COVID-19 Situation During the Study Period in Hong Kong
deafness, cognitive impairment, blindness
BLINDNESS, INFLUENZA
Inclusion criteria were age 65 years or older, possession of a Hong Kong identity card, ability to speak Cantonese and/or Mandarin, willingness to participate in follow-up by telephone, access to a smartphone, and no SIV uptake for the 2021 to 2022 influenza season. Exclusion criteria included cognitive impairment, blindness or deafness, inability to communicate effectively, and known contradictions to SIV as indicated by the Centre for Health Protection.Participants were recruited through random telephone sampling. All household telephone numbers listed in the most up-to-date telephone directories (approximately 350 000) were input into a spreadsheet file (Excel; Microsoft Corp). The function of select random cells generated 4000 household numbers. Trained interviewers conducted the telephone calls from 6 to 10 