Table 5.
Quality of Studies Included
| Citation | Data Quality a | Scientific Method b | Overall Quality Rating |
|---|---|---|---|
| Anders et al., 2011 [15] | Sufficient | Sufficient | Sufficient |
| Witzel et al., 2018 [16] | Sufficient | Sufficient | Sufficient |
| Ahn et al., 2013 [17] | Sufficient | Insufficient | Sufficient |
| Yap et al., 2012 [18] | Sufficient | Sufficient | Sufficient |
| Mounsey et al., 2018 [20] | Sufficient | Sufficient | Sufficient |
| Duchnowska et al., 2012 [21] | Sufficient | Insufficient | Sufficient |
| Duchnowska et al., 2009 [22] | Sufficient | Insufficient | Sufficient |
| Duchnowska et al., 2015 [23] | Sufficient | Sufficient | Sufficient |
| Gori et al., 2019 [24] | Sufficient | Sufficient | Sufficient |
| Hayashi et al., 2015 [25] | Sufficient | Sufficient | Sufficient |
| Maurer et al., 2018 [26] | Sufficient | Sufficient | Sufficient |
| Morikawa et al., 2018 [27] | Sufficient | Sufficient | Sufficient |
| Zhang et al., 2016 [28] | Sufficient | Sufficient | Sufficient |
| Heitz et al., 2009 e [29] | Sufficient | Sufficient | Sufficient |
| Berghoff et al., 2012 [30] | Sufficient | Sufficient | Sufficient |
| Brufsky et al., 2011 [31] | Sufficient | Sufficient | Sufficient |
| Kaplan et al., 2012 [33] | Sufficient | Sufficient | Sufficient |
| Jang et al., 2011 [34] | Sufficient | Insufficient | Sufficient |
| Kuba et al., 2014 [35] | Sufficient | Sufficient | Sufficient |
| Braccini et al., 2013 [36] | Sufficient | Sufficient | Sufficient |
| Niwinska et al., 2010 [39] | Sufficient | Sufficient | Sufficient |
| Sperduto et al., 2013 [37] | Sufficient | Insufficient | Sufficient |
| Martin et al., 2017 [38] | Insufficient | Sufficient | Sufficient |
| Anwar et al., 2021 [32] | Sufficient | Sufficient | Sufficient |
| Bergen et al., 2021 [19] | Sufficient | Sufficient | Sufficient |
a - Data attributes of exposure, outcomes (recording, objective measurement, validation) and important covariates/co-founders were assessed using 6 item checklist
b – Scientific methods were assessed using 5 item checklist and focused on the following areas
- New initiators of treatment
- Concurrent comparators
- Control of covariates/confounders/effect modifier
- Control of immortal time bias
- Analyses to evaluate the potential for bias for biased assessment