Comparison of Class-Specific Side Effects Across Preventative Pharmacologic Therapies for Kidney Stone Disease.

INTRODUCTION: Clinical guidelines recommend monitoring for metabolic derangements while on preventive pharmacologic therapy for kidney stone disease. The study objective was to compare the frequency of side effects among patients receiving alkali citrate, thiazides, and allopurinol. METHODS: Using claims data from working-age adults with kidney stone disease (2008-2019), we identified those with a new prescription for alkali citrate, thiazide, or allopurinol within 12 months after their index stone-related diagnosis or procedure. We fit multivariable logistic regression models, adjusting for cohort characteristics like comorbid illness and medication adherence, to estimate 2-year measured frequencies of claims-based outcomes of acute kidney injury, falls/hip fracture, gastritis, abnormal liver function tests/hepatitis, hypercalcemia, hyperglycemia/diabetes, hyperkalemia, hypokalemia, hyponatremia, and hypotension. RESULTS: Our cohort consisted of 1776 (34%), 2767 (53%), and 677 (13%) patients prescribed alkali citrate, thiazides, or allopurinol, respectively. Comparing unadjusted rates of incident diagnoses, thiazides compared to alkali citrate and allopurinol were associated with the highest rates of hypercalcemia (2.3% vs 1.5% and 1.0%, respectively, P = .04), hypokalemia (6% vs 3% and 2%, respectively, P < .01), and hyperglycemia/diabetes (17% vs 11% and 16%, respectively, P < .01). No other differences with the other outcomes were significant. In adjusted analyses, compared to alkali citrate, thiazides were associated with a higher odds of hypokalemia (OR=2.01, 95% CI 1.44-2.81) and hyperglycemia/diabetes (OR=1.52, 95% CI 1.26-1.83), while allopurinol was associated with a higher odds of hyperglycemia/diabetes (OR=1.34, 95% CI 1.02-1.75). CONCLUSIONS: These data provide evidence to support clinical guidelines that recommend periodic serum testing to assess for adverse effects from preventive pharmacologic therapy.

Associations Between Provider Specialty and Use of Follow-up Testing Among Patients on Preventive Pharmacological Therapy for Urinary Stone Disease.

INTRODUCTION: The AUA Medical Management of Kidney Stones guideline outlines recommendations on follow-up testing for patients prescribed preventive pharmacological therapy. We evaluated adherence to these recommendations by provider specialty. METHODS: Using claims data from working-age adults with urinary stone disease (2008-2019), we identified patients prescribed a preventive pharmacological therapy agent (a thiazide diuretic, alkali citrate therapy, allopurinol, or a combination thereof) and the specialty of the prescribing physician (urology, nephrology, and general practice). Next, we identified patients who completed a 24-hour urine collection prior to their prescription fill. We then measured adherence to 3 recommendations outlined in the AUA guideline. Finally, we fit multivariable logistic regression models evaluating associations between prescribing provider specialty and adherence to recommended follow-up testing. RESULTS: Among 2,600 patients meeting study criteria, 1,523 (59%) adhered to ≥1 follow-up testing recommendation, with a significant increase over the study period. Nephrologists had higher odds of adherence to ≥1 follow-up test compared to urologists (odds ratio, 1.52; 95% confidence interval, 1.19-1.94; P < .01). Significant differences in adherence to the 3 individual guideline recommendations were also observed by specialty. CONCLUSIONS: Following initiation of preventive pharmacological therapy, adherence to guideline-recommended follow-up testing was low overall. There exist meaningful specialty-specific differences in the use of this testing.

Comparison of Empiric Preventative Pharmacologic Therapies on Stone Recurrence Among Patients with Kidney Stone Disease.

