Construct validity of self-reported and interview-guided administration methods of the Danish version of the post-COVID-19 functional Status scale.

The interview questions in the PCFS manual were not all translated into Danish, which may have made the occupational therapist interviews less consistent. Patients were assessed at a median of approximately eight months after acute infection, and fewer than 10% had been hospitalized, so the study did not follow the usual post-discharge timing. 25% of patients did not complete the self-reported versions, and those who did not were assessed later, had lower educational level, and had been hospitalized more often. The 80% sick-leave threshold was predefined by the authors and may not be the only reasonable cut-off. The study used a single outpatient clinic and a cross-sectional measurement design, so it cannot show how scores change over time or prove that one administration method is better for all patients.

The study was supported by the Novo Nordisk Foundation under grant NNF21OC066984, and the authors declared financial support for the research and/or publication.

Do not read a PCFS grade below 3 as proof that a patient can return to work. Among 234 patients on sick leave, 54%, 53%, and 50% scored grade 3 or higher with the interview, questionnaire, and flowchart versions, and the methods did not agree.