Appendix Table 1.

Factors Associated with Emergency Department Visits for Asthma Using Cox Models (N = 7578)

VariablesCrude ModelAdjusted Model
HR95% CIHR95% CI
    1 (Reference)1.001.00
Patient characteristics at baseline
        Female (4eference)1.001.00
    Age (years)1.010.99––1.02
    Insurance premium (US$)
        <667 (Reference)1.001.00
    Asthma P4P program
        Not enrolled (reference)1.001.00
Medical conditions
    In a previous year
        0 (Reference)1.001.00
        No (reference)1.001.00
    In the COC period
    Ambulatory visits, n
        4–12 (Reference)1.001.00
        No (reference)1.001.00
    ED visits
        No (reference)1.001.00
  • 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.