Fatores associados á baixa adesão ao tratamento da haseníase em pacientes de 78 municípios do estado do Tocantins

Abstract

Background: Adherence to treatment of chronic diseases is a complex issue and involves not only responsibility of the diseased persons, but also the health professional teams and the patients’ social networks. In the last years, non-adherence to multidrug therapy (MDT) against leprosy has been reduced significantly in Brazil. However, low adherence to MDT is still an important obstacle of disease control, and may lead to remaining sources of infection, incomplete cure, irreversible complications, and multidrug resistance. Methods: We performed a population-based study in 78 municipalities pertaining to a leprosy hyperendemic cluster in northern Tocantins State, central Brazil. Tocantins is the State with highest leprosy detection rates (annual detection rate of 88.54/100.000 in the general population, and of 26.48/100.000 in <15 year-olds in 2009). We reviewed the database of the National Information System for Notifiable Diseases (Sistema de Informação de Agravos de Notificação – SINAN), and applied structured questionnaires on leprosy-affected individuals regarding socio-demographic, clinical, service-related and behavior-related characteristics. Two different outcomes for assessment of risk factors were used: defaulting (defined as individuals with incomplete MDT not presenting to the health care center for monthly supervised treatment for >12 months); and interruption of MDT (defined as duration PB treatment > 7 months; and of MB treatment > 13 months). In addition, we asked participants who said that they had interrupted MDT at least once in an open question about their reasons for interrupting. Results: Of the total of 936 individuals included in data analysis, 491 (52.5%) were males; the age ranged from 5 to 99 years (mean=42.1 years). Two-hundred and twenty-five (24.0%) were illiterate. In total, 497 (55.6%) were classified as PB, and 395 (44.1%) as MB leprosy. We identified 28 (3.0%) patients who defaulted MDT; 16 defaulters were included by reviewing the SINAN data information system, and an additional 12 locally in the patients’ charts during field work. In total, 147/806 (18,2%) interrupted MDT. Defaulting was significantly associated with: low number of rooms per household (OR=3.43; 95% confidence interval: 0.98–9.69; p=0.03); moving to another residence after diagnosis (OR=2.90; 0.95–5.28; p=0.04); and low family income (OR=2.42; 1.02– 5.63: p=0.04). Interruption of treatment was associated with: low number of rooms per household (OR=1.95; 0.98–3.70; p=0.04); difficulty in swallowing MDT drugs (OR=1.66; 1.03–2.63; p=0.02); temporal non-availability of MDT at the health center (OR=1.67; 1.11–2.46; p=0.01); and moving to another residence (OR=1.58; 1.03–2.40; p=0.03). Logistic regression identified temporal nonavailability of MDT as an independent risk factor for treatment interruption (adjusted OR=1.56; 1.05–2.33; p=0.03), and residence size as a protective factor (adjusted OR=0.89 per additional number of rooms; 0.80–0.99; p=0.03). Residence size was also independently associated with defaulting (adjusted OR=0.67; 0.52–0.88; p=0.003). In addition, we identified 334 (35.6%) participants who said that they had interrupted MDT at least once. The median time of interruption stated by study participants was 15 days, with a maximum of three years (interquartile range: 6-30 days). The most common reason for interruption given by these was non-availability of medication at the respective health care centre (211; 62.9%). Others forgot to take the medicine (44; 12.0%) or interrupted due to drug-related adverse events (28; 8.3%). Conclusions: The study shows that there are still challenges to be tackled regarding MDT in Brazil. As a consequence of the efforts done by the Tocantins State Leprosy Control Program, healthservice related factors played a minor role, despite intermittent shortage of drug supply. An integrated approach is needed for further improving control, focusing on the most vulnerable population groups such as the socio-economically underprivileged and migrants. MDT producers should consider oral drug formulations that may be more easily accepted by patients. Considering the consequences of low adherence to treatment, such as possible development of MDT resistance, and persisting sources of transmission, future in-depth studies are needed to improve further adherence, mainly in hyperendemic regions.