OBJECTIVE: To compare the frequency of stone-related events among patients receiving thiazides, alkali citrate, and allopurinol without prior 24 h urine testing.  It is unknown whether 1 preventative pharmacological therapy (PPT) medication class is more beneficial for reducing kidney stone recurrence when prescribed empirically. MATERIALS AND METHODS: Using medical claims data from working-age adults with kidney stone disease diagnoses (2008-2018), we identified those prescribed thiazides, alkali citrate, or allopurinol. We excluded those who received 24 h urine testing prior to initiating PPT and those with less than 3 years of follow-up. We fit multivariable regression models to estimate the association between the occurrence of a stone-related event (emergency department visit, hospitalization, or surgery for stones) and PPT medication class. RESULTS: Our cohort consisted of 1834 (60%), 654 (21%), and 558 (18%) patients empirically prescribed thiazides, alkali citrate, or allopurinol, respectively. After controlling for patient factors including medication adherence and concomitant conditions that increase recurrence risk, the adjusted rate of any stone event was lowest for the thiazide group (14.8%) compared to alkali citrate (20.4%) or allopurinol (20.4%) (each P < .001). Thiazides, compared to allopurinol, were associated with 32% lower odds of a subsequent stone event by 3 years (OR 0.68, 95% CI 0.53-0.88). No such association was observed when comparing alkali citrate to allopurinol (OR 1.00, 95% CI 0.75-1.34). CONCLUSION: Empiric PPT with thiazides is associated with significantly lower odds of subsequent stone-related events. When 24 h urine testing is unavailable, thiazides may be preferred over alkali citrate or allopurinol for empiric PPT.

Comparison of Selective vs Empiric Pharmacologic Preventive Therapy of Kidney Stone Recurrence With High-Risk Features.

OBJECTIVE: To compare the frequency of stone-related events among subgroups of high-risk patients with and without 24-hour urine testing before preventive pharmacological therapy (PPT) prescription. While recent studies show, on average, no benefit to a selective approach to PPT for urinary stone disease (USD), there could be heterogeneity in treatment effect across patient subgroups. MATERIALS AND METHODS: Using medical claims data from working-age adults and their dependents with USD (2008-2019), we identified those with a prescription fill for a PPT agent (thiazide diuretic, alkali therapy, or allopurinol). We then stratified patients into subgroups based on the presence of a concomitant condition or other factors that raised their stone recurrence risk. Finally, we fit multivariable regression models to measure the association between stone-related events (emergency department visit, hospitalization, and surgery) and 24-hour urine testing before PPT prescription by high-risk subgroup. RESULTS: Overall, 8369 adults with USD had a concomitant condition that raised their recurrence risk. Thirty-three percent (n = 2722) of these patients were prescribed PPT after 24-hour urine testing (median follow-up, 590 days), and 67% (n = 5647) received PPT empirically (median follow-up, 533 days). Compared to patients treated empirically, those with a history of recurrent USD had a significantly lower hazard of a subsequent stone-related event if they received selective PPT (hazard ratio, 0.83; 95% confidence interval, 0.71-0.96). No significant associations were noted for selective PPT in the other high-risk subgroups. CONCLUSION: Patients with a history of recurrent USD benefit from PPT when guided by findings from 24-hour urine testing.

Provider Care Team Segregation and Operative Mortality Following Coronary Artery Bypass Grafting.

BACKGROUND: Studies have shown that Black patients die more frequently following coronary artery bypass grafting than their White counterparts for reasons not fully explained by disease severity or comorbidity. To examine whether provider care team segregation within hospitals contributes to this inequity, we analyzed national Medicare data. METHODS: Using national Medicare data, we identified beneficiaries who underwent coronary artery bypass grafting at hospitals where this procedure was performed on at least 10 Black and 10 White patients between 2008 and 2014 (n=12 646). After determining the providers who participated in their perioperative care, we examined the extent to which Black and White patients were cared for by unique networks of provider care teams within the same hospital. We then evaluated whether a lack of overlap in composition of the provider care teams treating Black versus White patients (ie, high segregation) was associated with higher 90-day operative mortality among Black patients. RESULTS: The median level of provider care team segregation was high (0.89) but varied across hospitals (interquartile range, 0.85-0.90). On multivariable analysis, after controlling for patient-, hospital-, and community-level differences, mortality rates for White patients were comparable at hospitals with high and low levels of provider care segregation (5.4% [95% CI, 4.7%-6.1%] versus 5.8% [95% CI, 4.7%-7.0%], respectively; P=0.601), while Black patients treated at high-segregation hospitals had significantly higher mortality than those treated at low-segregation hospitals (8.3% [95% CI, 5.4%-12.4%] versus 3.3% [95% CI, 2.0%-5.4%], respectively; P=0.017). The difference in mortality rates for Black and White patients treated at low-segregation hospitals was nonsignificant (-2.5%; P=0.098). CONCLUSIONS: Black patients who undergo coronary artery bypass grafting at a hospital with a higher level of provider care team segregation die more frequently after surgery than Black patients treated at a hospital with a lower level.

