Determinants of poor adherence to secondary antibiotic prophylaxis for rheumatic fever recurrence on Lifou, New Caledonia: a retrospective cohort study

Abstract

Background: Incidence of acute rheumatic fever (ARF) and prevalence of rheumatic heart disease (RHD) in the Pacific region, including New Caledonia, are amongst the highest in the world. The main priority of long-term management of ARF or RHD is to ensure secondary prophylaxis is adhered to. The objectives of this study were to evaluate rates of adherence in people receiving antibiotic prophylaxis by intramuscular injections of penicillin in Lifou and to determine the factors associated with a poor adherence in this population.

Methods: We conducted a retrospective cohort study and we included 70 patients receiving injections of antibiotic prophylaxis to prevent ARF recurrence on the island of Lifou. Patients were classified as "good-adherent" when the rate of adherence was ≥80% of the expected injections and as "poor-adherent" when it was <80%. Statistical analysis to identify factors associated with adherence was performed using a multivariate logistic regression model.

Results: Our study showed that 46% of patients from Lifou receiving antibiotic prophylaxis for ARF or RHD had a rate of adherence <80% and were therefore at high risk of recurrence of ARF. Three independent factors were protective against poor adherence: a household with more than five people (odds ratio, 0.25; 95% confidence interval [CI], 0.08 to 0.75), a previous medical history of symptomatic ARF (odds ratio, 0.20; 95% CI, 0.04 to 0.98) and an adequate healthcare coverage (odds ratio, 0.21; 95% CI 0.06 to 0.72).

Conclusions: To improve adherence to secondary prophylaxis in Lifou, we therefore propose the following recommendations arising from the results of this study: i) identifying patients receiving antibiotic prophylaxis without medical history of ARF to strengthen their therapeutic education and ii) improving the medical coverage in patients with ARF or RHD. We also recommend that the nurse designated for the ARF prevention program in Lifou coordinate an active recall system based on an updated local register. But the key point to improve adherence among Melanesian patients is probably to give appropriate information regarding the disease and the treatment, taking into account the Melanesian perceptions of the disease.

Figure 1

Flow chart of the enrollment of subjects, Lifou, New Caledonia, 2011.

Figure 2

Rates of adherence in patients receiving antibiotic prophylaxis for acute rheumatic fever recurrence, Lifou, New Caledonia, 2011.