Strengths and limitations of the study
The main study limitation is the retrospective design. Another
limitation is that we did not examine symptom duration prior to the
first visit, mainly due to missing data. Although there were some
restrictions in outpatient visits and delays in the start of
radiotherapy, none of the units had to be closed for more than 2-3 days
and none of the doctors had to be transferred other hospitals to treat
Covid-19 patients. A final limitation is that we did not assess or
compare patient outcomes. By contrast, an important strength of this
study is that it is, to our knowledge, the first to examine the effect
of the pandemic on patients with head and neck cancer during an extended
time period (12-months) comprising several waves of the pandemic.