Table 3.
Needle placement accuracy (in mm)—Summary table of 3D, lateral and depth deviations—By operator.
| Parameter | N | Mean (SD) | Median (Q1 ; Q3) | Min ; max | LSmean [95% upper limit] | P value* | Effect of type of operator | ||
|---|---|---|---|---|---|---|---|---|---|
| 3D deviation (mm) | |||||||||
| Novice operator | 16 | 3.69 (1.31) | 3.40 (2.75 ; 4.95) | 1.50 ; 5.90 | |||||
| Experienced operators | 20 | 3.35 (1.22) | 3.30 (2.60 ; 4.10) | 0.80 ; 5.40 | |||||
| 3.62 [0 ; 4.04] | P = 0.0003 | 0.44 | |||||||
| Lateral deviation (mm) | |||||||||
| Novice operator | 16 | 2.98 (1.25) | 3.40 (1.90 ; 4.00) | 0.70 ; 5.00 | |||||
| Experienced operators | 20 | 2.69 (1.14) | 2.50 (1.80 ; 3.35) | 0.60 ; 5.00 | |||||
| 2.90 [0 ; 3.37] | P ≤ .0001 | 0.57 | |||||||
| Depth deviation (mm) | |||||||||
| Novice operator | 16 | 1.14 (2.40) | 0.90 (-0.05 ; 2.35) | -3.10 ; 6.20 | |||||
| Experienced operators | 20 | 1.02 (1.81) | 1.50 (0.40 ; 2.20) | -3.80 ; 3.30 | |||||
| 1.09 [0 ; 2.00] | P ≤ .0001 | 0.65 | |||||||
Analyses based on last needle insertion measure.
*P value for unilateral testing distance H0: > 5 mm versus H1: ≤ 5 mm.
Least Square (LS) Mean and 95% Confidence Interval (CI) taking into account type of operator in fixed effect, intra-animal and fiducial nested in animal variability structure.