Question special

It is mentioned in the paper that a nasopharyngeal sample from participants who had a lower respiratory tract infection or who were hospitalized for any respiratory infection was obtained for testing at the central laboratory. Results were included in the analysis if the sample was obtained between 7 days before and 14 days after the participant’s initial visit to a health care provider.

In the protocol, it states that respiratory secretions for RSV testing must be collected within 2 days of diagnosis of medically attended outpatient LRTIs and hospital admission for, or new onset in hospital of, a respiratory illness, except in Table 4.2.2-1 where it is mentioned that nasal samples will be collected for all LRTI within 2 days and up to 14 days after the diagnosis.

I wonder if the authors can expand on the sample collection in regards to timing, specifically 7 days before the initial visit to a heath care provider and the use of 7 -14 days in the final analysis of RT-PCR results.