Two randomised cessation trials run in Hong Kong community services between 2018 and 2021, one individually randomised and one cluster randomised, were reanalysed before and after the COVID-19 emergency response level was raised on 25 January 2020. Six-month biochemically validated abstinence fell from 12.3% to 6.8% (RR 0.55, 0.40 to 0.76), and self-reported seven-day abstinence was lower at both three and six months. Cut-offs at 8 February and 28 March gave consistent reductions, though the comparison is before and after a date rather than between randomised arms.
Why it is interesting: It puts a figure on how far a service-delivered quit rate fell when in-person support and pharmacotherapy were disrupted.