Of the 4006 questionnaires distributed for the first survey, 1866 were completed and returned, giving a response rate of 46.6%. Of the 42 targeted units, 31 (73.8%) participated (including emergency medicine, internal medicine, and paediatrics units), representing 20% of all doctors and nurses working in these units in Of the 810 questionnaires distributed in the second survey, 389 were completed and returned. The response rate was 48.0%. Details of the second survey are shown in figure 2. All three invited departments had also participated in the first survey. The age and sex distribution of respondents were similar to those of the respondents in the same hospital in the first survey. Demographics of all respondents in both surveys are shown in table 1.