Table 3.
Frequency of critical error with devices (quantitative and qualitative estimates)
| Device | Cross-sectional studies | RCTs | ||||
|---|---|---|---|---|---|---|
| Number of studies | Pooled estimate [95% CI] (I-squared)* | Range of error frequency | Number of studies | Pooled estimate [95% CI] (I-squared)* | Range of error frequency | |
| MDI | 10 | 45.6% [26.0–66.6] (98.4%) | 12.0–93.0% | 0 | N/A‡ | N/A‡ |
| MDI with spacer | 3 | 8.9% [0.9–50.5] (93.7%) | 2.6–47.0% | 0 | N/A‡ | N/A‡ |
| BA-MDI (Autohaler®) | 1 | N/A‡ | 11.0% | 0 | N/A‡ | N/A‡ |
| Turbuhaler® | 10 | 40.1% [28.6–52.9] (95.7%) | 18.0–100% | 1 | N/A‡ | 26.0% |
| Diskus® | 9 | 20.8% [13.7–30.2] (93.6%) | 6.8–43.0% | 3 | 18.0% [8.2–35.1] (84.2%) | 8.0–31.9% |
| Aerolizer® | 4 | 14.2% [11.0–18.1] (44.3%) | 9.1–16.8% | 0 | N/A‡ | N/A‡ |
| Handihaler® | 3 | 42.4% [28.8–57.1] (58.4%) | 35.0–53.1% | 0 | N/A‡ | N/A‡ |
N/A Not applicable
* I-squared statistic indicates the percentage of variance that is attributable to between-study heterogeneity. The higher the percentage, the greater the heterogeneity. ‡Not applicable as number of studies was ≤1