Int. J. Environ. Res. Public Health 2009, 6 2815 questions asking about the psychological impact, how to call for help, how to prevent such an event, etc. The Perpetrator Form includes 20 questions asking about who conducted the violence, (a patient, a co-worker, or a supervisor). All these forms were designed as a simple-click pattern, and it only took about three minutes to finish a report, if they did not complete all the questions before they sent out the data, the screen would return to the questions left blank and prompt for completion. They were regularly reminded by a study assistant in the ward to ensure that they routinely and consistently reported any assaults. In addition, to console the victims, the assistant gave them a gift worth about 2– 3 US dollars after they reported the event. Automatically, all the data we collected from website could be transferred to a database, which we could use for statistical analysis. 2.3. Statistic Analysis Every violent event was collected and classified into one of the following five different categories: physical violence (PV), verbal abuse (VA), bullying/mobbing (BM), sexual harassment (SH), and racial harassment (RH), and a clear definition for each type of violence was given to the reporter before they report. The incidence rates for different types of violence were calculated separately. Because violence events were usually rare and suitable for Poisson distribution, we used the following model as the analysis framework, ln(E(Y)) = β0 +β1 × Age +β2 × Sex +β3 × Education level +β4 × Marital status +β5 × Religious belief +β6 × Duration of employment +β7 × Place of working +β8 × Degree of anxiety, where E(Y) denotes the expected number of violence reported and rate ratio (RR) equals to eβ (RRi = eβi). And we estimated the crude rate ratio (CRR) for each variable in PV, VA, BM, SH and adjusted rate ratio (ARR), 95% confidence interval (95%CI) for PV and VA to identify the significant difference between the subgroups within each variable, e.g., <30 y/o vs. 30–44 y/o. 3. Results During the follow-up duration of one year, from 1/9/2005 to 31/8/2006, a total of 167 cohort members completed this study, three of them resigned and others retired, and dropped out from this study as early as 2 or 3 months; the drop-out rate was 0.04, and there were no violence reported by them. A total of 971 events were reported. Table 1 manifests the demographics of the 167 cohort member. There was no missing data in the table, and about one quarter of members was aged less than 30, and about one third were male and religious. Most were college educated, married, and working in acute ward. The mean of duration of employment was 7.6 (SD 7.1, minimum 0, maximum 31) years. More than half of them reported having “a little bit” anxiety level about workplace violence.