Table 1

Patients' background characteristics and main study parameters (N=149)

VariablesPart A (N=100)Part B (N=49)p Value
Boy/girl; N (%)61 (61)/39 (39)24 (49)/25 (51)0.16
Gestational age in weeks+days30+6 (28+5–33+2)30+6 (26+6–33+2)0.26
Birth weight in grams1483 (1158–2015)1280 (888–1950)0.18
Postnatal age in days4 (2–8)5 (2–10)0.11
Time interval in seconds48 (31–79)127 (107–153)<0.001
Non-nutritive sucking; N (%)48 (48)23 (47)0.90
Patients with one dose; N (%)*98 (98%)44 (90%)0.27
Total volume of sucrose in mL0.5 (0.5–0.75)0.5 (0.5–0.75)0.78
Size of the lance: preemie; N (%)/infant; N (%)12 (12)/88 (88)7 (14)/42 (86)0.69
Unable to score nasolabial furrow; N (%)44 (44)30 (61)0.05
Duration of procedure in seconds112 (59–191)154 (97–257)0.014
Number of squeezes17 (8–28)22 (13–36)0.04
Analgesics/sedatives; N (%)†5 (5)5 (10)0.23
PIPP-R6 (0–9)7 (2–9)0.22
  • Data are presented as median (IQR) for all continuous variables. Part A and part B data were compared using the χ2 test for categorical variables and the Mann-Whitney U test for continuous variables.

  • *Patients who received one dose during the total procedure (from sucrose administration until the end of the blood collection).

  • †Patients who received continuous or intermittent morphine/fentanyl and/or midazolam during or <3 hours before the heelstick procedure.

  • PIPP-R, Premature Infant Pain Profile-Revised.