Oral Presentation 20th Lancefield International Symposium on Streptococci and Streptococcal Diseases 2017

Measuring adherence to secondary prophylaxis for acute rheumatic fever and rheumatic heart disease: which indicators predict ARF recurrences and can be easily monitored? (#31)

Jessica de Dassel 1 2 , Anna Ralph 2 3 , Jonathan Carapetis 4
  1. Charles Darwin University, Darwin, NT, Australia
  2. Menzies School of Health Research, Casuarina, NT, Australia
  3. Department of Medicine, Royal Darwin Hospital, Darwin, NT, Australia
  4. Telethon Kids Institute, Subiaco, Western Australia, Australia

Background: Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) cause significant burdens worldwide. Many RHD control strategies depend on secondary prophylaxis (SP) – regular long-term antibiotics - to prevent disease progression, but few studies have examined associations between adherence and clinical outcomes.  Adherence to SP is typically reported as the percent of doses administered or, increasingly, as ‘days at risk’ (DAR). We sought to identify which measures of adherence predict ARF recurrences and are practical to monitor.

Methods: Associations between recurrences and adherence (percent, total annual DAR, annual maximum continuous DAR) were analysed using data from Australia’s Northern Territory. Logistic regression was used to estimate odds ratios (OR) for recurrence.

Results: ‘Non-adherent’ people (<80% doses) were approximately two and a half times more likely to have a recurrence than ‘adherent’ people (OR: 2.74, (95%CI: 1.22 – 6.16), p<0.05). People with ≥70 DAR were six times more likely to have a recurrence than people with <70 DAR (OR: 6.20 (95% CI: 1.40 – 27.56), p<0.05); people with >42 continuous DAR were twice as likely to have a recurrence than people with shorter DAR durations (OR: 2.17 (95% CI: 1.15 – 4.12), p<0.05).

Conclusions:We show for the first time that increased adherence to SP is associated with reduced risk of ARF recurrence in Australia. Several adherence measures significantly predict recurrences. Total DAR could be adopted for patient- and clinic-level monitoring. At jurisdiction level, percent adherence could be used, however programs should also report recurrence rates as a performance indicator.