Table 1

The 20 quality indicators used to rate information provided by STI self-test and self-sample test providers on their websites, the used weigh factors, scoring and additional comments

Decision making
Anal/oral testingDoes the provider describe:
  1. Possibility of anal/oral infections

  2. Advise on anal/oral sampling

4Good=both (+1)
Moderate=1 or 2 (+0.5)
Poor=0 (+0)
Providers selling tests including specific kits for anal or oral sampling automatically score ‘Good’
STI comorbidityDoes the provider mention that it is possible to acquire more than one kind of STI during intercourse and that it therefore would be advised to test for more than one STI?3Yes (+1) No (+0)
Basic STI informationBasic information about the concerned STI described:
  1. Symptoms

  2. Incubation time (window phase)

  3. Transmission route

  4. Type of sample (blood, urine or swab)

  5. Risk factors

  6. Ways of treatment

  7. Easy to find on website, discussed in separate section

3Good=All 7 (+1)
Sufficient=6 or 5 (+0.75)
Moderate=4 or 3 (+0.5)
Insufficient=2 or 1 (+0.25)
Poor=0 (+0)
Window phase
  1. Definition is explained (time between getting infected and moment the infection can be detected by a test)

  2. Given in days, weeks or months

3Good=both (+1)
Moderate=1 (+0.5)
Poor=0 (+0)
Incubation time (time between infection and symptoms) scores moderate
Testing toolDecision tool used for triage, what self-test(s) should be bought, based on gender, sexual preferences and sexual activity2Yes (+1) No (+0)
Risk preventionBasic information about prevention of STI described:
  1. Condom use during vaginal, oral and anal intercourse

  2. Avoid sharing potentially infected/dirty (drug) needles

  3. Tips for successful condom use

  4. Condom use is advised (based on sex behaviour)

  5. Condoms can be bought on website or link to condom shop

  6. Easy to find on website, discussed in separate section

2Good=all 6 (+1)
Sufficient=5 or 4 (+0.75)
Moderate=3 (+0.5)
Insufficient=1 or 2 (+0.25)
Poor=0 (+0)
LevelThe test has a sensitivity+specificity of 95% or higher4Yes (+1) No (+0)
DescribedDoes the provider describe the sensitivity and specificity of the test and are these numbers explained in a clear way that ignorant customers can understand what these numbers mean?2Yes (+1) No (+0)
SupportDoes the provider provide literature on the website, which describes/supports the sensitivity and specificity?2Yes (+1) No (+0)
Quality marks for laboratoryDoes the provider describe what marks/labels apply for their laboratory (performing the diagnose)?1Yes (+1) No (+0)Only self-sample test providers
Quality marks for testing kitDoes the provider describe what marks/labels apply for their sampling kit?1Yes (+1) No (+0)
Contact healthcare professionalPossibility to call or mail a healthcare professional for questions prior to testing2Yes (+1) No (+0)
Video instructionsIs there a video which shows how the sample kit works and what procedures are needed to gather a sample?1Yes (+1) No (+0)
Dutch instructionsIs there a Dutch leaflet and Dutch text on packaging?1Yes (+1) No (+0)Either be mentioned or derived from pictures on the website
Contact providerPossibility to call or mail the provider for further questions1Yes (+1) No (+0)
Diagnostic techniqueIs the type of test (NAAT or antibody) indicated on the website?1Yes (+1) No (+0)
Follow-upWhat follow-up procedure after receiving result is applied?
  1. Partner notification can be performed through provider (P)

  2. Ways of treatment explained, instruction given what to do next and how to get treatment (T)

  3. Counselling by health professional possible after receiving positive result (C)

  4. Get prescription or treatment through provider (R)

  1. (P)=+0.2

  2. (T)=+0.2

  3. (C)=+0.4

  4. (R)=+0.2

Just result=0
Referral to GPDoes the provider advise to visit a general practitioner (GP), hospital, nurse, STI clinic or any other professional healthcare worker/institute when the test result is positive?4Yes (+1) No (+0)
Result communicationResult communication:
  • Active (telephone=T, SMS=M or mail=E)

  • Passive (internet code=I) =+0.5

2Active (+1)
Passive (+0.5)
Not mentioned (+0)
Only self-sample test providers
Partner notificationDoes the provider mention that partner notification is important in case of positive result?2Yes (+1) No (+0)
  • NAAT, nucleic acid amplification test; SMS, short message service.