Table 3.
Incidence rates and adjusted incident rate ratios for movement side effects in people with and without ID prescribed antipsychotic drugs
| ID cohort | Non-ID cohort | Comparison | ||||||
| Variable | Events during follow-up (n) | Person-years (×10 000) (n) | Incidence per 10 000 person-years (95% CI) | Events during follow-up (n) | Person-years (×10 000) (n) | Incidence per 10 000 person-years (95% CI) | Incidence rate ratio* (95% CI) | p Value |
| Any movement disorder (defined by Read code or antimuscarinic prescription) | 743 | 2.7 | 275 (256 to 296) | 1750 | 7.0 | 248 (237 to 260) | 1.30 (1.18 to 1.42) | <0.001 |
| Any movement disorder (defined by Read code) | 446 | 4.4 | 111 (101 to 122) | 952 | 9.4 | 101 (95 to 108) | 1.30 (1.16 to 1.47) | <0.001 |
| Any movement disorder (defined by antimuscarinic prescription) | 564 | 2.9 | 196 (180 to 212) | 1299 | 7.6 | 172 (163 to 181) | 1.29 (1.16 to 1.44) | <0.001 |
| Acute dystonia | 60 | 4.4 | 14 (11 to 18) | 161 | 10.2 | 16 (14 to 19) | 1.00 (0.73 to 1.37) | 0.99 |
| Akathisia | 80 | 4.5 | 18 (15 to 23) | 112 | 10.3 | 11 (9 to 13) | 2.29 (1.69 to 3.12) | <0.001 |
| Parkinsonism | 270 | 4.4 | 64 (57 to 72) | 592 | 9.9 | 60 (55 to 65) | 1.20 (1.03 to 1.39) | 0.02 |
| Tardive dyskinaesia | 61 | 4.0 | 14 (11 to 18) | 123 | 10.3 | 12 (10 to 14) | 1.27 (0.91 to 1.75) | 0.16 |
| Neuroleptic malignant syndrome | 11 | 4.4 | 3 (1 to 5) | 12 | 10.4 | 1 (1 to 2) | 3.03 (1.26 to 7.30) | 0.013 |
| Other movement disorder | 43 | 4.2 | 10 (7 to 13) | 94 | 10.3 | 9 (7 to 11) | 1.26 (0.86 to 1.85) | 0.23 |
*Adjusted for sex, social deprivation score, time period, history of antipsychotic drug use, average daily dose, days on treatment.
ID, intellectual disability.