Factors Associated with Emergency Department Visits for Asthma Using Cox Models (N = 7578)
| Variables | Crude Model | Adjusted Model | ||
|---|---|---|---|---|
| HR | 95% CI | HR | 95% CI | |
| COCI | ||||
| 1 (Reference) | 1.00 | 1.00 | ||
| 0.47–0.99 | 2.03 | 1.34–3.09 | 1.21 | 0.76–1.91 |
| <0.47 | 2.73 | 1.99–3.74 | 2.11 | 1.52–2.92 |
| Patient characteristics at baseline | ||||
| Sex | ||||
| Female (4eference) | 1.00 | 1.00 | ||
| Male | 1.49 | 1.11–1.99 | 1.27 | 0.94–1.72 |
| Age (years) | 1.01 | 0.99–1.03 | 1.00 | 0.97–1.02 |
| Insurance premium (US$) | ||||
| <667 (Reference) | 1.00 | 1.00 | ||
| 667–1333 | 0.80 | 0.57–1.11 | 0.92 | 0.66–1.28 |
| ≥1333 | 0.65 | 0.42–1.02 | 0.85 | 0.54–1.34 |
| Asthma P4P program | ||||
| Not enrolled (reference) | 1.00 | 1.00 | ||
| Enrolled | 1.08 | 0.57–2.04 | 0.83 | 0.43–1.60 |
| Medical conditions | ||||
| In a previous year | ||||
| CCI | ||||
| 0 (Reference) | 1.00 | 1.00 | ||
| 1–2 | 1.21 | 0.65–2.26 | 0.84 | 0.41–1.73 |
| ≥3 | 2.28 | 1.69–3.06 | 1.39 | 0.86–2.24 |
| COPD | ||||
| No (reference) | 1.00 | 1.00 | ||
| Yes | 4.81 | 3.39–6.82 | 2.91 | 1.99–4.25 |
| In the COC period | ||||
| Ambulatory visits, n | ||||
| 4–12 (Reference) | 1.00 | 1.00 | ||
| 13–24 | 2.55 | 1.72–3.78 | 2.12 | 1.42–3.19 |
| ≥25 | 0.70 | 0.50–0.96 | 1.12 | 0.69–1.84 |
| Hospitalization | ||||
| No (reference) | 1.00 | 1.00 | ||
| Yes | 5.00 | 2.95–8.48 | 1.36 | 0.76–2.41 |
| ED visits | ||||
| No (reference) | 1.00 | 1.00 | ||
| Yes | 10.42 | 7.47–14.54 | 6.09 | 4.19–8.85 |
CCI, Charlson Comorbidity Index; CI, confidence interval; COCI, continuity of care index; COPD, chronic obstructive pulmonary disease; ED, emergency department; HR, hazard ratio; P4P, pay for performance.