PLoS One
. 2025 Feb 10;20(2):e0316198.
doi: 10.1371/journal.pone.0316198. eCollection 2025. Classifying COVID-19 hospitalizations in epidemiology cohort studies: The C4R study
Elizabeth C Oelsner 1 , Akshaya Krishnaswamy 1 , Rafail Rustamov 2 , Pallavi P Balte 1 , Tauqeer Ali 3 , Norrina B Allen 4 , Howard F Andrews 5 , Pramod Anugu 6 , Alexander Arynchyn 7 , Lori A Bateman 8 , Jianwen Cai 8 , Harry Chang 1 , Lucas Chen 9 , Mitchell S V Elkind 10 11 , James S Floyd 12 13 , Kelley Pettee Gabriel 14 , Sina A Gharib 15 , Jose D Gutierrez 10 , Karen Hinckley Stukovsky 16 , Virginia J Howard 14 , Carmen R Isasi 17 , Lauren Jager 16 , Ling Jin 9 , Suzanne E Judd 18 , Alka M Kanaya 19 , Namratha R Kandula 4 20 , Maureen R Kelly 1 , Sadiya S Khan 21 , Anna Kucharska-Newton 22 , Joyce S Lee 23 , Emily B Levitan 14 , Cora E Lewis 14 , Barry J Make 24 , Kimberly Malloy 3 , Jennifer J Manly 10 , David Mauger 25 , Yuan-I Min 6 , Joanne M Murabito 9 26 , Charles G Murphy 27 , Arnita F Norwood 6 , George T O'Connor 9 26 , Victor E Ortega 28 , Ashmi A Patel 1 , Amber Pirzada 29 , Elizabeth A Regan 30 , Kimberly B Ring 8 , Wayne D Rosamond 22 , David A Schwartz 23 , James M Shikany 7 , Daniela Sotres-Alvarez 8 , Cheryl Tarlton 3 , Janis Tse 9 , Elman M Urbina Meneses 31 , Maya Vankineni 1 , Sally E Wenzel 32 , Prescott G Woodruff 33 , Vanessa Xanthakis 9 34 , Ji Hyun Yang 9 35 , Neil A Zakai 36 37 , Ying Zhang 3 , Wendy S Post 38
Affiliations
Rationale: Robust COVID-19 outcomes classification is important for ongoing epidemiology research on acute and post-acute COVID-19 conditions. Protocolized medical record review is an established method to validate endpoints for clinical trials and cardiovascular epidemiology cohorts; however, a protocol to adjudicate hospitalizations for COVID-19 among epidemiology cohorts was lacking.
Objectives: We developed a protocol to ascertain and adjudicate hospitalized COVID-19 across a meta-cohort of 14 US prospective cohort studies. This report describes the first three years of protocol implementation (October 1, 2020-October 1, 2023) and evaluates its repeatability and performance compared to classification by administrative codes.
Methods: The protocol was adapted from cohort approaches to clinical cardiovascular events ascertainment and adjudication. Potential COVID-19 hospitalizations and deaths were identified by self-/proxy-report and, in some cases, active surveillance. Medical records were requested from hospitals and adjudicated for COVID-19 outcomes by clinically trained personnel according to a standardized rubric. Inter-rater agreement was assessed. The sensitivity and specificity of discharge diagnosis codes was compared to adjudicated diagnoses.
Measurements and main results: The study obtained medical records for 1,167 potential COVID-19 hospitalizations, which underwent protocolized adjudication. Adjudication confirmed COVID-19 infection was present for 1,030 (88%) events, of which COVID-19 was not the cause of hospitalization for 78 (8%). Of 952 hospitalizations determined by adjudicators to be caused by COVID-19, 319 (34%) participants were critically ill and 210 (22%) died. Pneumonia was confirmed in 822 (86%) and acute kidney injury in 350 (37%); other cardiovascular and thrombotic complications were rare (2-5%). Interrater reliability among adjudicators was high (kappa = 0.85-1.00) except for myocardial infarction (kappa = 0.60). Compared to adjudication, sensitivity of discharge diagnosis codes was higher for pneumonia (84%) and pulmonary embolism (81%) than for other complications (48-70%).
Conclusions: Protocolized adjudication confirmed four out of five COVID-19 hospitalizations in a US meta-cohort and confirmed cases of pneumonia, pulmonary embolism, and other conditions that were not indicated by discharge diagnosis codes. These results highlight the importance of validating health outcomes for use in research on COVID-19 and post-COVID-19 conditions, and some limitations of claims-based data.
