Publications

BACKGROUND: Active surveillance pharmacovigilance is an emerging approach to identify medications with unanticipated effects. We previously developed a framework called pharmacopeia-wide association studies (PharmWAS) that limits false positive medication associations through high-dimensional confounding adjustment and set enrichment. We aimed to assess the transportability and generalizability of the PharmWAS framework by using medical claims data to reproduce known medication associations with Clostridioides difficile infection (CDI) or gastrointestinal bleeding (GIB).

METHODS: We conducted case-control studies using Optum's de-identified Clinformatics Data Mart Database of individuals enrolled in large commercial and Medicare Advantage health plans in the United States. Individuals with CDI (from 2010 to 2015) or GIB (from 2010 to 2021) were matched to controls by age and sex. We identified all medications utilized prior to diagnosis and analysed the association of each with CDI or GIB using conditional logistic regression adjusted for risk factors for the outcome and a high-dimensional propensity score.

FINDINGS: For the CDI study, we identified 55,137 cases, 220,543 controls, and 290 medications to analyse. Antibiotics with Gram-negative spectrum, including ciprofloxacin (aOR 2.83), ceftriaxone (aOR 2.65), and levofloxacin (aOR 1.60), were strongly associated. For the GIB study, we identified 450,315 cases, 1,801,260 controls, and 354 medications to analyse. Antiplatelets, anticoagulants, and non-steroidal anti-inflammatory drugs, including ticagrelor (aOR 2.81), naproxen (aOR 1.87), and rivaroxaban (aOR 1.31), were strongly associated.

INTERPRETATION: These studies demonstrate the generalizability and transportability of the PharmWAS pharmacovigilance framework. With additional validation, PharmWAS could complement traditional passive surveillance systems to identify medications that unexpectedly provoke or prevent high-impact conditions.

FUNDING: U.S. National Institute of Diabetes and Digestive and Kidney Diseases.

BACKGROUND: Paediatric obesity disproportionately impacts individuals from minoritized racial and ethnic backgrounds. Recent guidelines support use of anti-obesity pharmacotherapy for adolescents with obesity, but the potential impact on disparities in obesity prevalence has not been evaluated.

OBJECTIVES: To model changes in obesity prevalence with increasing utilization of anti-obesity pharmacotherapy among adolescents.

METHODS: Data representative of American adolescents ages 12-17 years were obtained from the National Health and Nutrition Examination Survey, cycles 2011 through pre-pandemic 2020. A body mass index (BMI) reduction of 16.7% was applied to each participant based on clinical trial results of weekly subcutaneous semaglutide 2.4 mg among adolescents. Utilization disparities were based on utilization of the same medication class among adults. Obesity prevalence was calculated assuming utilization of 10%-100%, stratified by race and ethnicity.

RESULTS: Among 4442 adolescents representing 26 247 384 American adolescents, projected overall obesity prevalence decreased from 22.2% to 8.4% with 100% utilization. However, disparities increased relative to Non-Hispanic White youth, with prevalence among Non-Hispanic Black and Mexican American youth ranging from 40%-60% higher to 90%-120% higher, respectively.

CONCLUSIONS: Increasing utilization of anti-obesity pharmacotherapy may widen relative disparities in obesity, particularly if utilization is unequal. Advocacy for equitable access is needed to minimize worsening of obesity-related disparities.

BACKGROUND: Paediatric obesity disproportionately impacts individuals from minoritized racial and ethnic backgrounds. Recent guidelines support use of anti-obesity pharmacotherapy for adolescents with obesity, but the potential impact on disparities in obesity prevalence has not been evaluated.

OBJECTIVES: To model changes in obesity prevalence with increasing utilization of anti-obesity pharmacotherapy among adolescents.

METHODS: Data representative of American adolescents ages 12-17 years were obtained from the National Health and Nutrition Examination Survey, cycles 2011 through pre-pandemic 2020. A body mass index (BMI) reduction of 16.7% was applied to each participant based on clinical trial results of weekly subcutaneous semaglutide 2.4 mg among adolescents. Utilization disparities were based on utilization of the same medication class among adults. Obesity prevalence was calculated assuming utilization of 10%-100%, stratified by race and ethnicity.

RESULTS: Among 4442 adolescents representing 26 247 384 American adolescents, projected overall obesity prevalence decreased from 22.2% to 8.4% with 100% utilization. However, disparities increased relative to Non-Hispanic White youth, with prevalence among Non-Hispanic Black and Mexican American youth ranging from 40%-60% higher to 90%-120% higher, respectively.

CONCLUSIONS: Increasing utilization of anti-obesity pharmacotherapy may widen relative disparities in obesity, particularly if utilization is unequal. Advocacy for equitable access is needed to minimize worsening of obesity-related disparities.

INTRODUCTION: Administrative health data could contribute to generalizable microscopic colitis insights, but International Classification of Diseases (ICD) codes for microscopic colitis have not been validated.

METHODS: We identified individuals who received care for diarrhea in the Veterans Health Administration and classified them by receipt of microscopic colitis ICD codes. We reviewed random samples of charts to calculate the positive predictive value (PPV) and negative predictive value (NPV). We then calculated the sensitivity and specificity in clinically relevant cohorts.

