Table 2.
Type of potential bias and examination of identifiability assumptions
| Reference | Type of potential bias addressed | Positivity assessed | Weight truncated or trimmed | Uncontrolled confounding discussed |
|---|---|---|---|---|
| Cook et al.28 | Bias from blocking mediated effect | Mean: 1.01 Median (Inter Quartile Range): 1.00 (0.97–1.01) |
Weight truncation at 0.01th and 99.99th percentiles | Yes |
| Desai et al. 29 | Bias from blocking mediated effect; Selection bias owing to artificial censoring | Mean (Standard Deviation): 1.00 (0.06) | Not reported | Yes |
| Gerhard et al. 30 | Bias from blocking mediated effect | Not reported | Not reported | Yes |
| Gsponer et al. 31 | Bias from blocking mediated effect | Not reported | Not reported | Yes |
| Haukka et al. 32 | No details provided† | Not reported | Not reported | Yes |
| HCV working group of COHERE 33 | Bias from blocking mediated effect | Not reported | Not reported | Yes |
| Heffron et al. 34 | No details provided† | Mean (range): 1.07 (0.82–1.34) | Weight truncation at 1st and 99th percentiles | Yes |
| Hernández et al. 35 | Bias from blocking mediated effect | Not reported | Not reported | Yes |
| HIV-CAUSAL Collaboration 36 | Selection bias owing to artificial censoring | Not reported | Weight truncation at 99th percentile | Yes |
| HIV-CAUSAL Collaboration 37 | Bias from blocking mediated effect | Mean: 1.04 | Weight truncation at 10 | Yes |
| Jin et al. 38 | Selection bias owing to artificial censoring | Not reported | Not reported | No |
| Kalayjian et al. 39 | Selection bias owing to artificial censoring | Not reported | Not reported | Yes |
| McCoy et al. 40 | Bias from blocking mediated effect | Not reported | Not reported | Yes |
| Miller et al. 41 | Bias from blocking mediated effect | Not reported | Weight Trimming at 10 | Yes |
| Morrison et al. 42 | No details provided† | Not reported | Not reported | Yes |
| Scherzer et al. 43 | Bias from blocking mediated effect | Not reported | Not reported | Yes |
| Shinozaki et al. 44 | Bias from blocking mediated effect | Not reported | Not reported | Yes |
| Terrier et al. 45 | No details provided† | Not reported | Not reported | No |
| Tiihonen et al. 46 | No details provided† | Not reported | Not reported | Yes |
| Young et al. 47 | Selection bias owing to artificial censoring | Not reported | Not reported | No |
†
If studies reported “using IPW to control for time-varying confounding” without further specification of relationships between treatment, time-varying confounders and outcomes.