Sexual Activity and Contraceptive Use Among Teenagers Aged 15-19 in the United States, 2015-2017

May 6, 2020

Questions for Gladys Martinez, Health Statistician and Lead Author of “Sexual Activity and Contraceptive Use Among Teenagers Aged 15-19 in the United States, 2015-2017.”

Q: Why does NCHS conduct studies on sexual activity and contraception?

GM: We conduct studies on sexual activity and contraceptive use to better understand the risk for sexually transmitted diseases, birth and pregnancy rates, and differences between groups in the U.S. reproductive age population.

For this report they are crucial for understanding differences in the risk of teen pregnancy and to put into context recent declines in the U.S. teen birth rate.

Q: Can you summarize how the data varied by sex and age groups?

GM: There has been a decline in the percentage of male and female teens who ever had sex from 1988 to 2017.  But the percentage of male teens who ever had sex continues to decline in most recent time period 2011-2015 to 2015-2017, but has remained the same for female teens.

Male and female had similar:

  • cumulative probabilities of having had sex at each age in their teen years
  • relationship between age at first sex and contraceptive use: teens with younger ages at first sexual intercourse were less likely to use a method of contraception

Q: Was there a specific finding in the data that surprised you from this report?

GM: For the first time since we have been collecting these data, the cumulative probabilities of having had sex by each age in the teen years were similar for young males and females.

Ever use of implant is 15% which is an increase from 2011-2015 when it was only 3%.

Q: How did you obtain this data for this report?

GM: Data for this report are from the 2015-2017 National Survey of Family Growth, a nationally representative in-person survey of men and women aged 15-49 in the United States.

Q: Do you have older data that is comparable beyond 2002?

GM: Yes, we have been tracking these data since the 1970s and the earliest published NSFG report shows data from 1988.

Electronic Cigarette Use Among U.S. Adults, 2018

April 30, 2020

A new NCHS report examines e-cigarette use among U.S. adults aged 18 and over by selected sociodemographic characteristics and in relation to cigarette smoking status.

Click to access db365-h.pdf


Total and High-density Lipoprotein Cholesterol in Adults: United States, 2015–2018

April 22, 2020

Questions for Margaret Carroll, Health Statistician and Lead Author of “Total and High-density Lipoprotein Cholesterol in Adults: United States, 2015–2018.”

Q: How has the prevalence of high total cholesterol among US adults changed since 1999-2000 data and and low high-density lipoprotein cholesterol (HDL-C) since 2007-2008?

MC: There has been a declining trend in the prevalence of high total cholesterol since 1999-2000 and a declining trend in the prevalence of low HDL-C since 2007-2008.

Q: Can you summarize how the data varied by sex, age groups and race?

MC: The prevalence of high total cholesterol:

  • Higher in adults aged 40-59 than in adults aged 20-39 and those aged 60 and over
  • Not significantly different between men and women aged 20 and older
  • Not significantly different among non-Hispanic white, non-Hispanic black, non-Hispanic Asians and Hispanics

The prevalence of low HDL-C:

  • Higher in men than in women overall, within each age group and within each race and Hispanic origin group.
  • lower among NH black adults than in non-Hispanic white adults, non-Hispanic Asian adults and Hispanic adults over all and in men.
  • Higher among Hispanic adults than among non-Hispanic white, non-Hispanic black and non-Hispanic Asian adults overall, among men and among women.

Q: Was there a specific finding in the data that surprised you from this report?

MC: Although we weren’t surprised because the results have been seen in the past, men continue to have a much higher prevalence of low HDL-C compared to women.

Q: How did you obtain this data for this report?

