Catastrophe model for the exposure to blood-borne pathogens and other accidents in health care settings

Catastrophe models, which describe and predict discontinuous changes in sys tem state variables, were used to model the exposure to blood and bodily fl uids and more conventional occupational accidents among 1708 health care wo rkers. Workers at three hospitals completed a survey measuring HIV-relevant exposures (needlesticks, cuts, splashes, contact with open wounds), the ac cident rate for broadly-defined injuries, and several occupationally releva nt themes: safety climate, shift work, depression symptoms, work pace, verb al abuse, and professional group membership. A cusp (cubic polynomial) mode l predicting HIV-relevant exposures specifically was more accurate (R-2=0.5 6) than a comparable linear model containing the same variables (R-2 = 0.07 ). Some of the foregoing variables predisposed workers to greater differenc es in HIV-relevant and general accident exposures: shiftwork, climate, depr essive symptoms, and work pace. Other variables governed how close an indiv idual was to a critical threshold where a harmful incident would take place : verbal abuse, professional group membership. Similarly, a cusp model for accident incidents predicted from HIV-relevant exposures and occupational v ariables was also more accurate (R-2 = 0.751 than comparison models. Two va riables predisposed the worker to a greater accident risk: depression sympt oms and shift work. Four other variables predisposed the worker to lesser a ccident risk: job satisfaction, safety climate, environmental stressors, an d work pace. Compliance with the universal precautions and HIV-related trai ning were not relevant to either of the models. (C) 1999 Elsevier Science L td. All rights reserved.