Labour Q1 pain – poorly analysed and reported: a systematic review

Table 2 Repeated measures designs in 133 labour pain studies

		Number	Percent (%)
Study Design	Experiment - randomised	116	87.2
	Experiment - not randomised	13	9.8
	Observational - Cohort	3	2.3
	Not clear	1	0.8
Number of groups compared	2	96	72.2
	3	24	18.0
	> 4	13	9.8
Total number of women included in analysis	20–30	10	7.5
	31–50	32	24.1
	51–100	55	41.4
	101–500	32	24.1
Pain - number of time points measured	2	14	10.5
	3–5	48	36.1
	6–10	56	42.1
	> 10	15	11.3
Equally spaced time intervals	No	92	69.2
Equally spaced time intervals	Yes	40	30.1
	Not clear	1	0.8
Pain - outcome measure	Primary outcome	11	8.3
	Secondary outcome	4	3.0
	Not explicit	118	88.7
Pain - measurement Instrument^a	VAS (Visual analogue scale)	110	82.7
	NRS (numeric rating scale)	6	4.5
	MPQ, short version	1	0.8
	Verbal rating scale	14	10.5
	Other	2	1.5

^aAnchor labels for the instruments were specified in 65% (67/133)
Illustrative binomial exact 95% confidence intervals for percentages when sample size is 133: 1% (0 to 4%); 5% (2 to 10%); 10%(5 to 16%); 25%(18 to 33%); 50%(40 to 58%); 90(84 to 95%)

ISSN: 1471-2393