Routine Urine Test Can Screen for Medication Adherence at Primary Care Visit

A single urine spot sample can be used to objectively screen for nonadherence to diabetes medications in the primary care setting, according to a study published in the June issue of Diabetes Care. Further, adherence screening shows high nonadherence rates, which are associated with poorer control of diabetes and lipid levels.

“The difficulty in diagnosing medication adherence reliably in a clinically useful manner remains a major unmet clinical need,” write the authors led by Prashanth Patel, from University Hospitals of Leicester NHS Trust in the United Kingdom. “This study shows for the first time that a routine urine sample collected in the primary care setting for urine microalbumin screening at the time of annual review can be used to objectively detect, using liquid chromatography-tandem mass spectrometry, nonadherence to treatment in people with type 2 diabetes. Anecdotally, the test is well accepted by patients and helps to initiate a discussion about the reasons for nonadherence and ways to overcome them.”

While management of blood pressure, dyslipidemia, and glucose can lead to fewer microvascular and macrovascular complications with diabetes, it is estimated that up to one-third of patients with diabetes may fail to receive therapeutic benefit because of medication nonadherence.

LC-MS/MS (Agilent Technologies) has high specificity and sensitivity for compound detection in the low-nanogram range. It is capable of objectively assessing 60 of the most common cardiovascular medications (between four and six half-lives of the drug) in a spot urine sample to detect nonadherence.

In the present study, LC-MS/MS was used to assess nonadherence to cardiovascular medications in people with type 2 diabetes. Routine urine samples were received from 228 consecutive, consenting patients at the time of the annual diabetes review (March 2016 to July 2017) at six different primary care practices in the United Kingdom.

The researchers found that more than one-fourth of patients (28.1 percent) were not fully adherent to antidiabetic, antihypertensive, and/or lipid-lowering medications, with 5.7 percent of patients not taking any of the prescribed medications. Nonadherence was most common with statins (23.7 percent) and lowest with oral hypoglycemic agents (9.3 percent). HbA1c, albumin-to-creatinine ratio, and lipid profiles were significantly higher among patients with medication nonadherence, versus patients who were adherent to treatment.

“Since biochemical nonadherence testing indicates only short-term nonadherence, the higher HbA1c levels in the nonadherent population compared with the adherent population provides preliminary evidence that the test may predict longer-term nonadherent behavior. More research is needed to confirm whether biochemical testing is a predictor of longer-term outcomes. Furthermore, adherence is a complex, dynamic process, and whether biochemical adherence testing induces a change in behavior needs to be confirmed.”

Takeaway: Urine-based medication adherence screening is feasible and acceptable in the primary care setting. Further evaluation is needed in order to determine if testing for medication adherence improves outcomes.