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.

Association of Medicare Beneficiary and Hospital Accountable Care Organization Alignment With Surgical Cost Savings.

Importance: Although Medicare accountable care organizations (ACOs) account for half of program expenditures, whether ACOs are associated with surgical spending warrants further study. Objective: To assess whether greater beneficiary-hospital ACO alignment was associated with lower surgical episode costs. Design, Setting, and Participants: This retrospective cohort study was conducted between 2020 and 2022 using US Medicare data from a 20% random sample of beneficiaries. Individuals 18 years of age and older and without kidney failure who had a surgical admission between 2008 and 2015 were included. For each study year, distinction was made between beneficiaries assigned to an ACO and those who were not, as well as between admissions to ACO-participating and nonparticipating hospitals. Exposures: Time-varying binary indicators for beneficiary ACO assignment and hospital ACO participation and an interaction between them. Main Outcomes and Measures: Ninety-day, price-standardized total episode payments. Multivariable 2-way fixed-effects models were estimated. Results: During the study period, 2 797 337 surgical admissions (6% of which involved ACO-assigned beneficiaries) occurred at 3427 hospitals (17% ACO participating). Total Medicare payments for 90-day surgical episodes were lowest when ACO-assigned beneficiaries underwent surgery at a hospital participating in the same ACO as the beneficiary ($26 635 [95% CI, $26 426-$26 844]). The highest payments were for unassigned beneficiaries treated at participating hospitals ($27 373 [95% CI, $27 232-$27 514]) or nonparticipating hospitals ($27 303 [95% CI, $27 291-$27 314]). Assigned beneficiaries treated at hospitals participating in a different ACO and assigned beneficiaries treated at nonparticipating hospitals had similar payments (for participating hospitals, $27 003 [95% CI, $26 739-$27 267] and for nonparticipating hospitals, $26 928 [95% CI, $26 796-$27 059]). A notable factor in the observed differences in surgical episode costs was lower spending on postacute care services. Conclusions and Relevance: In this cohort study evaluating hospital and beneficiary ACO alignment and surgical spending, savings were noted for beneficiaries treated at hospitals in the same ACO. Allowing ACOs to encourage or require surgical procedures in their own hospitals could lower Medicare spending on surgery.

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.

Urologist practice structure and quality of prostate cancer care.

OBJECTIVE: To examine three aspects of urologist practice structure that may affect quality of prostate cancer care: practice size, ownership of an intensity modulated radiation therapy (IMRT) device, participation within a multi-specialty group (MSG). Health care reforms focused on improving quality are particularly relevant for prostate cancer given its prevalence and concerns for overdiagnosis and overtreatment. METHODS: Using data from the Surveillance, Epidemiology and End-Results (SEER)-Medicare linked registry, we examined quality of prostate cancer treatment according to each treating urologist's practice size, type (single-specialty vs. MSG) and ownership of IMRT. Mixed models were used to adjust for patient differences. RESULTS: We identified 22,412 men with newly diagnosed prostate cancer treated by 2,199 urologists during the study. We observed minimal differences for most quality metrics according to practice size, type, and ownership of IMRT. Adherence to all eligible quality metrics was better among MSGs compared to single specialty groups (20.0% adherence versus 18.2%, p=0.01) whereas there was no significant difference by ownership of IMRT (17.1% adherence in owners versus 18.9% non-owners, p=0.09). CONCLUSION: Differences in quality across practice size, type and ownership of IMRT were modest, with substantial room for improvement regardless of practice structure.

Active Surveillance vs Immediate Treatment-Which Has a Greater Financial Incentive for Urologists?

INTRODUCTION: We compared cumulative reimbursement to urologists following implementation of surveillance vs immediate treatment. Active surveillance for prostate cancer is widely considered beneficial and cost-effective for low risk patients, although many still receive immediate therapy. It is unknown whether reduced reimbursement may be a barrier to urologists recommending surveillance. METHODS: We used Medicare claims and a validated natural history model for low risk prostate cancer to simulate annual reimbursements associated with active surveillance and immediate treatments, including surgery and radiation therapy. The model accounts for misclassification due to biopsy under sampling, grade progression and discontinuation of surveillance due to patient preferences. RESULTS: Active surveillance provided approximately $907 to $2,041 less in the net present value of expected cumulative reimbursements for urologists over 10 years ($1,711.80 to $2,740.40 less over 5 years) compared to initial treatment. Sensitivity analysis showed that use of magnetic resonance imaging/ultrasound fusion based biopsy and frequency of biopsies and clinic visits under surveillance are major sources of uncertainty regarding reimbursement. CONCLUSIONS: Urologists have little financial incentive to implement active surveillance. New payment models may be needed to bring financial incentives in line with the recommended treatment for patients with low risk prostate cancer.

Cardiologist Participation in Accountable Care Organizations and Changes in Spending and Quality for Medicare Patients With Cardiovascular Disease.

