Table 3. Comparison between the ID (age–sex standardised) and non-ID groups of selected nervous system medication subgroups: rates per 100 encounters.

Medication subgroup	ID group		ID group (age–sex standardised)	Non-ID group
Medication subgroup	n	Per 100 encounters (95% CI)	Per 100 encounters (95% CI)	n	Per 100 encounters (95% CI)
Anticonvulsants^a	54	7.8 (4.7 to 11.0)	6.0 (3.2 to 8.7)	5764	0.6 (0.6 to 0.6)
Antipsychotics^a	48	7.0 (4.8 to 9.1)	6.1 (3.7 to 8.5)	5837	0.6 (0.6 to 0.6)
Antidepressants	30	4.3 (2.7 to 6.0)	3.5 (1.9 to 5.2)	36 054	3.7 (3.6 to 3.8)
Antianxiety	12	1.7 (0.8 to 2.7)	1.6 (0.6 to 2.6)	18 859	1.9 (1.9 to 2.0)
Sedatives or hypnotics	10	1.4 (0.6 to 2.3)	1.3 (0.4 to 2.3)	16 296	1.7 (1.6 to 1.7)

^aNon-overlapping 95% confidence intervals, comparing ID group (age–sex standardised) with non-ID group.
CI = confidence intervals. ID = intellectual disability.