Cross sectional analysis of an addiction consultation service, substance co-use patterns, and receipt of medications for opioid use disorder during hospitalization.

INTRODUCTION: Despite effective medications for opioid use disorder (MOUD), treatment engagement remains low. As the overdose crisis is increasingly characterized by opioids co-used with other substances, it is important to understand whether existing models effectively support treatment for patients who use multiple substances. Hospital-based addiction consultation services (ACS) have shown promise at increasing MOUD initiation and treatment engagement, but the effectiveness for patients with specific co-use patterns remains unknown. METHODS: Using 2016-2023 admissions data from a large safety net hospital, we estimated a random-effects logistic regression model to determine whether specific co-use (methamphetamine, cocaine, alcohol, sedative, and other) moderated the effect of being seen by ACS on the receipt of MOUD. Adjusting for patient sociodemographic, health, and admission characteristics we estimated the proportion of patients who received MOUD across specific co-use groups. RESULTS: Of 7679 total admissions indicating opioid use, of which 5266 (68.6 %) indicated co-use of one or more substances and 2387 (31.1 %) were seen by the ACS. Among admissions not seen by the ACS, a smaller proportion of admissions with any co-use received MOUD (23.5 %; 95 % CI: 21.9-25.1) compared to admissions with opioid use alone (34.0 %; 95 % CI: 31.9-36.1). However, among admissions seen by the ACS a similar proportion of admissions with any co-use received MOUD (57.8 %; 95 % CI: 55.5-60.1) as admissions with opioid use alone (56.2 %; 95 % CI: 52.2-60.2). The increase in proportion of admissions receiving MOUD associated with being seen by the ACS was larger for admissions with methamphetamine (38.6 percentage points; 95 % CI: 34.6-42.6) or cannabis co-use (39.0 percentage points; 95 % CI: 32.9-45.1) compared to admissions without methamphetamine (25.7 percentage points; 95 % CI: 22.2-29.2) or cannabis co-use (29.1 percentage points; 95 % CI: 26.1-32.1). CONCLUSIONS: The ACS is an effective hospital-based treatment model for increasing the proportion of admissions which receive MOUD. This study shows that ACSs are also able to support increased receipt of MOUD for patients who use other substances in addition to opioids. Future research is needed to further understand what transition strategies best support treatment linkage for patients who use multiple substances.

A proposed method for identifying Interfacility transfers in Medicare claims data.

OBJECTIVE: To develop a method of consistently identifying interfacility transfers (IFTs) in Medicare Claims using patients with ST-Elevation Myocardial Infarction (STEMI) as an example. DATA SOURCES/STUDY SETTING: 100% Medicare inpatient and outpatient Standard Analytic Files and 5% Carrier Files, 2011-2020. STUDY DESIGN: Observational, cross-sectional comparison of patient characteristics between proposed and existing methods. DATA COLLECTION/EXTRACTION METHODS: We limited to patients aged 65+ with STEMI diagnosis using both proposed and existing methods. PRINCIPAL FINDINGS: We identified 62,668 more IFTs using the proposed method (86,128 versus 23,460). A separately billable interfacility ambulance trip was found for more IFTs using the proposed than existing method (86% vs. 79%). Compared with the existing method, transferred patients under the proposed method were more likely to live in rural (p < 0.001) and lower income (p < 0.001) counties and were located farther away from emergency departments, trauma centers, and intensive care units (p < 0.001). CONCLUSIONS: Identifying transferred patients based on two consecutive inpatient claims results in an undercount of IFTs and under-represents rural and low-income patients.

Glucagon-Like Peptide-1 Receptor Agonists and Risk of Parkinson's Disease in Patients with Type 2 Diabetes: A Population-Based Cohort Study.

