Diagnosis of lower-extremity deep vein thrombosis in outpatients.

BACKGROUND AND PURPOSE Prompt identification of outpatients who may have proximal lower-extremity deep vein thrombosis (PDVT) is important, in part, because of the risk of pulmonary embolism. The purposes of our study were to determine the degree of accuracy of physical therapists' estimates of the probability of PDVT in hypothetical patient vignettes and to determine whether physical therapists would contact the referring physician about the hypothetical patients' condition as recommended in published evidence. SUBJECTS AND METHODS A survey instrument consisting of 6 vignettes was sent to a nationally representative random sample of 1,500 physical therapists. The clinical decision rule developed by Wells and colleagues served as the gold standard for PDVT probability. RESULTS A total of 969 (65% response rate) physical therapists completed the survey. We found no evidence of nonresponse bias. For the 2 high-probability vignettes, 87% and 64% of the physical therapists underestimated the probability of PDVT. For the 2 high-probability cases, 32% and 27% of the physical therapists reported that they would not have contacted the referring physician. For the 2 moderate-probability cases, 15% and 30% of the physical therapists would not have contacted the referring physician. Therapist experience, certification status, place of practice, and region of the country did not explain the findings. DISCUSSION AND CONCLUSION The care of outpatients who are at risk for PDVT could potentially be improved by use of the clinical decision rule developed by Wells and colleagues, although more study is warranted.