Table 1.

Baseline characteristics of NHS-DPPD and CPRD practices

Baseline characteristics of practices	NHS-DPPD (n= 6517)	CPRD (n= 587)
List per full-time equivalent GP, mean (SD)	2306.2 (12114.0)	n/a^a
Percentage of patients in London	5.7	12.8
Percentage of patients in North of England	49.7	54.3
Percentage of patients in South of England	44.6	32.9
Practice list size, mean (SD)	7558.0 (4194.8)	7732.2 (3516.3)
Index of Multiple Deprivation 2015 score, mean (SD)	25.9 (17.4)	n/a^a
Adult skills sub-domain deprivation score, mean (SD)	0.3 (0.1)	n/a^a
Health deprivation and disability score, mean (SD)	0.2 (0.9)	n/a^a
Percentage of female patients, mean (SD)	50.0 (2.2)	58.1 (2.1)
Rate of prescribing of other medicines, mean (SD)^b	17 631.3 (5707.8)	16 587.3 (5923.6)
Rate of prescribing of antibiotics, mean (SD)^b	576.1 (148.1)	578.9 (177.4)
Rate of prescribing of non-opioid painkillers, mean (SD)^b	1211.4 (544.4)	1365.7 (611.3)
Rate of prescribing of benzodiazepines, mean (SD)^b	274.8 (162.4)	325.1 (247.1)

↵a n/a means the dataset does not have the variable.
↵b Rate per 1000 patients per year. CPRD = Clinical Practice Research Datalink. DPPD = digital practice prescribing data. n/a = not applicable. SD = standard deviation.