Web Appendix Assessing network scale-up estimates for groups most at risk for HIV/AIDS: Evidence from a multiple method study of heavy drug users in Curitiba, Brazil

These supporting online materials have 9 sections. Section 1 describes the known population and summation methods of personal network size estimation and how we used the data from our study to decide between them. These personal network size estimates are used in the network scale-up and generalized network scale-up estimates described in Sections 2 and 3. Next, Sections 4 and 5 describe the multiplier and direct estimates, two commonly used alternatives to the network scale-up method. Section 6 considers the possibility of interviewer effects in the network scale-up estimates. Section 7 compares the scale-up based estimates to Brazilian and international benchmarks. Section 8 discusses the definitions used in each of our data sources. Finally, Section 9 provides the exact question text in Portuguese (along with English translations) that were used for the direct estimates.