Table 4. Included studies with response rates reported or able to be calculated (n = 30), by other reported characteristics.

Study	Survey mode	Reported response rate (%)	Reported information relevant to RR	How many and what type of attempts were made to contact subjects?*	Who approached potential subjects?*	Where were potential subjects approached?*	How was informed consent obtained?*	How did those who agreed differ from those who did not agree?*	What was the average time taken to complete survey (minutes)?	Was an incentive to participation offered?
Ahmed [28]	F2F interview	48	Number invited: 425 Number consented: 205	NR	NR	Mosques, local cafes, restaurants	Verbal	NR	60	No
Alvarez-del Arco, Fakoya et al. [30]	Device	70	Number invited: 3251 Number eligible: 3152 Number consented: 2209	NR	Researcher or member of clinical care team	Clinic	NR	Participation higher in men, decreased with age and was higher in migrants from Latin America and Eastern Europe and lower in those from Sub-Saharan Africa	NR	NR
Asante, Körner et al. [33]	Paper	>95 in Thai, Ethiopian and Sudanese communities Less in Cambodian community	Only reported for Cambodian community Number invited: 104 Number consented: 86	NR	Co-workers from the relevant language backgrounds, as well as some members of the reference groups, would lead the recruitment and assist participants to complete the questionnaires	Mainly at places of worship, community events and other social gatherings	NR	NR	20–25	NR
Bastani, Glenn et al. [34]	Paper Phone interview	94 (B) 86 (F)	Number screened: 1,866 Number eligible: 1,196 Number enrolled at baseline: 1,123	In-person on a single day	Staff members	Church	NR	NR	NR	NR
Coronado, Taylor et al. [40]	F2F interview	Figure not reported but relevant data presented (see next column)	Number screened: 1,902 Number enrolled: 436 (6 later excluded due to ineligibility) Number refused: 314 Number ineligible at screening: 628 households + 105 (non-residential) Number unable to be contacted: 419	Households received an introductory letter (traditional Chinese, simplified Chinese, and English versions). Called 2 weeks later. Up to 5 contact attempts made.	Chinese interviewer of same gender	Home	NR	NR	30	Calendar and $20
Duan, Ding et al. [26]	F2F interview	Figure not reported but relevant data presented (see next column)	Among the total of 7656 mixed couples, 6269 Chinese spouses and 7092 Burmese immigrant spouses gave informed consent to participate including both spouses of 5742 couples. Only the 5742 couples with both spouses participating in the survey were included.	NR	Trained public health worker (or, where necessary, village or community clinical doctors who were able to speak and understand Burmese)	NR (but interviews principally conducted in homes)	NR	NR	NR	$10
Evans, Suggs et al. [49]	Paper Online Phone Device (SMS)	61	Number invited: 281 Number consented: 172 (3 later excluded)	Not reported for baseline	Community researchers	Voluntary sector groups and community venues	Written	NR	NR	GBP 5 shopping voucher
Foster, McCormack et al. [55]	Paper	94	Number distributed: 488 Number returned: 460	NR	Sexual health clinic staff and health education officers	Sexual health clinic and sex work parlours	Implied (consent form prefaced survey)	NR	NR	NR
Grieb, Flores-Miller et al. [59]	Paper	Figure not reported but relevant data presented (see next column)	Number screened: 135 Number eligible: 113 Number consented: 104	NR	Trained research assistants	Street- and community-based venues	Verbal	NR for non-response/refusals but noted that no differences in age, country of origin, education, time in the United States, or time in Baltimore were observed between those who were eligible and those who were not.	10–15	$10
Hamdiui, Stein et al. [60]	Paper Online	69.1	Number invited: 350 Number participated: 242 (excluding 165 people recruited by participants who accepted the invitation–no RR reported for the total sample which included respondent-driven sampling methods)	Number of attempts NR Online-recruited respondents were enrolled through advertisements on Moroccan-Dutch forums, Facebook, Instagram, websites. Recruiting peers online was enabled through indirect email, WhatsApp, Facebook, or by sharing a hyperlink.	Peer (respondent-driven sampling)	Online and at community venues, such as community centres, day care centres, mosques, interest groups, and civil support foundations.	NR	NR	NR	Gift coupon when recruited at least three other respondents (value increased in three steps to enhance peer recruitment: €5, €10, and €25).
