Despite Improved Screening and Rates of Dyslipidemia, Prescribing Not Yet at Optimal levels

Seth Shay Martin, MD

An analysis of nationwide trends over 2 decades suggests the public health efforts and efforts of clinicians to improve cholesterol control on a population level have been paying dividends.

Using data from National Health and Nutrition Examination Survey cycles occurring from 1999-2018, results of the analysis indicate as education surrounding cholesterol management improved, so did the rates of cholesterol screenings and the mean levels of total cholesterol (TC), LDL-C, and triglycerides during the study period. However, investigators noted, while marked improvements were achieved, there was still room for improvement related to prescription of statins and nonstatin therapies.

“Our study found a continuation of favorable temporal trends in serum cholesterol screening, mean levels of TC, triglycerides, LDL‐C, and HDL‐C, and lipid‐lowering medication use among US adults aged ≥20 years from 1999 through 2018,” wrote investigators. “The proportions of ever cholesterol screening and cholesterol screening within 5 years increased over the past 2 decades, to 81.1% and 72.5%, respectively.”

One of the most impactful modifiable risk factors, education surrounding optimal lipid management has been an emphasis of public health efforts for decades. Citing a need for updated information on trends in cholesterol screening and lipid management, a team from the Ciccarone Center for the Prevention of Cardiovascular Disease Johns Hopkins University School of Medicine designed the current study with the intent of evaluating contemporary trends leveraging the most recent data from the NHANES.

In addition to assessing trends in cholesterol screening, mean levels of total cholesterol, triglycerides, low‐density‐lipoprotein cholesterol, and lipid‐lowering medication use from 1999-2018, investigators pointed out their interest in calculating point estimates using the 2017 to March 2020 prepandemic data set from within NHANES. Investigators determined 50,928 of the 55,081 participants within NHANES met inclusion criteria for the current study. Of note, the most common reasons for exclusion were missing laboratory data, were pregnant at time of examination, and were missing data for all variables of interest.

Initial analysis demonstrated the mean age of study participants increased from 46.4 years in 1999-2000 to 48.5 years in 2017-2019. Investigators noted the proportion of women was stable during the study period at approximately 51%, while the proportions of non‐Hispanic Asian, Hispanic, and non‐Hispanic Black participants increased during the study period. Additionally, the proportions of persons with a family income below the poverty threshold varied from 10.8% to 17.7% and those who did not have health insurance from 13.5% to 20.8% from 1999-2000 to 2017-2018.

When assessing rates of cholesterol screening during the study period, results indicated the age‐ and sex‐adjusted proportions of ever cholesterol screening increased from 70.3% (95% CI, 67.1-73.3) in 1999-2000 to 74.3% (95% CI, 72.5-76.0) in 2011-2012, then increased at a faster rate to 81.1% (95% CI, 78.8-83.2) in 2017-2018 among the overall study population (P=.009 for overall nonlinear trend). Although the increases were not of the same magnitude, increases in proportions of those with cholesterol screening with 5 years also increased during the study period, with the rate of screening within 5 years increasing from 63.2% (95% CI, 60.0-66.3) in 1999-2000 to 72.5% (95% CI, 69.5-75.3) in 2017-2018 (P <.001 for overall linear trend).

In analyses assessing the prevalence of LDL-C levels at or exceeding 130 mg/dL in adults without confirmed atherosclerotic cardiovascular disease (ASCVD), results demonstrated the rate decreased from 44.0% (95% CI, 41.5-46.4) in 1999-2000 to 26.4% (95% CI, 24.1-28.7) in 2017-2018 (P <.001 for overall linear trend). Similarly, the prevalence of those with an LDL-C at or exceeding 70 mg/dL in adults with confirmed ASCVD decreased from 95.8% (95% CI, 72.2-99.5) in 1999-2000 and 76.3% (95% CI, 64.7-84.9) in 2017-2018 (P=.017 for overall nonlinear trend).

Using the 2018 ACC/AHA guideline criteria for statin eligibility, investigators determined the age‐ and sex‐adjusted proportion of statin use among eligible patients increased from 14.9% (95% CI, 12.2-17.9) in 1999-2000 to 24.6% (95% CI, 20.4-29.3) in 2007-2008 and to 27.8% (95% CI, 23.0-33.2) in 2017-2018 (P <.001 for overall nonlinear trend). However, investigators noted, when stratifying according to eligibility subgroups, the adjusted proportion of statin use increased from 23.0% (95% CI, 18.9-28.8) in 1999-2000 to 37.0% (95% CI, 30.2-44.2) in 2011-2012, but did not increase after this point among a subgroup of US adults with a confirmed history of ASCVD (P=.005 for nonlinear trend). Investigators also noted the proportion of adults using statins plus another lipid-lowering medication remained below under 5% for the majority of the study period.

“In a nationally representative sample of US adults aged ≥20 years, cholesterol screening increased while mean TC, triglyceride, and LDL‐C levels decreased from 1999 to 2018. However, we found room for improvement with respect to LDL‐C levels in patients with ASCVD and statin use in statin‐eligible US adults,” investigators added.

This study, “US Trends in Cholesterol Screening, Lipid Levels, and Lipid‐Lowering Medication Use in US Adults, 1999 to 2018,” was published in the Journal of the American Heart Association.