MC: Results presented in this report are based on data from the National Health and Nutrition Examination Survey (NHANES), a nationally representative, cross sectional, probability survey representative of the United States non-institutionalized population.  Beginning in 1999 NHANES became a continuous survey and data have been released in 2-year cycles.  Data from 2015-2016 and 2017-2018 were used to test differences in the prevalence of high total and low HDL-C cholesterol between subgroups. Trends in the prevalence of high total cholesterol are based on data from ten 2-year cycles from 1999-2000 through 2017-2018. Trends in the prevalence of low HDL-C are based on six 2-year cycles from 2007-2008 through 2017-2018

Q: What is the take home message for this report?

MC: Over 1 in ten (11%) adults have high total cholesterol and over 17% have low HDL-C. The prevalence of high total cholesterol has declined since 1999-2000; the prevalence of low HDL-C has declined since 2007-2008.

Q & A: New Release of 2018 Mortality Data and New Data on Maternal Mortality

January 30, 2020


Robert Anderson is Chief of the Mortality Statistics Branch at NCHS. Dr. Anderson joined me to discuss the new release of 2018 mortality data as well as the new data on maternal mortality in the United States:

Q:           Before we get into the subject of maternal mortality, there are a number of other mortality topics in this release that are significant. Let’s start with life expectancy.

RA:         So as I’m sure you’re aware, life expectancy has, we’ve experienced a decline in life expectancy over the last few years. Since 2014, life expectancy declined 2 out of 3 years through 2017, and from 2017 to 2018, though, we saw a slight increase, so it appears that that trend is reversed.

Q:           Do we know what causes of death contributed to this increase in life expectancy?

RA:         Yeah we do – we did an analysis of the causes of death that contributed to that change and the main causes that are contributing to the increase in life expectancy are declines in cancer mortality and declines in unintentional injuries and in most instances that involves drug overdoses – so a slight decline in the rate for drug overdose.

Q:           How much of that impact you think was due to the decline in drug overdoses?

RA:         It probably accounts for about 15% of the decline – it’s not a whole lot.

Q:           Can you talk about which drugs we’re making progress on as far as overdose deaths and which are now emerging as the biggest threat to the country?

RA:         So, between 2017-2018 in particular we saw declines in the natural and semi synthetic opioids which are drugs that are commonly available by prescription – like oxycodone and hydrocodone. We saw declines in methadone overdose. And we also saw declines, a slight decline, in overdose deaths due to heroin. But the synthetic opioids, other than methadone, seem to be a continuing problem – the overdose death rate for the synthetic opioids other than methadone continued to increase from 2017 to 2018.

Q:           So just to be clear – these synthetic opioids we’re talking about are fentanyl?

RA:         Fentanyl and tramadol – a very large proportion of those deaths involve fentanyl.

Q:           Now, pivoting to maternal mortality. With maternal mortality there’s a whole back story – can you share that with us?

RA:         Yeah, it’s sort of a long and involved process that we’ve gone through over the last decade and a half or so. So in the past, as we’ve collected data on maternal deaths – and here we’re talking about years prior to 2003 in particular – research had shown that we tended to underestimate maternal deaths. And so in order to address that issue, we felt that adding a checkbox item to the death certificate asking whether the decedent was pregnant or recently pregnant was a good idea. And so we revised our standard death certificate – this is the standard that the states use to base their own state death certificates on – we revised that to include this checkbox item. So that was implemented in 2003 but only in a few states. Unfortunately, not all states implemented at the same time and so over the next, well, decade and a half – a little bit more than that actually – we had states implementing gradually this checkbox item and as a result that we saw increases in maternal mortality. And it got to the point that in 2007, we decided that we couldn’t adequately interpret what was going on and so we stopped reporting maternal mortality altogether, waiting for all of the states to get onto the standard certificate at which point we planned to resume. So the final state implemented the checkbox item in mid-year 2017, so 2018 is the first data year for which we have data from all states that is based on that checkbox. So we decided we needed to do an evaluation though, of the data because research post 2003 showed that there were some problems with the checkbox – some errors that were evident. And so we did this evaluation and we found indeed there were some problems and so we had to come up with a new method to code maternal mortality that would mitigate those errors. So with the 2018 data we’re now releasing a figure that we believe reasonably represents the risk of maternal mortality in the United States.

