How Accurate are At-Home STI Tests

It’s easy to see why at-home STI tests have become so popular in Canada — they offer privacy and convenience, allowing you to test for common sexually transmitted infections (STIs) right from the comfort of home. But with something as important as your sexual health, you might be wondering: how accurate are these tests, and can you rely on them?

In this article, we’ll explore what impacts the accuracy of at-home STI tests, how they stack up against traditional testing, and what you should consider if you’re considering trying one. We’ll also break down the differences between self-collection and lab-based testing, so you can make an informed decision that feels right for you.

Understanding the reliability of at-home STI tests

The accuracy of at-home STI testing depends on several key factors: the type of test, the manufacturer of the kit, and how well the user follows the instructions. Each of these plays a role in determining how reliable your results will be.

While many at-home STI tests claim to be just as accurate as those performed in a clinic, it’s important to remember that not all tests are created equal. When it comes to your health, here are some things to consider:

• Type of test: At-home tests typically involve urine, swabs, or blood samples. Blood tests for infections like HIV and syphilis are generally consistent. However, urine samples used to detect chlamydia or gonorrhea can be more sensitive to how the sample is collected and managed.
• Following instructions: To get the most accurate results, it’s essential to carefully follow the instructions included with the kit. Unlike tests done in a clinic, where trained professionals handle everything, you’re responsible for collecting and managing the sample yourself. Mistakes during this process can lead to inaccurate results, including false positives or negatives.
• Manufacturer and test quality: Not all testing kits are held to the same standards. While some manufacturers are known for their high-quality and rigorously tested kits, others may not be as reliable. To make sure you’re using a trusted brand, it’s a good idea to read reviews and research the company’s reputation.

Research on at-home test accuracy

There have been a few studies assessing the accuracy of at-home STI testing when compared to in-clinic testing. A 2023 study published in the Infectious Disease Reports indicated that meticulously, self-collected samples for chlamydia and gonorrhea were as accurate as samples that were collected by professionals.
In 2021, another study found that, when done appropriately, at-home HIV testing also carried a high degree of reliability. Although the studies show promise, they do highlight how critical it is to collect the samples correctly and carefully follow the directions provided to obtain the most accurate results. The research generally suggests that at-home testing can be almost as reliable as lab testing if samples are obtained while following the instructions. 

Factors influencing at-home test accuracy

It’s important to understand the factors that can influence the accuracy of at-home STI tests.

To properly mitigate risks, you should consider the below: 

• User error: Not reading or misinterpreting the instructions, contaminating the sample or not collecting enough of a sample can all influence your results, resulting in false positives or negatives. This is the most significant contributor to weakening the accuracy of the results. 
• Sample collection methods: Depending on the STI being tested for, sample types vary. The samples required could be blood, urine, or swabs of the oral, genital, cervical, or rectal area. The precision of the test results relies on the sample being collected correctly. For example, insufficient blood or swabbing the wrong area can compromise the results. Many self-collection kits contain detailed instructions with visual aids; however, there is still room for user error.
• Quality of the testing kit: Not every kit available is of equally high-quality. Some kits may lack the quality control found in kits from reputable companies backed with extensive research and development. 

Comparing at-home tests to lab tests

Both at-home and lab-based STI testing have their own advantages and drawbacks. Understanding the pros and cons of each can help you decide which method is right for you. Here’s what to consider:

Some important considerations include: 

Accuracy and reliability: Lab tests are widely regarded as the gold standard for accuracy. Conducted by medical professionals, these tests involve immediate processing of samples and a comprehensive collection process, which increases sensitivity and reduces the chance of erroneous results.

In contrast, at-home testing offers unmatched convenience — you can collect the sample at your own pace and avoid the discomfort of a clinic visit. However, accuracy can suffer if the sample is not collected, managed, or delivered properly to the lab.

False positives and negatives: While lab tests are generally more reliable due to expert handling, both at-home and lab-based tests have the potential for false positives and negatives. The key difference is that at-home testing carries a higher risk of user error, which can affect the outcome.