Comparison of Selective Versus Empiric Pharmacologic Preventative Therapy With Kidney Stone Recurrence.

OBJECTIVE: To assess the effectiveness of an empiric approach to metabolic stone prevention. METHODS: Using medical claims from a cohort of working age adults with kidney stone diagnoses (2008-2017), we identified the subset who were prescribed thiazides, alkali therapy, or allopurinol-collectively known as preventive pharmacologic therapy (PPT). We distinguished between those who had 24-hour urine testing prior to initiating PPT (selective therapy) from those without it (empiric therapy). We conducted a survival analysis for time to first recurrence for stone-related events, including ED visits, hospitalizations, and surgery, up to 2 years after initiating PPT. RESULTS: Of 10,125 patients identified, 2744 (27%) and 7381 (73%) received selective and empiric therapy, respectively. The overall frequency of any stone-related event was 11%, and this did not differ between the 2 groups on bivariate analysis (P = .29). After adjusting for sociodemographic factors, comorbidities, medication class, and adherence, there was no difference in the hazard of a stone-related event between the selective and empiric therapy groups (hazard ratio, 0.97; 95% confidence interval, 0.84-1.12). When considered individually, the frequency of ED visits, hospitalizations, and surgeries did not differ between groups. Greater adherence to PPT and older age were associated with a lower hazard of a stone-related event (both P < .05). CONCLUSION: Compared to empiric therapy, PPT guided by 24-hour urine testing, on average, is not associated with a lower hazard of a stone-related event. These results suggest a need to identify kidney stone patients who benefit from 24-hour urine testing.

Accountable Care Organizations and Spending for Patients Undergoing Long-Term Dialysis.

BACKGROUND AND OBJECTIVES: Despite representing 1% of the population, beneficiaries on long-term dialysis account for over 7% of Medicare's fee-for-service spending. Because of their focus on care coordination, Accountable Care Organizations may be an effective model to reduce spending inefficiencies for this population. We analyzed Medicare data to examine time trends in long-term dialysis beneficiary alignment to Accountable Care Organizations and differences in spending for those who were Accountable Care Organization aligned versus nonaligned. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In this retrospective cohort study, beneficiaries on long-term dialysis between 2009 and 2016 were identified using a 20% random sample of Medicare beneficiaries. Trends in alignment to an Accountable Care Organization were compared with alignment of the general Medicare population from 2012 to 2016. Using an interrupted time series approach, we examined the association between Accountable Care Organization alignment and the primary outcome of total spending for long-term dialysis beneficiaries from prior to Accountable Care Organization implementation (2009-2011) through implementation of the Comprehensive ESRD Care model in October 2015. We fit linear regression models with generalized estimating equations to adjust for patient characteristics. RESULTS: During the study period, 135,152 beneficiaries on long-term dialysis were identified. The percentage of long-term dialysis beneficiaries aligned to an Accountable Care Organization increased from 6% to 23% from 2012 to 2016. In the time series analysis, spending on Accountable Care Organization-aligned beneficiaries was $143 (95% confidence interval, $5 to $282) less per beneficiary-quarter than spending for nonaligned beneficiaries. In analyses stratified by whether beneficiaries received care from a primary care physician, savings by Accountable Care Organization-aligned beneficiaries were limited to those with care by a primary care physician ($235; 95% confidence interval, $73 to $397). CONCLUSIONS: There was a substantial increase in the percentage of long-term dialysis beneficiaries aligned to an Accountable Care Organization from 2012 to 2016. Moreover, in adjusted models, Accountable Care Organization alignment was associated with modest cost savings among long-term dialysis beneficiaries with care by a primary care physician.

