The Ontario Asthma Regional Variation Study: emergency department visit rates and the relation to hospitalization rates.
Lougheed MD, Garvey N, Chapman KR, Cicutto L, Dales R, Day AG, Hopman WM, Lam M, Sears MR, Szpiro K, To T, Paterson NA. The Ontario Asthma Regional Variation Study: emergency department visit rates and the relation to hospitalization rates. Chest. 2006 Apr; 129(4):909-17.