Publications

In February 2017, the Department of Veterans Affairs (VA) restructured outpatient medication copayments, creating three medication tiers comparable with private-sector value-based insurance designs (with copayments: US$5, US$8, US$11 per 30-day supply for Tiers 1-3, respectively); however, Veteran medication management experiences have not been assessed following this change. We invited a random sample of Veterans with chronic conditions (e.g., diabetes, hypertension) who utilized VA services to complete a mailed survey about VA and non-VA pharmacy use and medication management experiences following this restructuring. There were 2,884 respondents (29% response rate). Veterans with the lowest proportion of medications from Tier 1 after the restructuring had the highest predicted probability of non-VA pharmacy use from regression analyses. Among respondents subject to VA copayments, 27% reported being better able to afford medications after the restructuring. However, 29% reported worrying about paying for medications, and 18% reported making tradeoffs (e.g., spending less on utilities, food) to pay for prescriptions.

IMPORTANCE: The utilization of elective surgical procedures is lower for patients enrolled in Medicare Advantage (MA) than in traditional Medicare (TM), but it remains unclear whether surgical episode costs differ between MA and TM for comparable patients.

OBJECTIVE: To compare the estimated costs, markers of resource use (eg, length of stay and location of surgery), and outcomes of surgical episodes for similar patients enrolled in MA and TM.

DESIGN, SETTING, AND PARTICIPANTS: In this retrospective cohort study, 2019 Medicare claims and encounters data were analyzed to compare differences in surgical episode costs for beneficiaries with MA vs TM who underwent common elective surgical procedures across 11 categories. Procedures performed in either inpatient or outpatient settings were included in the analysis. Data were analyzed from January 2023 to March 2025.

EXPOSURES: Enrollment in MA or TM.

MAIN OUTCOMES AND MEASURES: The primary outcomes were estimated 30-day costs of surgical episodes and factors affecting costs and/or outcomes, including share of inpatient procedures, length of stay, share of patients discharged home, and 30-day readmission rates. A secondary outcome explored potential facility selection and patient steering by estimating the distance traveled to surgery. Multivariable linear regression models adjusted for the type of surgical procedure, patient characteristics, and their Elixhauser Comorbidity Index were used to compare outcomes of surgical episodes in patients with MA vs TM within hospital referral regions.

RESULTS: The analysis included 1 177 700 surgical procedures among 1 110 263 Medicare beneficiaries (mean [SD] age, 73.42 [5.8] years; 686 708 females [58.3%]). The overall rate of surgery utilization was lower among MA patients vs TM patients (difference in rate, -4.4%; 95% CI, -4.8% to -4.1%), with variation found across surgical categories. Across procedures, 30-day surgical episode costs for MA patients vs TM patients were, on average, $671 (95% CI, $639-$702) lower. The share of procedures billed at the higher inpatient rate was 5.41 (95% CI, 5.23-5.58) percentage points (pp) lower for MA patients than for TM patients, and the mean length of inpatient stay was 0.27 (95% CI, 0.26-0.29) days shorter. The share of patients discharged home was higher for those with MA vs TM (3.82 [95% CI, 3.65-3.99] pp). MA patients traveled a mean of 2.32 (95% CI, 1.62-3.01) miles farther for surgery. Readmission rates were lower for patients with MA (-0.70 [95% CI, -0.83 to -0.58] pp).

CONCLUSIONS AND RELEVANCE: This study found that in addition to lower utilization of common elective surgical procedures, the costs of surgical episodes were lower for patients enrolled in MA than those enrolled in TM. MA plans had lower costs because more procedures were performed in outpatient settings, required shorter lengths of stay, and less expensive postacute care, with no apparent harm to overall quality. Physician and surgical facility selection and patient steering likely contributed to these cost differences. These findings highlight potential mechanisms by which MA plans may achieve cost savings compared with TM plans.

PURPOSE: To characterize trajectories of nephrotoxic potential (NxP) drug use among older adults with Type 2 Diabetes (T2D) treated with SGLT2is and identify associated patient characteristics.

METHODS: Using 2012-2019 Medicare data, we selected patients with T2D who filled at least one prescription for SGLT2is. Index date was the date of the first SGLT2i prescription filled. We quantified the number of drugs with NxP used every month during the first 12 months following the index date. The monthly counts of drugs with NxP were incorporated into the group-based trajectory model to identify groups with similar drug use patterns. Finally, we performed a multinomial logistic regression model to examine the association between patient characteristics and group membership.

