Use of injectable drugs with oral-formulation alternatives for outpatients in South Korea.

This study analyzed the use of injectable drugs with oral-formulation alternatives in the outpatient setting in South Korea. We conducted a retrospective cross-sectional data analysis using 2008 National Health Insurance claims data. All active ingredients were categorized into dual-formulation ingredients (DFIs) and single formulation ingredients (SFIs), and were identified by the type of healthcare service provider (HSP) and anatomical therapeutic chemical (ATC) group. 14.6 % (102/701) of total drugs were extracted as DFIs at about the same rate as that for drugs in the World Health Organization database (14.45 %), showing similar patterns by ATC group. The rate of injectable drug use varied more substantially for DFIs (range 0.94-4.54 %) than for SFIs (range 0.27-1.12 %) by the type of HSP. For DFIs, the highest proportion of injectable drug use was observed in group H (all hormonal preparations, 22.74 %) and group M (anti-inflammatory and anti-rheumatic preparations, 10.23 %) among ATC groups. The proportion of injectable drug use was higher in clinics and small hospitals than in tertiary hospitals and general hospitals where patients with more severe cases tend to visit. The results imply the potentially inappropriate or excessive use of injectable drugs and suggest the need to develop standard guidelines for injectable drug use and strategies to promote high-quality healthcare including education on rational prescribing.