BackgroundNon-steroidal anti-inflammatory drugs (NSAIDs) are commonly prescribed for pain and inflammation. NSAID complications include acute kidney injury (AKI), causing burden to patients and health services through increased morbidity, mortality, and hospital admissions.AimThis study aimed to measure the extent of NSAID prescribing in an adult population, the degree to which patients with potential higher risk of AKI were exposed to NSAIDs, and to quantify their risk of AKI.Design & settingRetrospective two-year closed-cohort study.MethodA retrospective cohort of adults was identified from a pseudonymised electronic primary care database in Hampshire, UK. The cohort had clinical information, prescribing data and complete GP- and hospital- ordered biochemistry data. NSAID exposure (minimum one prescription in a two-month period) was categorised as never, intermittent and continuous, and first AKI using the national AKI eAlert algorithm. Descriptive statistics and logistic regression were used to explore NSAID prescribing patterns and AKI risk.ResultsThe baseline population was 702,265. NSAID prescription fell from 19,364 (2.8%) to 16,251 (2.4%) over two years. NSAID prescribing was positively associated with older age, women, greater socioeconomic deprivation, and certain comorbidities (diabetes, hypertension, osteoarthritis and rheumatoid arthritis) and negatively with cardiovascular disease (CVD) and heart failure. Among those prescribed NSAIDs, AKI was associated with older age, greater deprivation, CKD, CVD, heart failure, diabetes, and hypertension.ConclusionsDespite generally good prescribing practice, we identified NSAID prescribing in some people at higher risk of AKI (CKD, older people) for whom medication review and NSAID de-prescribing should be considered.