BACKGROUND: Despite widespread adoption of Medicare accountable care organizations (ACOs), healthcare spending reductions have been modest. This may relate to variable participation in ACOs by specialist physicians, who disproportionately drive spending. To examine whether specialist participation in Medicare ACOs was associated with changes in healthcare spending and clinical quality, we analyzed national Medicare data. METHODS AND RESULTS: Working with a 20% random sample of Medicare beneficiaries (2008 to 2015), we identified those with cardiovascular disease. We estimated linear regression models at the beneficiary-quarter level to evaluate changes in healthcare spending and clinical quality after the start of the Shared Savings Program in 2012. We then examined whether changes in spending and quality across ACOs were conditional on cardiologist participation. Our study included ≈1.6 million beneficiaries per year. Although the number of ACOs increased over the study period (from 114 in 2012 to 392 in 2015), the proportion with any cardiologist participation remained stable (from 80% in 2012 to 83% in 2015). Compared with unaligned beneficiaries, those cared for by ACOs without cardiologist participation were associated with a spending reduction (per quarter) of -$75 (95% CI, -$105 to -$46; P<0.001). Care receipt in an ACO with cardiologist participation was associated with an additional difference in spending of -$56 (95% CI, -$87 to -$25; P<0.001), driven by lower spending for skilled nursing facilities, evaluation and management services, procedural care, and testing. While heart failure admission rates were similar among aligned and unaligned beneficiaries, ACO care was associated with fewer all-cause readmissions (P<0.001) and emergency department visits (P<0.001). Rates of these outcomes did not vary by cardiologist participation. CONCLUSIONS: Annual spending for beneficiaries with cardiovascular disease was ≈$200 lower when cared for by ACOs with cardiologist participation (compared with those without). These spending reductions did not come at the expense of clinical quality.

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.

Urologist Practice Structure and Spending for Prostate Cancer Care.

OBJECTIVE: To investigate the impact of urologist practice structure on health care spending for men with prostate cancer. We hypothesize that 3 elements of urologist practice structure may influence spending for prostate cancer care: urologist participation within a multispecialty group (MSG), practice size among single specialty urology groups, and intensity-modulated radiation therapy (IMRT) ownership. MATERIALS AND METHODS: We used a 20% sample of fee-for-service Medicare beneficiaries to identify men newly diagnosed with prostate cancer between 2011 and 2014. We identified each man's urologist and used data from the Healthcare Relational Spheres provider files to identify practice type, size, and IMRT ownership for each urologist. We then fit generalized linear mixed models to estimate the association between these practice features and Medicare payments in the year after diagnosis. All models were adjusted for patient and healthcare market characteristics. RESULTS: We identified 35,929 men with newly diagnosed prostate cancer who were treated by 6381 urologists. Medicare payments for men with newly diagnosed prostate cancer were significantly lower in MSGs ($19,181 v. $22,366 large single specialty group, P < 0.001) and significantly higher among practices with IMRT ownership ($23,801 v. $20,162 for non-owners, P < 0.001). These differences persisted in sensitivity analyses including only men treated with radiotherapy and examining only prostate cancer-related claims. CONCLUSION: Urologist practice structure is associated with payments for prostate cancer care. MSGs had the lowest Medicare payments per episode of prostate cancer care while groups with IMRT ownership had the highest.

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 .

Informal Clinical Integration in Medicare Accountable Care Organizations and Mortality Following Coronary Artery Bypass Graft Surgery.

BACKGROUND: Accountable care organizations' (ACOs') focus on formal clinical integration to improve outcomes overlooks actual patterns of provider interactions around shared patients. OBJECTIVE: To determine whether such informal clinical integration relates to a health system's performance in an ACO. RESEARCH DESIGN: We analyzed national Medicare data (2008-2014), identifying beneficiaries who underwent coronary artery bypass grafting (CABG). After determining which physicians delivered care to them, we aggregated across episodes to construct physician networks for each health system. We used network analysis to measure each system's level of informal clinical integration (defined by cross-specialty ties). We fit regression models to examine the association between a health system's CABG mortality rate and ACO participation, conditional on informal clinical integration. SUBJECTS: Beneficiaries age 66 and older undergoing CABG. MEASURES: Ninety-day CABG mortality. RESULTS: Over the study period, 3385 beneficiaries were treated in 161 ACO-participating health systems. The remaining 49,854 were treated in 875 nonparticipating systems or one of the 161 ACO-participating systems before the ACO start date. ACO systems with higher levels of informal clinical integration had lower CABG mortality rates than nonparticipating ones (2.8% versus 5.5%; P<0.01); however, there was no difference based on ACO participation for health systems with lower to relatively moderate informal clinical integration. Regression results corroborate this finding (coefficient for interaction between ACO participation and informal clinical integration level is -0.25; P=0.01). CONCLUSIONS: Formal clinical integration through ACO participation may be insufficient to improve outcomes. Health systems with higher informal clinical integration may benefit more from ACO participation.

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.