Table 1. Comparison of risk estimators in published cohort studies of cancer risk following computed tomography (CT) in childhood.
| Country (study) | Year | Study population | Risk estimator | Comparison | Leukemia | Brain/CNS tumors | ||
| Cases | Risk estimator [95% CI] | Cases | Risk estimator [95% CI] | |||||
| Great Britain (9) | 2012 | 178 604 | RR | 0–5 versus 50 mGy | 74 | 3.18 [1.46; 6.94] |
135 | 2.82 [1.33; 6.03] |
| Australia (10) | 2013 | 10 939 680 | IRR | CT versus no CT | 211 | 1.23 [1.08; 1.41] |
283 | 2.13 [1.88; 2.41] |
| Taiwan (11) | 2014 | 122 086 | HR | Head CT versus no CT | 17 | 1.9 [0.82; 4.40] |
30 | 2.56 [1.44; 4.45] |
| France (12) | 2015 | 67 274 | RR* | CT versus no CT | 25 | 1.57 [0.21; 2.93] |
27 | 1.22 [0.84; 1.61] |
| Germany (13) | 2015 | 44 584 | SIR | CT versus general population | 12 | 1.72 [0.89; 3.01] |
7 | 1.35 [0.54; 2.78] |
| Great Britain (14) | 2016 | 178 254 | RR* | CT versus no CT | 67 | 1.20 [0.89; 1.89] |
107 | 1.10 [1.02; 1.26] |
*Our calculations (18);
CI, confidence interval; HR, hazard ratio; IRR, incidence rate ratio; RR, relative risk; SIR, standardized incidence ratio