RESULTS: The PPV was 0.790 and the NPV was 0.995. In a cohort of individuals with diarrhea who underwent colonoscopy, the sensitivity and specificity were 0.734 and 0.996, respectively.

CONCLUSION: Alternative ascertainment methods for microscopic colitis are needed because ICD codes have suboptimal performance.

INTRODUCTION: Few studies have evaluated multitarget stool DNA (mt-sDNA) in clinical practice. We analyzed mt-sDNA utilization at the University of Pittsburgh Medical Center.

METHODS: We assessed mt-sDNA orders between January 1, 2017, and December 31, 2021. Data collection included electronic capture of mt-sDNA orders, completed stool submissions, and test results. Multivariable models were used to assess associations between mt-sDNA completion and results and age, sex, and race.

RESULTS: There were 91,664 mt-sDNA orders in 73,704 patients. A total of 54.7% (40,337/73,704) completed an mt-sDNA test, and 7,424 (18.6%) tested positive. Completion rates increased by age <50-59 years (N = 12,818; 48.2%), 60-69 years (14,982; 56.3%), and ≥70 years (N = 9,850; 55.6%) ( P < 0.0001). The completion rate for males (52.7%; 15,297/29,025) did not differ significantly from females (53.3%; 22,353/41,901) ( P = 0.09). By race, the completion rates of White patients (54.1%; 34,874/64,512) and Asian patients (56.9%; 493/867) were higher than those of Black patients (38.8%; 1,699/4,376) ( P < 0.0001). Test completion declined with repeat mt-sDNA orders, with ≤32% completion rate after ≥3 orders. In a multivariable model, older age was associated with greater likelihood of a positive test (odds ratio 1.22, 95% confidence interval 1.20-1.24, P < 0.0001), and Black patients had lower odds of a positive test (odds ratio 0.65, 95% confidence interval 0.56-0.76, P < 0.0001).

DISCUSSION: Only 54.7% of patients completed their mt-sDNA test order. Older individuals were more likely to complete testing and test positive. Black patients were less likely to complete testing and, unexpectedly, less likely to test positive. Further exploration of mt-sDNA utilization including better understanding of the determinants of uptake, appropriateness, and evaluation of outcomes at colonoscopy is needed.

BACKGROUND: Active surveillance pharmacovigilance is an emerging approach to identify medications with unanticipated effects. We previously developed a framework called pharmacopeia-wide association studies (PharmWAS) that limits false positive medication associations through high-dimensional confounding adjustment and set enrichment. We aimed to assess the transportability and generalizability of the PharmWAS framework by using medical claims data to reproduce known medication associations with Clostridioides difficile infection (CDI) or gastrointestinal bleeding (GIB).

METHODS: We conducted case-control studies using Optum's de-identified Clinformatics Data Mart Database of individuals enrolled in large commercial and Medicare Advantage health plans in the United States. Individuals with CDI (from 2010 to 2015) or GIB (from 2010 to 2021) were matched to controls by age and sex. We identified all medications utilized prior to diagnosis and analysed the association of each with CDI or GIB using conditional logistic regression adjusted for risk factors for the outcome and a high-dimensional propensity score.

FINDINGS: For the CDI study, we identified 55,137 cases, 220,543 controls, and 290 medications to analyse. Antibiotics with Gram-negative spectrum, including ciprofloxacin (aOR 2.83), ceftriaxone (aOR 2.65), and levofloxacin (aOR 1.60), were strongly associated. For the GIB study, we identified 450,315 cases, 1,801,260 controls, and 354 medications to analyse. Antiplatelets, anticoagulants, and non-steroidal anti-inflammatory drugs, including ticagrelor (aOR 2.81), naproxen (aOR 1.87), and rivaroxaban (aOR 1.31), were strongly associated.

INTERPRETATION: These studies demonstrate the generalizability and transportability of the PharmWAS pharmacovigilance framework. With additional validation, PharmWAS could complement traditional passive surveillance systems to identify medications that unexpectedly provoke or prevent high-impact conditions.

FUNDING: U.S. National Institute of Diabetes and Digestive and Kidney Diseases.

BACKGROUND: Vaccine hesitancy persists alongside concerns about the safety of coronavirus disease 2019 (COVID-19) vaccines. We aimed to examine the effect of COVID-19 vaccination on risk of death among US veterans.

METHODS: We conducted a target trial emulation to estimate and compare risk of death up to 60 days under two COVID-19 vaccination strategies: vaccination within 7 days of enrollment versus no vaccination through follow-up. The study cohort included individuals aged ≥18 years enrolled in the Veterans Health Administration system and eligible to receive a COVID-19 vaccination according to guideline recommendations from 1 March 2021 through 1 July 2021. The outcomes of interest included deaths from any cause and excluding a COVID-19 diagnosis. Observations were cloned to both treatment strategies, censored, and weighted to estimate per-protocol effects.