Benefits of at-home testing: At-home testing is especially beneficial for individuals in rural areas with limited access to clinics. It offers quick results — often within a few days — and the primary advantage is privacy. Many people prefer the comfort of testing at home, avoiding the stress or embarrassment that can come with visiting a clinic.

Benefits of clinic testing: The entire process — from sample collection to diagnosis — is supervised by trained professionals, reducing the chance of error. Clinics also provide additional support, including treatment options, counselling, and assistance with partner notification if needed. For those seeking a more comprehensive approach to testing and treatment, visiting a clinic may be the best choice. 

Instructions and user error

When using at-home testing kits, following the instructions to the letter is extremely important. Not doing so can greatly influence the accuracy of your testing results.

Let’s examine two hypothetical at-home testing kits, one for chlamydia and the other HIV.

• Chlamydia test: This test may use a urine sample. The instructions would likely specify that the sample should be obtained from the first portion of your urine stream as the bacterial concentration will be the highest as opposed to the midstream collection. Failing to follow that specific instruction could result in an inaccurate result. 
• HIV Test: This test requires a small sample of your blood. Like a glucose test that a diabetic would take, it would require a finger prick, and a drop of blood placed on a test strip. If the blood does not completely cover the test strip, the result may produce a false negative. 

These two hypothetical tests show that even a small deviation from the instructions can impact your results. To avoid this, take your time, read the directions, and double-check each step to maintain the accuracy of your results. 

Sample collection process

The type of sample required depends on the type of STI you’re testing for, and the sample collection process directly influences the accuracy of at-home testing. 

• Urine sample collection: Urine sampling is commonly used to detect chlamydia and gonorrhea. Due to the abundance of bacteria in the first part of your urine stream, collecting the sample from that portion is essential. Collecting the urine from midstream could alter the results due to dilution, resulting in a misleading negative test. 
• Blood sample collection: To test for HIV or syphilis, a finger prick is required to draw a blood sample. You must ensure that there is enough blood to fully cover the test strip or fill the collection vial for the most accurate results.
• Swab sample collection: Swab samples are usually taken from the genital area, throat, or rectum. Not using the proper technique or correct swab can result in an inadequate sample, giving inaccurate results. 

Recommendations for at-home STD testing

If you’re contemplating using STI testing in your home, here are some recommendations for obtaining the most accurate results possible.

• Research the test: Read reviews and choose a credible company with a good reputation and who provides clear instructions.
• Follow instructions carefully: Take your time to read and perform the instructions carefully. Double-check each step. Even small deviations can impact your results. 
• Ensure proper sample collection: Be thorough and meticulous during the sample collection process. 
• Consider timing: Remember that some STIs take time to be measurable on a test after an exposure. Ensure the timing of the test is appropriate.
• Seek medical advice if needed: If you receive a positive result, it’s very important to seek medical guidance. Conversely, if you receive a negative result but are experiencing symptoms, it’s equally important to follow up for more testing. 

You may want to speak to a primary care provider if you’re not sure about your next steps. If you’re among the millions of Canadians without a primary care provider, remember that you can always try Maple. 

A membership on Maple allows you to speak with a primary care provider, like a doctor or nurse practitioner, 24/7/365 over secure text, audio, or video call in minutes. Primary care providers on Maple can talk to you about any symptoms you may have, offer advice on having safe sex or talking to a partner about STI testing, and help you find a place to go for testing.

While making well-informed decisions about your health, consider the factors that affect a self-collected STI kit’s reliability. When used as intended, at-home STI tests are a reliable, private, and convenient way to monitor your sexual health. Remember that regular testing is essential to maintain your sexual health, regardless of whether you choose at-home testing or visiting a clinic.

The information presented here is for educational purposes and is not meant to replace the advice from your medical professional. Virtual care is not meant for medical emergencies. If you are experiencing an emergency like chest pain or difficulties breathing, for example, please call 911 or go to your nearest emergency room.