Table 6

Clinician assessment of cause of asthma onset

Cause of Morbidity*
Total Cases, N (%)
New-onset Cases N (%)
Reactivated Cases N (%)
Relative Risk,** [95% C.I.]

     Infection Induced
275 (59)
144 (70)
131 (51)
1.4, [1.2, 1.6]
     Allergy Induced
63 (14)
19 (9)
44 (17)
0.54, [0.32, 0.89]
     Exercise Induced
20 (4)
9 (4)
11 (4)
1.02, [0.43, 2.41]
     Other
23 (5)
12 (6)
11 (4)
1.36, [0.61, 3.02]
     No Etiology Given
84 (18)
23 (11)
61 (24)
0.47, [0.30, 0.73]
     Total
465*
207
258


*4 missing observations **Unadjusted Relative Risk, New-onset cases versus reactivated cases with reference group representing all other etiologic categories combined, including "no etiology given"

Sama et al. Environmental Health: A Global Access Science Source 2003 2:10   doi:10.1186/1476-069X-2-10