RESULTS: We included 3 158 507 veterans. Under the vaccination strategy, 364 993 received vaccine within 7 days. At 60 days, there were 156 deaths per 100 000 veterans under the vaccination strategy versus 185 deaths under the no vaccination strategy, corresponding to an absolute risk difference of -25.9 (95% confidence limit [CL], -59.5 to 2.7) and relative risk of 0.86 (95% CL, .7 to 1.0). When those with a COVID-19 infection in the first 60 days were censored, the absolute risk difference was -20.6 (95% CL, -53.4 to 16.0) with a relative risk of 0.88 (95% CL, .7 to 1.1).

CONCLUSIONS: Vaccination against COVID-19 was associated with a lower but not statistically significantly different risk of death in the first 60 days. These results agree with prior scientific knowledge suggesting vaccination is safe with the potential for substantial health benefits.

BACKGROUND: Improving medication adherence remains an important goal to improve therapeutic outcomes and lower health care costs. Point-of-sale prescription costs and forgetfulness remain top reasons why patients do not adhere to medications. Programs using both text message-based reminders and financial incentives may encourage patients to refill their prescriptions on time by reducing copays through discounts at the point of sale. Sempre Health, the subject of our analysis, provides both text message refill reminders and a dynamic discount incentive program to improve medication adherence.

OBJECTIVE: To evaluate the impact of a financial incentive/refill reminder program on medication adherence and total cost of care for patients taking the antithrombotic agents ticagrelor, apixaban, or rivaroxaban in a large regional health plan.

METHODS: After propensity-score matching on demographics, socioeconomic status, baseline copay, prior pharmacy/medical spend, and morbidity, we compared-using a difference-in-differences analytic approach-adherence (measured by proportion of days covered), unplanned health care utilization, and costs (total cost of care, medical, and pharmacy cost) of health plan members who did and did not enroll in the financial incentive/refill reminder program between February 1, 2019, and October 31, 2021, over 1 and 2 years. Because of differences in patient characteristics, we analyzed patients on ticagrelor (the antiplatelet group), apixaban, and rivaroxaban (the anticoagulant group) separately.

RESULTS: There were a total of 1,292 one-to-one program and control propensity-matched patients: 166 each for the antiplatelet group and 480 each for the anticoagulant group. The average age of the anticoagulant group was 62 years; more than 60% were male, and approximately 45% had no prior unplanned care events. In contrast, the average age of the antiplatelet group was 57 years; more than 70% were male, and approximately 21% had no prior unplanned care events. In the antiplatelet group, the proportions adherent (proportion of days covered ≥80%) were 63.3% vs 42.8% (P = 0.0002) for program vs controls. Similarly, in the anticoagulant group, the proportion adherent was 77.9% vs 60.2% (P < 0.0001) for program vs controls. Reflecting improved adherence, costs of apixaban and rivaroxaban increased by $79 per member per month (PMPM) (P < 0.0001), with no statistically significant differences in other costs. Similarly, the cost of ticagrelor increased by $77 PMPM (P = 0.0102) with no statistically significant differences in other costs. Finally, there was a 16% (P = 0.032) reduction in emergency department use for those in the program.

CONCLUSIONS: The financial incentive and refill reminder program was associated with improved adherence to antithrombotic medications, reduced emergency department use, and increased medication costs, but not in total pharmacy, medical, or total cost of care in both subgroups.

BACKGROUND: Outcomes-based agreements (OBAs) are agreements between payers and manufacturers in which payment for medications is tied to patient outcomes. These contracts aim to measure the value of prescription medications on predefined clinical indicators in real-world patient populations. OBAs are gaining traction in the United States as the health care industry shifts from volume-based to value-based care. Multiple sclerosis (MS) is an appealing therapeutic area for OBAs because of its prevalence, high cost of medications, and multiple effective therapeutic options.

OBJECTIVE: To describe findings from an OBA that was prospectively conducted in a large regional health system for patients with MS taking interferon β-1a or dimethyl fumarate.

METHODS: In this prospective real-world analysis, commercial or health insurance exchange members were included based on the parameters of the OBA. Disability progression was assessed using a patient-reported outcome, patient-determined disease steps (PDDS). In the OBA, members aged 18 years or older with an MS diagnosis were included in the contract. A baseline score was collected for eligible members, with follow-up scores occurring between a 90-day and 180-day postbaseline score. If a follow-up score was greater than the baseline score, a subsequent PDDS score was collected between 90-days and 120-days to determine if the PDDS score remained elevated, indicating that the member had disability progression.

RESULTS: During the contract period, 410 patients were eligible for PDDS collection, with 241 and 169 patients in the dimethyl fumarate and interferon β-1a cohorts, respectively. There were 162 patients who were lost to follow-up, and 64 patients who were ineligible per contract parameters. Of the remaining 184 eligible patients (107 on dimethyl fumarate and 77 on interferon β-1a), 21 (11%) patients had confirmed disability progression (6 on dimethyl fumarate [5.6%] and 15 on interferon β-1a [19.5%]).

CONCLUSIONS: Our findings suggest that meaningful patient-reported outcomes, such as disability progression, can be operationalized in an innovative OBA.