RESULTS: The study cohort comprised 8811 Medicare beneficiaries with T2D who initiated SGLT2i during the study period with the mean age 67.5 ± 10.6 years. We identified 3 trajectories NxP drug use: no (n = 2142, 24%), low (n = 4752, 54%) and high (n = 1917, 22%) use of drugs with NxP, with patients falling into these categories based on the number of drugs with NxP they used over the time: no drugs, one drug, or two or more drugs. Age, gender, low-income subsidy eligibility and clinical characteristics were associated with group membership.

CONCLUSIONS: We successfully identified three trajectory groups, with a substantial proportion of patients showing low use of drugs with NxP. Both social and clinical factors were associated with the use of NxP drugs.

IMPORTANCE: Veterans with mental health conditions (MHC) face unique challenges obtaining high-quality, coordinated health care. With a growing number of veterans receiving VA-purchased community care (CC) provided outside the Veterans Health Administration (VA), evidence is needed on how veterans in this high-prevalence, marginalized subgroup experience CC.

OBJECTIVE: To compare experiences with CC over time for US veterans with and without MHC.

DESIGN, SETTING, AND PARTICIPANTS: This retrospective, cross-sectional survey study analyzed responses to the Survey of Healthcare Experiences of Patients-Community Care Survey (SHEP-CCS) from 2016 to 2021. Ratings of CC were examined across 9 domains and compared for veterans with and without MHC, adjusting for differences in baseline characteristics using regression models. Data were analyzed from March 2023 to September 2024.

EXPOSURE: Diagnosis of MHC, defined as bipolar disorder, major depression, posttraumatic stress disorder, schizophrenia, or psychosis.

MAIN OUTCOMES AND MEASURES: Veterans' ratings of CC across 9 domains, overall satisfaction, overall clinician rating, clinician communication, eligibility determination, first appointment access, recent appointment access, nonappointment access, care coordination, and billing, were assessed on a scale of 1 to 100. Unadjusted annual ratings of care experiences were analyzed by survey domain. A series of 4 respondent-level linear regression models were examined for each domain and survey responses were pooled to test for differences in experiences between veterans with vs without MHC.

RESULTS: This study included 231 869 veterans, including 62 911 veterans with MHC (27.1%) and 168 958 without MHC (72.9%). Veterans with MHC had a mean (SD) age of 55.8 (14.7) years, 8327 were female (18.5%), and 24 792 had 3 or more comorbidities (29.9%). Veterans without MHC had a mean (SD) age of 62.5 (15.2) years, 11 277 were female (11.0%), and 49 689 had 3 or more comorbidities (24.0%). In fully adjusted models, veterans with vs without MHC had lower adjusted overall satisfaction with CC by -1.8 (95% CI, -2.3 to -1.3) points (P < .001). Ratings in all domains were lower for veterans with vs without MHC (-0.09 to -0.05 SDs of domain scores) (P < .001 for all comparisons). Although ratings improved from 2016 to 2021, significant differences persisted over time for veterans with vs without MHC for all domains.

CONCLUSIONS AND RELEVANCE: In this survey study of veterans receiving CC from 2016 to 2021, those diagnosed with MHC reported lower ratings of CC across all measured domains, and these differences persisted over time. These findings highlight where focused care coordination and quality improvement efforts could improve CC experiences for this vulnerable subpopulation of veterans.

INTRODUCTION: Long-acting insulin analogues are the standard of care for people with type 1 diabetes (T1D) in high-income countries but remain largely inaccessible and understudied in low-resource settings. In settings where glycaemic control is typically poor and food insecurity is common, long-acting insulin analogues may offer tangible clinical benefits for people with T1D. To determine whether insulin glargine, a long-acting insulin analogue, reduces the risk of serious hypoglycaemia and/or improves glycaemic time-in-range (TIR) versus human insulin regimens in this population, we are conducting the Human vs Analogue Insulin for Youth with Type 1 Diabetes in Low-Resource Settings randomised controlled trial.

