Figures & data
Figure 1. PRISMA flow diagram. Abbreviation: PRISMA: preferred reporting items for systematic reviews and meta-analyses.
![Figure 1. PRISMA flow diagram. Abbreviation: PRISMA: preferred reporting items for systematic reviews and meta-analyses.](/cms/asset/469301e8-222b-43b2-8b0f-78d771fc3b8a/isum_a_2019783_f0001_c.jpg)
Table 1. Bias risk assessment ratings.
Table 2. Kappa statistics by biospecimen, substance, and self-report period among studies that reported kappa values.