Hislop, Teh et al. [61]	F2F interview	59	Households selected: 1500 Number of non-residential: 41 Number unable to contact: 149 Number ineligible: 375 Number refused: 384 Number of interviews completed: 551 (504 when non-migrants excluded)	Five door-to-door attempts	Trilingual Chinese interviewer	Home	NR	NR	45	$20
Jenkins, McPhee et al. [63]	Phone interview	93	Call attempts: 12,094 Call attempts that reached eligible respondents: 1624 Number consented: 1508	Up to five attempts by phone	NR	Phone	NR	NR	NR	NR
Juon, Lee et al. [67]	Paper	98 (B) 78 (F)	Eligible program participants: 940 Number of no-shows: 47 Number who did not complete baseline or did not participate: 13 Number who participated in program in past year: 3 Number who completed baseline: 877 Number who completed follow-up: 688	NR	NR	Community based organisations, college cultural organisations, Asian grocery stores, restaurants, nail salons	NR	NR for baseline Differences at follow-up described	NR	NR
Kara [68]	Paper Online	35	Number of surveys distributed: 525 Number of surveys returned: 186	NR	Partners from member organisations made initial contact	Online	Electronic (for online survey) Implied (for written survey)	NR	10–30	NR
Lessard, Lebouche et al. [71]	Phone interview	54	Number eligible: 74 Number refused: 4 Number unable to be contacted: 30 Number participants: 40	NR	Service staff member made initial contact, followed up by researcher	Phone	Written	NR	10–15	None
Maxwell, Bastani et al. [76]	F2F interview Phone interview	51 (B) 68 (F)	Number recruited at clinic: 98 Number who attended workshop: 46 (+ 8 peer recruits) Number who completed baseline survey: 54 Number who completed follow-up survey: 44 workshop attenders and 28 non-attenders	NR	Clinical phlebotomist briefly described study, researcher followed up with those interested	Clinic	Written	Participants who completed post-test reported significantly more years of schooling than those who did not complete.	NR	$5 for initial interview, $10 for workshop participation, $15 for post-test
Montealegre, Risser et al. [79]	F2F interview	Figure not reported but relevant data presented (see next column)	Number screened: 230 Number eligible: 222 Number consented: 221 (one did not complete interview and data from ten excluded from analysis or lost)	Number of attempts NR Seeds and eligible participants were given three serially numbered study coupons to recruit peers. Study coupons provided recruits with the name and a short description of the study, project phone number, name and address of the interview sites, hours of operation, and the coupon’s expiration date.	Peer (respondent-driven sampling)	NR	Verbal	NR	60	Seeds and participants were given $20 for completing the interview and $5 for each of up to three peers they recruited into the survey.
