Table 2.
Pooled analysis in subgroups of studies
| Cohort studies | RCT | |||||||
|---|---|---|---|---|---|---|---|---|
| N | I2 |
Pooled RR* [95% CI] |
P values§ |
N | I2 |
Pooled RR* [95% CI] |
P values§ |
|
| ALL STUDIES | 27# | 80% | 0.80 [0.69, 0.93] | 11 | 0% | 1.08 [0.97, 1.20] | ||
| Peer-reviewed Studies | ||||||||
| Pre-printed studies | 4 | 80% | 0.68 [0.41, 1.12] | 0.51 | 3 | 0% | 0.73 [0.46, 1.15] | 0.08 |
| Peer-reviewed studies | 23 | 81% | 0.81 [0.69, 0.95] | 8 | 0% | 1.10 [0.99, 1.23] | ||
| Adjustment | ||||||||
| Not adjusted | 4 | 4% | 1.02 [0.74, 1.41] | 0.15 | - | - | - | |
| Adjusted | 23 | 82% | 0.78 [0.67, 0.92] | 11 | 0% | 1.08 [0.97, 1.20] | ||
| Sample size | ||||||||
| <1,000 COVID-19 patients | 16 | 42% | 0.93 [0.75, 1.15] | 0.08 | 9 | 0% | 0.89 [0.64, 1.23] | 0.21 |
| ≥1,000 COVID-19 patients | 11 | 90% | 0.72 [0.58, 0.88] | 2 | 0% | 1.10 [0.99, 1.24] | ||
| Mortality incidence in the sample | ||||||||
| ≤20% | 15 | 79% | 0.80 [0.62, 1.03] | 0.93 | 9 | 0% | 1.08 [0.85, 1.36] | 0.99 |
| >20% | 12 | 83% | 0.81 [0.66, 0.99] | 2 | 0% | 1.08 [0.96, 1.22] | ||
| HCQ treatment in the sample | ||||||||
| ≤33.3% | 10 | 54% | 0.89 [0.69, 1.14] | 0.02 | 1 | - | 1.09 [0.96, 1.23] | 0.73 |
| 33.3–66.6% | 11 | 74% | 0.95 [0.79, 1.16] | 10 | 0% | 1.04 [0.84, 1.29] | ||
| >66.6% | 6 | 89% | 0.52 [0.35, 0.75] | - | - | - | ||
| HCQ treatment, duration | ||||||||
| ≤ 5 days | 12 | 85% | 0.67 [0.52, 0.87] | 0.35 | 4 | 0% | 0.94 [0.56, 1.59] | 0.61 |
| > 5 days | 8 | 46% | 0.79 [0.63, 1.00] | 7 | 0% | 1.08 [0.97, 1.21] | ||
| HCQ treatment, total dose | ||||||||
| ≤4,000 mg | 13 | 84% | 0.67 [0.52, 0.87] | 0.19 | 6 | 0% | 0.85 [0.60, 1.21] | 0.16 |
| >4,000 mg | 5 | 80% | 0.86 [0.66, 1.14] | 5 | 0% | 1.10 [0.99, 1.24] | ||
| HCQ treatment, daily dose | ||||||||
| ≤400 mg | 15 | 83% | 0.69 [0.57, 0.85] | 0.050 | 6 | 0% | 0.85 [0.60, 1.19] | 0.14 |
| >400 mg | 5 | 0% | 1.05 [0.73, 1.53] | 5 | 0% | 1.11 [0.99, 1.24] | ||
| Country | 0.14 | 0.81 | ||||||
| Asia | 3 | 46% | 0.48 [0.24, 0.95] | - | - | - | ||
| Europe | 12 | 59% | 0.74 [0.62, 0.89] | 3 | 2% | 1.06 [0.89, 1.27] | ||
| North America | 12 | 86% | 0.91 [0.72, 1.15] | 5 | 0% | 0.94 [0.56, 1.59] | ||
| Others | - | - | - | 3 | 0% | 1.18 [0.90, 1.56] | ||
*Relative risk for mortality in HCQ versus non HCQ patients. #Three independent cohorts have been included in the meta-analysis from the article of Kim et al.46 §for difference among subgroups.
HCQ means hydroxychloroquine; NA means Not Applicable; RCT means randomized clinical trial.