Covid-19

During peak Covid response, I contributed in 3 main ways:

Information disclosure: For the first time in CDC’s history, CDC was preparing to make de-identified, person-level surveillance data publicly available with county identified. I served as government technical lead on a project to assess empirically and to mitigate the disclosure risks from what became known as COVID-19 Case Surveillance Public Use Data with Geography. I also worked to understand analytic implications of data suppression.

Post-vaccine vaginal bleeding: Karen Wong applied state-of-the-art text-analytic methods to characterize self-reported symptoms. I supplied a multiple-response categorical-variable analysis of 4 themes to test for differences in respondent characteristics.

Case-finding: Scott Lee advanced the brute-force combinatorial analysis that I had developed for TB screening by using efficient mixed-integer programming to apply the same concept to screening for Covid.

6 works filed here — presentation 2 · publication 4. 4 prepared, none published on this site yet.

All 4 citable works filed here are in the works index.

In this domain

year	form	subdomain	work
2021	publication	covid	pu_2021_reses_covid-case-definitions — Performance of existing and novel surveillance case definitions for COVID-19 in household contacts of PCR-confirmed COVID-19
2022	publication	covid	pu_2022_wong_covid-vaccine-menstrual — Menstrual irregularities and vaginal bleeding after COVID-19 vaccination reported to v-safe active surveillance, USA in December, 2020–January, 2022: an observational cohort study
2023	publication	covid	pu_2023_lee_covid-case-definitions — Performance of existing and novel symptom- and antigen testing–based COVID-19 case definitions in a community setting
2025	publication	covid	pu_2025_armstead_covid-disparities-grants — Effects of investments from the Centers for Disease Control and Prevention’s COVID-19 Health Disparities Grant on health departments’ capacity to address public health emergencies

2 further works are filed here without a render — not cite-only, simply not yet prepared.

Crossings

No crossings recorded in either direction.

Cited, not served

Nothing in this domain is cite-only.

Hooks

3 of the 36 closed hooks sit on work filed here — Chad’s own first person, published as written.

pu_2021_reses_covid-case-definitions · tier abstract+ · ready

I created the figures in this manuscript.

pu_2022_wong_covid-vaccine-menstrual · tier abstract+ · ready

I designed and implemented the multiple response categorical variables portion of the analysis in this manuscript.

pu_2025_armstead_covid-disparities-grants · tier abstract+ · ready

I created the figure in this manuscript, along with several precursor versions. After the figure was created, the publisher required that it be rerendered in Excel, which detracted from characteristics that had been fine-tuned in R.