The overall number of mistakes in each step at the three visits
| Step number and details | 1st visit | 2nd visit | 3rd visit | p Value |
|---|---|---|---|---|
| 1. Remove the protective cap from the MDI mouthpiece | – | – | – | NS |
| 2. Shake the MDI | 216 | 144 | 54 | <0.001 |
| 3. Breathe out as far as comfortable | 348 | 236 | 198 | <0.001 |
| 4. Place the MDI mouthpiece between the teeth and seal with the lips | 384 | 355 | 322 | <0.001 |
| 5. Ensure your tongue does not obstruct the mouthpiece | – | – | – | NS |
| 6. Depress the inhaler to release the dose at the start of inhalation | – | – | – | NS |
| 7. Maintain a slow inhalation rate until the lungs are full* | 385 | 397 | 334 | <0.001 |
| 8. Remove the MDI from the mouth and hold your breathe for 5–10 s | 332 | 247 | 124 | <0.001 |
| 9. If more than one dose is being taken, wait about 30 s before taking the next dose | 277 | 229 | 140 | <0.001 |
| 10. Rinse the mouth and if possible brush the teeth after dosing | 187 | 123 | 51 | <0.001 |
| 11. Replace the cap on the MDI | – | – | – | NS |
| Total number of mistakes | 2129 | 1731 | 1223 | <0.001 |
*No significant difference between the first and second visit. Cochran test followed by McNemar test.
MDI, metered dose inhaler; NS, no significant difference,