Back injuries among nursing personnel — identification of work conditions with cluster analysis

The aim of the present study was to identify work conditions that are typical for nursing personnel and relevant for the risk of back injuries, and to analyse how individual characteristics contribute to the risk of injuries in these situations. Six well-defined clusters were identified by cluster analysis. Two clusters had an over-representation of injuries and they were characterised by a combination of full-time work, work on a rolling schedule, regular patient transfers and a high proportion of assistant nurses. In the three clusters with a lower proportion of injuries the nurses worked part-time. In the cluster with the lowest rate of injuries no one performed regular patient transfers. Working part-time seemed to be a preventive factor for back injury, even when regular patient transfers were performed. The decreased risk of injury among the general registered nurses may thus be a joint effect of fewer working hours, fixed working schedule and less patient handling. The advantages of cluster analysis for detecting the pattern of interacting risk indicators and modifiers are discussed.