Patients Attending Shared Medical Appointments for Metabolic Stone Prevention Have Decreased Stone Risk Factors

Shared medical appointments (SMAs) have decreased patients' wait time to initial stone clinic appointment, standardized education, and increased exposure to nutrition therapy. We assessed the effectiveness of SMAs in reducing patients' urinary stone risk factors.

Patients who established care in our stone clinic in an SMA between March 2012 and August 2015 were sequentially identified. After eliminating those without follow-up urine collections or whose urinary creatinine excretion between the two collections varied by >40%, 113 patients were included (M:F 63:50; 54 ± 15 years; body mass index [BMI] 30.6 ± 6.7). Results from before and after the SMA were compared with those from a similar cohort of patients who attended individual patient appointments (IPAs) for their first stone clinic visit (n = 63; M:F 37:26; 54 ± 14 years; BMI 30.1 ± 8.2). All patients received individualized medical therapy for stone prevention.

After medical and nutritional therapy, SMA patients with elevated risk(s) at baseline achieved significant reductions in uric acid, calcium, and sodium; p ≤ 0.001 for all. Those with low urine magnesium, low urine volume, low urine pH, and/or low urine citrate at baseline achieved increases; p ≤ 0.0008 for all. IPA patients with elevated baseline risk factors achieved reductions in oxalate and uric acid (p ≤ 0.004 for both) but neither calcium nor sodium and an increase in citrate (p = 0.003) but not magnesium.

Patients from SMAs reduced their stone recurrence risk and compared favorably with patients from IPAs. Contributing factors may include shorter time from stone event to appointment and more standardized education for patients attending SMAs.