Table 3. Clinical, therapeutic and technical factors related to the maximum skin dose (mGy) occurring during percutaneous transluminal coronary angioplasties (n=111).
| Factors | Estimations on √(dose) scalea |
Back-transformed coefficients | p-value | |
| Coefficients | 95% CI | |||
| Constant | 37.88 | (27.13, 48.63)c | 397.59 | – |
| BMI (kg m–2) | 1.34 | (0.55, 2.14)c | 2.79 | <0.01 |
| Antecedentb (vs no) | 0.79 | |||
| Yes | 1.07 | (−7.02, 9.16) | 2.36 | |
| Sum of material for dilatation (vs 1–2) | <0.05 | |||
| 3–4 | 4.58 | (−3.98, 13.14) | 10.83 | |
| >4 | 15.72 | (4.97, 26.47)c | 78.51 | |
| Presence of occluded lesion(s) (vs no) | 0.21 | |||
| Yes | 4.28 | (−2.39, 10.95) | 9.85 | |
| Artery approach (vs femoral) | 0.73 | |||
| Radial | −1.33 | (−9.02, 6.36) | −2.77 | |
| Overall fluoroscopy duration (min) | 0.88 | (0.21, 1.55)c | 2.07 | <0.05 |
| Number of cine frames (c100) | 0.82 | (0.17, 1.48)c | 1.99 | <0.05 |
| Practitioners (vs A) | <0.001 | |||
| B | 19.30 | (10.24, 28.36)c | 113.42 | |
| C | 12.42 | (3.94, 20.89)c | 51.95 | |
BMI, body mass index; CI, confidence interval; PTCA, percutaneous transluminal coronary angioplasties.
aBoxcox transformed coefficients (λ=0.5).
bPrevious angioplasty and/or coronary artery bypass surgery.
cConfidence intervals that did not include 0.
95% CI: confidence intervals at a=0.05.
Five PTCAs performed by practitioners (not practitioners A, B or C) were excluded from the analysis. The model was performed at mean values of continuous variables (BMI=27.8 kg m−2, radioscopy duration at 11.1 min and at 914 cine frames), r2=0.602.