Researchers at Brigham and Women’s Hospital Target Managed Care (Comparing area-level patient density and physician prescribing preference instruments for the effect of antidiabetics on adverse cardiovascular events among Medicare beneficiaries): Managed Care

2025 DEC 30 (NewsRx) -- By a News Reporter-Staff News Editor at Insurance Daily News -- Fresh data on Managed Care are presented in a new report. According to news reporting out of Boston, Massachusetts, by NewsRx editors, research stated, “Randomized trials (RCT) of major adverse cardiovascular events found no effect of dipeptidyl-peptidase-4 inhibitors (DPP-4i) medications compared to second-generation sulfonylureas while non-randomized studies estimated a benefit of DPP-4i. Socioeconomic residual confounding was thought to be implicated.”

Our news journalists obtained a quote from the research from Brigham and Women’s Hospital, “We compared area-level prescribing density and physician prescribing preference as candidate instrumental variables for the effect of DPP-4i medications on major adverse cardiovascular events. Using Medicare claims data, we built two cohorts emulating RCTs of sitagliptin or saxagliptin starters, each compared to sulfonylurea starters. The proportion of DPP-4i prescribing in a ZIP Code tabulation area defined the area-level prescribing density instrumental variable at various cutoffs (0% vs. 100% to <50% vs. 50%). Patients’ physician prescribing history using the same proportion cutoffs was the physician prescribing preference candidate instrumental variable. An instantaneous physician preference instrumental variable used a physician’s most recent prescription. We adjusted two-stage instrumental variable regression models for propensity score quintiles. Unadjusted analyses for sitagliptin and saxagliptin, each compared to sulfonylurea, estimated a reduced risk of major adverse cardiovascular events (sitagliptin hazard ratio (HR)=0.86; 95% confidence interval 0.83 to 0.88); saxagliptin HR=0.68; 0.64 to 0.73). All instrumental variables were strong and reduced covariate imbalance. Analyses of area-level prescribing density found no meaningful difference for sitagliptin (0% vs. 100% HR=1.1; 0.79 to 1.6). Analyses of physician prescribing preference estimated reduced risk for sitagliptin (<50% vs. 50% HR=0.69; 0.48 to 0.98). Instantaneous physician prescribing preference analyses showed little to no difference for sitagliptin (HR=0.86; 0.60 to 1.1) and saxagliptin (HR=0.98; 0.56 to 1.7).”

According to the news editors, the research concluded: “Candidate instrumental variables focusing on short-term prescribing preference hold promise over area-based variables but remain inefficient.”

This research has been peer-reviewed.

For more information on this research see: Comparing area-level patient density and physician prescribing preference instruments for the effect of antidiabetics on adverse cardiovascular events among Medicare beneficiaries. Epidemiology, 2025. Epidemiology can be contacted at: Lippincott Williams & Wilkins, Two Commerce Sq, 2001 Market St, Philadelphia, PA 19103, USA. (Lippincott Williams and Wilkins - www.lww.com; Epidemiology - http://journals.lww.com/epidem/pages/default.aspx)

Our news journalists report that additional information may be obtained by contacting Robert J. Glynn, Division of Pharmacoepidemiology and Pharmacoeconomics, Dept. of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA. Additional authors for this research include Jack Cordes, Alexander M. Walker and Sebastian S. Schneeweiss.

The direct object identifier (DOI) for that additional information is: https://doi.org/10.1097/ede.0000000000001938. This DOI is a link to an online electronic document that is either free or for purchase, and can be your direct source for a journal article and its citation.

Publisher contact information for the journal Epidemiology is: Lippincott Williams & Wilkins, Two Commerce Sq, 2001 Market St, Philadelphia, PA 19103, USA.

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