Comparing the Predicted Benefits and Harms of Using Adult versus Child Guidelines for Lipid Testing and Treatment in 17- to 21-Year-Olds

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What was the research about?

Some people have high levels of lipids (or fats) in their blood. High lipid levels increase the risk of heart disease and early death. Most of the time, high lipid levels affect older adults. But high lipid levels also affect teens and young adults who are overweight or have a family history of high cholesterol.

Early testing and treatment for high lipid levels may help prevent heart problems. Doctors use guidelines based on research to decide when to test for high lipid levels and how to treat them. Two guidelines for lipid testing and treatment apply to teens and young adults (17- to 21-year-olds). But these guidelines offer different advice. Adult guidelines recommend treatment for patients with high lipid levels. Child guidelines recommend treatment for patients with slightly high lipid levels if heart disease runs in their family. Doctors don’t know which guideline is best for teens and young adults.

This study compared the effects of using adult or child guidelines. The research team created a computer program using data from 17- to 21-year-olds who took a national health survey. The computer program predicted how each guideline would affect the health of teens and young adults in the United States.

What were the results?

• Treatment recommendations. The computer program predicted that more teens and young adults would be treated for high lipid levels using the child guidelines versus adult guidelines. Six times as many teens and young adults would receive lipid-lowering medicine using the child guidelines. Also, the program predicted that about 2 million teens and young adults would be urged to improve their diet and exercise under either guideline.
• Health benefits in the first year. The computer program predicted that using either guideline would lower body mass index in teens and young adults by the same amount. Body mass index is a measure of excess weight that takes height into account. For teens and young adults with high lipid levels, either guideline would lower lipid levels by the same amount. For those with slightly high lipid levels, using the child guidelines would lower lipid levels three times as much as the adult guidelines would.
• Long-term health benefits. The computer program predicted that teens and young adults would have fewer heart problems over the next 30 years if they followed either guideline. Those with high lipid levels would live about two years longer if they followed either guideline. Those with slightly high lipid levels would live about two months longer using the child guidelines than the adult guidelines.
• Quality of life. Teens and young adults told researchers that having their lipid levels tested and receiving treatment made them feel like their health was worse. Because more teens and young adults would get treated using the child guidelines, those guidelines could reduce quality of life more than the adult guidelines would.

What did the research team do?

The research team used health data from 6,338 people aged 17 to 21 years in the computer program. The computer program predicted the effects of each guideline on treatment decisions in teens and young adults. Treatment included taking medicine, following a healthy diet, and exercising. The computer program used data from previous studies to predict how each treatment would affect lipid levels and body mass index. It predicted the number of heart problems teens and young adults would have over 30 years and how long they would live. The team also asked teens and young adults how they would rate their health if they knew their lipid levels and received treatment. The computer program used these ratings to predict quality of life.

What were the limits of the study?

The national survey had missing health data for some groups of people. Missing data might affect the computer program’s predictions. The research team didn’t look at the costs or side effects of medicines. Those things may change the quality-of-life predictions.

Future research could look at how taking lipid-lowering medicines affects teens and young adults over time. Researchers could also study how testing lipid levels affects quality of life.

How can people use the results?

Doctors can talk with teens and young adults about which guideline might be best to follow. Doctors can also talk to teens and young adults about how following the guidelines might affect their treatment and future health.

Objective

To compare pediatric and adult lipid screening and treatment guidelines for adolescents and young adults (17- to 21-year-olds) in the United States by predicting the guidelines’ impacts on health outcomes and quality of life

Study Design

Although pediatric and adult guidelines for lipid-level screening and treatment both include recommendations for young adults, the recommendations differ. For example, adult guidelines prescribe statins to patients with low-density lipoprotein cholesterol (LDL-C) ≥190 mg/dL. In contrast, pediatric guidelines recommend statins to patients with LDL-C levels that are lower than 190 mg/dL if they have certain cardiovascular risk factors. As a result, healthcare providers are uncertain which guidelines to follow for adolescents and young adults.

