Table 4

Interactions between differences in analgesic use during daytime and night-time and characteristics of children, centres and procedures in univariate analysis

Factor	Univariate analysis
	Procedures carried out with specific analgesic				Daytime compared with night-time: relative reduction* (%)	Daytime compared with night-time: OR	Interaction test (p Value)†
	Daytime		Night-time
	n/N	%	n/N	%
Day of procedure‡
D1	272/1789	15.2	276/1667	16.6	−8.9	0.90 (0.75–1.09)
D2–D14	3989/17 164	23.2	3187/17 392	18.3	21.2	1.35 (1.28–1.42)	<10.3
Mechanical ventilation
Yes	1668/11 908	14.0	1501/12 327	12.2	13.1	1.18 (1.09–1.27)
No	2593/7045	36.8	1962/6732	29.1	20.8	1.42 (1.32–1.52)	<10.3
Parental presence
Yes	331/1488	22.2	131/485	27.0	−21.4	0.77 (0.61–0.98)
No	3930/17 465	22.5	3332/18 574	17.9	21.0	1.33 (1.26–1.40)	<10.3
Continuous analgesic
Yes	738/6341	11.6	722/6864	10.8	9.6	1.12 (1.01–1.25)
No	3523/12 612	27.9	2741/12 195	22.5	19.5	1.34 (1.26–1.42)	0.005
Surgery
Yes	337/1576	21.4	300/1714	17.5	18.2	1.28 (1.08–1.53)
No	3924/17 377	22.6	3163/17 345	18.2	19.5	1.31 (1.24–1.38)	0.829
Sex
Male	2363/10 758	22.0	1877/10 757	17.4	20.9	1.33 (1.25–1.43)
Female	1898/8198	23.2	1586/8302	19.1	17.6	1.28 (1.18–138)	0.410
Gestational age
≥37 weeks	583/3803	15.3	435/3796	11.5	25.2	1.40 (1.22–1.60)
<37 weeks	3678/15 150	24.3	3028/15 263	19.8	18.3	1.30 (1.23–1.37)	0.295
Nurse shift
3 per day	1634/5995	27.3	1276/5907	21.6	20.7	1.36 (1.25–1.48)
2 per day	2627/12 958	20.3	2187/13 152	16.6	18.0	1.28 (1.20–1.36)	0.230
Nurse rotation
No	1853/7507	24.7	1477/7704	19.2	22.3	1.38 (1.28–1.49)
Yes	2408/11 446	21.0	1986/11 355	17.5	16.9	1.26 (1.18–1.34)	0.068
Pain coordinator
No	502/2844	17.7	368/2933	12.5	28.9	1.49 (1.29–1.73)
Yes	3759/16 109	23.3	3095/16 126	19.2	17.8	1.28 (1.22–1.35)	0.053
Written protocols for sucrose analgesia
Yes	3663/15 325	23.9	3155/15 508	20.3	14.9	1.23 (1.17–1.30)
No	598/3628	16.5	308/3551	8.7	47.4	2.08 (1.80–2.41)	<10-3
Parental presence authorised 24 hours
No	2510/11 949	21.0	2091/12 023	17.4	17.2	1.26 (1.18–1.35)
Yes	1751/7004	25.0	1372/7036	19.5	22.0	1.28 (1.27–1.49)	0.102
Night head nurse
No	2843/12 348	23.0	2399/12 889	18.6	19.2	1.31 (1.23–1.39)
Yes	1418/6605	21.5	1064/6170	17.2	19.7	1.31 (1.20–1.43)	0.955
Teaching status
Minor	1798/7222	24.9	1511/7516	20.1	19.2	1.32 (1.22–1.42)
Major	2463/11 731	21.0	1952/11 543	16.9	19.5	1.31 (1.22–1.40)	0.864

*If positive, analgesia was higher during daytime.
†p Value <0.05 indicates that the factor modified the difference in analgesic use between daytime and night-time in univariate.
‡Related to admission.