Abstract

The National Center for Health Statistics (NCHS), the Centers for Disease Control and Prevention, releases its latest annual estimate of health insurance coverage for the US population. Another new NCHS report provides guidelines for the analysis of trend data from health surveys conducted and vital records collected by NCHS. The latest data on dental caries among children and adolescents, by demographic and socioeconomic characteristics, are also examined.
Health Insurance Estimates for 2017
NCHS released the latest in a series of annual reports on health insurance coverage of the US population. These findings are based on data from the National Health Interview Survey, a large-scale household interview survey of a sample of the US civilian, noninstitutionalized population. “Health Insurance Coverage: Early Release of Estimates From the National Health Interview Survey, 2017” 1 presents estimates of coverage by insurance type, period of insurance coverage, age (primarily for those aged <65), sex, race/ethnicity, and poverty status. The report documents the extent of private health insurance obtained through the Health Insurance Marketplace, state-based exchanges, and enrollment in high-deductible health plans. The report includes data on trends in insurance coverage from 1997 through 2017. In addition to national data, estimates are shown for 18 US states: California, Florida, Georgia, Illinois, Indiana, Massachusetts, Michigan, Missouri, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Tennessee, Texas, Virginia, Washington, and Wisconsin.
In 2017, among people of all ages, 9.1% were uninsured at the time of interview. Among adults aged 18-64, 12.8% were uninsured, 19.3% had public health insurance, and 69.3% had private health insurance, which included 4.3% covered by private health insurance obtained through the Health Insurance Marketplace or state-based exchanges. The percentage of people aged <65 with private health insurance enrolled in a high-deductible health plan was 43.7% in 2017. Among children aged 0-17, 5% were uninsured, 41.3% had public health insurance, and 55.0% had private health insurance. Overall, males were slightly more likely than females to be uninsured at the time of interview (9.1% vs 8.0%). By race/ethnicity, 20.5% of Hispanic people aged <65 were uninsured, whereas 7.5% of non-Hispanic white people, 11.2% of non-Hispanic black people, and 6.7% of non-Hispanic Asians were uninsured. By poverty status, 17.7% of those aged <65 who were classified as poor (ie, <100% of the federal poverty level) were uninsured in 2017, whereas 18.2% of those classified as near poor (100% to <200% of the federal poverty level) and 7.2% of those classified as not poor (≥200% of the federal poverty level) were uninsured.
The percentage of the total population that was uninsured declined from 15.4% in 1997 to 9.1% in 2017. By age group, from 1997 to 2017, the percentage of uninsured declined from 18.9% to 10.7% for adults aged 18-64 and from 13.9% to 5.0% for children aged 0-17.
Guidelines for Analysis of NCHS Data
NCHS produces a variety of health data from various sources during lengthy time periods. These population-based health surveys have collected data through household interviews and health examinations for more than 50 years. Vital statistics data on births and deaths are based on certificates of these events filed in state vital statistics offices and processed centrally by NCHS for even decades longer. Health care surveys based on samples of data from hospitals and other medical records started in the 1960s. Analysis of the trends in these data depends on numerous analytical choices whose selection can result in differing results. “National Center for Health Statistics Guidelines for Analysis of Trends” 2 addresses issues that should be considered when conducting a time-trend analysis using NCHS data and presents guidelines for making trend analysis choices. It also summarizes the strengths and limitations of various approaches.
Trend analysis issues discussed in the guidelines include choosing the observed time points to include in the analysis, considerations for survey data and vital records data (record level and aggregated), a general approach for conducting trend analyses, other analytic issues, and joinpoint regression. This report provides 12 guidelines for trend analyses, examples of analyses using NCHS survey and vital records data, statistical details for some analysis issues, and SAS and SUDAAN codes for specifying joinpoint regression models. The NCHS Trends Analysis Workgroup, which represents the various NCHS data systems and their methodological, research, and analytical programs, developed the guidelines.
Dental Caries Among Young People
The oral health component of the National Health and Nutrition Examination Survey is the source of estimates of various measures of dental health, including the prevalence of dental caries. A new NCHS report, “The Prevalence of Total and Untreated Dental Caries Among Youth: United States, 2015-2016,” 3 presents estimates of the prevalence of total and untreated caries in primary or permanent teeth among children and adolescents aged 2-19 for 2015-2016 and trends from 2011-2012 through 2015-2016.
The prevalence of total dental caries (untreated and treated) in primary or permanent teeth among children and adolescents aged 2-19 was 43.1%. The prevalence of dental caries increased with age: 17.7% among children aged 2-5, 45.2% among children aged 6-11, and 53.5% among adolescents aged 12-19. The prevalence of untreated caries in primary or permanent teeth among children and adolescents aged 2-19 was 13.0%. The prevalence of untreated caries was lower among children aged 2-5 (8.8%) than among children aged 6-11 (15.3%) or adolescents aged 12-19 (13.4%).
The report also documents differences in the prevalence of total dental caries by race/ethnicity. The prevalence of total caries was highest among Hispanic children and adolescents (52.0%) and lowest among non-Hispanic white children and adolescents (39.9%). The prevalence of untreated caries among those aged 2-19 ranged from 10.5% of non-Hispanic Asian children to 17.1% of non-Hispanic black children. The prevalence of total and untreated dental caries decreased as family income levels increased. Young people in families with incomes >300% of the federal poverty level had the lowest prevalence (34.3%) of both untreated and total dental caries, whereas young people in families living below the federal poverty level had the highest prevalence (51.8%).
