The annual incidence of pulmonary nodules is estimated at 1.57 million. Guidelines recommend utilizing an initial assessment of nodule probability for malignancy (pCA). A previous study found that despite this recommendation, physicians did not follow guidelines.
Physician (n= 337) and two previously validated risk model assessment of cancer pre-test probability were evaluated for performance in 337 patients with pulmonary nodules based on final diagnosis and compared. Physician assessed pCA was categorized into low, intermediate and high risk and the next test ordered was evaluated.
The prevalence of malignancy was 47% (n=158) at one year. Physician assessed pCA performed better than nodule prediction calculators (AUC 0.85 vs 0.75, p<0.001 and 0.78, p=0.0001). Physicians did not follow indicated guidelines when selecting the next test in 61% of cases (n=205). Despite recommendations for serial CT imaging in those with low pCA, 52%(n=13) were managed more aggressively with PET imaging or biopsy; 12%(n=3) had biopsy for benign disease. Alternatively, in the high risk category, the majority (n=103, 75%) were managed more conservatively. Stratified by diagnosis, 92% (n=22) with benign disease underwent more conservative management with CT scan (20%), PET scan(15%), or biopsy(8%) though 3(8%) had surgery.
Physician assessment as a means for predicting malignancy in pulmonary nodules is more accurate than previously validated nodule prediction calculators. Despite the accuracy of clinical intuition, physicians did not follow guideline based recommendations when selecting the next diagnostic test. To provide optimal patient care, focus in the areas of guideline refinement, implementation and dissemination is needed.