Table 2

Study characteristics for observational studies

StudySettingStudy populationStudy characteristics

  • Clinic/community

  • Country

  • Gender

  • Sexual orientation

  • Selection criteria for recall

  • Recall test

  • HIV status

  • Number (N)

Study designInterventionControlRecall interval
Type of intervention: SMS
Bourne et al27
Clinic
Australia

  • ▸ Male

  • ▸ MSM

  • ▸ High-risk sexual behaviour

  • ▸ HIV/STI screen

  • ▸ HIV-negative

  • ▸ Number=3551

Non-randomised before–after studySMS

  1. Concurrent control

  2. Historic control

4 months
Zou et al28
Clinic
Australia

  • ▸ Male

  • ▸ MSM

  • ▸ All MSM

  • ▸ Syphilis test

  • ▸ HIV status not specified

  • ▸ Number=4179

Non-randomised before–after studySMS or email

  1. Concurrent control

  2. Historic control

3 months /6 months /12 months
Burton et al29
Clinic
UK

  • ▸ M (243/539: 45%), F (296/539: 55%)

  • ▸ Heterosexual, MSM

  • ▸ Patients at higher risk of STIs and in HIV window period

  • ▸ HIV/STI screen

  • ▸ HIV status not specified

  • ▸ Number=539

Non-randomised before–after studySMSHistoric control4 months
Guy et al9
Clinic
Australia

  • ▸ M (192/343: 56%), F (151/343: 44.0%)

  • ▸ Heterosexual

  • ▸ Chlamydial infection

  • ▸ Chlamydia test

  • ▸ HIV status not specified

  • ▸ Number=681

Non-randomised before–after studySMS

  1. Concurrent control

  2. Historic control

3 months
Type of intervention: Postcard/letter
Paneth-Pollak et al30
Clinic
USA

  • ▸ M (4168/6220: 67%), F (2079/6220: 33%)

  • ▸ All sexual orientation

  • ▸ Chlamydia or gonorrhoea diagnosis

  • ▸ Chlamydia/gonorrhea test

  • ▸ HIV status not specified

  • ▸ Number=6220

Non-randomised before–after studyPostcard

  1. Standard care in non-intervention clinics

  2. Historic control

3 months
Type of intervention: Phone
Harte et al31
Clinic
UK

  • ▸ Male

  • ▸ MSM

  • ▸ Diagnosis with acute bacterial STI (chlamydia, gonorrhoea, syphilis, LGV)

  • ▸ HIV/STI screen

  • ▸ HIV-positive and HIV-negative

  • ▸ Number=301

Non-comparative studyPhoneN/A3 months
Type of intervention: send home sampling kit
Bloomfield et al32
Clinic
USA

  • ▸ M (186/312: 59%), F (127/312: 41%)

  • ▸ MSM (57/312: 18%)

  • ▸ Chlamydia diagnosis

  • ▸ Chlamydia test

  • ▸ HIV status not specified

  • ▸ Number=399

Non-comparative studyMailed home sampling kitN/A1–6 months
Gotz et al33Community
Netherlands

  • ▸ M (1177/4191: 28%); F (3014/4191: 72%)

  • ▸ Sexual orientation not specified

  • ▸ Chlamydia diagnosis

  • ▸ Chlamydia test

  • ▸ HIV status not specified

  • ▸ Number=4191

CohortHome sampling kit mailedn/a6 months
LaMontagne et al34
Clinic
UK

  • ▸ Female

  • ▸ Chlamydia diagnosis

  • ▸ Chlamydia test

  • ▸ HIV status not specified

  • ▸ Number=592

Non-comparative studyHome sampling kit mailedN/A3 months
Walker et al35
Community
Australia

  • ▸ Female

  • ▸ Chlamydia diagnosis

  • ▸ Chlamydia test

  • ▸ HIV status not specified

  • ▸ Number=1116

Prospective cohortHome sampling kit mailedN/A3 months if STI
6 months and 12 months for everyone
Cameron et al36
Community UK

  • ▸ Female

  • ▸ Chlamydia diagnosis

  • ▸ Chlamydia test

  • ▸ HIV status not specified

  • ▸ Number=330

Non-comparative studyHome sampling kit mailed and telephone reminderN/A3 months

  • MSM, men who have sex with men; STD, sexually transmitted disease; STI, sexually transmitted infection.