Out-Of-Network Primary Care Is Associated With Higher Per Beneficiary Spending In Medicare ACOs.

Despite expectations that Medicare accountable care organizations (ACOs) would curb health care spending, their effect has been modest. One possible explanation is that ACOs' inability to prohibit out-of-network care limits their control over spending. To examine this possibility, we examined the association between out-of-network care and per beneficiary spending using national Medicare data for 2012-15. While there was no association between out-of-network specialty care and ACO spending, each percentage-point increase in receipt of out-of-network primary care was associated with an increase of $10.79 in quarterly total ACO spending per beneficiary. When we broke down total spending by place of service, we found that out-of-network primary care was associated with higher spending in outpatient, skilled nursing facility, and emergency department settings, but not inpatient settings. Our findings suggest an opportunity for the Medicare program to realize substantial savings, if policy makers developed explicit incentives for beneficiaries to seek more of their primary care within network.

New Persistent Opioid Use After Outpatient Ureteroscopy for Upper Tract Stone Treatment.

OBJECTIVE: To measure the incidence of persistent opioid use following ureteroscopy (URS). Over 100 Americans die every day from opioid overdose. Recent studies suggest that many opioid addictions surface after surgery. METHODS: Using claims data, we identified adults who underwent outpatient URS for treatment of upper tract stones between January 2008 and December 2016 and filled an opioid prescription attributable to URS. We then measured the rate of new persistent opioid use-defined as continued use of opioids 91-180 days after URS among those who were previously opioid-naive. Finally, we fit multivariable models to assess whether new persistent opioid use was associated with the amount of opioid prescribed at the time of URS. RESULTS: In total, 27,740 patients underwent outpatient URS, 51.2% of whom were opioid-naïve. Nearly 1 in 16 (6.2%) opioid-naïve patients developed new persistent opioid use after URS. Six months following surgery, beneficiaries with new persistent opioid use continued to fill prescriptions with daily doses of 4.2 oral morphine equivalents. Adjusting for measured sociodemographic and clinical differences, patients in the highest tercile of opioids prescribed at the time of URS had 69% higher odds of new persistent opioid use compared to those in the lowest tercile (odds ratio, 1.69; 95% CI, 1.41-2.03). CONCLUSION: Nearly 1 in 16 opioid-naive patients develop new persistent opioid use after URS. New persistent opioid use is associated with the amount of opioid prescribed at the time of URS. Given these findings, urologists should re-evaluate their post-URS opioid prescribing patterns.

Performance in the Medicare Shared Savings Program After Accounting for Nonrandom Exit: An Instrumental Variable Analysis.

Background: Accountable care organizations (ACOs) in the Medicare Shared Savings Program (MSSP) are associated with modest savings. However, prior research may overstate this effect if high-cost clinicians exit ACOs. Objective: To evaluate the effect of the MSSP on spending and quality while accounting for clinicians' nonrandom exit. Design: Similar to prior MSSP analyses, this study compared MSSP ACO participants versus control beneficiaries using adjusted longitudinal models that accounted for secular trends, market factors, and beneficiary characteristics. To further account for selection effects, the share of nearby clinicians in the MSSP was used as an instrumental variable. Hip fracture served as a falsification outcome. The authors also tested for compositional changes among MSSP participants. Setting: Fee-for-service Medicare, 2008 through 2014. Patients: A 20% sample (97 204 192 beneficiary-quarters). Measurements: Total spending, 4 quality indicators, and hospitalization for hip fracture. Results: In adjusted longitudinal models, the MSSP was associated with spending reductions (change, -$118 [95% CI, -$151 to -$85] per beneficiary-quarter) and improvements in all 4 quality indicators. In instrumental variable models, the MSSP was not associated with spending (change, $5 [CI, -$51 to $62] per beneficiary-quarter) or quality. In falsification tests, the MSSP was associated with hip fracture in the adjusted model (-0.24 hospitalizations for hip fracture [CI, -0.32 to -0.16 hospitalizations] per 1000 beneficiary-quarters) but not in the instrumental variable model (0.05 hospitalizations [CI, -0.10 to 0.20 hospitalizations] per 1000 beneficiary-quarters). Compositional changes were driven by high-cost clinicians exiting ACOs: High-cost clinicians (99th percentile) had a 30.4% chance of exiting the MSSP, compared with a 13.8% chance among median-cost clinicians (50th percentile). Limitation: The study used an observational design and administrative data. Conclusion: After adjustment for clinicians' nonrandom exit, the MSSP was not associated with improvements in spending or quality. Selection effects-including exit of high-cost clinicians-may drive estimates of savings in the MSSP. Primary Funding Source: Horowitz Foundation for Social Policy, Agency for Healthcare Research and Quality, and National Institute on Aging.

