Table 4.
Variables associated with change to combination therapy from monotherapy within 1 year of patients who initiated treatment with one medication for Alzheimer’s disease (AD) from 2012 to 2014
| Variable | Univariate analysis | Multivariable analysis | ||||
|---|---|---|---|---|---|---|
| Odds ratio | 95% CI | p value | Odds ratio | 95% CI | p value | |
| Sex | ||||||
| Male (vs. female) | 1.00 | 0.92–1.09 | 0.952 | |||
| Age | ||||||
| 65–74 (vs. ≤64) | 0.72 | 0.65–0.81 | <0.0001 | 1.04 | 0.82–1.32 | 0.767 |
| 75–84 (vs. ≤64) | 0.79 | 0.73–0.86 | <0.0001 | 1.19 | 0.95–1.49 | 0.140 |
| ≥85 (vs. ≤64) | 1.77 | 1.60–1.95 | <0.0001 | 2.16 | 1.68–2.77 | <0.0001 |
| Medications for AD | ||||||
| Memantine (vs. donepezil) | 1.45 | 1.27–1.66 | <0.0001 | 1.26 | 1.10–1.45 | 0.001 |
| Galantamine (vs. donepezil) | 0.68 | 0.62–0.76 | <0.0001 | 0.74 | 0.67–0.82 | <0.0001 |
| Rivastigmine (vs. donepezil) | 0.76 | 0.66–0.87 | 0.000 | 0.73 | 0.64–0.85 | <0.0001 |
| Co-prescribed drugs | ||||||
| Antidepressants (vs. none) | 1.52 | 1.35–1.72 | <0.0001 | 1.22 | 1.07–1.39 | 0.004 |
| Antipsychotics (vs. none) | 1.34 | 1.19–1.50 | <0.0001 | 1.08 | 0.96–1.23 | 0.202 |
| Antihypertensives (vs. none) | 1.22 | 1.11–1.35 | <0.0001 | 0.91 | 0.81–1.02 | 0.090 |
| Antihyperlipidemics (vs. none) | 1.15 | 1.01–1.29 | 0.030 | 0.92 | 0.81–1.05 | 0.237 |
| Antidiabetics (vs. none) | 1.32 | 1.12–1.56 | 0.001 | 1.10 | 0.92–1.32 | 0.271 |
| Polypharmacy | ||||||
| ≥5 (vs. 0–4 drugs) | 1.69 | 1.55–1.85 | <0.0001 | 1.68 | 1.47–1.91 | 0.004 |
| Interaction effect | ||||||
| Age (≥85) × polypharmacy (vs. none) | 0.71 | 0.57–0.87 | 0.001 | |||