| Factor/Category |
Odds ratio |
95％CI |
Test |
| Grade of smear positivity |
3+ |
1.4 |
0.7-2.0 |
NS |
| |
1+ or 2+ |
1 |
|
| Chest X-ray Cavity |
Present |
2.1 |
1.2-3.5 |
P＜0.01 |
| |
Absent |
1 |
|
| Duration of cough |
2 months or over |
1.2 |
0.7-2.0 |
NS |
| |
Less than 2 months |
1 |
|
| Duration of contact (hours) |
100- |
2.5 |
1.5-4.1 |
P＜0.01 |
| |
-99 |
1 |
|
Space of contact
(sq. meters) |
-49 |
2.0 |
1.2-3.4 |
P＜0.01 |
| 50- |
1 |
|
|
|
