Task-related risk factors for spinal injury: validation of a self-administered questionnaire on hospital employees

Is information about task-related risk factors for spinal injury provided by workers, reliable enough to be used by clinicians in determining recommendations for return to work? To answer that question, a study was conducted on a non-random stratified sample of 96 hospital employees to compare their perception with that of a trained independent observer, on the following: static posture, muscular efforts and exposure to vibrations. The sample included the following categories: white collar (16); direct patient care providers (32); laboratory technicians (28); and blue collar (20). A self-administered questionnaire was completed by the employee. Following a worksite visit, the independent observer, blind to the employee's answers completed the same questionnaire. The response rate was superior to 82% except for nursing which was 18%. Perceptions of muscular efforts and exposure to vibrations showed good agreement between employee and observer. Agreement was poor for perceptions of static posture, bending and twisting of the trunk, because employees underestimated their involvement in these job situations. More work is needed to increase employee awareness and improve questionnaire formulation in these areas of working activities.