In Reply In response to the question from Dr Bai and colleagues about our COVID-19 long-term outcome study, only validated Dutch versions of questionnaires were used. These questionnaires are recommended in the core outcome measurement set for survivors of acute respiratory failure based on a Delphi study. Although not all mental aspects are included in these questionnaires, and the concept of mental symptoms is indeed broad, the questionnaires used in our study covered the main mental symptoms experienced by patients after an ICU admission. Although the cutoff scores used in our study are all generally accepted, only the HADS questionnaire determined cutoff scores in a general Dutch population. To be consistent with international studies, missing data were handled according to the specific recommendations in the manual for each questionnaire. Importantly, and as mentioned in the Limitations section of our study, the patient-reported outcome measures identify signs of mental symptoms and cannot be used as psychiatric diagnostic instruments.