Table 2. Comparison of changes in the prevalence of asthma in the Middle East over the period of 1996-2011 .
| Trend of change | The prevalence of asthma in the second study% | The prevalence of asthma in the First study% | Interval of 2 reviews | Age group | Country / City |
| Increase | 11.2 | 4.5 | 2 Years | 6 to 12 years | Palestine / Ramallah |
| Constant | 2.5 | 2.6 | 6 Years | 13 to 14 years | Iran / Tehran |
| Constant | 10.6 | 10.5 | 6 Years | 6 to7years | Oman / Sultanat |
| Decrease | 19.8 | 20.7 | 6 Years | 13 to14years | Oman/Sultanat |
| Increase | 13.2 | 10.9 | 6 Years | 13 to14years | Iran |
| Increase | 2 | 1.4 | 8 Years | 13 to14years | Iran / Tabriz |
| Increase | 7.1 | 4.1 | 6 Years | 6 to 7 years | Iran / Rasht |
| Increase | 4.5 | 2.7 | 6 Years | 13 to 14 years | Iran / Rasht |
| Decrease |
Girls:1.2 Boys:1.0 |
Girls:1.5 Boys:1.9 |
6 Years | 6 to 7 years | Iran / Tehran |