Geographic and Clinical Variation in Clozapine Use in the United States
Abstract
Objective
Methods
Results
Conclusions
Methods
Study population
Predictor variables
Statistical analysis
Results
Clozapine (N=15,524) | Other antipsychotic (N=614,285) | ||||
---|---|---|---|---|---|
Characteristic | N | % | N | % | p |
Sex | <.001 | ||||
Male | 8,941 | 57.6 | 309,014 | 50.3 | |
Female | 6,583 | 42.4 | 305,262 | 49.7 | |
Age | <.001 | ||||
18–24 | 1,566 | 10.1 | 44,607 | 7.3 | |
25–34 | 3,414 | 22.0 | 110,083 | 17.9 | |
35–44 | 4,846 | 31.2 | 190,027 | 30.9 | |
45–54 | 4,072 | 26.2 | 182,162 | 29.7 | |
55–64 | 1,626 | 10.5 | 87,406 | 14.2 | |
Race-ethnicity | <.001 | ||||
White, non-Hispanic | 10,025 | 64.6 | 325,328 | 53.0 | |
African American, non-Hispanic | 2,871 | 18.5 | 168,201 | 27.4 | |
Hispanic | 805 | 5.2 | 42,977 | 7.0 | |
Other | 10,025 | 64.6 | 325,328 | 53.0 | |
Past-year co-occurring disorder or condition | |||||
Substance use disorder | 2,003 | 12.9 | 90,848 | 14.8 | .03 |
Depression | 5,583 | 36.0 | 223,975 | 36.5 | .44 |
Anxiety | 2,426 | 15.6 | 96,938 | 15.8 | .74 |
Deliberate self-harm | 202 | 1.3 | 6,560 | 1.1 | .06 |
Diabetes or cardiovascular disease | 7,742 | 49.9 | 311,178 | 50.7 | .60 |
HIV | 86 | .6 | 11,487 | 1.9 | <.001 |
Schizophrenia subtype | <.001 | ||||
Schizophreniform | 748 | 4.8 | 21,204 | 3.5 | |
Schizoaffective | 6,792 | 43.8 | 256,349 | 41.7 | |
Past-year acute services | |||||
Mental health emergency service | 2,003 | 12.9 | 90,848 | 14.8 | <.001 |
Outpatient visits for schizophrenia | <.001 | ||||
0–9 | 3,970 | 25.6 | 236,786 | 38.6 | |
10–29 | 4,122 | 26.6 | 176,163 | 28.7 | |
30–49 | 2,254 | 14.5 | 66,137 | 10.8 | |
≥50 | 5,178 | 33.4 | 135,199 | 22.0 | |
Hospital admissions for psychiatric illness | <.001 | ||||
0 | 6,902 | 44.5 | 353,514 | 57.6 | |
1 | 3,781 | 24.4 | 134,811 | 22.0 | |
2 | 2,049 | 13.2 | 59,275 | 9.7 | |
3 | 1,069 | 6.9 | 26,982 | 4.4 | |
≥4 | 1,723 | 11.0 | 39,703 | 6.5 | |
Treatment resistance | <.001 | ||||
Present | 4,367 | 28.1 | 75,567 | 12.3 | |
Absent | 11,157 | 71.9 | 538,718 | 87.7 |
Geographic variation
![](/cms/10.1176/appi.ps.201300180/asset/images/large/186f1.jpeg)
Demographic and clinical predictors of clozapine initiations
Patient group | AOR | 95% CI |
---|---|---|
Male (reference: female) | 1.26 | 1.22–1.30 |
Age (reference: 55–64) | ||
18–24 | 1.81 | 1.62–2.02 |
25–34 | 1.53 | 1.40–1.67 |
35–44 | 1.29 | 1.19–1.41 |
45–54 | 1.15 | 1.09–1.22 |
Race-ethnicity (reference: white, non-Hispanic) | ||
African American, non-Hispanic | .663 | .61–.72 |
Hispanic | .788 | .71–.87 |
Other | .889 | .84–.94 |
Diagnosis (reference: schizophrenia) | ||
Schizophreniform | .93 | .83–1.05 |
Schizoaffective | .91 | .86–.97 |
Substance use disorder diagnosis, past year (reference: absent) | .71 | .65–.76 |
Deliberate self-harm, past year (reference: absent) | .98 | .85–1.13 |
Diabetes diagnosis, past year (reference: absent) | .90 | .86–.95 |
Cardiovascular diagnosis, past year (reference: absent) | 1.03 | 1.00–1.07 |
HIV diagnosis, past year (reference: absent) | .42 | .35–.50 |
Mood stabilizers, past year (reference: absent) | 1.55 | 1.47–1.62 |
Long-acting injectable antipsychotic, past year (reference: absent) | 1.16 | 1.06–1.27 |
Mental health emergency service use, past year (reference: none) | .96 | .90–1.04 |
Outpatient visits for schizophrenia, past year (reference: 0–9 visits) | ||
10–29 | 1.32 | 1.23–1.42 |
30–49 | 1.77 | 1.57–1.98 |
≥50 | 2.06 | 1.82–2.33 |
Mental health hospital admissions, past year (reference: 0) | ||
1 | 1.19 | 1.11–1.27 |
2 | 1.36 | 1.25–1.48 |
3 | 1.51 | 1.35–1.68 |
≥4 | 1.62 | 1.41–1.87 |
Treatment resistance (reference: absent) | 1.92 | 1.83–2.03 |
Predictors of clozapine use by patient county characteristics
Patient group | AOR | 95% CI |
---|---|---|
Clozapine-treated patients in county, % (reference: 0%–5%) | ||
Low (5%–10%) | 1.26 | 1.12–1.42 |
Medium (10%–15%) | 1.71 | 1.52–1.94 |
High (>15%) | 2.03 | 1.75–2.30 |
Psychiatrists per 100,000 residents (reference: 0) | ||
Medium (.01–14.90) | .97 | .88–1.07 |
High (≥15) | 1.17 | 1.03–1.33 |
Annual income per capita, county (reference <$25,000) | ||
Medium ($25,000–49,999) | .99 | .87–1.12 |
High (≥$50,000) | .84 | .69–1.02 |
County population in poverty, % (reference: 0%–14.9%) | ||
Medium (15.0%–19.9%) | .96 | .87–1.06 |
High (≥20%) | 1.01 | .86–1.19 |
County population per square mile (reference: ≤399) | ||
Medium (400–1,000) | 1.08 | .98–1.20 |
High (>1,000) | 1.005 | .90–1.12 |
Predictors of clozapine use among treatment-resistant patients
Discussion
Conclusions
Acknowledgments and disclosures
Supplementary Material
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