Antibiotic treatment and antimicrobial resistance in urinary tract infections among the older population in Denmark, 1999 to 2023

BACKGROUND Antimicrobial resistance is highly correlated with inappropriate antimicrobial use. Urinary tract infections (UTIs) are the main infections treated with antibiotics in the population ≥ 70 years. AIM We aimed to investigate antibiotic prescribing patterns for UTIs treatment among older people in Denmark and resistance trends to assess impact of antibiotic stewardship interventions and quality improvement strategies. METHODS This national register-based surveillance study included people ≥ 70 years in Danish primary healthcare and assessed consumption of pivmecillinam, trimethoprim, nitrofurantoin and sulfamethizole from 1999 to 2023 and resistance levels from 2018 to 2023. Consumption data were obtained from the Register of Medicinal Product Statistics and resistance data from the Danish Microbiology Database. A review of quality improvement strategies from 2005 to 2020 was conducted to provide context for the study. RESULTS The highest level of antibiotic consumption for UTIs in older people was in 2014 (447 prescriptions/1,000 people ≥ 70 years) and gradually decreased by 28.4% in 2023. Resistance to pivmecillinam, trimethoprim, sulfamethizole and nitrofurantoin in Escherichia coli and Klebsiella pneumoniae decreased significantly from 2018 to 2023, alongside the decline in antibiotic consumption. Focus on antibiotic stewardship was intensified after 2013, with several quality improvement initiatives and updated treatment guidelines aiming at improving diagnosis and antibiotic treatment. CONCLUSION Antibiotic consumption for UTIs in people ≥ 70 years decreased notably, accompanied by a decrease in resistance levels, reflecting a positive impact of antibiotic stewardship programmes to improve diagnosis and treatment. However, a growing older population could place a strain on healthcare resources in the future.