How Many Doses Make a Difference? An Analysis of Secondary Prevention of Rheumatic Fever and Rheumatic Heart Disease.

Background Acute rheumatic fever ( ARF ) and rheumatic heart disease cause substantial burdens worldwide. Long-term antibiotic secondary prophylaxis is used to prevent disease progression, but evidence for benefits of different adherence levels is limited. Using data from northern Australia, we identified factors associated with adherence, and the association between adherence and ARF recurrence, progression to rheumatic heart disease, worsening or improvement of rheumatic heart disease, and mortality. Methods and Results Factors associated with adherence (percent of doses administered) were analyzed using logistic regression. Nested case-control and case-crossover designs were used to investigate associations with clinical outcomes; conditional logistic regression was used to estimate odds ratios ( OR ) with 95% CIs Adherence estimates (7728) were analyzed. Being female, younger, having more-severe disease, and living remotely were associated with higher adherence. Alcohol misuse was associated with lower adherence. The risk of ARF recurrence did not decrease until ≈40% of doses had been administered. Receiving <80% was associated with a 4-fold increase in the odds of ARF recurrence (case-control OR : 4.00 [95% CI : 1.7-9.29], case-crossover OR : 3.31 [95% CI : 1.09-10.07]) and appeared to be associated with increased all-cause mortality (case-control OR : 1.90 [95% CI : 0.89-4.06]; case-crossover OR 1.91 [95% CI : 0.51-7.12]). Conclusions We show for the first time that increased adherence to penicillin prophylaxis is associated with reduced ARF recurrence, and a likely reduction in mortality, in our setting. These findings can motivate patients to receive doses since even relatively low adherence can be beneficial, and additional doses further reduce adverse clinical outcomes.

A systematic review of adherence in Indigenous Australians: an opportunity to improve chronic condition management.

BACKGROUND: Indigenous Australians experience high rates of chronic conditions. It is often asserted Indigenous Australians have low adherence to medication; however there has not been a comprehensive examination of the evidence. This systematic literature review presents data from studies of Indigenous Australians on adherence rates and identifies supporting factors and impediments from the perspective of health professionals and patients. METHODS: Search strategies were used to identify literature in electronic databases and websites. The following databases were searched: Scopus, Medline, CINAHL Plus, PsycINFO, Academic Search Premier, Cochrane Library, Trove, Indigenous Health infonet and Grey Lit.org . Articles in English, reporting original data on adherence to long-term, self-administered medicines in Australia's Indigenous populations were included. Data were extracted into a standard template and a quality assessment was undertaken. RESULTS: Forty-seven articles met inclusion criteria. Varied study methodologies prevented the use of meta-analysis. KEY FINDINGS: health professionals believe adherence is a significant problem for Indigenous Australians; however, adherence rates are rarely measured. Health professionals and patients often reported the same barriers and facilitators, providing a framework for improvement. CONCLUSIONS: There is no evidence that medication adherence amongst Indigenous Australians is lower than for the general population. Nevertheless, the heavy burden of morbidity and mortality faced by Indigenous Australians with chronic conditions could be alleviated by enhancing medication adherence. Some evidence supports strategies to improve adherence, including the use of dose administration aids. This evidence should be used by clinicians when prescribing, and to implement and evaluate programs using standard measures to quantify adherence, to drive improvement in health outcomes.

Adherence to secondary prophylaxis for rheumatic heart disease is underestimated by register data.

OBJECTIVE: In high-burden Australian states and territories, registers of patients with acute rheumatic fever and rheumatic heart disease are maintained for patient management, monitoring of system performance and research. Data validation was undertaken for the Australian Northern Territory Rheumatic Heart Disease Register to determine quality and impact of data cleaning on reporting against key performance indicators: overall adherence, and proportion of patients receiving ≥80% of scheduled penicillin doses for secondary prophylaxis. METHODS: Register data were compared with data from health centres. Inconsistencies were identified and corrected; adherence was calculated before and after cleaning. RESULTS: 2780 penicillin doses were validated; 426 inconsistencies were identified, including 102 incorrect dose dates. After cleaning, mean adherence increased (63.5% to 67.3%, p<0.001) and proportion of patients receiving ≥80% of doses increased (34.2% to 42.1%, p = 0.06). CONCLUSIONS: The Northern Territory Rheumatic Heart Disease Register underestimates adherence, although the key performance indicator of ≥80% adherence was not significantly affected. Program performance is better than hitherto appreciated. However some errors could affect patient management, as well as accuracy of longitudinal or inter-jurisdictional comparisons. Adequate resources are needed for maintenance of data quality in acute rheumatic fever/rheumatic heart disease registers to ensure provision of evidence-based care and accurate assessment of program impact.