| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 5 |
0.4%
|
| 0 | Not at all effective | 76 |
6.3%
|
| 1 | Not very effective | 147 |
12.3%
|
| 2 | Somewhat effective | 383 |
31.9%
|
| 3 | Very effective | 395 |
32.9%
|
| 9 | Don't know | 194 |
16.2%
|
| 98 | Refused | 0 |
0%
|