The authors assessed how accurately the RECOVER PASC score classified people with a clinical diagnosis of Long COVID after comprehensive specialty-clinic evaluation, compared with people who recovered from SARS-CoV-2 infection without persistent symptoms.
Approach:
Study population: Participants with suspected Long COVID underwent comprehensive multidisciplinary evaluation; the Long COVID group met the 2024 NASEM consensus definition. Recovered SARS-CoV-2 controls served as the comparator.
Reference standard: Because Long COVID lacks a biological gold standard, the authors describe expert clinical diagnosis using the NASEM definition as the most appropriate available clinical reference.
Enrollment criterion: Participants were required to have at least one neuropsychiatric manifestation under the parent study design. Enrollment did not depend on RECOVER PASC scores or score thresholds, and brain fog was not required.
Key Findings:
The RECOVER PASC score showed high specificity versus recovered SARS-CoV-2 controls, while sensitivity was limited in the clinically characterized Long COVID cohort.
Positive and negative predictive values were reported descriptively for the study cohort and should not be extrapolated to populations with different disease prevalence.
The 2024 revision of the RECOVER-Adult Long COVID research index incorporated additional data, broader symptom ascertainment, and changes to symptom weighting and threshold.
Interpretation:
The authors describe the study as external clinical validation in a well-characterized specialty referral cohort, not population-based validation. They state that the study was not designed to assess performance in the general population or among patients with other conditions that share symptoms.
Limitations:
The specialty referral cohort and neuropsychiatric-symptom enrollment criterion represent a particular clinical spectrum of Long COVID.
The recovered-control comparison does not assess discrimination from other conditions with overlapping symptoms, including ME/CFS, fibromyalgia, dysautonomia, or mood disorders.
The study was not designed to estimate disease prevalence or diagnostic performance at the population level.
Conclusion:
The authors state that future studies should evaluate the RECOVER PASC score in community-based populations, primary care settings, and broader clinical phenotypes of Long COVID.
Investigators linked distinct odor patterns to life stage, sex, and skin microbes, while limited longitudinal evidence leaves their clinical utility uncertain.