To predict the impact of following each of the two guidelines on the health outcomes of adolescents and young adults, the research team built a computer simulation model. The team collected data on 6,338 participants aged 17 to 21 years in the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2012 and extrapolated from these data to the US population. The model predicted how many adolescents and young adults would need treatment for high lipid levels and which treatment they would receive under each guideline. Researchers then used data from previous studies of patients’ lipid levels and body mass index after taking statins, participating in intensive lifestyle interventions, or receiving lifestyle advice. They used these data to predict one-year changes in outcomes for individuals based on their assigned treatment.

To assess perceptions of health following lipid screening and one year of treatment, researchers interviewed 37 adolescents and young adults and 35 of their parents. The team recruited these participants from academically affiliated practices in urban settings. Participants rated their health or their child’s health in hypothetical screening-and-treatment scenarios using a visual analog scale. The simulation model incorporated these ratings, using the assumption that poorer health perceptions indicated lower quality of life.

Researchers predicted the survival of adolescents and young adults and 30-year cardiovascular disease incidence conditional on treatment received using two models. Researchers modeled the effects of following pediatric and adult guidelines on cardiovascular and survival outcomes in 20.4 million 20-year-olds.

Results

• Treatment recommendations. The simulation model predicted that following the pediatric guidelines would lead to 330,000 new statin prescriptions for adolescents and young adults. The model also predicted that 2 million adolescents and young adults would receive intensive lifestyle interventions, and 1.7 million would receive lifestyle advice. Following the adult guidelines would lead to 70,000 new statin prescriptions and 2.2 million adolescents and young adults receiving lifestyle advice.
• Changes in body mass index and lipid levels. The simulation model predicted that following either guideline would result in similar one-year reductions in body mass index and lipid levels for adolescents and young adults with LDL-C ≥190 mg/dL. The model predicted a decrease in LDL-C for young adults with LDL-C of 130–189 mg/dL that would be threefold larger if they followed the pediatric guidelines than if they followed the adult guidelines.
• Quality of life. Interview responses to hypothetical scenarios showed that screening and treatment recommendations caused adolescents and young adults to rate their health as poorer than they would have without screening. Because following the pediatric guidelines would yield more diagnoses and treatments than the adult guidelines, the model predicted lower quality of life in adolescents and young adults when following the pediatric guidelines.
• Cardiovascular disease incidence. The model predicted the 30-year cardiovascular disease incidence to be lower if adolescents and young adults followed the pediatric guidelines than if they followed the adult guidelines (3.13% [95% CI 2.97, 3.30] versus 3.18% [95% CI 3.00, 3.35]). The result would be 10,200 fewer cardiovascular disease events under the pediatric guidelines.
• Survival. The model predicted that young adults with LDL-C ≥190 mg/dL would survive 2.1 years longer when they followed either guideline compared with not following any guideline. The model predicted that young adults with LDL-C of 160–189 mg/dL would survive 64 days longer when following the pediatric guidelines rather than the adult guidelines.

Limitations

Researchers made assumptions when building the simulation model that may affect its predictions. Although NHANES data represent the US population, several subgroups had small patient numbers or were missing information. These limited data may affect predictions, such as those about the prevalence of familial hypercholesterolemia. The research team based the quality of life model on responses to hypothetical scenarios by participants from academic urban practices. Participants may not represent the general population. Their responses may have differed if they had been collected during an actual screening-and-treatment encounter. The study did not assess adverse events and treatment costs; these factors could inform potential harms of screening and subsequent treatment.

Conclusions and Relevance

Simulation modeling predicted that if people aged 17 to 21 years followed the pediatric guidelines, the result would be substantially more new statin prescriptions, reduced lipid levels, and reduced cardiovascular disease events than if those people followed the adult guidelines. The model also predicted that, due to early detection, following either guideline would increase survival among adolescents and young adults with LDL-C ≥190 mg/dL. Because of increased diagnoses and interventions, following the pediatric lipid screening-and-treatment recommendations may negatively affect quality of life more than the adult guidelines would, but the extent of the impact is unclear.

Future Research Needs

Future studies should look at the long-term health effects of treating high lipid levels in adolescents and young adults. Studies should also investigate the potential harms of diagnosing and treating high lipid levels in real-world settings.