We assessed the presence and the direction of nonresponse bias by comparing the distribution of personal characteristics for the respondents and for all health department personnel. The lack of significant difference in age and gender distribution, as well as the lack of significant difference in job classification other than technical/ support staff indicates that the extent of such a bias in the study is probably limited. The small yet statistically significant over-representation of technical/support staff in our study group may potentially have caused a slight underestimation of overall willingness to report. However, as the internal associations between the various variables were also studied separately for the technical/support staff and professional staff (Figure 2) , this over-representation should not impact the general conclusions presented above.