1. Matilu Mwau, M.D., MTM, D.Phil(Oxon)
Performance and usability of INSTI, a blood-based rapid HIV self test for qualitative detection of HIV antibodies in intended use populations in Kenya
Matilu Mwau, M.D., MTM, D.Phil(Oxon)

2. Kenya in 2015 Kenya 1.5 million PLWHIV 5.9% adult HIV prevalence
Some counties >25% eg Homa Bay
78,000 new infections
58% of infected adults are on ART
83% HIV+ unaware of partners’ status
May, 2017, PrEP approved
-“Be Self Sure” HIV self testing program

3. Study Objectives
Determine the performance and usability of the INSTI blood-based HIV self test (bioLytical Laboratories, Richmond, BC, Canada) for an intended-use self test population in Kenya.
Device performance
Label comprehension
Readability
Results interpretation

4. INSTI HIV Self Test Key Features
Same platform as INSTI HIV-1/HIV-2 Ab Test
Blood-based
Use a 50uL free-flowing blood drop
fingerstick collection Sensitivity 100%
Specificity 99.8% 4

5. Procedure (English and Swahili)
INSTI Self Test
Procedure (English and Swahili)
Sample. Pour. 60s 5

6. Study site and design Site: Western Kenya (Busia County)
Matayos, Bumutiru,Khunyangu, Aterait and Asinge villages
Time: 22nd Mar -11Apr 2017
688 study participants
554 consented for fingerstick and venous blood draws
134 consented for fingerstick only
354 participated in the label comprehension (usability) study
91 subjects completed the results interpretation study

7. Accuracy (1) Fingerstick blood used for observed self testing
476 participants completed accuracy study
201 known HIV positive.
Demographics,
> 18 years of age,
able to provide informed consent,
able to read, write and speak English/Swahili
Fingerstick blood used for observed self testing
Venous blood sent to KEMRI Lab for Bioelisa HIV-1+2 Ag/Ab kit (Biokit S.A, Barcelona, Spain)
INSTI HIV Self Test results produced by subjects
Self Test results interpreted and recorded by HCW

8. Accuracy (2) Subject HIV Status INSTI Negative Positive Total 267 2
269 3
198
201
Invalid 6 6*
270
206
476
INSTI Sensitivity: 198/201 = 98.5% ( %)
INSTI Specificity: 267/269 = 99.26% ( %)
* Invalid results not used in the calculations

9. Usability Results (n=350)
Observed IFU Element
Subject Completed Correctly
Preparation of finger fingerstick
346 (98.9%)
Correct use of lancet with no assistance
291 (83.1%)
Correct use of lancet with assistance
58 (16.6%)
Able to form “hanging” blood drop on finger with no assistance
348 (99.4%)
Able to easily get the blood drop to fall into INSTI sample diliuent
349 (99.7%)
Properly mixed and added sample diluent/blood to INSTI blotted membrane unit
Correctly completed remaining INSTI test procedure
University: 22. Secondary: 123. Primary No formal education. 48. Not recorded. 5.
354 participants were recruited and 350 completed the survey-based usability, label comprehension and ease of use elements as observed and recorded by the health care staff

10. Acceptability (n=350) Questionnaire Item Responses
Used the INSTI instructions for use to perform the test
343 (98.0%)
Found instructions easy to comprehend
339 (96.9%)
Considered the INSTI test easy to perform
330 (94.3%)
Found results interpretation easy to comprehend
342 (97.7%)
Indicated willingness to use INSTI again
Would recommend INSTI to partner, family
344 (98.3%)

11. INSTI Results Readability(n=91)
Correct Interpretation (n=91)
Strong Positive
91 (100%)
Weak Positive
31 (34.1%)*
Negative
Invalid (no control spot)
Subjects were asked to interpret a range of INSTI results using the IFU for contrived membrane cartridges representing strong positive, weak positive, negative and invalid results.
* The remaining 65.9% of subjects saw the weak spot but were unsure on how to interpret the result

12. Conclusions INSTI PPV=89.3%, INSTI NPV=99.9%
Based on the performance of the INSTI HIV Self Test in this study
HIV prevalence in Kenya of 5.9%:
INSTI HIV Self Test device performance meets the Kenya MoH threshold.
Overall label comprehension is high (96.9%)
57.1% of participants had primary or no formal education.
In the usability study, more males (206) than females (142) took part
likely due to the use of county administration and village events to mobilize participants
Poor interpretation for the weak positive result
? discordance in the IFU image between the English and Swahili versions.
The manufacturer has revised the IFU to provide more clear instructions on weak positive interpretation.

13. Acknowledgements Priska Bwana Lydia Ochieng Alupe HIV Lab
KEMRI HQ HIV Lab