A recent study led by Dr. Lisandro D. Colantonio, doctoral candidate in the department of epidemiology at the University of Alabama at Birmingham, analyzed the agreement between use of lipid-lowering medications (LLMs) and Medicare pharmacy claims among American adults enrolled in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study. Data on LLM use from 899 REGARDS participants aged 65 and older were obtained at the time of their enrollment in this study in 2006 to 2007 through a phone interview followed by an in-home inventory of medications. All REGARDS participants included in the analysis had Medicare Part D (pharmacy benefits) from 120 days prior to the interview through to the inventory.
[Photo: Dr. Lisandro D. Colantonio]
Study results indicate that 39.2 and 39.5 percent of study participants had filed a Medicare claim for an LLM in the 120 days prior to their interview and inventory, respectively, while 42.7 percent self-reported taking LLMs and 41.8 percent were found to have an LLM in their medication inventory.
“The Kappa statistic (95 percent confidence interval [CI]) for agreement of Medicare claims with self-report and medication inventory was 0.68 (0.63–0.73) and 0.72 (0.68–0.77), respectively. No Medicare claims for LLMs were present for 22.1 percent (95 percent CI: 18.1–26.6 percent) of participants who self-reported taking LLMs and 18.9 percent (15.1–23.3 percent) with LLMs in their medication inventory. Agreement between Medicare claims and self-report was lower among Black male individuals (Kappa = 0.34 [95 percent CI: 0.14–0.54]) compared with Black female individuals (0.70 [0.61–0.79]), White male individuals (0.65 [0.56–0.75]), and White female individuals (0.79 [0.72–0.86]). Agreement between Medicare claims and the medication inventory was also low among Black male individuals (Kappa = 0.48 [95 percent CI: 0.29–0.66]),” notes Dr. Colantonio.
The investigators concluded that a substantial number of the study participants with Medicare pharmacy coverage who reported using LLMs or were found to have them in their medication inventory had not filed claims for such treatment with Medicare.
Co-investigators are department colleagues Dr. Shia T. Kent, postdoctoral fellow; Dr. Elizabeth Delzell, professor emeritus; and Dr. Paul Muntner, professor and vice chair; as well as Dr. Meredith Kilgore, professor and chair in the department of health care organization and policy; Dr. George Howard, professor in the department of biostatistics; Dr. Jeffrey R. Curtis, professor in the division of immunology and rheumatology; and Dr. Monika M. Safford, professor in the division of preventive medicine, at UAB.
“Agreement between Medicare Pharmacy Claims, Self-report, and Medication Inventory for Assessing Lipid-lowering Medication Use” was published online in January in the journal Pharmacoepidemiology and Drug Safety.