Table 2

Factors associated with initiation of antipsychotics among adults with intellectual and developmental disabilities, overall and stratified by presence of mental health diagnosis at time of initiation

Overall
Adjusted ORs (95% CI)
No psychiatric diagnosis
Adjusted ORs (95% CI)
Psychiatric diagnosis
Adjusted ORs (95% CI)
Demographic characteristics
Age category (years)
 18–291.001.001.00
 30–450.84 (0.77 to 0.92)0.88 (0.76 to 1.02)0.86 (0.78 to 0.96)
 46+0.96 (0.88 to 1.05)1.19 (1.03 to 1.38)0.87 (0.77 to 0.97)
Male1.21 (1.13 to 1.29)1.27 (1.14 to 1.41)1.15 (1.06 to 1.25)
Urban residence0.97 (0.89 to 1.05)0.89 (0.78 to 1.01)1.06 (0.94 to 1.19)
Residing in group home1.20 (1.08 to 1.34)1.11 (0.95 to 1.29)1.12 (0.96 to 1.29)
Neighbourhood income quintile
 11.001.001.00
 21.05 (0.96 to 1.15)0.99 (0.86 to 1.15)1.10 (0.98 to 1.23)
 31.13 (1.02 to 1.24)1.10 (0.95 to 1.28)1.14 (1.01 to 1.29)
 41.16 (1.04 to 1.28)1.20 (1.03 to 1.40)1.14 (1.00 to 1.30)
 51.19 (1.07 to 1.32)1.25 (1.06 to 1.46)1.09 (0.95 to 1.25)
 Missing0.51 (0.34 to 0.76)0.83 (0.46 to 1.48)0.43 (0.26 to 0.69)
Medication use
Number of drugs dispensed in past year
 01.001.001.00
 10.98 (0.86 to 1.12)1.09 (0.88 to 1.35)0.78 (0.65 to 0.92)
 2–50.97 (0.88 to 1.08)1.23 (1.04 to 1.45)0.66 (0.58 to 0.76)
 5+0.95 (0.84 to 1.08)1.24 (1.02 to 1.51)0.62 (0.53 to 0.73)
Past use of other medications (prior 1 year)
 Antidepressants1.96 (1.82 to 2.12)2.80 (2.47 to 3.18)1.57 (1.43 to 1.73)
 Benzodiazepines1.60 (1.46 to 1.74)2.08 (1.82 to 2.39)1.46 (1.32 to 1.62)
 Lithium or antiepileptic drugs0.84 (0.74 to 0.94)0.79 (0.67 to 0.94)0.83 (0.70 to 0.98)
 Stimulants1.20 (0.96 to 1.49)2.19 (1.45 to 3.29)0.96 (0.75 to 1.22)
 Cognitive enhancers5.10 (3.78 to 6.87)5.49 (3.80 to 7.94)3.56 (2.21 to 5.72)
Health services utilisation
Hospitalisation in prior 2 years1.14 (0.96 to 1.36)1.31 (1.00 to 1.71)0.88 (0.70 to 1.10)
Emergency department visit in prior 2 years1.43 (1.33 to 1.54)1.23 (1.09 to 1.37)1.55 (1.41 to 1.70)
Mental health hospitalisation prior 2 years1.84 (1.61 to 2.09)1.71 (1.33 to 2.21)3.27 (2.85 to 3.76)
Number of physician visits in prior year1.01 (1.00 to 1.01)1.03 (1.02 to 1.03)1.00 (1.00 to 1.01)
Specialist visit in prior 90 days
 Psychiatrist4.82 (4.31 to 5.40)10.86 (7.87 to 15.00)5.11 (4.56 to 5.72)
 Family practice1.67 (1.55 to 1.79)1.62 (1.44 to 1.82)1.56 (1.42 to 1.71)
 Neurologist1.17 (0.99 to 1.39)1.22 (0.95 to 1.56)1.12 (0.90 to 1.40)
Comorbidities
Charlson score (past 3 years of hospitalisation data)
 No hospitalisation1.001.001.00
 01.07 (0.91 to 1.27)1.29 (1.00 to 1.66)1.02 (0.83 to 1.25)
 11.05 (0.83 to 1.32)0.92 (0.64 to 1.32)1.04 (0.78 to 1.38)
 2+2.75 (2.22 to 3.42)3.50 (2.57 to 4.75)1.60 (1.19 to 2.15)
Major mental illness5.18 (4.65 to 5.77)
Other psychiatric diagnosis3.18 (2.96 to 3.42)
Diabetes0.85 (0.76 to 0.94)0.83 (0.71 to 0.98)0.91 (0.80 to 1.04)
Hypertension0.76 (0.69 to 0.83)0.66 (0.57 to 0.76)0.86 (0.77 to 0.97)
Myocardial infarction0.54 (0.37 to 0.79)0.42 (0.24 to 0.73)0.68 (0.41 to 1.13)