Comparing frequency of testing between individuals accessing sexually transmitted and blood-borne infection testing online and those testing in clinic

Background
Internet-based sexually transmitted and blood-borne infection (STBBI) testing services reduce testing barriers by bypassing face-to-face clinical encounters, thereby potentially enabling clients at ongoing sexual risk to test more frequently. To our knowledge, this hypothesis has not been previously tested. We compared the frequency of repeat testing between Vancouver-based clients of GetCheckedOnline (GCO)—an internet-based STI testing service in British Columbia, Canada—and clients of a large Vancouver STI clinic for 2.5 years after GCO launched.

Methods
An administrative data cohort (N=19,995) was assembled using GCO, clinical, and laboratory databases. We included all individuals who tested for HIV, gonorrhea/chlamydia, syphilis, or hepatitis C at the STI clinic or using GCO, between September 2014 and February 2017 (29 months). The rate of repeat testing (>30 days after first episode) was compared between those clients who used GCO at least once and those who tested only in the STI clinic. Poisson regression was used to generate rate ratios (RR) for repeat testing, with adjustment for age, gender and gender of partners, STBBI risk (based on whether they were a contact to STBBI or history of STBBI diagnosis), and pre-intervention rate of testing.

Results
1108 GCO clients were identified, of whom 684 (62%) tested more than once, and 277 (25%) also tested at least once in the STI clinic. 9646/18887 (50%) of clinic clients tested more than once. During the 29-month analysis period, GCO clients re-tested 1.81 times per person-year, while clinic clients re-tested 1.53 times per person-year, resulting in a crude RR of 1.19 (95% CI: 1.13, 1.24). Adjustment for covariates increased the RR to 1.45 (95% CI: 1.37, 1.53).

Conclusions
In this cohort, individuals using internet-based STBBI testing had a rate of repeat testing 19% greater than clinic-based clients. This effect was increased after adjusting for characteristics associated with higher test frequency. The online interface of GCO appears to facilitate more frequent testing and may therefore contribute to earlier STBBI diagnosis.