RA:         We’re releasing data for 2018 and it’s based on this new coding method. We will be releasing some data for previous years as well, coded in multiple ways. Our goal is to make the data as transparent as possible so that the researchers can see what we did and what went into the new coding method and, you know, what went into the statistics that we’re releasing. But also, you know, if they choose to make some different decisions in their research they would be able to do that as well – they’ll be able to count them however they like.

Q:           So how many maternal deaths are we seeing in the U.S. according to 2018 data?

RA:         In 2018, we found 658 maternal deaths for the United States – it’s a rate of 17.4 deaths for every 100,000 live births.

Q:           Can we say that the maternal mortality deaths and the maternal mortality rate increased over time?

RA:         Well, we can’t really say that with any sort of certainty. We do know that the increases that we’ve seen compared to the older data that we released, the increases that we’ve seen are largely – mostly even – due to implementation of the checkbox. They don’t appear to be real increases.

RA:         We did an analysis based on 2015 and 2016 data. The purpose of that particular analysis was to look at the effect of the checkbox on maternal mortality and what we found was that there was a dramatic increase in the number of maternal deaths detected as a result of using the checkbox. And we also found that that increased very dramatically by age, so at the older ages, the checkbox increased the number of maternal deaths detected by quite a lot

Q:           So the checkbox you feel then is giving a clearer picture of what the scope of the problem is?

RA:         I wish I could say that was the case – we feel like it is definitely allowing us to detect maternal deaths that we weren’t able to detect before. That said, we know that there are some errors in the checkbox and we’re not entirely sure why these errors are occurring. This is something that we’re going to be exploring over the course of the next year. We’re trying to sort that out so we can actually correct it. But the effect of these errors on the checkbox is that we are finding deaths to women who were not pregnant but for whom that the checkbox was checked that they were pregnant. And some of these women are quite old actually – beyond reproductive age.

Q:           So when did you start uncovering those problems along this process?

RA:         Well, we didn’t actually discover this. There were some states that were doing their own research on this – the state of Texas, for example, did some important research and they found errors. CDC’s Division of Reproductive Health did some work with four states recently, that they recently published, that showed that this was the case as well. And so we were really taking the results of that research, along with our own evaluation, to determine what was going on.

Q:           What else have you found – are there any geographic patterns that suggest maternal deaths are more prevalent in certain parts of the country?

RA:         Well, we can’t really say much about maternal mortality by state or by region. Unfortunately, we really don’t understand very well the variation in data quality from state to state and in addition you’re talking about 658 deaths in a year spread over 50 states. The numbers get quite small and it’s difficult to make judgments based on small numbers – the death rates, mortality rates, get to be very unstable with small numbers.

Q:           So some have been saying or arguing that the problem has been getting worse over time, that even now we don’t have a complete picture. What would you say to that?

RA:         Well, I would agree that we don’t have a complete picture. The evidence that we’re seeing suggests that the problem isn’t really getting worse, but it doesn’t appear to be getting better either. And that’s, uh, that’s something to be concerned about. We have data from maternal mortality back to 1915 and we saw substantial declines – they’re really dramatic declines, we’ve seen dramatic decline since then and in recent decades the rate has been rather flat in comparison.

Q:           So one of these new reports looks at a 20 year period prior to the 2018 data. Could you talk about that?

RA:         Sure. As part of our evaluation we did this initial study based on the 2015 and 2016 data to get a sense of the impact of the checkbox and that was based on actual data that we had, we recoded not using the checkbox and then compared it to what we had with the checkbox. This other study was a little more involved and involves some statistical modeling, and so what we wanted to do with that study was to get a sense for what things would have looked like had all of the states implemented in 2003. So that was the goal and so we have this trend based on these statistical modeling procedures that shows a fairly stable trend .

