Table 2 Stratified meta-analyses of the proportion of MSM who use nitrite inhalants in China
Category | Subgroup | Number of studies | Proportion estimate (%) and 95% CI | Heterogeneity | |
|---|---|---|---|---|---|
I2 | P-value | ||||
Study period | 2011–2013 | 6 | 27.7 (21.8, 33.7) | 95.8% | < 0.01 |
2014–2016 | 7 | 18.9 (14.3, 23.5) | 97.1% | < 0.01 | |
Study site | Northern China | 6 | 26.0 (21.1, 31.0) | 95.9% | < 0.01 |
Southern China | 5 | 22.4 (14.6, 30.2) | 97.7% | < 0.01 | |
Othera | 4 | 22.5 (15.8, 29.2) | 97.6% | < 0.01 | |
Sample size | ≤1000 | 7 | 28.4 (20.4, 36.3) | 97.1% | < 0.01 |
> 1000 | 8 | 20.3 (15.8, 24.8) | 98.0% | < 0.01 | |
Data collection method | Self-administrated questionnaire | 6 | 25.2 (17.2, 33.3) | 98.2% | < 0.01 |
Face-to-face interview | 9 | 23.1 (19.3, 26.9) | 96.5% | < 0.01 | |
Recall window of nitrite inhalants use (months) | 3 | 6 | 23.7 (18.3, 29.2) | 96.1% | < 0.01 |
6 | 7 | 22.0 (16.4, 27.5) | 98.1% | < 0.01 | |
12 | 2 | 31.4 (11.3, 51.5) | 98.3% | < 0.01 | |
Publication language | English | 7 | 27.6 (20.0, 35.2) | 98.5% | < 0.01 |
Chinese | 8 | 20.8 (16.9, 24.8) | 96.0% | < 0.01 | |