Followup Care after Emergency Department Visits for Kidney Stones: A Missed Opportunity.

INTRODUCTION AND OBJECTIVE: Follow-up care after an ED visit for kidney stones may help reduce ED revisits and increase use of stone prevention strategies. To test these hypotheses, we analyzed medical claims from working-age adults with kidney stones. METHODS: Using data from MarketScan (2003 to 2006), we first identified patients with an ED visit for kidney stones. We then determined which patients had an outpatient visit within 90 days of ED discharge. Finally, we used multivariable logistic regression to evaluate the association between receipt of follow-up care and ED revisit, as well as use of stone prevention strategies (24-hour urine testing and PPT prescription). RESULTS: Only 48.0% (n=33,741) of patients seen in the ED for kidney stones received follow-up care, 68.3% of which was with a urologist. While follow-up care was not associated with fewer ED revisits, patients who received it were more likely to undergo 24-hour urine testing (predicted probability, 2.2% vs. 0.9%; P<0.001) and be prescribed PPT (predicted probability, 10.6% vs. 8.9%; P<0.001), when compared to those who did not. Among patients who received follow-up care, use of stone prevention strategies was higher when the care was delivered by a urologist (predicted probability, 13.7% vs. 12.3%; P=0.001). CONCLUSIONS: Over half of patients seen acutely in the ED for kidney stones do not receive follow-up care. Given that follow-up care is associated with greater use of stone prevention strategies, efforts to enhance linkages across healthcare settings are needed to provide patients with urinary stone disease higher quality care.

Risk Adjustment In Medicare ACO Program Deters Coding Increases But May Lead ACOs To Drop High-Risk Beneficiaries.

The Medicare Shared Savings Program (MSSP) adjusts savings benchmarks by beneficiaries' baseline risk scores. To discourage increased coding intensity, the benchmark is not adjusted upward if beneficiaries' risk scores rise while in the MSSP. As a result, accountable care organizations (ACOs) have an incentive to avoid increasingly sick or expensive beneficiaries. We examined whether beneficiaries' exposure to the MSSP was associated with within-beneficiary changes in risk scores and whether risk scores were associated with entry to or exit from the MSSP. We found that the MSSP was not associated with consistent changes in within-beneficiary risk scores. Conversely, beneficiaries at the ninety-fifth percentile of risk score had a 21.6 percent chance of exiting the MSSP, compared to a 16.0 percent chance among beneficiaries at the fiftieth percentile. The decision not to upwardly adjust risk scores in the MSSP has successfully deterred coding increases but might discourage ACOs to care for high-risk beneficiaries in the MSSP .

Complications of Delivery Among Mothers With Spina Bifida.

OBJECTIVE: To determine rates and types of peripartum morbidity among delivering women with spina bifida (SB) compared to those without SB. The rates of pregnancy and delivery among women with SB have been significantly increasing. Current knowledge of peripartum outcomes for these women is limited. METHODS: Using 2004-2013 National Inpatient Sample data, we identified all hospitalizations for delivery, distinguishing between women with and without SB. Using a code-based algorithm, we determined whether a complication occurred during the hospitalization. We then fit a series of multivariable logistic models to examine for associations between a complication occurrence during vaginal or cesarean delivery and a woman's SB status. RESULTS: We identified 38,319,814 weighted admissions for delivery, 9516 of which were made by women with SB. Women with SB had a significantly higher rate of cesarean delivery than women without this diagnosis (53% vs 32%, P < .001). The 46.7% of women with SB who delivered vaginally did not have significantly increased odds of a complication associated with their delivery compared to women without SB [odds ratio 1.15, 95% confidence interval 0.99-1.34, P = .066]. However, women with SB who underwent a cesarean delivery did have higher odds of morbidity compared to those without (odds ratio 1.49, 95% confidence interval 1.25-1.78, P < .001). Common complications included preterm delivery, urinary tract infection, hematologic event, and blood transfusion. CONCLUSION: Compared to women without SB, those with SB deliver more frequently by cesarean section and have higher odds of morbidity associated with cesarean delivery, but not vaginal delivery.

