Detecting referral and selection bias by the anonymous linkage of practice, hospital and clinic data using Secure and Private Record Linkage (SAPREL): case study from the evaluation of the Improved Access to Psychological Therapy (IAPT) service

Table 4 Mean deprivation (IMD) score for each study population

	In-depth study cohort	IAPT clinic referral	CMHP	Use hospital services	GP list population
n	166	1,117	12,143	59,903	151,556
Mean IMD score	36.6	38.7	37.6	38.1	38
95% Confidence Intervals	34.2-38.9	37.9-39.6	37.3-37.9	38.0-38.2	38.0-38.1

ISSN: 1472-6947