Toung tuberculosis patients – including those co-infected with HIV, recently hospitalised and those with lower CD4 counts – are likely to default on TB treatment or miss their appointments, resulting in poor health outcome, a new study has suggested.

According the Wits University research, which observed missed appointments among rifampicin-resistant (RR) TB patients at a decentralised TB outpatient clinic in Johannesburg, researchers found that 60% of missed appointments among TB patients occurred within the first three months following rifampicin-resistant TB treatment initiation.

Rifampicin is one of the most effective first-line anti-TB antibiotics used to treat TB across the world.

Of the 172 patient records reviewed as part of the study, mostly among patients co-infected with HIV, 53.5% of patients missed one or more appointments during outpatient treatment for RR-TB – raising worry among the researchers.

Patients referred from inpatient care or hospital, HIV-infected patients with a low CD4 count of about 100, and young patients (18 – 24 years) were at a significantly increased risk of missing an appointment.

Missing at least one scheduled appointment at the RR-TB clinic was strongly associated with poor treatment outcomes, while patients missing three or more appointments were considered less likely to complete treatment successfully.

The study also found a high degree of immunosuppression among RR-TB patients co-infected with HIV – suggesting that sicker patients were more prone to missed appointments.

While the study was a review of medical records and therefore could not determine the reasons for the missed appointments or causality, the latest findings that showed that patients between the ages of 18 and 24 years were at a three times higher risk of treatment default, was raised as a concern by researchers.

They also found that the age group 25 – 34 years was at a two times higher risk of missing an appointment compared with patients aged 35 – 44 years – similar to other studies that had been done previously.

Writing in the SA Medical Journal, lead researcher, Kathryn Schnippel from Right to Care, and Wits University said the latest findings showed that it was critical to develop targeted and age-appropriate interventions for the young ­patient initiated on RR-TB.

She raised concerns that patients with low CD4 counts seemed to miss appointments, saying this was alarming given the fact that a low CD4 count was a strong predictor of opportunistic infections and mortality among HIV-positive patients.

“Furthermore, the finding that a high proportion of HIV-infected patients (39.2%) were not on ART at the time of RR-TB treatment initiation confirms that they were not initiated on effective treatment for their HIV. The high risk of missed appointments among HIV-positive patients with a (low) CD4 count may be a result of these patients being too sick to attend outpatient appointments,” she said.

The study also found that missed appointments occurred earlier among patients referred from hospital than those referred from outpatient care, again suggesting that sicker patients were more prone to missed appointments.