OBJECTIVES: To assess the association between drug exposure and fall-related injuries and to identify fall risk increasing drugs (FRIDs) in the elderly in South Korea.

METHODS: A nested case-control and a case-crossover study were conducted using a nationwide claims senior cohort database from 2002-2016 provided by National Health Insurance Service. Patients aged between 65 and 90 years who experienced an initial fall during 1/1/2007-12/31/2015 were identified using ICD-10 codes for fractures (including hip, pelvis, ribs, humerus, radius/ulna, navicular, hand, femur/tibia/fibula, patella, or ankle), head injury, joint dislocation, and accidental falls. Those with a history of these falls/injuries prior to the index fall were excluded. Cases were matched to controls in a 1:1 ratio with exact block matching by index year, gender, income, age, and 10 common comorbidities. We used a case-control design to assess the association between drugs exposed for longer than 14 days before the index date and incidence of fall-related injury. To identify drugs associated with falls, we used a case-crossover design to examine drugs exposed within 7 days before the index date to various control periods (i.e.,30-37, 60-67, 90-97 days before index date). Conditional logistic regression was performed to calculate odds of falls with and without adjustment for the study variables.

RESULTS: A total of 44,591 patients were matched with control patients. The risk of falls significantly increased in patients exposed to central nervous system-related drugs including opioids, antiepileptics, anti-Parkinson drugs, antipsychotics, anxiolytics, antidepressants, antidementia drugs as well as for other drug such as antigout agents, drugs for disorders of the musculo-skeletal system, muscle relaxants, and non-steroidal anti-inflammatory drugs.

CONCLUSIONS: This population-based study identified FRIDs for the elderly in South Korea. Categorizing drugs that are associated with higher fall risk can be useful when creating a comprehensive list of FRIDs and developing the guideline to prevent falls.