. 2025 Feb 10;20(2):e0316198.
doi: 10.1371/journal.pone.0316198. eCollection 2025. Classifying COVID-19 hospitalizations in epidemiology cohort studies: The C4R study
Elizabeth C Oelsner 1 , Akshaya Krishnaswamy 1 , Rafail Rustamov 2 , Pallavi P Balte 1 , Tauqeer Ali 3 , Norrina B Allen 4 , Howard F Andrews 5 , Pramod Anugu 6 , Alexander Arynchyn 7 , Lori A Bateman 8 , Jianwen Cai 8 , Harry Chang 1 , Lucas Chen 9 , Mitchell S V Elkind 10 11 , James S Floyd 12 13 , Kelley Pettee Gabriel 14 , Sina A Gharib 15 , Jose D Gutierrez 10 , Karen Hinckley Stukovsky 16 , Virginia J Howard 14 , Carmen R Isasi 17 , Lauren Jager 16 , Ling Jin 9 , Suzanne E Judd 18 , Alka M Kanaya 19 , Namratha R Kandula 4 20 , Maureen R Kelly 1 , Sadiya S Khan 21 , Anna Kucharska-Newton 22 , Joyce S Lee 23 , Emily B Levitan 14 , Cora E Lewis 14 , Barry J Make 24 , Kimberly Malloy 3 , Jennifer J Manly 10 , David Mauger 25 , Yuan-I Min 6 , Joanne M Murabito 9 26 , Charles G Murphy 27 , Arnita F Norwood 6 , George T O'Connor 9 26 , Victor E Ortega 28 , Ashmi A Patel 1 , Amber Pirzada 29 , Elizabeth A Regan 30 , Kimberly B Ring 8 , Wayne D Rosamond 22 , David A Schwartz 23 , James M Shikany 7 , Daniela Sotres-Alvarez 8 , Cheryl Tarlton 3 , Janis Tse 9 , Elman M Urbina Meneses 31 , Maya Vankineni 1 , Sally E Wenzel 32 , Prescott G Woodruff 33 , Vanessa Xanthakis 9 34 , Ji Hyun Yang 9 35 , Neil A Zakai 36 37 , Ying Zhang 3 , Wendy S Post 38
Affiliations
- PMID: 39928595
- DOI: 10.1371/journal.pone.0316198
Rationale: Robust COVID-19 outcomes classification is important for ongoing epidemiology research on acute and post-acute COVID-19 conditions. Protocolized medical record review is an established method to validate endpoints for clinical trials and cardiovascular epidemiology cohorts; however, a protocol to adjudicate hospitalizations for COVID-19 among epidemiology cohorts was lacking.
Objectives: We developed a protocol to ascertain and adjudicate hospitalized COVID-19 across a meta-cohort of 14 US prospective cohort studies. This report describes the first three years of protocol implementation (October 1, 2020-October 1, 2023) and evaluates its repeatability and performance compared to classification by administrative codes.
Methods: The protocol was adapted from cohort approaches to clinical cardiovascular events ascertainment and adjudication. Potential COVID-19 hospitalizations and deaths were identified by self-/proxy-report and, in some cases, active surveillance. Medical records were requested from hospitals and adjudicated for COVID-19 outcomes by clinically trained personnel according to a standardized rubric. Inter-rater agreement was assessed. The sensitivity and specificity of discharge diagnosis codes was compared to adjudicated diagnoses.
Measurements and main results: The study obtained medical records for 1,167 potential COVID-19 hospitalizations, which underwent protocolized adjudication. Adjudication confirmed COVID-19 infection was present for 1,030 (88%) events, of which COVID-19 was not the cause of hospitalization for 78 (8%). Of 952 hospitalizations determined by adjudicators to be caused by COVID-19, 319 (34%) participants were critically ill and 210 (22%) died. Pneumonia was confirmed in 822 (86%) and acute kidney injury in 350 (37%); other cardiovascular and thrombotic complications were rare (2-5%). Interrater reliability among adjudicators was high (kappa = 0.85-1.00) except for myocardial infarction (kappa = 0.60). Compared to adjudication, sensitivity of discharge diagnosis codes was higher for pneumonia (84%) and pulmonary embolism (81%) than for other complications (48-70%).
Conclusions: Protocolized adjudication confirmed four out of five COVID-19 hospitalizations in a US meta-cohort and confirmed cases of pneumonia, pulmonary embolism, and other conditions that were not indicated by discharge diagnosis codes. These results highlight the importance of validating health outcomes for use in research on COVID-19 and post-COVID-19 conditions, and some limitations of claims-based data.