Table 1.

Characteristics of the study sample by year

	Fiscal year
	2003/4	2007/8	2011/12	p-value
Sample size (unweighted)	3882	4756	5262
	Weighted % (95 % CI)	Weighted % (95 % CI)	Weighted % (95 % CI)
Age				0.862
65 to 84 years	86.6 (86.0, 87.2)	86.6 (86.0, 87.1)	86.4 (86.0, 86.8)
85 years or over	13.4 (12.8, 14.0)	13.4 (12.9, 14.0)	13.6 (13.2, 14.0)
Sex				0.997
Women	56.0 (50.9, 61.0)	55.8 (51.5, 59.9)	55.8 (51.4, 60.2)
Socio-economic status (index of multiple deprivation quintile)				0.430
Least deprived quintile	15.9 (12.7, 19.7)	17.8 (14.3, 22.0)	20.0 (16.8, 23.6)
2nd quintile	16.0 (13.5, 18.9)	18.7 (16.3, 21.3)	16.6 (14.4, 19.2)
3rd quintile	14.2 (11.9, 16.7)	13.3 (11.1, 15.7)	13.2 (10.6, 16.4)
4th quintile	12.6 (9.9, 15.9)	10.5 (8.3, 13.2)	9.4 (7.7, 11.4)
Most deprived quintile	8.4 (6.2, 11.2)	8.2 (6.5, 10.3)	6.0 (4.6, 7.7)
Missing (no linkage)	33.0 (27.4, 39.0)	31.6 (26.7, 37.0)	34.7 (29.3, 40.6)
Multimorbidity (number of chronic conditions)				<0.001
0	21.9 (19.5, 24.6)	18.7 (16.9, 20.8)	16.6 (14.9, 18.3)
1 to 2	50.1 (47.5, 52.8)	46.9 (44.5, 49.2)	46.4 (44.3, 48.5)
3 or more	27.9 (25.8, 30.2)	34.4 (32.3, 36.6)	37.0 (35.0, 39.2)
Medications count (number of drugs prescribed at least once during the year)				<0.001
0	12.2 (10.5, 14.0)	9.7 (8.4, 11.3)	7.8 (6.6, 9.2)
1	8.7 (7.4, 10.2)	7.1 (6.0, 8.4)	5.9 (4.9, 7.0)
2 to 4	26.9 (24.8, 29.2)	25.3 (23.4, 27.3)	25.7 (23.8, 27.6)
5 to 9	35.8 (33.5, 38.0)	36.6 (34.7, 38.5)	36.1 (34.0, 38.2)
10 or more	16.4 (14.7, 18.3)	21.2 (19.6, 23.0)	24.6 (22.8, 26.5)
Medications count (number of drugs prescribed all quarters)				<0.001
0	33.9 (31.5, 36.4)	26.5 (24.5, 28.5)	21.7 (19.8, 23.8)
1	14.0 (12.5, 15.8)	12.8 (11.5, 14.4)	12.3 (10.9, 13.7)
2 to 4	35.6 (33.3, 37.9)	35.7 (33.9, 37.5)	37.1 (35.0, 39.2)
5 to 9	15.1 (13.6, 16.8)	23.2 (21.6, 24.9)	25.2 (23.3, 27.0)
10 or more	1.3 (0.8, 2.2)	1.8 (1.4, 2.4)	3.8 (3.1, 4.6)