METHODS AND ANALYSIS: This is a 1:1 randomised, parallel-group clinical trial comparing biosimilar insulin glargine with human insulin (Neutral Protamine Hagedorn (NPH) or premixed 70/30 insulin) in 400 youth with type 1 diabetes (T1D) recruiting in Dhaka, Bangladesh (n=250) and Mwanza, Tanzania (n=150). Blinded continuous glucose monitors will be used to assess glycaemic control in both study arms over 14-day periods at baseline and at 3, 6 and 12 months after randomisation. The co-primary outcomes are the per cent time in serious hypoglycaemia (<54 mg/dL) and TIR (70-180 mg/dL) at 6 months of follow-up. Secondary outcomes include TIR at 12 months and time-in-hypoglycaemia, time-above-range, nocturnal hypoglycaemic events and glycaemic control (ie, haemoglobin A1C (HbA1c)) at 6- and 12-months of follow-up. Treatment satisfaction and quality of life are assessed at baseline, 6- and 12 month follow-up. Additionally, the study is conducting qualitative interviews, quantitative assessments of treatment satisfaction and quality of life, as well as assessing the cost-effectiveness of analogue insulin use in low-resource settings.

ETHICS AND DISSEMINATION: This study was approved by the Institutional Review Board at the University of Pittsburgh (STUDY21110122), the National Health Research Ethics Committee at the National Institute for Medical Research in Tanzania (NIMR/HQ/R.8a/Vol.IX/4265) and the Ethical Review Committee (ERC) of Diabetic Association of Bangladesh (BADAS-ERC/EC/22/405). Research findings will be shared by the local partner organisations and institutions with relevant stakeholders including youth living with diabetes, policy makers, healthcare workers and the general public. Findings will also be shared at local, regional and international scientific meetings.

TRIAL REGISTRATION NUMBER: ClinicalTrials.gov: NCT05614089.

BACKGROUND: Proton-pump inhibitors (PPIs) are effective in treating peptic ulcer disease (PUD), but they are often prescribed beyond the approved duration. Because PPIs are associated with adverse effects, there is a need for effective stewardship.

OBJECTIVE: To identify the frequency of and healthcare factors associated with PPI prescriptions exceeding the approved eight-week treatment duration for PUD.

METHODS: We conducted a retrospective cohort study of patients diagnosed with acute PUD without other indications for PPI use using data from the Veterans Health Administration in the United States. Exposures were patient, provider, and facility factors that could influence PPI prescribing. The outcome was time to a filled PPI prescription exceeding the approved treatment duration for PUD. Associations were assessed using a multivariable time-to-recurrent-event model to calculate adjusted hazard ratios (aHR) and population-attributable fractions. Patients who developed indications for long-term PPI use were censored.

RESULTS: We identified 7708 patients with PUD who met eligibility criteria and received PUD treatment (median age 79 [IQR 71-85], 7% female). Thirty-five percent had PPI prescriptions exceeding the approved duration for a median of 346 days (IQR 165-643) of overuse. On the patient level, inpatient PUD diagnosis (aHR 1.32, 95% CI 1.25-1.39), use of nonsteroidal anti-inflammatory drugs (NSAIDs) (aHR 1.26, 95% CI 1.18-1.34), use of anticoagulants (aHR 1.25, 95% CI 1.13-1.38), and moderate frailty (1.15, 95% CI 1.06-1.26) had the strongest associations with filled PPI prescriptions exceeding the approved duration. On the health-system level, inpatient PUD diagnosis had the highest peak population attributable fraction at 0.26, followed by NSAIDs and anticoagulants at 0.18.

CONCLUSIONS: Markers of patient complexity and medication use not meeting gastroprotection guidelines are associated with inappropriate PPI persistence among patients with PUD. These data may inform future targeted PPI deprescribing programs.

BACKGROUND: One of the largest-ever retail drug shortages began in 2018 when several angiotensin II receptor blockers (ARBs) for treating hypertension, heart failure, and chronic kidney disease-valsartan, losartan, and irbesartan-were recalled for carcinogenic impurities. The long-term consequences of the ARB shortages and whether certain groups experienced more adverse outcomes is unknown.

OBJECTIVE: To evaluate changes in adherence and health outcomes after ARB recalls and to identify patients who experienced greater changes in access and adverse clinical outcomes.