BACKGROUND: Previous studies have suggested that glucagon-like peptide-1 receptor agonists (GLP-1RAs) may have a disease-modifying effect in the development of Parkinson's disease (PD), but population studies yielded inconsistent results. OBJECTIVE: The aim was to compare the risk of PD associated with GLP-1RAs compared to dipeptidyl peptidase 4 inhibitors (DPP4i) among older adults with type 2 diabetes (T2D). METHODS: Using U.S. Medicare administrative data from 2016 to 2020, we conducted a population-based cohort study comparing the new use of GLP-1RA with the new use of DPP4i among adults aged ≥66 years with T2D. The primary endpoint was a new diagnosis of PD. A stabilized inverse probability of treatment weighting (sIPTW)-adjusted Cox proportional hazards regression model was employed to estimate the hazard ratio (HR) and 95% confidence intervals (CI) for PD between GLP-1RA and DPP4i users. RESULTS: This study included 89,074 Medicare beneficiaries who initiated either GLP-1RA (n = 30,091) or DPP4i (n = 58,983). The crude incidence rate of PD was lower among GLP-1RA users than DPP4i users (2.85 vs. 3.92 patients per 1000 person-years). An sIPTW-adjusted Cox model showed that GLP-1RA users were associated with a 23% lower risk of PD than DPP4i users (HR, 0.77; 95% CI, 0.63-0.95). Our findings were largely consistent across different subgroup analyses such as sex, race, and molecular structure of GLP-1RA. CONCLUSION: Among Medicare beneficiaries with T2D, the new use of GLP-1RAs was significantly associated with a decreased risk of PD compared to the new use of DPP4i. © 2024 International Parkinson and Movement Disorder Society.

Characteristics and co-morbidities associated with hospital discharges for opioid and methamphetamine co-use, United States 2016-2019.

Introduction: The US overdose crisis is increasingly characterized by opioid and methamphetamine co-use. Hospitalization is an important opportunity to engage patients in substance use treatment. Understanding characteristics of co-use-related hospital stays can inform the development of services to better support this growing patient population. Methods: We used 2016-2019 National Inpatient Sample data to conduct a cross sectional analysis of hospitalizations involving use of opioids, methamphetamine, or both. We used bivariate analysis to compare patient demographics. We then used multinomial logistic regressions to compare the proportion of hospital stays which indicated co-morbid diagnosis. To account for correlated data, we used generalized linear models to compare outcomes in hospital mortality, patient-directed discharge, and length of stay. Results: Co-use-related stays had a higher proportion of co-morbid mental health (60.7%; 95% CI: 59.9-61.4%) and infectious diseases (41.5%; 95% CI: 40.8-42.2%), than opioid- or methamphetamine-related stays. Co-use-related stays increased between 2016 and 2019 and were associated with a higher proportion of patient directed discharge (10.7%; 95% CI: 10.4-11.0%) and longer length of stay (6.3 days; 95% CI: 6.2-6.4 days) compared to opioid (8.1%; 95% CI: 7.9-8.3% and 5.8 days; 95% CI: 5.8-5.9 days) and methamphetamine-related stays (6.5%; 95% CI: 6.3-6.6% and 5.5 days; 95% CI: 5.4-5.5 days). Conclusion: Patients discharged with co-use differ from patients with opioid or methamphetamine use alone, representing a range of challenges and opportunities. In addition to offering treatment for both substance use disorders, hospital-based services that address co-occurring conditions may better support patients with co-use through targeted and tailored approaches.

Providers' Experiences and Perspectives in Treating Patients With Co-Occurring Opioid and Stimulant Use Disorders in the Hospital.

BACKGROUND: The overdose crisis is increasingly characterized by opioid and stimulant co-use. Despite effective pharmacologic treatment for both opioid use disorder (OUD) and contingency management for stimulant use disorders, most individuals with these co-occurring conditions are not engaged in treatment. Hospitalization is an important opportunity to engage patients and initiate treatment, however existing hospital addiction care is not tailored for patients with co-use and may not meet the needs of this population. METHODS: Semi-structured interviews were conducted with hospital providers about their experiences and perspectives treating patients with opioid and stimulant co-use. We used directed content analysis to identify common experiences and opportunities to improve hospital-based treatment for patients with co-use. RESULTS: From qualitative interviews with 20 providers, we identified 4 themes describing how co-use complicated hospital-based substance use treatment: (1) patients' unstable circumstances impacting the treatment plan, (2) co-occurring withdrawals are difficult to identify and treat, (3) providers holding more stigmatizing views of patients with co-use, and (4) stimulant use is often "ignored" in the treatment plans. Participants also described a range of potential opportunities to improve hospital-based treatment of co-use that fall into 3 categories: (1) provider practice changes, (2) healthcare system changes, and (3) development and validation of clinical tools and treatment approaches. CONCLUSIONS: We identified unique challenges providing hospital addiction medicine care to patients who use both opioids and stimulants. These findings inform the development, implementation, and testing of hospital-based interventions for patients with co-use.

