Table 3.

Factors Associated with Emergency Department Visits for Asthma Using Cox Models (n = 3395)

VariablesCrude ModelAdjusted model
HR95% CIHR95% CI
COCI
    1 (Reference)1.001.00
    0.47–0.991.500.92–2.421.150.70–1.87
    <0.472.781.81–4.252.111.37–3.25
Patient characteristics at baseline
    Sex
        Female (reference)1.001.00
        Male1.581.09–2.301.290.88–1.90
    Age (years)1.000.97–1.030.980.95–1.01
    Insurance premium (US$)
        <667 (Reference)1.001.00
        667–13330.980.65–1.481.130.74–1.72
        ≥13330.670.38–1.190.940.52–1.69
    P4P participating status
        Not participating (reference)1.001.00
        Participating0.810.42–1.550.780.40–1.50
Medical conditions
    In a previous year
        CCI
            0 (Reference)1.001.00
            1–20.440.14–1.340.370.12–1.15
            ≥31.851.04–3.291.000.53–1.87
        COPD
        No (reference)
        Yes2.972.07–4.272.201.46–3.30
In the COC period
    Ambulatory visits for asthma, n
        4–12 (Reference)1.001.00
        13–242.551.72–3.782.241.49–3.36
        ≥254.402.12–9.153.031.44–6.39
    Hospitalization for asthma
        No (reference)1.001.00
        Yes3.081.61–5.891.000.50–1.99
    ED visits for asthma
        No (reference)1.001.00
        Yes8.896.02–13.136.694.40–10.17
  • 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.