Emergency Department Switching and Duplicate Computed Tomography Scans in Patients With Kidney Stones.

OBJECTIVE: To test whether duplicate imaging relates to a lack of information sharing among providers, we measured the association between emergency department (ED) switching during a kidney stone episode and receipt of a repeat computed tomography (CT) scan. METHODS: Using the MarketScan Commercial Claims and Encounters Database, we identified adults between the ages 18 and 64 with an ED visit for a diagnosis of kidney stones. Among patients who had an abdominal or pelvic CT scan at their initial encounter, we then determined the subset that made an ED revisit within 30 days of their first, distinguishing between those to the same vs a different ED. Finally, we fit multivariable logistic regression models to estimate the risk of receiving a repeat CT scan associated with ED switching. RESULTS: Twelve percent of patients who received a CT scan at their initial ED encounter had a revisit within 30 days of discharge. One-third of their revisits were made to a different ED than the index one. Duplicate CT scans were obtained at nearly 40% of all revisits. On multivariable analysis, the risk of receiving a repeat CT was 12% higher if this revisit was made to a different ED (risk ratio, 1.12; 95% confidence interval, 1.03-1.21; P = .010). CONCLUSION: Our study reveals that ED switching during an acute kidney stone episode is associated with higher levels of repeat CT imaging. These findings support the role of better health information exchange among providers to help reduce waste in the health-care system.

Pregnancy among mothers with spina bifida.

INTRODUCTION: Recognizing the importance of sexual and reproductive health to patients with spina bifida (SB), pediatric urologists have taken responsibility for initiating conversations regarding this topic with adolescent and young adult SB patients. However, the sexual and reproductive health of women with SB remains under-investigated. It is unknown how many women are having babies, what mode of delivery is used, and if this has changed over time with the increasing life expectancy of these patients. A better understanding of pregnancy and delivery among young women with SB will enable urologists to provide more informed, comprehensive counseling to patients. OBJECTIVE: We sought to compare hospitalizations for delivery in women with and without SB to determine differences in the mode of delivery used and changes in the rate of deliveries over time. STUDY DESIGN: Using the Healthcare Cost and Utilization's National Inpatient Sample, we identified all hospitalizations for delivery in 2003-2013. After distinguishing between hospitalizations among women with and without SB, temporal trends analysis and bivariate comparison were performed to determine differences in patient and hospital characteristics and mode of deliveries. RESULTS: We identified 10,147 hospitalizations for deliveries among women with SB and 42,197,763 among women without. Of all hospitalizations for deliveries, the percentage of deliveries by women with SB increased by 56% between 2003 and 2013 (629-925 deliveries per year, p < 0.001). Women with SB hospitalized for a delivery differed from those without SB. They had a higher number of comorbidities and were more likely to be white, have Medicare or private insurance, live outside a city, and deliver at an urban teaching hospital (all p < 0.001). Women with SB were significantly more likely to undergo a caesarean section (see Figure, 52.4% of women with SB vs. 31.9% of those without, p < 0.001), although nearly half were able to undergo vaginal delivery. For women with SB, 25.9% of all deliveries occurred by age 22, which did not differ significantly from women without SB (24.7% of all deliveries). DISCUSSION: There are significant differences in the characteristics and mode of delivery between women with and without SB who are hospitalized for a delivery. The number of deliveries among these women are significantly increasing and over a quarter of the deliveries occur by age 22. CONCLUSION: With increasing rates of deliveries and young age at delivery for women with SB, it is imperative that pediatric and transitional urologists initiate discussions on sexual and reproductive health beginning in adolescence.