Table 3 Interpretation, posttest disease probability estimates and management after receiving abnormal laboratory results.
| Â | Test interpretation | Posttest probability | Management |
|---|---|---|---|
| Â | = normal | = no disease | = no action |
Reason for ordering lab tests | Â | Â | Â |
   reassure patient | 75 (65.8%)* | 90 (76.9%)* | 85 (75.2%)* |
   exclude disease | 220 (50.9%) | 224 (51.1%) | 214 (49.4%) |
   confirm diagnosis | 41 (27.7%) | 34 (23.0%) | 43 (28.9%) |
Pretest probability estimate | Â | Â | Â |
   definitely no disease | 37 (66.1%)* | 48 (84.2%)* | 42 (76.4%)* |
   probably no disease | 139 (67.1%) | 150 (71.8%) | 137 (66.8%) |
   maybe | 95 (45.2%) | 101 (47.6%) | 91 (43.1%) |
   probably disease | 55 (31.4%) | 43 (24.0%) | 58 (32.8%) |
   definitely disease | 9 (19.6%) | 6 (13.0%) | 14 (29.8%) |