Trends in Health Insurance Coverage by Poverty Status Among Persons Under 65 Years of Age: United States, 1997-2002

by Robin A. Cohen, Ph.D.; Hanyu Ni, Ph.D., M.P.H.; and Cathy Hao

Highlights

Preliminary data from the early 2002 National Health Interview Survey (NHIS) showed a decline from 1997 to 2002 in the percent of U.S. children (under 18 years of age) who lacked health insurance coverage (Table 1). This decrease is attributable to a reduction in the percent of the uninsured among children whose family income categorized them as being poor or near poor. During the same time period, the percent uninsured among not poor children remained stable (see Source of Data for poverty definitions). The decline in the percent uninsured among children may be attributable to the State Children’s Health Insurance Program (SCHIP), also known as Title XXI, which was enacted in 1997 to help children without health insurance, many of whom come from working families with incomes too high to qualify for Medicaid, but too low to afford private health insurance. NHIS data for January-September 2002 show that despite increasing coverage, 14.8% of poor and 15.5% of near poor children did not have health insurance at the time of the interview. In the first three quarters (January-September) of 2002, poor and near poor children were more than twice as likely as not poor children to lack health insurance coverage.

The NHIS data revealed that the overall percent of children under 18 years of age who had a public health plan increased from 20.0% in 1998 to 27.2% in January-September 2002 (Table 2). The largest increase was seen among children in the near poor category (22.9% in 1998 to 42.2% during the first three quarters of 2002). A slight increase was also seen among other children. During the same time period, private coverage among children who were in the near poor category decreased from 56.3% in1998 to 45.1% in the first three quarters of 2002 (Table 3). A slight decrease was also observed among children in the not poor group.

Among adults aged 18-64 years, the overall percent uninsured decreased from 18.9% in 1997 to 17.8% in 1999, and since then has not changed significantly (Table 1). Public coverage increased among near poor adults from 15.2% in 2000 to 18.6% in January -September 2002 (Table 2). During the first three quarters of 2002, 33.4% of poor adults were covered by a public health plan.

Private coverage increased for poor adults aged 18-64 years from 26.8% in 1997 to 30.4% in 1999, but did not change significantly (Table 3) in later years. From January to September 2002, 31.2% of poor adults had private health insurance coverage. Private coverage for near poor adults remained at about 50% from 1997 to the first three quarters of 2002. Private health insurance coverage decreased among not poor adults from 86.9 percent in 2001 to 85.9% in the first three quarters.

Source of Data

The NHIS is a multistage probability sample survey of the civilian noninstitutionalized population in the United States. It is conducted continuously throughout the year by interviewers of the U.S. Census Bureau for the Centers for Disease Control and Prevention’s National Center for Health Statistics. For further information, see the NHIS Web site. This analysis uses preliminary data from NHIS 2002. Final data editing and weighting have not been done, but the data on health insurance status were edited using an automated system based on logic checks and keyword searches. The estimates for all years were created using these same procedures to ensure comparability. The resulting estimates for persons not having health insurance coverage are generally within 0.1 percentage point of those produced from the final data files. These methods are consistent with those used by the NHIS Early Release Program to generate estimates of health insurance coverage at the NHIS Web site.

Poverty is categorized based on the ratio of the family’s income in the previous calendar year to the appropriate poverty threshold (given the family’s size and number of children) defined by the U.S. Census Bureau for that year (1-6). Persons who are categorized as “poor” had a ratio less than 1.0 (that is, their family income was strictly below the poverty threshold). The “near poor” category includes persons with incomes of 100% to less than 200% of the poverty threshold. Finally, “not poor” persons have incomes that are 200% of the poverty threshold or greater. The remaining group of respondents are coded as “unknown” with respect to poverty status. The estimates for those respondents with unknown poverty status (19.1% in 1997, 23.6% in 1998, 26.4% in 1999, 27.0% in 2000, 27.1% in 2001, and 27.0% in the first three quarters of 2002) are shown in the tables. Please visit our NHIS Web site for more information on the unknown income and poverty status categories.

References

1. Lamison-White, L. U.S. Bureau of the Census. Current Population Reports, Series P60-198. Poverty in the United States, 1996. U.S. Government Printing Office, Washington. 1997.
2. Dalaker J, Naifeh M. U.S. Bureau of the Census. Current Population Reports, Series P60-201, Poverty in the United States, 1997. U.S. Government Printing Office, Washington. 1998.
3. Dalaker J. U.S. Census Bureau. Current Population Reports, Series P60-207, Poverty in the United States, 1998. U.S. Government Printing Office, Washington. 1999.
4. Dalaker J., Proctor B. U.S. U.S. Census Bureau. Current Population Reports, Series P60-210, Poverty in the United States, 1999. U.S. Government Printing Office, Washington. 2000.
5. Dalaker J. U.S. Census Bureau. Current Population Reports, Series P60-214, Poverty in the United States, 2000. U.S. Government Printing Office, Washington. 2001.
6. Proctor B., Dalaker J. U.S. Census Bureau. Current Population Reports, Series P60-219, Poverty in the United States, 2001. U.S. Government Printing Office, Washington. 2002.