METHODS: Using an integrated claims and electronic health record dataset and a difference-in-differences design, we evaluated changes in the proportion of days covered (PDC) for ARBs and similar drugs (angiotensin-converting enzyme inhibitors [ACE-Is]), uncontrolled blood pressure, major cardiovascular event (MACE)-related acute care visits, and all-cause ambulatory care visits in the 12 months before vs 18 months after recalls for valsartan, losartan, and irbesartan users vs patients taking similar, nonrecalled drugs (ACE-Is, nonrecalled ARBs). Triple-difference models characterized heterogeneous associations by pre-recall patient demographic (race, ethnicity, age), clinical (baseline indication, mental health conditions), and adherence variables.

RESULTS: Adjusting for pre-recall patient characteristics, we observed no significant changes in PDC for ARBs and ACE-Is (combined), uncontrolled blood pressure, or ambulatory care visits among 86,507 recalled ARB users vs 123,583 comparison drug users in the 18 months after the recalls. Following the recalls, medication switches increased on average by an additional 2.08 percentage points (p.p.) per quarter (95% CI = 2.01-2.15) for recalled ARB vs comparison drug users, a 195.9% relative increase. We observed the most switches in the 90-day period immediately after valsartan's recall (difference-in-difference: 9.48 p.p.; 95% CI = 9.36-9.59; relative change = 892%). Cumulatively, 55.2% of valsartan, 7.6% of losartan, and 18.9% of irbesartan users switched medications after 18 months. We observed an increase in the proportion of recalled ARB vs comparison patients who experienced medication gaps exceeding 30 days (1.13 p.p. per quarter on average; 95% CI = 0.97-1.30), which was most apparent after approximately 15 months (5 quarters). Although MACE-related acute care visits did not change in the quarter (90 days) immediately after valsartan's recall, we observed an increase of 1.40 additional visits per 1,000 recalled ARB vs comparison drug patients in each subsequent quarter, a 9.3% relative increase. Results were similar across most subgroups.

CONCLUSIONS: The 2018 ARB recalls were associated with immediate changes in antihypertension medication use. Many patients transitioned to alternative medications. Although overall impacts on clinical outcomes were minimal and not statistically significant, small increases in medication gaps and MACE-related acute care visits among some patients occurred after more than 1 year. The ARB recalls may have been associated with fewer adverse events than other recent shortages owing to the widespread availability of alternative treatments in the same or similar drug class.

BACKGROUND: Clinical guidelines recommend the use of proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9is) in patients with atherosclerotic cardiovascular disease (ASCVD) and nonoptimal low-density lipoprotein.

OBJECTIVE: To evaluate the association between discontinuation of statin use after PCSK9i initiation and subsequent ASCVD events.

METHODS: This pre-post retrospective comparative study used national administrative data of adult statin medication users (age ≥18 years) with an index PCSK9i claim (January 1, 2019, to April 30, 2021), prior ASCVD diagnosis, and a 2-year follow-up period. Proportions and probability of ASCVD events post-index (PCSK9i) vs pre-index (PCSK9i) for patients who discontinued statins (discontinued cohort) and those who continued statins (continued cohort) were compared. Propensity score weighting was used to balance patient baseline characteristics. Multivariate Poisson regression and time-to-event Cox regression models were used to assess the association between statin discontinuation and ASCVD events.

RESULTS: There were 294 and 46 patients in the continued and discontinued cohorts, respectively. Unweighted results showed that patients in the continued cohort were more likely to receive high-intensity statins (32% vs 22%; P = 0.4) and have a Charlson Comorbidity Index score of 3 or more (62% vs 54%; P  =  0.5) at baseline. Baseline statin adherence was lower in the discontinued cohort (6.7% vs 59%; P < 0.001) but 30% each in the propensity 1:1 matched cohort. The 2 cohorts (after matching) had similar ASCVD event prevalence (discontinued cohort: 24% vs continued cohort: 26%) in the baseline and the same lower prevalence (6.5% each; P > 0.9) in the 24-month follow-up period. The odds of any ASCVD event post-index was comparable between the 2 cohorts (reference: continued cohort; odds ratio = 1.88; 95% CI = 0.28-14.6; P = 0.51). There were no statistically significant differences between the 2 groups in the Cox regression (P = 0.47).

CONCLUSIONS: Post-ASCVD event rates were significantly lower in both cohorts, but discontinuation of statins was not associated with unfavorable ASCVD outcomes.