Prevalence and Characteristics of Interruptions and Distractions During Surgical Counts.

BACKGROUND: Surgical counting is a complex and safety-critical task that requires sustained attention by multiple members of the surgical team in order to prevent the occurrence of an unintentionally retained foreign object. Interruptions and distractions in the operating room are common and can negatively affect task performance. However, the prevalence and sources of interruptions and distractions during safety-critical tasks, such as surgical counting, have not previously been quantified. An understanding of the characteristics of these events could be used to inform targeted improvements to patient safety. METHODS: Observations were conducted of surgical procedures in order to quantify and describe interruptions and distractions during surgical counting activities. Analysis was separated into phases: the initial count, additions to the surgical field, removals from the surgical field, and closure counts. RESULTS: Thirty-six surgical procedures were observed. Interruptions occurred in 10.0% of initial counts, 15.4% of additions, 23.5% of removals, and 33.3% of closure counts observed. The source of 80.4% of interruptions was a surgeon, usually asking the scrub nurse for an item. Distractions were present in 46.7% of initial counts, 38.5% of additions, 41.2% of removals, and 40.9% of closure counts observed. Common sources of distraction included music, conversations, people entering and exiting the theater, and ringing phones. CONCLUSION: Interruptions and distractions are common during surgical counts and can significantly affect patient safety by jeopardizing the accuracy of the count. A number of suggestions are provided that could reduce interruptions and distractions and their consequences.

Predictive displays for a process-control schematic interface.

OBJECTIVE: Our objective was to examine the extent to which increasing precision of predictive (rate of change) information in process control will improve performance on a simulated process-control task. BACKGROUND: Predictive displays have been found to be useful in process control (as well as aviation and maritime industries). However, authors of prior research have not examined the extent to which predictive value is increased by increasing predictor resolution, nor has such research tied potential improvements to changes in process control strategy. METHOD: Fifty nonprofessional participants each controlled a simulated chemical mixture process (honey mixer simulation) that simulated the operations found in process control. Participants in each of five groups controlled with either no predictor or a predictor ranging in the resolution of prediction of the process. RESULTS: Increasing detail resolution generally increased the benefit of prediction over the control condition although not monotonically so. The best overall performance, combining quality and predictive ability, was obtained by the display of intermediate resolution. The two displays with the lowest resolution were clearly inferior. CONCLUSION: Predictors with higher resolution are of value but may trade off enhanced sensitivity to variable change (lower-resolution discrete state predictor) with smoother control action (higher-resolution continuous predictors). APPLICATION: The research provides guidelines to the process-control industry regarding displays that can most improve operator performance.

Predictors of web navigation performance in a life span sample of adults.

The influence of age, subject matter knowledge, working memory, reading abilities, spatial abilities, and processing speed on Web navigation was assessed in a sample of 41 participants between the ages of 19 and 83 years. Each participant navigated a stand-alone tourism Web site to find answers to 12 questions. Performance was measured using time per trial, number of pages per trial, and number of revisited pages per trial. Age did not influence the number of total pages or repeat pages visited, which were predicted by domain knowledge, working memory, and processing speed. Age was associated with slower times per trial, and the effect remained significant after controlling for working memory, processing speed, and spatial abilities. Only with the addition of subject matter knowledge and World Wide Web experience was the age effect eliminated. Actual or potential applications of this research include redesigning Web sites to minimize memory demands and enhance visual segmentation. The data also suggest that age differences in Web navigation can be offset partially by taking advantage of older adults' prior experiences in the domain.