Table 5.
Associations with new antipsychotic drug prescription in adults with intellectual disability in UK primary care, 1999-2013
| Factor | IRR* (95% CI) | P value | IRR† (95% CI) | P value |
|---|---|---|---|---|
| Sex: | ||||
| Male | 1 (reference) | NS | 1 (reference) | NS |
| Female | 1.04 (0.95 to 1.12) | 1.01 (0.93 to 1.11) | ||
| Age group, years: | ||||
| 18-29 | 1 (reference) | <0.001 | 1 (reference) | <0.001 |
| 30-39 | 0.95 (0.84 to 1.07) | 0.99 (0.88 to 1.13) | ||
| 40-49 | 0.91 (0.80 to 1.03) | 0.96 (0.85 to 1.10) | ||
| 50-59 | 1.01 (0.88 to 1.16) | 1.08 (0.93 to 1.25) | ||
| 60-69 | 1.14 (0.97 to 1.35) | 1.32 (1.11 to 1.57) | ||
| 70-79 | 1.65 (1.34 to 2.02) | 1.81 (1.46 to 2.24) | ||
| ≥80 | 2.39 (1.82 to 3.13) | 2.72 (2.06 to 3.61) | ||
| Townsend deprivation fifth: | ||||
| 1 (least deprived) | 1 (reference) | NS | 1 (baseline) | NS |
| 2 | 1.02 (0.88 to 1.19) | 0.96 (0.82 to 1.12) | ||
| 3 | 1.03 (0.89 to 1.19) | 0.97 (0.83 to 1.13) | ||
| 4 | 1.03 (0.89 to 1.19) | 0.94 (0.81 to 1.09) | ||
| 5 (most deprived) | 0.94 (0.81 to 1.10) | 0.81 (0.69 to 0.95) | ||
| Missing | 1.21 (0.96 to 1.52) | 1.1 (0.87 to 1.39) | ||
| Neuropsychiatric diagnosis: | ||||
| Severe mental illness | 8.87 (7.76 to 10.15) | <0.001 | 6.69 (5.83 to 7.68) | <0.001 |
| Challenging behaviour | 2.51 (2.30 to 2.76) | <0.001 | 2.08 (1.90 to 2.27) | <0.001 |
| Autism | 1.87 (1.66 to 2.12) | <0.001 | 1.79 (1.56 to 2.04) | <0.001 |
| Depression | 2.49 (2.27 to 2.72) | <0.001 | 1.79 (1.62 to 1.98) | <0.001 |
| Anxiety | 2.36 (2.15 to 2.60) | <0.001 | 1.63 (1.47 to 1.81) | <0.001 |
| Dementia | 1.91 (1.54 to 2.40) | 0.003 | 1.42 (1.12 to 1.81) | 0.003 |
| Epilepsy | 1.04 (0.94 to 1.15) | NS | 1.15 (1.04 to 1.28) | 0.007 |
IRR=incidence rate ration; NS=not significant.
*Univariable analysis.
†Multivariable analysis adjusted for age, sex, Townsend deprivation fifth, neuropsychiatric diagnoses, and year of study entry.