Adherence to Renal Function Monitoring Guidelines in Patients Starting Antihypertensive Therapy with Diuretics and RAAS Inhibitors: A Retrospective Cohort Study

Background Acute kidney injury (AKI) might complicate antihypertensive therapy. In The Netherlands, general practitioner clinical practice guidelines provide clear recommendations on monitoring of renal function to minimize this risk. Our objective was to investigate how day-to-day clinical practice corresponds to the guidelines. Methods We conducted a retrospective cohort study in a dynamic population, using data on > 9,000 adults that was retrieved from the Integrated Primary Care Information database. We investigated whether serum creatinine (SCR) was measured within 30 and 365 days after the start of (combined) use of a diuretic, an angiotensin-converting enzyme inhibitor, and/or angiotensin receptor blocker. We also investigated the association between calendar year, sex, type of therapy, risk factors for AKI and practice and SCR measurement. Results Of 6,593 subjects who met the study criteria for single drug therapy, SCR was measured in 1,233 subjects within 30 days and in 3,896 subjects within 365 days. For combined drug therapy recipients (n = 2,497), these were 545 and 1,687, respectively. Associated cumulative probabilities were 19 % and 66 % with single drug therapy, and 22 % and 74 % with combined drug therapy. Significant differences were observed between practices. SCR measurement was associated with other characteristics, except for sex. Within 365 days, SCR increased > 30 % of baseline in 103 subjects (1.6 %) after the start of single drug therapy, and in 85 (3.4 %) subjects who initiated combined drug therapy. In the majority (> 70 %) of these subjects, this did not result in subsequent monitoring or adjustment of antihypertensive treatment. Conclusion Results from this study suggest that, on average, renal function is not monitored as strictly as recommended by relevant clinical practice guidelines.