Inhaler Refill Adherence among Patients with COPD/Asthma at a General Hospital in Northern Peninsular Malaysia

Background: Most adherence studies are based on self-report measures. There are limited studies on medication refill adherence (MRA) conducted in Malaysia, especially on bronchial asthma (BA) and chronic obstructive pulmonary disease (COPD). The study aimed to investigate the MRA for inhalers with fixed dosing indicated for BA or COPD, prescribed from paediatric and medical clinics in Hospital Tuanku Fauziah and the factors that may affect MRA of COPD/BA inhalers. Methods: A cross-sectional study was conducted on repeat prescriptions (fixed-dose inhalers dispensed as the units of analysis) collected from 1st January 2015 to 31st December 2015 from the specialist clinic pharmacy. Descriptive analysis was conducted based on satisfactory MRA which was set as the dispensed refill of inhalers covering 80-120% of the prescribed treatment time. Logistic regression analysis was used to explore each variable (diagnosis, gender, ethnicity and age) in relation to MRA: overall satisfactory MRA (≥80% MRA) with undersupply (<80% MRA) as the reference group. Results:  Out of the repeat prescriptions analysed (N=199), the majorities were COPD (N=118; 64.3%), male (N=122; 61.4%), Malay (N=175; 88.0%), and aged 60-69 years old (N=56; 28.3%). 44.5% of repeat prescriptions (N=57) for COPD showed satisfactory MRA, compared to only 25.4% (N=18) in BA. Repeat prescriptions for fluticasone/salmeterol accuhalers showed the highest satisfactory MRA at 18.1% (N=36). Diagnosis, gender and ethnicity did not significantly influence the overall MRA while age marginally influenced the overall MRA. Conclusion: More than half of the repeat prescriptions for BA and COPD inhalers showed undersupply and oversupply: patients may not be compliant nor using the inhaler correctly.