Meta-analysis of Association between Newer Glucose-Lowering Drugs and Risk of Parkinson's Disease.

Background: The association between newer classes of glucose-lowering drugs (GLDs) and the risk of Parkinson's disease (PD) remains unclear. Objective: The aim was to examine the effect of newer GLDs on the risk of PD through a meta-analysis of randomized outcome trials. Methods: The methods included randomized placebo-controlled outcome trials that reported PD events associated with three newer classes of GLDs (ie, dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists, and sodium-glucose co-transporter-2 inhibitors) in participants with or without type 2 diabetes. The pooled odds ratio (OR) and 95% confidence interval (CI) were estimated using Peto's method. Results: The study included 24 trials involving 33 PD cases among 185,305 participants during a median follow-up of 2.2 years. Newer GLDs were significantly associated with a lower PD risk (OR: 0.50; 95% CI: 0.25-0.98) than placebo. Conclusion: Newer GLDs may possibly be associated with a decreased risk of PD; however, larger datasets are required to confirm or refute this notion.

Was Unstable Medicaid Coverage Among Older Medicare Beneficiaries Associated With Worse Clinical Outcomes? Evidence From the Delivery of Breast Cancer Care.

BACKGROUND: Medicare and Medicaid dually eligible beneficiaries (duals) could experience Medicaid coverage changes without losing Medicaid. It is unknown whether health care use and clinical outcomes among elderly duals with coverage changes would be like those among duals without coverage changes or duals ever lost Medicaid and whether various types of unstable coverage due to income/asset changes are associated with worse clinical outcomes. OBJECTIVES: Examine the associations of unstable Medicaid coverage with clinical outcomes among older Medicare beneficiaries. RESEARCH DESIGN: Population-based cohort study. SUBJECTS: A total of 131,202 women newly diagnosed with breast cancer at 65 years and older between 2007 and 2015 were identified from the Surveillance, Epidemiology, and End Results-Medicare linked database. MEASURES: We examined 2 types of unstable Medicaid coverage: (1) those who had changes in the types of Medicaid support they received and (2) those who ever lost Medicaid. We examined outcomes that predict better cancer survival and involve the use of inpatient and outpatient services and prescription drugs: early diagnosis, receiving surgery, receiving radiation, hormonal therapy adherence, and discontinuation. We used logistic regressions to estimate the predicted probabilities of outcomes for dual groups. RESULTS: Duals had poorer outcomes than those who were "never dual." Women with the 2 types of unstable Medicaid coverage had similarly worse outcomes than those with stable coverage. Those with stable coverage had similar outcomes regardless of the generosity of Medicaid support. CONCLUSIONS: These patterns are concerning and, in the context of well-defined clinical guidelines for beneficial treatments that extend survival, point to the importance of stable insurance coverage and income.

Trends in Ransomware Attacks on US Hospitals, Clinics, and Other Health Care Delivery Organizations, 2016-2021.

Importance: Anecdotal evidence suggests that health care delivery organizations face a growing threat from ransomware attacks that are designed to disrupt care delivery and may consequently threaten patient outcomes. Objective: To quantify the frequency and characteristics of ransomware attacks on health care delivery organizations. Design, Setting, and Participants: This cohort study used data from the Tracking Healthcare Ransomware Events and Traits database to examine the number and characteristics of ransomware attacks on health care delivery organizations from 2016 to 2021. Logistic and negative binomial regression quantified changes over time in the characteristics of ransomware attacks that affected health care delivery organizations. Main Outcomes and Measures: Date of ransomware attack, public reporting of ransomware attacks, personal health information (PHI) exposure, status of encrypted/stolen data following the attack, type of health care delivery organization affected, and operational disruption during the ransomware attack. Results: From January 2016 to December 2021, 374 ransomware attacks on US health care delivery organizations exposed the PHI of nearly 42 million patients. From 2016 to 2021, the annual number of ransomware attacks more than doubled from 43 to 91. Almost half (166 [44.4%]) of ransomware attacks disrupted the delivery of health care, with common disruptions including electronic system downtime (156 [41.7%]), cancellations of scheduled care (38 [10.2%]), and ambulance diversion (16 [4.3%]). From 2016 to 2021, ransomware attacks on health care delivery organizations increasingly affected large organizations with multiple facilities (annual marginal effect [ME], 0.08; 95% CI, 0.05-0.10; P < .001), exposed the PHI of more patients (ME, 66 385.8; 95% CI, 3400.5-129 371.2; P = .04), were less likely to be restored from data backups (ME, -0.04; 95% CI, -0.06 to -0.01; P = .002), were more likely to exceed mandatory reporting timelines (ME, 0.06; 95% CI, 0.03-0.08; P < .001), and increasingly were associated with delays or cancellations of scheduled care (ME, 0.02; 95% CI, 0-0.05; P = .02). Conclusions and Relevance: This cohort study of ransomware attacks documented growth in their frequency and sophistication. Ransomware attacks disrupt care delivery and jeopardize information integrity. Current monitoring/reporting efforts provide limited information and could be expanded to potentially yield a more complete view of how this growing form of cybercrime affects the delivery of health care.

