Overcrowding in psychiatric wards and physical assaults on staff: data-linked

of its high prevalence and its likely adverse effects on the health of employees and the quality of psychiatric care. Overcrowding in wards is another well-known problem in psychiatric hospitals worldwide resulting, in part, from the dramatic decline in psychiatric in-patient beds during past decades. It typically arises when there is shortage of beds in relation to need or when acute beds are ‘blocked’ by individuals who no longer need hospital care but for whom suitable community support is not available. Patient overcrowding has been hypothesised to increase the risk of violence in psychiatric settings, but previous studies have been small in scale, ranging between one to two psychiatric units, or conducted at the hospital level as opposed to the ward level. Some studies have shown that more violent incidents occur in the unit when the numbers of patients is high. However, null findings and even the opposite result, whereby patient overcrowding is related to a lower risk of violence, have also been reported. Furthermore, earlier studies have focused on the occurrence of violence in general without specifying whether it is targeted towards hospital personnel, other patients, or the environment and equipment. To examine the association between patient overcrowding and violent assaults on staff, we collected monthly bed occupancy records for 90 psychiatric in-patient wards in 13 hospitals providing specialised acute psychiatric care in Finland. More than 1000 physicians and nurses reported whether they were assaulted and the timing of violent assaults carried out by patients. These data were linked to the bed occupancy record over a period of 5 months. Method