Table 1.

Survey sections and operationalization.

Section	Details and items (numbered)
Administrative information given by peer researcher	Peer ID, mode of administration of questionnaire, date of administration, and city where participant was recruited
Sociodemographic and personal characteristics	Sex, age, country of birth, country of birth of parents, time spent living in Germany, German language proficiency, visiting country of origin, living situation, steady relationship and time spent with steady partner, religious affiliation and participation in religious community life, level of education, sources of income and height of monthly net income, health insurance status, and health care utilization
Knowledge on hepatitis B/C: Use of informing statements “Did you know this before now?”	(1) Hepatitis is a disease of the liver. (2) Hepatitis B and C can be transmitted through blood or used needles. (3) Hepatitis B can be transmitted through sexual contact. (4) Hepatitis B can also be transmitted from mother to child. (5) Chronic hepatitis is a disease that often progresses unnoticed. (6) An untreated hepatitis can lead to cancer. (7) Chronic hepatitis can be treated successfully. (8) There is a vaccination to protect against hepatitis B. (9) There is no vaccination against hepatitis C.
Knowledge on HIV: Use of informing statements “Did you know this before now?”	(10) HIV and AIDS also exist in Germany. (11) AIDS is caused by a virus called HIV. (12) You cannot tell from someone’s appearance whether he or she has HIV or not. (13) There is a test which shows whether someone is HIV positive or not. (14) Africans are NOT deported from Germany just for having HIV. (15) In [study site] you can get tested for HIV anonymously and for free, eg, at the LPHDa (see flyer). (16) People that have sexually transmitted infections have an increased risk of contracting HIV. (17) HIV is not transmitted through kissing or shaking hands. (18) HIV can be transmitted through sexual intercourse. (19) People with HIV have an increased risk of contracting tuberculosis. (20) There is no cure for HIV infection. (21) There are medications that can help people with HIV stay healthy.
Knowledge on STIsb “Have you ever heard of these STIs?”	(22) gonorrhea, (23) syphilis, (24) herpes, (25) genital warts, (26) chlamydia, (27) I do not know any of them
HIV, hepatitis C, and STI testing	Ever tested for hepatitis C or HIV, last time tested and results, country where last HIV test was done, testing for HIV without consent, last time tested for STI and last time diagnosed with STI, preferred HIV- and STI-testing sites
Sexual behavior and risk factors	Age at first sexual intercourse, sexual attraction, sexual activity within the last 12 months, number of male and female sexual partner(s) within the last 12 months, steady sexual partner(s) and origin of steady sexual partner(s), sex with nonsteady sexual partner(s) within the last 12 months, condom use with nonsteady sexual partner(s), condom use at last sexual intercourse, reasons for not using condoms, experience of sexualized violence and country where that happened
Circumcision and female genital mutilation/cutting (FGM/C) Knowledge on FGM/C: Use of informing statements “Did you know this before now?”	Circumcision and female genital mutilation/cutting (28) Did you know that a reconstruction of the female genitalia is possible for persons who have undergone female circumcision? (29) Did you know that the state health insurance in Germany can cover the cost for the reconstruction?
Behavior toward people living with HIV (PLWH)	Reaction and behavior toward PLWH, personal connection to PLWH, ever heard of PLWH being treated badly in community, HIV/AIDS as a topic discussed in community
Self-stated information needs	Relevant topics for prevention, preferred mode of dissemination

^aLPHD: local public health department.

^bSTI: sexually transmitted infection.