Background Ankylosing spondylitis (AS) is a chronic disease requiring long-term treatment. Patients' beliefs about medicines and treatment may affect their treatment adherence and treatment success.
Objectives In this study, we aimed to investigate the relationship between beliefs about medicines and treatment adherence in AS patients.
Methods This cross-sectional study was conducted in a single tertiary rheumatology clinic. One hundred and fifty three AS patients were enrolled to the study. Socio-demographic and medical characteristics of the patients were recorded to a patient interview form. In order to evaluate the general and personal views of the patients about drugs, the Turkish Translation of the Beliefs about Medicines Questionnaire (BMQ-T) (Cinar et al in 2016) was used. According to this survey, the beliefs about medicines are composed of the following sections: Specific Necessity, Specific Concerns, General Overuse and General Harm. Medication adherence was assessed by using the Morisky Green Levine Medication Adherence Scale (MGLS) (1986). Adherence was measured on a scale of 0 to 4, in which higher scores represent lower medication adherence and vice versa. Patients who reported a score of 0 on the MGLS were classified as adherent. All other patients were classified as nonadherent. Categorical variables were compared with Chi-square test, while continuous variables were compared with independent samples t test. To evaluate potential risk factors for non adherence, logistic regression method was used.
Results The mean age of the patients was 35.15±8.19 years. The mean time from first symptom (disease duration) was 10.0±6.1 years. The vast majority of the patients (n=145; 94.8%) were male. One hundred patients (65.4%) were using NSAIDs and 83 patients (54.2%) were using anti-TNF. According to the MGLS scores, 56 (36.6%) patients were compatible with treatment, and 97 patients (63.4%) were found to be incompatible with the treatment. As the BMQ-T-Specific Necessity scores increased, drug compliance was also increased (p=0.006), on the other hand, as the BMQ-T-Specific Concerns, BMQ-T-General Overuse and BMQ-T-General Harm scores increased, drug compliance was decreased (p=0.023, 0.002, <0.001, respectively). There were significant positive correlations between Specific Concerns (p=0.002), General Overuse (p=0.031) and General Harm (p=0.024) score levels with the increase in patients' BASDAI score. While there was significant correlation between the disease duration and the General Overuse scores in the negative direction (p=0.016), there was significant correlation between the disease duration and the Specific Necessity scores in the positive direction (p=0.002). As 1 unit increase in the BMQ-T-Specific Necessity score decreased the risk of treatment nonadherence by 0.38 fold, on the other hand, 1 unit increase in the BMQ-T-General Harm score raised the risk to 3.21.
Conclusions In our study, the belief of AS patients about the necessity of treatment they were using, found to increase treatment adherence, while harm potential of the treatment was decreasing the adherence. In other words, to enhance the treatment adherence of AS patients, it is essential to convince the patients about the necessity of treatment and relieve the anxiety they carry about potential adverse effects.
Disclosure of Interest None declared