Clinical background of the infants, number of sampling procedures, and number of punctures
| Microlance (n=38) | Tenderfoot preemie (n=32) | t Value | p Value | |
| Gestational age (weeks) | 29 (24–35) | 29 (24–33) | −0.17 | 0.87 |
| Birth weight (g) | 1209 (580–2070) | 1195 (585–2170) | 0.13 | 0.89 |
| Blood sampling/infant (n) | 24 (4–50) | 18 (3–41) | 1.74 | 0.09 |
| Skin punctures/infant (n) | 57 (11–142) | 22 (3–47) | 5.57 | <0.001 |
Values are expressed as mean (range).