Q:           The second report was more focused on the years 2015 and 2016 – can you talk about that work?

RA:         Sure. Yeah, the report based on the data years 2015 and 2016 is really an evaluation of the effect of the checkbox. And those years were chosen because those were years for which we had data coded without the checkbox. So we took these data, assuming no checkbox existed, and then we compared that with the data that we had that included the checkbox to get a sense for, to evaluate the effect of the checkbox on the maternal mortality.

Q:           Looking forward, are there any more initiatives underway in terms of improving this whole process and the quality of the data?

RA:         Yeah, there’s a lot of, a lot more work to do, really. I mean, we have to understand better why these errors are occurring in the checkbox. It may have something to do with electronic registration systems in the way they’re configured. We’re not really sure, but what we really need to understand if we’re going to correct these errors – we really need to understand why they are occurring and so that’s something that we’ll be working on over the course of the next year. In addition, we need to work with states and our plan is to do this, to work with states to investigate deaths to women of reproductive age to determine if a pregnancy or recent pregnancy was a factor in their death and this is this can be done using some data linkage to look in birth records and fetal death records for evidence of a pregnancy. I think we can glean a lot of information if we just, you know, take the time and effort to go and look and see. What we have to do is, we have to work with the states to do this because they are the keeper of those records. They’re the ones that will have to do it and if we can support them in those efforts then hopefully we can get information that will feed back into the vital statistics system and provide us with better data in the future.

Q:           Robert Anderson thank you for joining us.

Vision testing among children aged 3-5 years in the United States, 2016-2017

November 20, 2019

Questions for Lindsey Black, M.P.H., Health Statistician and Lead Author of “Vision testing among children aged 3-5 years in the United States, 2016-2017

Q: Why did you decide to focus on vision testing for children aged 3-5?

LB: Over a quarter of all children aged 0-17 years have vision problems (1). Two common eye problems, amblyopia (lazy eye) and strabismus (crossed eyes) can be treated and prevent further vision problems if they are found early (2). The USPSTF recommends children between 3-5 years old have vision screening (3) and Healthy People 2020 target for vision screening is 44.1% of preschool aged children (1). Despite this, little is known about the current prevalence of vision screening and how this may differ by population subgroups. We focused on children 3-5 years old as they are the focus of the USPSTF recommendations.

  1. Office of Disease Prevention and Health Promotion. Healthy People 2020. Washington, DC. Accessed at :
  2. Office of Disease Prevention and Health Promotion. Get your child’s vision checked. Washington DC. Accessed at:
  3. US Preventive Services Task Force. Vision Screening for Children 1 to 5 Years of Age: US Preventive Services Task Force Recommendation Statement. Pediatrics 127, 2 p340

Q: How did the data vary by age, race and health insurance?

LB: Overall, as children aged, they were more likely to have ever had their vision tested. Additionally, as children aged, they were also more likely to have had their vision tested in the past 12 months. There was also variation by race and Hispanic origin. About 65% of Non-Hispanic white children, 63% of non-Hispanic black children and 59% of Hispanic children have ever had their vision tested. Children with private health insurance (66.7%) were most likely to have ever had their vision tested compared with children with public insurance (61.2%) and children who are uninsured (43.3%).

Q: Was there a specific finding in your report that surprised you?

LB: It was surprising how much of an impact a recent well-child visit had on ever having a vision test. Children who did not receive a well-child visit in the past 12 months (44.1%) were less likely to have ever had their vision tested when compared to children that had received a well-child visit in the past 12 months (65.9%). Since vision screenings are recommended to be part of well-child visits, these visits provide valuable opportunities to detect problems and offer intervention efforts.

Q: How did you obtain this data for this report?

LB: Data are from the pooled 2016-2017 National Health Interview Survey and can be accessed via: Questions on vision testing are from supplement questions, which focused on expanded content related to child vision. This supplement was asked most recently in 2016-2017.

