2023 CHAS: Methods and Terminology

A brief overview of the methods and terms used in the Colorado Health Access Survey

May 8, 2024

The Colorado Health Access Survey — the CHAS — is the premier source of information on health coverage, access to health care, and the factors that influence health in Colorado. The CHAS is a biennial survey of approximately 10,000 households that has been conducted since 2009. 

The 2023 CHAS was fielded between March 22 and September 4, 2023, by NORC at the University of Chicago, an independent research company. Survey data are weighted to reflect the demographics and distribution of the state’s population. The survey was conducted in English and Spanish.

The survey is sampled geographically to ensure reliable estimates for the state’s 21 Health Statistics Regions (HSRs), which were developed by the Colorado Department of Public Health and Environment for public health reporting purposes. HSRs are comprised of single counties or groups of counties. Data for some HSRs are not reported due to sample size. For example, even in some large counties, the uninsured rate is not reportable because the uninsured sample is so small, making the estimate unreliable. 

NORC oversampled rural HSRs, people of Hispanic/Latino ethnicity, people of Black or African American race, adults ages 18 to 29, people without insurance, households with children, and households with incomes below the Medicaid eligibility level of 138% of the federal poverty level. Oversampling makes data more reliable for smaller groups of people.

The 2023 CHAS also included a pilot community engagement strategy under which NORC oversampled one urban HSR and two rural HSRs. The goal of the strategy is to provide a greater understanding of health issues in southeast Colorado and El Paso and Teller counties. 

The 2023 CHAS was administered mostly online. NORC sent letters to randomly selected households throughout Colorado asking them to participate in the survey and directing them to a website or toll-free number to call. All responses to the survey are self-reported and anonymous.

The Colorado Health Institute (CHI) added new questions to the 2023 survey, modified some existing questions, and removed others. New questions focused on the health impacts of climate change, long COVID, access to reproductive health care, sources of health information, broadband access, behavioral health, and transportation, among other topics. 

A publication detailing the survey methods is available on the upper left side of this page.

Statistically Speaking

CHI identifies differences and changes that have statistical significance, meaning that it is relatively certain they are not due to chance alone. Small differences may result from random coincidence in who was surveyed rather than indicating a change in Colorado’s population as a whole. If there is at least a 5% chance that our result is coincidental, it is not considered to be significant. For example, while the 2015 uninsured rate was 6.7% and the 2021 uninsured rate was 6.6%, this is not a significant difference, so it is described as essentially unchanged. In addition, estimates are not displayed when CHI has determined that there are not sufficient survey responses to produce a reliable estimate.

CHI also reports estimates that are statistically representative. In many cases, based on what CHAS metric is being analyzed, there could be issues with sample size. This can occur when there are too few people included in the numerator of an estimate, which can result in a high degree of error. 

An example of this is the 2023 CHAS uninsured rates. While CHI had a very robust sample of each HSR, there were several counties or regions that didn’t have enough uninsured people sampled for CHI to feel confident that the estimate was representative of the uninsured population of that area. Because of this, these estimates (and ones that experience similar issues with sample size) are not included in the report or other data products. CHI reports estimates that we feel confident represent Colorado’s populations.

Insurance Terminology 

Private Insurance

Also known as commercial insurance, this is insurance provided through an employer or purchased by an individual.

  • Employer-Sponsored Insurance: Health insurance that is offered through an employer. Generally, employees will pay a portion of the premium price, often through a payroll deduction. CHI includes TRICARE and other military coverage options in this category.
  • Individual Market: Health insurance purchased by an individual through a broker; through the state’s health insurance marketplace, Connect for Health Colorado; or from an insurance company directly, including student plans.

Public Insurance

  • Medicaid (Health First Colorado): A federal-state partnership that provides health care coverage primarily to people who have low incomes. The term “Medicaid” and the Colorado program’s name, Health First Colorado, were both used in the survey language.
  • Child Health Plan Plus (CHP+): A federal-state health insurance program for children and pregnant people. It is for people who earn too much to qualify for Medicaid, but not enough to pay for private health insurance.
  • Medicare: The federal health insurance program for adults 65 or older and people with disabilities. Most people in those categories qualify for Medicare, regardless of income or assets.

Other Insurance

This category includes a Railroad Retirement Plan and anyone who selected “other.”


This category includes people who indicated they have no insurance. It also includes other self-reported sources not considered to be comprehensive coverage, such as health care sharing ministries or coverage through the Indian Health Service.

Federal Poverty Level

Federal Poverty Level (FPL): The U.S. Department of Health and Human Services sets poverty guidelines to use for administrative purposes such as determining eligibility for programs like Medicaid. In 2023, the FPL was $14,580 for a single person and $30,000 for a family of four.

Race, Ethnicity, Gender, and Gender Identity

People who responded to the CHAS were asked about race, ethnicity, gender, gender identity, and sexual orientation. CHI developed wording and categories on all survey items. Certain items were developed in consultation with question sponsors or outside advisors or based on other surveys.

This section includes an explanation of some terms used in this report. In some cases, estimates are not displayed because the number of people reporting a particular identity was too small to provide a sufficient sample for analysis. To avoid erasing these groups and identities, CHI identifies which groups were not shown in figures or analysis because the estimate may not be representative of the population.

Race and Ethnicity

The survey asked respondents if they are Hispanic or Latino — considered by CHI to be an ethnic identity. Separately, respondents were asked which race(s) they identify as. Racial categories in the CHAS are: American Indian or Alaska Native, Asian, Black or African American, Hispanic/Latino (asked only of those identifying Hispanic/Latino ethnicity), Middle Eastern or North African, Native Hawaiian or other Pacific Islander, white, or some other race. Respondents could mark more than one choice. Separately, CHI analyzed the data using mutually exclusive racial/ethnic groupings, such as Black or African American (non-Hispanic/Latino), white (non-Hispanic/Latino), and Hispanic/Latino (of any race). All racial groups identified in this report, unless otherwise specified, are considered “non-Hispanic/Latino.” 

Gender and Gender Identity

CHI included a question on the 2023 CHAS about what sex a person was assigned at birth and a question about a person’s current gender, which may or may not be the same as their sex assigned at birth. The gender categories on the CHAS include female, male, transgender, or an option for the respondent to write in a different term. 

CHAS respondents were asked if they consider themselves to be transgender. CHAS analyses use the terms transgender and cisgender, respectively, to describe individuals whose gender identities do and do not differ from the sex they were assigned at birth.

Sexual Orientation

CHAS respondents were asked how they identify their sexual orientation. Response options included straight, gay or lesbian, bisexual, and other sexual orientation.


CHI combined responses of people identifying as lesbian, gay, bisexual, transgender, or other sexual orientation into a single category (LGBTQ+) for analysis. The “Q+” is intended to include people identifying different orientations and all non-male or non-female gender identities not captured in the questionnaire options.