The least costly pharmacy for cancer supportive care medications over time: the logistic toxicity of playing catch up.

PURPOSE: No single pharmacy in an urban zip code is consistently the least expensive across medications. If medication prices change differently across pharmacies, patients and clinicians will face challenges accessing affordable medications when refilling medications. This is especially pertinent to people with cancer with multiple fills of supportive care medications over time. We evaluated if the lowest-priced pharmacy for a formulation remains the lowest-priced over time. METHODS: We compiled generic medications used to manage nausea/vomiting (14 formulations) and anorexia/cachexia (12 formulations). We extracted discounted prices in October 2021 and again in March 2022 for a typical fill at 8 pharmacies in Minneapolis, Minnesota, USA (zip code 55,414) using GoodRx.com. We examined how prices changed across formulations and pharmacies over time. RESULTS: Data were available for all 208 possible pharmacy-formulation combinations (8 pharmacies × 26 formulations). For 172 (83%) of the 208 pharmacy-formulation combinations, the March 2022 price was within 20% of the October 2021 price. Across pharmacy-formulation combinations, the price change over time ranged from - 76 to + 292%. For 12 (46%) of the 26 formulations, at least one pharmacy with the lowest price in October 2021 no longer was the least costly in March 2022. For one formulation (dronabinol tablets), the least expensive pharmacy became the most expensive, with an absolute and relative price increase of a fill of $22 and 85%. CONCLUSION: For almost half of formulations studied, at least one pharmacy with the lowest price was no longer the least costly a few months later. The lowest price for a formulation (across pharmacies) could also change considerably. Thus, even if a patient accesses the least expensive pharmacy for a medication, they may need to re-check prices across all pharmacies with each subsequent fill to access the lowest prices. In addition to safety concerns, directing medications to and accessing medications at multiple pharmacies can add time and logistic toxicity to patients with cancer, their care partners, prescribers, and pharmacy teams.

Price Comparison of Human and Veterinary Formulations of Common Medications.

This cross-sectional study compares prices of commonly prescribed medications used to treat both humans and pets.

Breast-conserving surgery versus mastectomy for older women with triple-negative breast cancer: population-based study.

Purpose: To assess whether the poor prognosis of triple-negative breast cancer (TNBC) necessitates a more aggressive surgical approach. Methods: We examined the association of: breast-conserving surgery (BCS); BCS plus radiotherapy; mastectomy; and mastectomy plus radiotherapy with overall and breast cancer-specific survival of stage I-III TNBC patients aged 66 years and older. We used unweighted and inverse probability of treatment weighted Cox proportional hazards regression and the Fine and Gray sub-distribution model. Results: Among 4333 women, individuals who were selected for BCS, mastectomy or mastectomy plus radiotherapy had lower adjusted overall and breast cancer-specific survival compared with women who had BCS plus radiotherapy. Conclusion: In this population-based study, women with TNBC treated with BCS plus radiotherapy have a better prognosis than those treated with BCS, mastectomy or mastectomy plus radiotherapy. Given the poor prognosis of TNBC and selection bias inherent in observational studies, these findings should be confirmed in further studies such as randomized clinical trials.

Hormonal Therapy Drug Switching, Out-of-Pocket Costs, and Adherence Among Older Women With Breast Cancer.