Q: What is the take home message for this report?

LB: Approximately 64% of children aged 3-5 have ever had their vision tested by a doctor or other health professional. As children age, they are more likely to have had their vision tested. Disparities exist by race, and health insurance status. Receipt of a recent well-child visit was also associated with a higher prevalence of receiving a vision test.


Death Rates Due to Suicide and Homicide Among Persons Aged 10–24: United States, 2000–2017

October 17, 2019

Questions for Lead Author Sally Curtin, Health Statistician, of “Death Rates Due to Suicide and Homicide Among Persons Aged 10–24: United States, 2000–2017.”

Q: Why did you decide to focus on ages 10 through 24 for suicides and homicides?

SC: Suicide and homicide are among the leading causes of death for this age range.  As there are almost no suicides below the age of 10, we began with age 10 and decided to go through the young adults age range, through age 24.

Q: How did the data vary by age groups?

SC: For the 10-24 age range, rates of both suicide and homicide are lowest for 10-14, intermediate for 15-19 and highest for 20-24.  The patterns differed between age groups.  For children and adolescents aged 10-14, suicide rates nearly tripled from 2007 to 2017 whereas homicide rates gradually declined over the period.  For 15-19 and 20-24, both suicide and homicide rates increased, with the increase beginning earlier for the suicide rates.

Q: Is this the first time you have published a report on this topic?

SC: We have published some similar reports recently, but this is the first one which focuses on these two causes of death for this age range.  Suicide and homicide are often referred to as the two major components of violent death.

Q:  Was there a specific finding in your report that surprised you?

SC: That both suicide and homicide have increased recently for 15-19 and 20-24 year olds.  Homicide has only been increasing since 2014, but this is after years of decline whereas suicide began to increase sooner.

Q: Why do you think suicide and homicide death rates have risen?

SC: That is for others in the prevention and research community to answer.  However, other studies have shown that some of the risk factors for suicide and homicide have increased.  In particular, depression and other mental health disorders have been shown to be increasing in youth.

Is Twin Childbearing on the Decline? Twin births in the United States, 2014-2018

October 3, 2019

Questions for Joyce Martin, Lead Author of, “Is Twin Childbearing on the Decline? Twin births in the United States, 2014-2018.”

Q: Is this the first time you have published a report on this topic?

JM: General information on twin births is published annually in the National Vital Statistics Report series “Births: Final Data.”   A number of special reports have also been published on the topic in the past.

Q: Why did you decide to do a report on trends in twin births?

JM: There appears to be a reversal in the direction of trends in twin childbearing in the US. After increasing for decades, the number and rate of twin births trended downward for 2014-2018.  This is important to public health because of the greater risk of poor pregnancy outcome, such as preterm birth and infant death, for babies born in twin pregnancies compared with those born in single pregnancies.

Q: How did the data vary by maternal age, race and Hispanic origin and state of residence?

JM: Trends differed by all of these characteristics.  Rates for women in their 30s and over declined by 10%-12% and rates for women 40 and over by more than 20%.  In contrast, there was no significant change in trends for women in their twenties.  Among the three race/Hispanic origin groups studied, twin childbearing declined for 2014-2018 among non-Hispanic white women but were essentially unchanged among non-Hispanic black and Hispanic women. Rates declined significantly in 17 states and increased in only three states.

Q: Was there a specific finding in your report that surprised you?

JM: The steady decline in twinning from 2014 through 2018 after many years of increases was surprising as was the fairly large declines among women aged 30 and over.

Q: Do you foresee the decline in twins continuing?

JM: As fertility procedures continue to improve, twin births, and especially higher-order multiple births, would be expected to continue to decline.  However, it is important to note that older mothers, those aged 35 and over, are more likely to have a twin delivery without the use of fertility therapies.  The older age of women at birth may also affect twining rates.