Representativeness in health research studies: an audit of Greater Manchester Clinical Research Network studies between 2016 and 2021

Table 3 The variation in sample characteristics as the sampling strategy becomes less biased

Unbiased estimates	Age		Women		Ethnic minority group		Smoking^a
Unbiased estimates	Eligible N	Mean	Eligible N	%	Eligible N	%	Eligible N	%
Age	16,909	58.4	16,909	65.4	9037	6.2	9307	34.2
Age + sex	11,476	60.2	11,475	49.8	5307	6.8	6026	48.0
Age + sex + ethnicity	5218	64.8	5218	43.5	5218	6.3	2956	65.7

ISSN: 1741-7015