BACKGROUND: Adherence to aromatase inhibitors (AIs) and tamoxifen has considerable survival benefits for postmenopausal women diagnosed with hormone receptor-positive breast cancer. Reduced out-of-pocket costs and treatment-related side effects could increase therapy adherence. Given that individuals' side effect profiles could differ across AIs, generic AI entry could facilitate switching between AIs to manage side effects and improve adherence. METHODS: From Surveillance, Epidemiology, and End Results-Medicare, we selected women first diagnosed with hormone receptor-positive breast cancer at age 65+ years and initiated an AI within 1 year of diagnosis between January 1, 2007, and May 31, 2008, or June 1, 2011, and December 31, 2012, and followed them for up to 2 years (N = 20 677). We estimated changes in probabilities of adherence with and without switching for Part D enrollees with and without the low-income subsidy (LIS vs non-LIS) before and after generic entry using linear probability models. Tests of statistical significance are 2-sided. RESULTS: After generic entry reduced out-of-pocket costs of AIs (larger reduction for non-LIS), the percentage of women who ever switched from one AI to another AI increased from 8.8% to 14.6% for non-LIS and from 7.3% to 12.5% for LIS. Adherence without switching increased by 8.0 percentage points (pp) for non-LIS (P < .001) but decreased by 4.9 pp (P < .001) for LIS. Adherence with switching increased for both non-LIS (6.4 pp, P < .001) and LIS (4.4 pp, P < .001). CONCLUSIONS: Increased switching after generic entry contributed to increased adherence, suggesting switching allowed better management of treatment-related side effects. Subsidized women also experienced increased adherence with switching after generic entry, suggesting that patients and physicians might not understand Part D benefit design when making decisions.

Why Men Fare Worse: A Mixed-Methods Study Examining Gender Differences in Nursing Home Resident Quality of Life.

BACKGROUND AND OBJECTIVES: Despite research documenting gender differences in numerous outcomes in later life, we know little about gender differences in quality of life (QoL) for nursing home (NH) residents. This study examines the relationship between gender and residents' QoL, including possible reasons for differences observed. RESEARCH DESIGN AND METHODS: We used a mixed-methods design including surveys with a random sample of Minnesota NH residents using a multidimensional measure of QoL (n = 9,852), resident clinical data, facility-level characteristics (n = 364), interviews with residents (n = 64), and participant observations. We used linear mixed models and thematic analysis of resident interviews and observations to examine possible gender-related differences in residents' QoL. RESULTS: After controlling for individual and facility characteristics, men reported lower overall QoL than women, including significantly lower ratings in several QoL domains. In interviews, men noted being less satisfied with activities than women, having fewer friends, and being less able to rely on family for support. Some women described the NH as a place of respite, but men more often described being dissatisfied with life in the NH and undesirable for long-term living. Our observations were consistent with interview findings but provide additional nuances, such as that some men organized their own social groups. DISCUSSION AND IMPLICATIONS: Our findings suggest that men and women experience QoL differently in NHs, with men reporting lower QoL in several domains. Tailoring more activities for men and finding ways to strengthen relationships for men in NHs could help reduce the gender differences in QoL we observed.

Financial Burden of Drugs Prescribed for Cancer-Associated Symptoms.

PURPOSE: The financial toxicity of anticancer drugs is well-documented, but little is known about the costs of drugs used to manage cancer-associated symptoms. METHODS: We reviewed relevant guidelines and compiled drugs used to manage seven cancer-associated symptoms (anorexia and cachexia, chemotherapy-induced peripheral neuropathy, constipation, diarrhea, exocrine pancreatic insufficiency, cancer-associated fatigue, and chemotherapy-induced nausea and vomiting). Using GoodRx website, we identified the retail price (cash price at retail pharmacies) and lowest price (discounted, best-case scenario of out-of-pocket costs) for patients without insurance for each drug or formulation for a typical fill. We describe lowest prices here. RESULTS: For anorexia and cachexia, costs ranged from $5 US dollars (USD; generic olanzapine or mirtazapine tablets) to $1,156 USD (brand-name dronabinol solution) and varied widely by formulation of the same drug or dosage: for olanzapine 5 mg, $5 USD (generic tablet) to $239 USD (brand-name orally disintegrating tablet). For chemotherapy-induced peripheral neuropathy, costs of duloxetine varied from $12 USD (generic) to $529 USD (brand-name). For constipation, the cost of sennosides or polyethylene glycol was <$15 USD, whereas newer agents such as methylnaltrexone were expensive ($1,001 USD). For diarrhea, the cost of generic loperamide or diphenoxylate-atropine tablets was <$15 USD. For exocrine pancreatic insufficiency, only brand-name formulations were available, range of cost, $1,072 USD-$1,514 USD. For cancer-associated fatigue, the cost of generic dexamethasone or dexmethylphenidate was <$15 USD, whereas brand-name modafinil was more costly ($1,284 USD). For a 4-drug nausea and vomiting prophylaxis regimen, costs ranged from $181 USD to $1,430 USD. CONCLUSION: We highlight the high costs of many symptom control drugs and the wide variation in the costs of these drugs. These findings can guide patient-clinician discussions about cost-effectively managing symptoms, while promoting the use of less expensive formulations when possible.