Tables

Table 1. Percent of persons under 65 years of age without health insurance coverage, by age group and poverty status: United States, 1997-2002

Notes: Poverty is categorized based on the ratio of the family’s income in the previous calendar year to the appropriate poverty threshold (given the family’s size and number of children) defined by the U.S. Census Bureau for that year. Persons who are categorized as “poor” had a ratio less than 1.0 (that is, their family income was strictly below the poverty threshold). The “near poor” category includes persons with incomes of 100% to less than 200% of the poverty threshold. Finally, “not poor” persons have incomes that are 200% of the poverty threshold or greater. The remaining group of respondents are coded as “unknown” poverty status. The estimates for those respondents with unknown poverty status (19.1% in 1997, 23.6% in 1998, 26.4% in 1999, 27.0% in 2000, 27.1% in 2001, and 27.0% in the first three quarters of 2002) are shown in the table. Please visit NHIS Web site for more information on the unknown income and poverty status categories. A person was defined as uninsured if he or she did not have any private health insurance, Medicaid, State Children’s Health Insurance Program (SCHIP), Medicare (disability), State-sponsored or other government-sponsored health plan or military plan at the time of the interview. A person was also defined as uninsured if he or she had only Indian Health Service coverage or had only a private plan that paid for one type of service such as accidents or dental care. The analysis excluded persons with unknown health insurance status (about 1% of respondents). The data on health insurance status were edited using an automated system based on logic checks and keyword searches. The resulting estimates of health insurance coverage are generally within 0.1 percentage point of those based on both automated and manual editing procedures used for the final data files.

Data Source: Family Core component of the 1997-2002 National Health Interview Survey. The estimates for 2002 were based on data collected from January through September.

Table 2. Percent of persons under 65 years of age with public health plan coverage, by age group and poverty status: United States, 1997-2002

Notes: Poverty is categorized based on the ratio of the family’s income in the previous calendar year to the appropriate poverty threshold (given the family’s size and number of children) defined by the U.S. Census Bureau for that year. Persons who are categorized as “poor” had a ratio less than 1.0 (that is, their family income was strictly below the poverty threshold). The “near poor” category includes persons with incomes of 100% to less than 200% of the poverty threshold. Finally, “not poor” persons have incomes that are 200% of the poverty threshold or greater. The remaining group of respondents are coded as “unknown” poverty status. The estimates for those respondents with unknown poverty status (19.1% in 1997, 23.6% in 1998, 26.4% in 1999, 27.0% in 2000, 27.1% in 2001, and 27.0% in the first three quarters of 2002) are shown in the table. Please visit for more information on the unknown income and poverty status categories. The category “public health plan coverage” includes Medicaid, SCHIP, Medicare (disability), State-sponsored or other government-sponsored health plan and military plans. A small number of persons who were covered by both public and private insurance (table 3) are included in both categories. The analysis excluded persons with unknown health insurance status (about 1% of respondents). The data on health insurance status were edited using an automated system based on logic checks and keyword searches. The resulting estimates of health insurance coverage are generally within 0.1 percentage point of those based on both automated and manual editing procedures used for the final data files.

Data Source: Family Core component of the 1997-2002 National Health Interview Survey. The estimates for 2002 were based on data collected from January through September.

Table 3. Percent of persons under 65 years of age with private health insurance coverage, by age group and poverty status: United States, 1997-2002

Notes: Poverty is categorized based on the ratio of the family’s income in the previous calendar year to the appropriate poverty threshold (given the family’s size and number of children) defined by the U.S. Census Bureau for that year. Persons who are categorized as “poor” had a ratio less than 1.0 (that is, their family income was strictly below the poverty threshold). The “near poor” category includes persons with incomes of 100% to less than 200% of the poverty threshold. Finally, “not poor” persons have incomes that are 200% of the poverty threshold or greater. The remaining group of respondents are coded as “unknown” poverty status. The estimates for those respondents with unknown poverty status (19.1% in 1997, 23.6% in 1998, 26.4% in 1999, 27.0% in 2000, 27.1% in 2001, and 27.0% in the first three quarters of 2002) are shown in the table. Please visit for more information on the unknown income and poverty status categories. The category “private health insurance” excludes plans that paid for only one type of service such as accidents or dental care. A small number of persons who were covered by both public (table 2) and private insurance are included in both categories. The analysis excluded persons with unknown health insurance status (about 1% of respondents). The data on health insurance status were edited using an automated system based on logic checks and keyword searches. The resulting estimates of health insurance coverage are generally within 0.1 percentage point of those based on both automated and manual editing procedures used for the final data files.

Data Source: Family Core component of the 1997-2002 National Health Interview Survey. The estimates for 2002 were based on data collected from January-September.