.86-2.40) | 1.61 (0.91-2.85) | 1.06 (0.45-2.47) |
| Rheumatoid | 0.87 (0.53-1.43) | 0.91 (0.51-1.62) | 0.88 (0.38-2.04) |
| Other CTD | 1.40 (0.62-3.16) | 1.26 (0.47-3.39) | 1.33 (0.40-4.48) |
Abbreviations: CTD, connective tissue disease; NP, no patients in these categories; OR, odds ratio.
a
Low pretest probability is consistent with the definition used in the NQF-endorsed measure (Wells score <2)
b
Statistically significant based on 95% CIs not crossing unity.
c
Active cancer includes malignant disease being actively treated or palliated