The goal of this observational study is to identify the impact of incretin-based obesity medications (e.g., GLP-1 and GLP-1/GIP) on health and economic outcomes among adults who get their health insurance through their employers. The main questions it aims to answer are:

1. Is obesity medication usage is associated with reduced body mass index (BMI) and weight?
2. Is obesity medication usage is associated with reduced utilization of emergency department and inpatient care or obesity-related conditions over time?
3. Is obesity medication usage is associated with increased utilization of outpatient care over time?
4. Is obesity medication usage is associated with slower growth in direct medical costs over time?
5. Is obesity medication usage is associated with improvements in health measures?
6. Is obesity medication usage associated with reduced workplace costs?

Researchers will compare individuals who have prescriptions for obesity medications to those without to see if differences in health and costs of care exist.

The study uses existing medical and pharmacy claims data.

Incretin-based therapies that work by mimicking the action of the natural hormone GLP-1 and GLP-1/GIP have garnered the most excitement and demonstrated promising results in the management of obesity. This project seeks to estimate the impact of incretin-based obesity medications on clinical and economic outcomes in real-world settings. It proposes to fill gaps in the current literature by focusing on patients from self-insured organizations, measuring direct and indirect costs, establishing a long-term cohort, and by merging claims with electronic health record (EHR) data for more comprehensive measures.

The impact of incretin-based obesity medications on clinical and economic outcomes will be assessed in a dynamic cohort design. The cohort will be drawn from the employees and their working age dependents of large, self-insured (or "self-funded") organizations in the state of Indiana (i.e., "employers"). Employer organizations agreeing to participate will provide medical and pharmacy claims as well as data on workplace performance (if available) from 2018-2029. The primary exposure of interest is documented receipt of any GLP-1 obesity medication (regardless of manufacturer or brand name). A series of fixed-effects regression models will estimate the association between exposure to incretin-based obesity medications and clinical, utilization, and cost outcomes. This dynamic cohort approach, 1) individuals and participating employer organizations may enter and exit the cohort over time and 2) individuals may switch between on or off exposure over time.

The study cohort is limited to employees and adult dependents aged 18-64 who receive their health insurance coverage from self-insured Indiana employers that agree to participate in the study.

To be included in the study, the individuals must:

1. Be an Indiana resident;

2. Have health insurance benefits provided by participating employers (includes employees and dependents);

3. Be between the ages of 18 and 64;

4. Meet the eligibility criteria for an obesity medication prescription:

   1. BMI of ≥ 30 (obesity) or
   2. BMI of ≥ 25 (overweight) and at least one body weight-related comorbid condition (e.g., hypertension, dyslipidemia, type 2 diabetes mellitus, obstructive sleep apnea, or cardiovascular disease). If the prescribing eligibility criteria are updated in the future, we will update accordingly.

5. Individuals must have at least 6 months of enrollment prior to study inclusion (i.e., prior to the index date), though we may use additional pre-treatment data if available.

An individual who meets any of the following criteria will be excluded from participation in the cohort:

1. Has a condition associated with weight loss: a diagnosis of cancer (except for non-melanoma skin cancer), pancreatitis, eating disorders (e.g., anorexia nervosa and avoidant restrictive food intake disorder), HIV, unintentional weight loss, or cirrhosis at baseline;
2. Has a condition for which obesity medications are contraindicated (for example, medullary thyroid carcinoma, multiple endocrine neoplasia, etc.).
3. Receipt of diabetes-indicated incretin-based medications. If an individual has a claim for a related incretin-based therapy diabetes medication (e.g., Mounjaro, Ozempic, Rybelsus, Victoza) without an obesity-medication claim during the study period, the individual will be excluded from analysis.
4. Prior bariatric surgery.
5. Evidence of prior use of incretin-based obesity medications for weight loss.

Working-age adults and their adult dependents who receive their health insurance coverage from participating, self-insured Indiana employers.

Raw and derived data at the patient level will not be publicly posted due to our use of secondary data from privately held claims, electronic health records, and health information exchange systems. Because of data use restrictions among the participating employer organizations contributing claims to the analysis and because of the data use restrictions established by consortium agreements among the health system partners contributing EHR data to the project, patient-level data cannot be shared or disseminated beyond this project. Nevertheless, de-identified derived health information exchange data (only) at the patient-level used in this study may be shared with investigators whose formal requests are approved by the data owners. Requests can be sent to askRDS@regenstrief.org. Access to this data requires investigator support and a signed data access agreement between the Regenstrief Institute and the investigator's institution.