Six RCTs were included in the review (n=14,055 patients), including 7,078 patients in the low-dose CT groups and 6,977 in the control groups. Sample sizes ranged from 190 to 4,104 patients. Drop-out rates ranged from 0 to 21%.
The detection of stage 1 non-small cell lung cancer was statistically significantly higher in the low-dose CT groups than in the control groups (OR 3.91, 95% CI 2.05 to 7.43; six RCTs), as was the detection of any non-small cell lung cancer (OR 5.51, 95% CI 3.13 to 9.70; six RCTs).
The detection of false-positive nodules was statistically significantly higher in the low-dose CT (OR 3.12, 95% CI 2.62 to 3.72; six RCTs). The odds ratio for rate of thoracotomy for benign lesions was 3.71 (95% CI 3.55 to 3.87; seven comparisons) higher in the low-dose CT groups.
Analysis of the subgroup of three RCTs that used chest x-ray in the control groups did not differ substantially from the results of the main analysis.
The fail safe N was calculated as 14 for the outcome of stage 1 non-small cell lung cancer and 279 for the outcome of thoracotomies for benign lesions.