O'Connor, Shaw et al. [80]	Phone interview	66	Number invited: 761 Number consented: 506 (seven later excluded from analysis)	NR	Men were telephoned by a Vietnamese speaking woman	Phone	NR	NR	NR	NR
Ogungbade [81]	Paper	86	Number of surveys distributed: 194 Number of surveys returned: 167	Flyers distributed. Researcher addressed potential participants at an event. Returned one week later to conduct survey.	Researcher (Nigerian migrant)	Faith-based organisations	Implied consent form given explaining that completion of survey was considered consent	NR	NR	NR
Organista and Kubo [82]	F2F interview	>90	Notes from outreach workers indicate that less than 10% of men approached refused participation.	NR	Spanish-speaking project team members who introduced themselves as local public health outreach workers	Street corner	NR	NR	45	$20 fast food voucher
Ramanathan and Sitharthan [86]	Online	42	Number surveys attempted: 438 Number of surveys completed: 278 Number of completed surveys in which SHBBV section also completed: 184	Advertisements on Indian specific websites and social networking websites (e.g. Google, Facebook).	N/A (internet advertising)	Indian specific websites and social networking websites	NR	NR	NR	NR
Rangel, Martinez-Donate et al. [87]	Paper	90	Number invited: 1,606 Number consented: 1,429	NR	Trained Mexican interviewers	International airport, bus stations, deportation stations	Verbal	NR	NR	NR
Salabarria-Pena, Lee et al. [89]	F2F interview	97	Number invited: 222 Number ineligible: 42 Number refused: 5	In-person (quantity unclear)	NR	Clinic waiting room	Verbal	NR	60	NR
Santos-Hovener, Marcus et al. [91]	Paper F2F interview Phone interview	Figure not reported but relevant data presented (see next column)	Surveys distributed: 950 Number returned: 649 Number eligible: 569	NR	Peer researchers	NR	Verbal	NR	NR	Key chain, shopping cart chip, referral to health promotion information sessions, condom, informational flyers and free testing services
Şimşek, Yentur Doni et al. [94]	F2F interview	100	A total of 961 married women were identified in 458 houses. One eligible woman from each selected house was randomly selected. A total of 458 women provided written and signed informed consent; the response rate among eligible women was 100.0 percent.	12 attempts made to contact	Trained Syrian midwife research assistant, lab technician and a translator from the area	Home	Written and verbal	NA	NR	NR
Taylor, Jackson et al. [99]	Phone interview	70	Initial sampling frame: 161 Number unable to contact/ phone disconnected: 42 Number ineligible: 12 Number consented: 75	Number of attempts NR Introductory letter followed by telephone call	Bilingual, bicultural Vietnamese survey workers	Home	NR	NR	NR	$10 voucher
Taylor, Jackson et al. [100]	F2F interview	73 (B) 56 (F)	NR for baseline Three hundred and twenty (77 percent) of the 413 women who participated in the baseline survey also completed the follow-up survey. Therefore, the estimated overall response rate with respect to the hepatitis B questions was 56 percent (i.e., 77 percent of 73 percent).	NR	Bilingual, bicultural Cambodian women	Home	NR	NR	NR	Calendar at baseline, $5 at follow up
Taylor, Choe et al. [101]	F2F interview	80–82	Details obtained from related papers cited. Number of unsuccessful contact attempts: 41 (women); 47 (men) Number ineligible: 116 (women); 131 (men) Number eligible but refused: 66 (women); 70 (men) Number completed: 370 (women); 345 (men) Estimated proportion of eligible where eligibility was not established: 79% (women); assume proportion of eligible same as those not contactable (men)	Five door-to-door attempts	Bilingual, bicultural interviewers (gender matched)	Home	NR	NR	45	Posters
Taylor, Tu et al. [102]	F2F interview	Figure not reported but relevant data presented (see next column)	Interviews completed: 436 Number of households refused: 314 Number of households ineligible: 628 Number of uncontactable households: 419 (plus 105 non-residential addresses)	Introductory letter followed by five door-to-door attempts	Chinese interviewer of same gender	Home	NR	NR	NR	$20
UNHCR [106]	F2F interview	Figure not reported but relevant data presented (see next column)	Kala camp Number of forms completed: 828 Number of refusals: 34 Number unable to contact: 224 Kala communities Number of forms completed: 880 Number of refusals: 17 Number unable to contact: 169 Mwange camp Number of forms completed: 916 Number of refusals: 20 Number unable to contact: 389 Mwange communities Number of forms completed: 854 Number of refusals: 16 Number unable to contact: 349	In-person 1–3 times	Research assistants	Home	Oral (with interviewer’s signature)	NR	NR	NR