PTP (Wells Score)
CTPAs
+ve for PE
-ve for PE
Positive predictive value
Total
289
69 (24%)
220 (76%)
23.8%
Low Risk
188
35
153
18.6%
Moderate Risk
64
23
41
35.9%
High Risk
37
12
25
32.4%
< 4 PE Unlikely
238
40
198
16.8%
> 4 PE Likely
51
29
22
56.8%