Table 1.

Sociodemographic and clinical characteristics of the n=1153 individuals in NDTMS linked to Hospital Episode Statistics Admitted Patient Care (HES APC) using National Health Service (NHS) number characterised as either linked or non-linked to HES APC using the four-stage algorithm

		Linked pairs n (%)	Non-linked residuals n (%)	OR (95% CI) for positive linkage	P value	aOR† (95% CI) for positive linkage	P value
All	All	951 (82.5)	202 (17.5)	–	–	–	–
Sociodemographic	Sex
	Female	320 (86.5)	50 (13.5)	Reference		Reference
	Male	631 (80.6)	152 (19.4)	0.66 (0.46 to 0.95)	0.03*	0.48 (0.30 to 0.79)	0.003*
	Age in years (at presentation to D&A services)
	18–30	97 (81.5)	22 (18.5)	Reference		Reference
	31–45	497 (79.1)	131 (20.9)	0.79 (0.46 to 1.36)	0.40	1.10 (0.56 to 2.19)	0.78
	46–60	336 (87.7)	47 (12.3)	1.53 (0.85 to 2.76)	0.16	2.28 (1.08 to 4.82)	0.03*
	60+	21 (91.3)	2 (8.7)	1.62 (0.34 to 7.83)	0.55	1.79 (0.33 to 9.62)	0.50
	Deprivation (IMD) quintile
	First (most deprived)	328 (81.6)	74 (18.4)	Reference		Reference
	Second	275 (85.1)	48 (14.9)	0.96 (0.62 to 1.49)	0.87	0.81 (0.50 to 1.32)	0.40
	Third	210 (90.5)	22 (9.5)	1.38 (0.77 to 2.47)	0.28	1.04 (0.55 to 1.98)	0.90
	Fourth	89 (89.9)	10 (10.1)	1.07 (0.49 to 2.34)	0.87	1.22 (0.46 to 3.23)	0.69
	Fifth (least deprived)	17 (85.0)	3 (15.0)	1.14 (0.30 to 4.30)	0.85	0.49 (0.12 to 1.99)	0.32
	Residential status‡
	Non-NFA postcode	913 (81.9)	202 (18.1)	Reference		Reference
	NFA postcode	38 (100.0)	0 (0.0)	–	–	–	–
	Ethnicity§
	White	840 (88.9)	105 (11.1)	Reference		Reference
	Non-white	80 (73.4)	29 (26.6)	0.42 (0.24 to 0.71)	<0.001*	0.35 (0.20 to 0.63)	<0.001*
Clinical	Substance misuse¶
	Opioid	503 (77.3)	148 (22.7)	Reference		Reference
	Alcohol only	311 (90.7)	32 (9.3)	2.41 (1.57 to 3.68)	<0.001*	1.57 (0.95 to 2.61)	0.08
	Non-opioid and alcohol	75 (91.5)	7 (8.5)	2.16 (0.95 to 0.4.93)	0.07	2.03 (0.76 to 5.44)	0.16
	Non-opioid only	62 (80.5)	15 (19.5)	1.12 (0.59 to 2.12)	0.73	0.98 (0.44 to 2.18)	0.96

*p<0.05.

†Adjusted for all other covariates listed in table.

‡Residential status was omitted from the model as all people with an NFA postcode were linked.

§Office of Population Censuses and Surveys (OPCS) categories A, B and C collapsed as white, all other OPCS categories (D–S) collapsed as non-white.

¶NDTMS categorisation opioid: clients with any mention of opioid use in any treatment episode during the year irrespective of other substances cited; alcohol only: clients who present with problems related to alcohol but no other substances; non-opioid and alcohol: clients with non-opioid drug and alcohol use problems (but not opioids) recorded in any treatment episode during the year; non-opioid only: clients who present for treatment related to non-opioid drug use but not opioids or alcohol.

aOR, Adjusted OR; D&A, Drug and Alcohol; IMD, Index of Multiple Deprivation; NDTMS, National Drug Treatment Monitoring System; NFA, no fixed abode.