Table 3.
Associations between covariates, medications, and risk of herpes zoster.
| Variable | HR (95%CI) | P |
|---|---|---|
| Age, per year* | 1.036 (1.03–1.04) | < 0.001 |
| Female sex | 1.10 (1.04–1.17) | 0.001 |
| Urbanization level | ||
| Low | Reference | – |
| Moderate | 1.02 (0.92–1.14) | 0.666 |
| High | 1.00 (0.89–1.11) | 0.939 |
| Very high | 1.04 (0.93–1.15) | 0.527 |
| Comorbid conditions* | ||
| Diabetes mellitus | 0.92 (0.84–1.01) | 0.068 |
| Hypertension | 1.11 (1.03–1.19) | 0.004 |
| Dyslipidemia | 1.18 (1.08–1.29) | < 0.001 |
| Chronic kidney disease | 0.95 (0.84–1.08) | 0.451 |
| Gouty arthritis | 0.92 (0.82–1.03) | 0.141 |
| Psoriasis arthritis | 1.25 (1.01–1.53) | 0.035 |
| Charlson Comorbidity Index score* | 1.18 (1.15–1.22) | < 0.001 |
| Medication of primary interest* | ||
| Control period | Reference | – |
| Methotrexate with any biological agents | 3.10 (0.97–9.92) | 0.056 |
| Etanercept without Methotrexate | 4.78 (1.51–15.17) | 0.008 |
| Adalimumab without Methotrexate | 5.52 (1.72–17.71) | 0.004 |
| Ustekinumab without Methotrexate | NA | NA |
| Methotrexate with PUVA or UVB | 0.29 (0.09–0.90) | 0.032 |
| Methotrexate with Acitretin | 0.58 (0.15–2.32) | 0.442 |
| Methotrexate with Azathioprine | 4.17 (1.78–9.82) | 0.001 |
| Methotrexate only | 1.01 (0.80–1.27) | 0.958 |
| Acitretin only | 0.39 (0.24–0.64) | < 0.001 |
| Acitretin with PUVA or UVB | 0.44 (0.17–1.18) | 0.104 |
| PUVA or UVB only | 0.76 (0.60–0.96) | 0.023 |
| Azathioprine only | 1.59 (0.76–3.33) | 0.218 |
| Other combinations | 1.50 (0.78–2.85) | 0.222 |
| Medication not of primary interest | ||
| Steroid (prednisone-equivalent dose)* | ||
| Never user | Reference | – |
| < 5 mg/day | 0.99 (0.91–1.08) | 0.786 |
| ≥ 5 mg/day | 1.68 (1.24–2.27) | 0.001 |
| Statin* | 1.54 (1.38–1.71) | < 0.001 |
PUVA photochemotherapy, UVB ultraviolet B, HR hazard ratio, CI confidence interval, NA not applicable.
*Time-varying covariates that may change in each person-quartile.