Table 2. Factors Associated with Antipsychotic Polypharmacy (vs. Monotherapy) among Patients with Schizophrenia across Four Systems: Veterans Health Administration (VA), National Ambulatory Medical Care Survey (NAMCS), and Two HMO Research Network Sites (HMORN).
| Characteristics a | VA (TAPERED) | VA | VA-WEEK | NAMCS | HMORN SITE 1 | HMORN SITE 2 | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| OR (95% CI) |
P-Value | OR (95% CI) |
P-Value | OR (95% CI) |
P-Value | OR (95% CI) |
P-Value | OR (95% CI) |
P-Value | OR (95% CI) |
P-Value | |
| Age (in decades) | 0.98 (0.95,1.00) |
0.082 | 0.79 (0.78,0.81) |
<0.001 | 0.91 (0.88,0.94) |
<0.001 | 0.84 (0.69,1.02) |
0.074 | 0.69 (0.54,0.89) |
0.004 | 0.82 (0.73,0.93) |
0.002 |
| Female | 1.07 (0.99,1.16) |
0.105 | 1.11 (1.05,1.18) |
<0.001 | 0.93 (0.83,1.04) |
0.193 | 1.0 (0.67,1.61) |
0.876 | 1.08 (0.58,2.03) |
0.812 | 1.23 (0.89,1.68) |
0.211 |
| FY02 | 0.83 (0.35,1.98) |
0.679 | 0.99 (0.39,2.51) |
0.977 | 0.82 (0.45,1.48) |
0.509 | ||||||
| FY03 | 0.69 (0.25,1.91) |
0.233 | 0.56 (0.18,1.73) |
0.314 | 1.17 (0.62,2.23) |
0.631 | ||||||
| FY04 | 0.70 (0.25,1.91) |
0.484 | 0.42 (0.13,1.35) |
0.144 | 0.97 (0.48,1.92) |
0.926 | ||||||
| FY05 | 1.61 (1.46,1.77) |
<0.001 | 1.12 (1.05,1.19) |
<0.001 | 1.35 (1.23,1.47) |
<0.001 | 0.60 (0.30,1.18) |
0.137 | 0.40 (0.11,1.51) |
0.177 | 1.10 (0.56,2.16) |
0.784 |
| FY06 | 0.96 (0.85,1.08) |
0.469 | 0.91 (0.84,0.98) |
0.010 | 0.54 (0.48,0.60) |
<0.001 | 0.68 (0.27,1.76) |
0.430 | 0.73 (0.24,2.18) |
0.568 | 0.93 (0.46,1.89) |
0.837 |
| FY07 | 0.90 (0.79,1.03) |
0.110 | 0.96 (0.88,1.04) |
0.274 | 1.01 (0.91,1.13) |
0.838 | 0.75 (0.37,1.53) |
0.432 | 1.09 (0.37,3.17) |
0.878 | 1.31 (0.66,2.61) |
0.440 |
| Charlson (range:0-37) | 1.04 (1.02,1.06) |
<0.001 | 0.99 (0.98,1.00) |
0.113 | 1.00 (0.94,1.06) |
0.975 | 0.55 (0.21,1.45) |
0.228 | 0.78 (0.49,1.24) |
0.288 | 0.94 (0.84,1.06) |
0.292 |
| Selim Total (range: 0-36) | 0.97 (0.96,0.98) |
<0.001 | 1.09 (1.08,1.09) |
<0.001 | 0.94 (0.91,0.97) |
0.001 | 1.20 (0.93,1.56) |
0.169 | 1.46 (1.15,1.86) |
0.002 | 1.13 (1.04,1.23) |
0.003 |
a
Each year (FY02-FY07) in the model denotes patients' study entry, where FY08 was used as reference. FY09 was not included as the outcome of one-year polypharmacy could not be assessed. VA data prior to FY05 was not available.