TABLE 3.
Association of Other Drug and Patient Factors With Not Filling an Antidepressant Prescription Within 90 Days
| Variables | No. Prescriptions (N=38,751) | % Unfilled at 90 d | Adjusted OR* (95% CI) for Not Filling the Prescription Within 90 d |
|---|---|---|---|
| Drug factors | |||
| Pharmacological class | |||
| SSRI † | 16,471 | 5.9 | 1.00 (reference) |
| SNRI ‡ | 7690 | 7.1 | 1.24 (1.07–1.42) |
| TCA § | 5095 | 10.5 | 1.77 (1.44–2.17) |
| Other ‖ | 9495 | 9.0 | 1.48 (1.30–1.69) |
| Drug prescribed on a “take-as-needed” basis | |||
| No | 37,967 | 7.3 | 1.00 (reference) |
| Yes | 784 | 17.0 | 1.49 (1.11–2.00) |
| Patient factors | |||
| Sex | |||
| Female | 26,914 | 7.3 | 1.00 (reference) |
| Male | 11,837 | 8.1 | 1.00 (0.88–1.14) |
| Age (y) | |||
| 18–50 | 9476 | 12.3 | 1.00 (reference) |
| 51–62 | 9885 | 6.8 | 0.72 (0.60–0.87) |
| 63–72 | 9425 | 6.5 | 0.62 (0.53–0.74) |
| 73+ | 9965 | 4.7 | 0.50 (0.42–0.61) |
| Copayment plan for medications | |||
| No copayment (free) | 12,139 | 3.5 | 1.00 (reference) |
| Partial copayment (up to 600 CAD/year) | 7323 | 9.0 | 2.23 (1.73–2.89) |
| Maximum copayment (up to 1000 CAD/year) | 19,289 | 11.0 | 2.90 (2.42–3.47) |
| Chronic conditions in the Charlson Comorbidity Index | |||
| Myocardial infarction | |||
| No | 38,124 | 7.6 | 1.00 (reference) |
| Yes | 627 | 4.0 | 0.79 (0.56–1.11) |
| Congestive heart failure | |||
| No | 37,596 | 7.6 | 1.00 (reference) |
| Yes | 1155 | 4.9 | 0.95 (0.67–1.37) |
| Peripheral vascular disease | |||
| No | 37,843 | 7.6 | 1.00 (reference) |
| Yes | 908 | 5.3 | 1.10 (0.70–1.73) |
| Cerebrovascular disease | |||
| No | 37,840 | 7.6 | 1.00 (reference) |
| Yes | 911 | 4.7 | 0.93 (0.71–1.24) |
| Dementia | |||
| No | 37,598 | 7.7 | 1.00 (reference) |
| Yes | 1153 | 3.5 | 0.77 (0.58–1.04) |
| Chronic pulmonary disease | |||
| No | 31,011 | 7.9 | 1.00 (reference) |
| Yes | 7740 | 5.9 | 1.00 (0.89–1.12) |
| Rheumatic disease | |||
| No | 37,950 | 7.6 | 1.00 (reference) |
| Yes | 801 | 3.8 | 0.87 (0.63–1.21) |
| Peptic ulcer disease | |||
| No | 38,278 | 7.5 | 1.00 (reference) |
| Yes | 473 | 7.8 | 1.17 (0.85–1.61) |
| Mild liver disease | |||
| No | 37,989 | 7.6 | 1.00 (reference) |
| Yes | 762 | 6.0 | 1.10 (0.80–1.50) |
| Diabetes without chronic complication | |||
| No | 33,012 | 7.9 | 1.00 (reference) |
| Yes | 5739 | 5.4 | 1.09 (0.94–1.25) |
| Diabetes with chronic complication | |||
| No | 38,498 | 7.5 | 1.00 (reference) |
| Yes | 253 | 6.7 | 1.07 (0.65–1.76) |
| Hemiplegia or paraplegia | |||
| No | 38,521 | 7.5 | 1.00 (reference) |
| Yes | 230 | 9.1 | 1.17 (0.75–1.84) |
| Renal disease | |||
| No | 37,866 | 7.6 | 1.00 (reference) |
| Yes | 885 | 4.3 | 1.03 (0.78–1.35) |
| Any malignancy | |||
| No | 36,145 | 7.6 | 1.00 (reference) |
| Yes | 2606 | 6.0 | 1.04 (0.88–1.24) |
| Moderate or severe liver disease | |||
| No | 38,709 | 7.5 | 1.00 (reference) |
| Yes | 42 | 2.4 | 0.15 (0.03–0.79) |
| Metastatic solid tumor | |||
| No | 37,875 | 7.6 | 1.00 (reference) |
| Yes | 876 | 4.2 | 0.72 (0.48–1.07) |
| AIDS/HIV | |||
| No | 38,588 | 7.5 | 1.00 (reference) |
| Yes | 163 | 9.2 | 0.70 (0.43–1.14) |
| No. outpatient visits in the past year | |||
| 0–3 | 8574 | 9.3 | 1.00 (reference) |
| 4–6 | 8828 | 6.9 | 1.13 (1.01–1.26) |
| 7–11 | 10,414 | 6.7 | 1.20 (1.04–1.37) |
| 12+ | 10,935 | 7.5 | 1.35 (1.15–1.58) |
| Hospitalized in the past year | |||
| No | 32,031 | 7.9 | 1.00 (reference) |
| Yes | 6720 | 5.9 | 0.95 (0.86–1.06) |
| Visited the ED in the past year | |||
| No | 24,506 | 7.9 | 1.00 (reference) |
| Yes | 14,245 | 6.9 | 1.16 (1.07–1.25) |
| Continuity of care with the prescribing physician ¶ | |||
| <0.33 | 9594 | 9.3 | 1.00 (reference) |
| 0.33–0.55 | 9989 | 7.3 | 1.05 (0.96–1.15) |
| 0.56–0.82 | 9458 | 6.8 | 1.09 (0.98–1.22) |
| 0.83+ | 9710 | 6.7 | 1.02 (0.92–1.13) |
| No. non-antidepressant drugs dispensed in the past year | |||
| 0 | 1609 | 56.3 | 1.00 (reference) |
| 1–4 | 7888 | 8.7 | 0.27 (0.23–0.33) |
| 5–9 | 15,425 | 3.8 | 0.20 (0.16–0.24) |
| 10+ | 13,829 | 5.3 | 0.15 (0.12–0.18) |
From a multivariable model that additionally included all variables in Table 1 (treatment indication, therapy status, and a 2-way interaction between treatment indication and therapy status).
Includes citalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline.
Includes venlaxafine.
Includes amitriptyline, clomipramine, desipramine, doxepin, imipramine, nortriptyline, and trimipramine.
Includes trazodone, bupropion, mirtazapine, and maprotiline.
Measured as the proportion of all outpatient visits in the past year that were made to the prescribing physician.
AIDS/HIV indicates acquired immunodeficiency syndrome/human immunodeficiency virus; CAD, Canadian dollars; CI, confidence interval; ED, emergency department; OR, odds ratio; SNRI, serotonin-norepinephrine reuptake inhibitor; SSRI, selective serotonin reuptake inhibitor; TCA, tricyclic antidepressant.