Nonadherence to blood pressure lowering medication is common clinically (one in four) and a simple urine test can help clinicians identify these patients and potentially avoid further costly work-ups, according to a study published online April 2 in Heart. This urine test could potentially fill a gap by providing an objective and direct-detection clinical tool to identify hypertension therapy noncompliance and could aid in better stratifying patients needing further costly intervention. In the present study, 208 hypertensive patients (125 new referrals, 66 follow-up patients with inadequate blood pressure control previously seen in the specialty clinic, and 17 renal denervation referrals) were evaluated for anti-hypertensive drug compliance using high-performance liquid chromatography-tandem mass spectrometry (HP LC-MS/MS) urine analysis. The researchers found that one-quarter of patients were totally or partially nonadherent to anti-hypertensive treatment (total nonadherence equaled 10.1 percent; partial nonadherence equaled 14.9 percent). Follow-up patients with inadequate blood pressure control (28.8 percent) and those referred for consideration of renal denervation (23.5 percent) had the highest prevalence of nonadherence. “A majority of these [nonadherent] patients in any secondary/tertiary care center would routinely undergo many additional tests and procedures in search of the explanation for their apparent unresponsiveness to standard therapy prescribed by primary […]
Nonadherence to blood pressure lowering medication is common clinically (one in four) and a simple urine test can help clinicians identify these patients and potentially avoid further costly work-ups, according to a study published online April 2 in Heart. This urine test could potentially fill a gap by providing an objective and direct-detection clinical tool to identify hypertension therapy noncompliance and could aid in better stratifying patients needing further costly intervention.
In the present study, 208 hypertensive patients (125 new referrals, 66 follow-up patients with inadequate blood pressure control previously seen in the specialty clinic, and 17 renal denervation referrals) were evaluated for anti-hypertensive drug compliance using high-performance liquid chromatography-tandem mass spectrometry (HP LC-MS/MS) urine analysis. The researchers found that one-quarter of patients were totally or partially nonadherent to anti-hypertensive treatment (total nonadherence equaled 10.1 percent; partial nonadherence equaled 14.9 percent). Follow-up patients with inadequate blood pressure control (28.8 percent) and those referred for consideration of renal denervation (23.5 percent) had the highest prevalence of nonadherence.
“A majority of these [nonadherent] patients in any secondary/tertiary care center would routinely undergo many additional tests and procedures in search of the explanation for their apparent unresponsiveness to standard therapy prescribed by primary care,” write the authors, led by Maciej Tomaszewski, from University of Leicester (United Kingdom). “Our data suggest that in 20 percent of such patients, these investigations (along with follow-up appointments and exposure to unnecessary additional treatment) could be potentially avoided if HP LC-MS/MS urine analysis was used as a routine screening for non-adherence.”
The authors argue the advantages to a urine-based biochemical screening for therapeutic adherence holds many advantages, including that it is noninvasive and can be conducted prior to a clinic appointment (with an estimated three-hour turnaround time), it provides a clear yes-or-no answer with “excellent sensitivity” and is relatively inexpensive (approximately $50, although the cost of the analyzer can be substantial at approximately $250,000). However, the authors caution about “several imperfections” associated with such a screening tool, including that a single spot urine analysis is only a snapshot and may not give a full picture of compliance.
“Furthermore, intuitively, one might expect some patients to better adhere to treatment on the day of clinic attendance (the so-called ‘tooth brush effect’),” write the authors. “Further studies on utility and cost effectiveness of HP LC-MS/MS urine analysis should be conducted against indirect measures of adherence to inform future health policies and clinical practice.”
Takeaway: If further study demonstrates the utility and cost-effectiveness of such a screening test, a urine-based test for common medication noncompliance could improve resource and patient management.
