IPT Adherence: Are You Maximizing Your TB Prevention?
"Discover key factors influencing isoniazid preventive therapy (IPT) adherence among HIV-positive patients and practical strategies to improve TB prevention efforts."
Tuberculosis (TB), an airborne disease caused by Mycobacterium tuberculosis, remains a significant global health challenge, especially for individuals with HIV. When someone has latent TB, it means the TB bacteria is in their body, but they aren't sick because their immune system is keeping it in check. However, in people with HIV, who often have weakened immune systems, this latent TB can easily turn into active TB disease.
That's where Isoniazid Preventive Therapy (IPT) comes in. IPT is a medication regimen designed to prevent latent TB infection from progressing to active TB disease. For HIV-positive individuals, IPT is a crucial part of comprehensive care, significantly reducing their risk of developing active TB and improving their overall health outcomes.
But here's the catch: IPT only works if people take it consistently and correctly. This is where 'adherence' comes into play. Adherence refers to how well a person follows their prescribed treatment plan – taking the right dose at the right time, every time. Unfortunately, adherence to IPT can be challenging for various reasons. A recent study conducted at Adama Hospital Medical College in Ethiopia sheds light on the factors affecting IPT adherence among HIV-positive patients, offering valuable insights for healthcare providers and individuals alike.
IPT Adherence and Completion
A 2017 study reported median IPT adherence of 97.6% (IQR: 94.2–99.4), with 22 cases of incident TB. Women represented 61.3% of those who initiated IPT in that study. A 2026 review reported IPT completion prevalence of 82.40% (95% CI: 50.54–99.41) and TB cases among people receiving IPT of 2.72%, indicating that adherence and outcomes can vary across settings.
Benefits and Barriers of Standard IPT
WHO evidence summarized from randomized controlled trials found that IPT reduced overall TB risk among people living with HIV by 33% (RR 0.67; 95% CI reported by WHO). An ACTG analysis also found that self-reported adherence to TB medication lowered the probability of death by more than 20% in the IPT group. However, IPT implementation faces barriers including limitations in TB screening and diagnostic capacity, as well as concerns about treatment delivery.
From Isoniazid to Shorter Regimens
The history of tuberculosis preventive treatment began in 1950, when isoniazid was first used in TB treatment, and its potential preventive effect was identified in 1954. A review of IPT efficacy reported that, among participants with good adherence who completed therapy, 52 weeks of IPT was more effective than 24 weeks, with reported efficacy of 93%. WHO notes that shorter preventive-treatment regimens are associated with better adherence and higher treatment completion.
Why IPT Adherence Matters: Unpacking the Research
The study, published in the Journal of Infectious Diseases & Preventive Medicine, involved 168 HIV-positive patients undergoing IPT at Adama Hospital Medical College in Ethiopia. Researchers aimed to determine the level of adherence to IPT and identify the factors that influenced it. The findings revealed a concerningly low self-reported adherence rate of 68.5%.
- Forgetfulness: The most common reason for missing doses.
- Being Away from Home: Disrupting routines and access to medication.
- Being Busy: Leading to missed doses due to time constraints.
- Abdominal Side Effects: Discomfort causing patients to skip doses.
- Unclear Information from Healthcare Providers: Lack of understanding about the importance and proper use of IPT.
- Not Using Memory Aiding Tools: Difficulty remembering doses without reminders.
- Perceived Lack of Confidentiality: Concerns about stigma affecting adherence.
Evidence from Ethiopia and Implementation Reviews
A systematic review from Ethiopia concluded that IPT alone or combined with antiretroviral therapy significantly reduced TB incidence and mortality among people living with HIV compared with those without IPT. A 2024 review of factors influencing IPT uptake examined implementation issues and included research on the effect of m-health on IPT adherence. Together, these reviews point to both clinical benefits and ongoing interest in delivery strategies that may improve adherence.
The Consequences of Non-Adherence
A systematic review reported that poor adherence to TB treatment leaves people infectious for longer and makes relapse and death more likely. The review also identified broader consequences for TB control. Another review described non-adherence as the main challenge for TB control and prevention programs, even though TB can be cured with a six-month first-line antibiotic regimen.
Continuous Versus Six-Month IPT
A report comparing continuous IPT with a six-month course followed by placebo found that 36 months of continuous IPT reduced TB risk by 56% compared with the shorter strategy. This comparison suggests that longer preventive therapy may provide greater protection in some populations. The finding applies specifically to the regimen comparison described in that report and does not establish that continuous IPT is preferable for every patient or setting.
Boosting IPT Adherence: Practical Steps for Better TB Prevention
The study underscores the urgent need for targeted interventions to improve IPT adherence among HIV-positive patients. Healthcare providers play a pivotal role in this effort. Clear and consistent patient education is essential. Providers should take the time to explain the importance of IPT, how to take it correctly, and how to manage any potential side effects.
Prevention Depends on Completion
WHO’s summary of 12 randomized controlled trials involving 8,578 people living with HIV found that preventive treatment reduced overall TB risk by 33%. A clinical trial cited by Johns Hopkins found that 12 months of IPT given with antiretroviral therapy reduced TB incidence by 37% compared with antiretroviral therapy alone. In one reported study, the IPT adherence rate was 83.75%, and patients cited counselling and physicians’ advice as major reasons for good adherence.
Extending Prevention in High-Burden Settings
A 2025 review of TB preventive treatment in high-TB-burden settings reported that meta-analyses found IPT reduced the risk of developing TB disease by more than 60% in children. The review frames effectiveness in children as an important area for preventive-treatment policy and delivery. A 2026 article on moving from targeted preventive therapy to integrated approaches identifies future priorities for TB prevention and notes the continuing goal of reducing TB incidence and mortality in high-burden countries.
Protection Against Progression, Not Certain Reinfection
A 2026 study reported that IPT protects against progression to TB disease. The same source stated that IPT’s effect on preventing new TB infection remains uncertain. This distinction is important when interpreting IPT’s role: preventing progression after infection is not the same as demonstrating prevention of every new infection.
Early Prevention Can Save Lives
A study from a high-TB- and HIV-burden, resource-limited setting indicated that adding IPT to antiretroviral therapy could reduce TB risk among people living with HIV. CDC reporting found that people who started TB preventive treatment soon after entering HIV care had 61% fewer TB cases and 45% fewer deaths. These findings connect adherence and timely preventive-treatment delivery with measurable real-world outcomes.
Here are some practical strategies that can make a real difference:
<ul> <li><b>Simplify the Regimen:</b> Make the dosing schedule as easy to follow as possible.</li> <li><b>Provide Clear Information:</b> Ensure patients understand the benefits and potential side effects of IPT.</li> <li><b>Address Concerns:</b> Create a safe space for patients to discuss their concerns about stigma or confidentiality.</li> <li><b>Offer Support:</b> Connect patients with support groups or peer mentors.</li> </ul>