How has COVID-19 affected 2020 data collection efforts?

By Julia A. Rivera Drew, Sarah M. Flood, Renae Rodgers

IPUMS integrates data from several major US surveys that collect data throughout the year. Below, we discuss how COVID-19 has affected how US statistical agencies have collected these survey data in 2020.

Current Population Survey (CPS)

The Bureau of Labor Statistics (BLS) and the Census Bureau have continued to collect data on a monthly basis during the COVID-19 pandemic, implementing some procedural modifications to protect the safety of respondents and Census Bureau employees and adding a short supplement to capture the effects of the pandemic on work in the United States.

Changes to Interviewing Procedures

Current Population Survey (CPS) data collection for March had already begun when the Census Bureau suspended in-person data collection on March 20th, 2020. Two call centers that assist with CPS data collection also closed down at this time. However, data collection continued exclusively by phone through June of 2020. In July, in-person interviews began in some areas of the country and the call centers that had been closed in March re-opened. In-person interviews were resumed in all areas of the country in September 2020 and data collection has returned to a normal routine. More information on how alternative data collection procedures affected response rates, attrition, and employment data is available on the IPUMS CPS website.

Additional COVID-related content

The COVID-19 outbreak prompted the BLS to add five questions to the monthly CPS survey about work in the time of COVID-19. These questions were first asked in May. Though the question about foregoing medical care due to the pandemic was dropped from the survey after October of 2020, all other questions will remain in the survey until further notice. Researchers may preview the questions or access the COVID-specific variables via IPUMS CPS.

IPUMS CPS will continue to update our documentation on the effects of the pandemic on CPS data collection and to make new data available as quickly as possible. Follow @ipums on Twitter for the latest updates.

American Time Use Survey (ATUS)

ATUS data are collected throughout the year, enabling national estimates of the time Americans spend doing various activities (e.g., paid work, childcare, unpaid work, leisure). The 2020 ATUS data collection was impacted by the COVID-19 pandemic in two ways.

Break in Data Collection

The pandemic resulted in the temporary closure of the call center in which ATUS interviews are conducted by phone. Accordingly, data collection was paused from March 19, 2020 through May 10, 2020. Data collection resumed at a reduced capacity on May 11, 2020.

Disruption to Underlying Sampling Frame

Individuals are invited to participate in the ATUS following completion of the eighth monthly interview in the Current Population Survey (CPS). CPS response rates declined from March to August 2020 due to the pandemic. BLS indicates that this affects ATUS data collection, though at this time it is unclear how.

We expect additional documentation from BLS on how the COVID-19 pandemic affected the ATUS to be available when the 2020 data are released in the summer of 2021.

National Health Interview Survey (NHIS)

The National Center for Health Statistics has continued to field the NHIS throughout 2020 with several notable changes to the survey design and questionnaire content to accommodate COVID and COVID-related nonresponse. For additional information and updates, please refer to the NCHS website on NHIS 2020 data collection efforts.

Introduction of Separate NHIS Survey Designs

Four separate NHIS survey designs were fielded during the course of 2020: 1) normal data collection in quarter 1; 2) telephone-only in quarter 2; 3) telephone-first in quarters 3 and 4; and 4) the introduction in August 2020 of a separate sample with known representativeness and nearly complete telephone contact information. The separate sample of roughly 20,000 people was drawn from respondents who completed the NHIS in 2019 and were invited to participate again. These participants were administered the 2020 questionnaire, and the longitudinal data collected on this sample will allow users to evaluate health, health care, and well-being from before and during the pandemic.

Changes to Interviewing Procedures

Between mid-March and July, the NHIS temporarily became a telephone survey. While the telephone-only approach was in the field, household response rates dropped from 60% in calendar quarter 1 of 2020 to 42.7% in quarter 2; sample adult and sample child response rates fell from 57.9% to 41.1% and 57.6% to 40.1%, respectively (Dahlhamer, et al. 2021). In July, a telephone-first approach was implemented in selected areas, and then rolled out in all areas in September. Under the telephone-first approach, household contacts were still attempted by telephone first, and personal visits were reserved for follow-up on nonresponse, to deliver recruitment materials, and to conduct interviews when telephone numbers were unknown. The telephone-first approach will continue for the foreseeable future.

Additional COVID-related content

A set of nearly 30 questions related to COVID were added to the 2020 NHIS sample adult questionnaire starting in quarter 3. The additional questionnaire content can be previewed directly on the NCHS website. Nine COVID-related questions identical to those fielded to sample adults were also added to the sample child questionnaire. To view the additional COVID-related content added by NCHS through IPUMS NHIS, please see our longer note on COVID-related changes to NHIS data collection to view a full list of the COVID-related questions added in quarter 3.

For more information

Dahlhamer JM, Bramlett MD, Maitland A, Blumberg SJ. Preliminary Evaluation of Nonresponse Bias Due to the COVID-19 Pandemic on National Health Interview Survey Estimates, April-June 2020. Hyattsville, MD: National Center for Health Statistics. February 2021,

SHADAC. NHIS: Early Release Estimates Show Unchanged Coverage Rates during First Half of 2020, although NCHS Reports Evidence of Nonresponse Bias due to COVID-19. 15 February 2021,

Medical Expenditure Panel Survey (MEPS)

The Agency for Healthcare Research and Quality (AHRQ) continued to field the MEPS Household Component survey throughout 2020. To mitigate the impacts of the COVID pandemic on data collection, AHRQ made several changes to MEPS field operations and sample design. AHRQ also modified questionnaire prompts to better reflect health and health care delivery under COVID and added COVID-related questionnaire content.

Sample Design Changes

In the fall of 2020, AHRQ made the decision to extend Panels 23 and 24 (those that were introduced in 2018 and 2019) to a maximum possible nine rounds of data collection, rather than the standard five rounds of data collection.

Field Operations

AHRQ stopped in-person MEPS interviews on March 17, 2020 and replaced them with telephone interviews. In the fall of 2020, after developing COVID in-person mitigation protocols and implementing PPE training, in-person interviewing briefly resumed in some PSUs for Rounds 1, 2, and 4, and for hard to reach or hearing impaired Round 6 cases (from Panel 23). Data collection for Round 1 was extended through December 2020, rather than ending in July, as was the case in previous years. Round 1 interviews that were conducted in the fall were not administered the fall supplemental questionnaires.

To address low return rates of Authorization Forms (AF) permitting MEPS data collection, AHRQ implemented a formal AF re-mail effort with reminder calls and implemented a modified in-person process for AF collection in the fall of 2020, which considerably improved the return rate. Interview procedures were updated to better accommodate attempts to contact households via telephone and adapt the interview to the telephone.

In the spring of 2021, field materials, including the Informed Consent form, the brochure, and the advance letters, were updated with COVID language. The training of newly hired interviewers was shifted entirely to distance training, and portions of the new hire training materials were redesigned to focus on telephone interviewing procedures.

Questionnaire Prompts

Beginning in the fall of 2020, the CAPI instrument used for interviews was updated to add three COVID conditions to the conditions look-up list and to adjust the text in health care provider probes to remind respondents to include telemedicine. Interviewer training protocols were adjusted slightly to emphasize the importance of collecting information about telemedicine events. In the spring of 2021, language around specific rounds was removed from the CAPI instrument and supporting systems to make it generic enough to accommodate 9 rounds of data collection with no “exit” round.

COVID-Related Questionnaire Content

In the spring of 2021, the CAPI instrument was modified to add a new telehealth event type and telehealth utilization section. Additionally, questions about COVID-related delays in the receipt of needed healthcare were added to the access to care section.

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