In a recent study conducted by Dauw and colleagues, the effects of nonadherence were observed among patients with kidney stone disease. Adherence to primary treatment with thiazide diuretics, alkali citrate, and allopurinol among 8,890 patients was studied over a period of two years.
Adherence to kidney stone therapy within the first six months of initiating treatment was studied, with adherence defined as a proportion of days covered (PDC) at or above 80%. PDC is calculated as the number of days available or “covered” by a certain medication divided by the total number of days in the followup period, multiplied by 100. In addition, they assessed whther each patient had an emergency room visit, hospitalization, and/or surgery for kidney stone disease within two years of his/her initial prescription fill.
Of the patients in the study, 51.1% were adherent to their pharmacological kidney stone therapy. Adherence to therapy showed 27% lower odds of an emergency department visit, 41% lower odds of hospitalization, and 23% lower odds of a surgical procedure for kidney stones compared to nonadherent patients. This evidence clearly outlines the consequences of nonadherence to reventative treatment of kidney stone disease. In general, adherence rates among this patient population are very low. Realizing that improved medication adherence is associated with tangible benefits for patients with kidney stones, healthcare providers should be vigilant in their counseling of patients with kidney stone disease on the use of preventative pharmacological therapy.