Table 1.

Participant details (final sample) at measurement. Mean [standard deviation] Min-max.

	All subjects N = 20	Group Fixed N = 11	Group Jittered N = 9
Gestational age at birth (weeks)	32.1 [0.5]31.3–32.7	32.1 [0.6]31.1–32.7	32.1 [0.4]31.1–32.7
Birth weight (g)	1608 [273]1010–2100	1657 [329]1010–2100	1547 [185]1300–1800
Number of intrauterine growth restriction	7	5	2
Number of males/females	9/11	4/7	5/4
Chronological age at measurement (days)	8.2 [3.1] 3–15	8.5 [3.5]5–15	7.9 [2.9]3–13
Corrected gestational age at measurement (weeks)	33.3 [0.2] 33.0–33.4	33.3 [0.2]33.0–33.4	33.2 [0.2]33.0–33.4
Number of painful events recorded at the first measurement	25.1 [8.6]10–42	24.5 [8.5]10–37	25.9 [9.1]12–42