Travel, Treatment Choice, and Survival Among Breast Cancer Patients: A Population-Based Analysis.

Background: Travel distance to care facilities may shape urban-rural cancer survival disparities by creating barriers to specific treatments. Guideline-supported treatment options for women with early stage breast cancer involves considerations of breast conservation and travel burden: Mastectomy requires travel for surgery, whereas breast-conserving surgery (BCS) with adjuvant radiation therapy (RT) requires travel for both surgery and RT. This provides a unique opportunity to evaluate the impact of travel distance on surgical decisions and receipt of guideline-concordant treatment. Materials and Methods: We included 61,169 women diagnosed with early stage breast cancer between 2004 and 2013 from the Surveillance Epidemiology and End Results (SEER)-Medicare database. Driving distances to the nearest radiation facility were calculated by using Google Maps. We used multivariable regression to model treatment choice as a function of distance to radiation and Cox regression to model survival. Results: Women living farthest from radiation facilities (>50 miles vs. <10 miles) were more likely to undergo mastectomy versus BCS (odds ratio [OR]: 1.48, 95% confidence interval [CI]: 1.22-1.79). Among only those who underwent BCS, women living farther from radiation facilities were less likely to receive guideline-concordant RT (OR: 1.72, 95% CI: 1.32-2.23). These guideline-discordant women had worse overall (hazards ratio [HR]: 1.50, 95% CI: 1.42-1.57) and breast-cancer specific survival (HR: 1.44, 95% CI: 1.29-1.60). Conclusions: We report two breast cancer treatments with different clinical and travel implications to show the association between travel distance, treatment decisions, and receipt of guideline-concordant treatment. Differential access to guideline-concordant treatment resulting from excess travel burden among rural patients may contribute to rural-urban survival disparities among cancer patients.

Generic entry of aromatase inhibitors and pharmaceutical access: Initiation of hormonal therapy, timeliness of initiation, and drug choice.

BACKGROUND: The trade-offs between innovation and pharmaceutical access are central to the policy debate on drug pricing. High prices may limit access, result in medication underuse, and negatively affect outcomes. Generic drugs make treatments more affordable. Prior research measured access as utilization without a defined population that should receive certain drugs, it is unknown whether generic entry reduces underuse and thus improves access. OBJECTIVES: To measure changes in access (use, timeliness) with the introduction of three generic aromatase inhibitors (AIs, oral breast cancer drugs) between June 2010 and June 2011. METHODS: This population-based study included 93,650 older (65+) women diagnosed with hormone receptor-positive breast cancer between 2007 and 2013 in the Surveillance, Epidemiology and End Results-Medicare linked database. We examined changes in access with generic entry for initiation of any adjuvant hormonal therapy drug (AIs or tamoxifen) within one year of diagnosis, time from diagnosis to initiation, and choice of initial therapy. RESULTS: Among 93,650 newly diagnosed breast cancer cases, 67,372 initiated one of the four drugs. With generic entry, initiation rates increased from 69.5% to 74.3%, but non-initiation remained high (up to 25.7%). After controlling for demographics, clinical factors, and insurance coverage, the probability of initiation increased by 4.6 percentage points (P < 0.001, 95%CI: [4.1,5.2]) after generic entry. With generic entry, estimated time to initiation decreased by 0.3 months (P < 0.001, 95%CI: [0.2,0.3]) from 4.1 months, and the probability of choosing AIs over tamoxifen increased by 5.9 percentage points (P < 0.001, 95%CI: [5.3,6.5]). Patterns did not substantially differ by level of cost-sharing. CONCLUSIONS: Generic entry of AIs was associated with increased probability of receiving recommended treatments, timeliness of treatment, and the probability of receiving clinically preferred treatments. Price changes with generic entry only partially explained these improvements. High non-initiation rates after generic entry suggest prices are not the sole determinant of access.