Patients with urolithiasis: Empirical or selective prophylactic drug therapy reduces the incidence of stone-related events?

Introduction Urolithiasis (USD) is a chronic disease in which preventive pharmacotherapy (PPT) can play an important role
.

Doctors generally decide whether to use PPT based on the patient's 24-hour urine collection results
.

Previous studies have compared the effectiveness of selective and empirical PPT
.

This study hypothesized that the effect of elective PPT on the risk of stone recurrence would not vary by population
.

This study ignores the possibility that selective PPT has different effects on different individuals, i.
e.
heterogeneity of treatment effects
.

To investigate whether selective PPT produces nonrandom differences in clinical outcomes in USD patients based on individual risk of relapse, we conducted this study to observe the effect of selective PPT in patients at high risk of relapse
.

The findings were published today in UROLOGY
.

Methods: Data and population studies included in the Optum database between January 1, 2008 and December 31, 2018, 0-64 years of age, diagnosed with USD by 2 physicians or had at least 1 stone-specific surgery.
Patients; patients who had taken PPT medication for other diseases in the 6 months prior to diagnosis of USD were excluded
.

The flow chart of the study cohort is shown in Figure 1
.

Figure 1.
Study flow chart in patients at high risk of recurrence The study grouped patients according to the following criteria: (1) the presence of other diseases or symptoms that increased the patient's risk of recurrence; (2) recurrent USD
.

Elective vs Empirical PPT Patients were defined as receiving elective PPT if they had had a 24-hour urine test between the diagnosis of USD and the first PPT prescription
.

Patients were defined as undergoing empirical PPT if they had not had a 24-hour urine test
.

Stone-related events were recorded for the recurrence-free rate of stone-related emergency department visits, hospitalizations, or surgery within 2 years after patients first received PPT
.

Results A total of 8369 patients were included in the study, which were divided into high-risk patients (5183 cases) and USD recurrence patients (4036 cases), of which 850 patients belonged to both high-risk patients and USD recurrence patients (accounting for 21% of USD recurrence patients)
.

Thirty-three percent of patients received PPT with a median follow-up of 590 days (IQR, 385); 67% received empirical PPT with a median follow-up of 533 days (IQR, 426)
.

In addition, patients with selective PPT received more basic citrate combination therapy, and less use of allopurinol and thiazides (p < 0.
01)
.

The most commonly used drugs in PPT were hydrochlorothiazide (39%, n=3274) and potassium citrate (33%, n=2732)
.

Table 1 shows the differences in baseline characteristics between patients who received empirical and elective PPT
.

The compliance rate of patients in both groups was 42%
.

Patients who received elective PPT were younger, were more likely to be female and Caucasian, and had higher levels of education (p < 0.
01)
.

Table 1.
Baseline characteristics of high-risk patients who received elective PPT versus empirical PPT.
The 2-year recurrence-free survival rate of recurrent USD patients who received elective PPT was significantly higher than that of patients who received empirical PPT (0.
77 vs 0.
75, p=0.
26 )
.

Table 2 is the results of the multivariate analysis
.

Patients in the recurrent USD subgroup who received elective PPT had a lower risk of stone-related events (HR, 0.
83; 95% CI, 0.
71-0.
96)
.

Gout and hypertension may be present in some patients, leading to differences in baseline use of allopurinol and thiazides
.

The researchers controlled for related factors by sensitivity analysis
.

Sensitivity analysis results were similar to those of the main model, supporting the use of selective PPT in patients with recurrent USD (HR, 0.
82; 95Cl, 0.
71-0.
95)
.

Table 2 HR multivariate analysis of stone-related time in patients who received and did not receive a 24-hour urine test before PPT Figure 2 shows the predicted probability of stone-related events within 2 years of follow-up in patients with recurrent USD
.

After controlling for variables, patients who received elective PPT were 5% less likely to have a stone-related event than those who received empirical PPT (28% vs 33%, p=0.
01)
.

This difference was also present in emergency (19% vs 23%, p=0.
02) and hospitalized (5% vs 7%, p=0.
02) patients, but not in stone-related surgery (18% vs 20%, p=0.
02).
0.
15) there is no significant difference
.

Figure 2.
Predicted probability of stone-related events at 2-year follow-up in patients with recurrent USD.
Summary Among patients with USD and other factors that increase the risk of stone recurrence, one third of patients underwent selective PPT based on 24-hour urine testing
.

Compared with patients who did not receive a 24-hour urine test, patients who received elective PPT generally received alkaline citrate and combination therapy and had lower rates of thiazide and allopurinol use
.

Patients with recurrent USD who received elective PPT had significantly lower rates of stone-related events than patients who received empirical PPT
.

Reference: Hsi RS, Yan PL, Crivelli JJ, Goldfarb DS, Shahinian V, Hollingsworth JM.
Comparison of Selective vs Empiric Pharmacologic Preventive Therapy of Kidney Stone Recurrence With High-Risk Features.
Urology.
2022 Feb 17;S0090-4295(22 )00140-6.
Editor: LR Reviewer: XY Execution: LR