Analysis of dominant factors affecting fatigue caused by soft-copy reading

Rationale and Objectives: The aim of this study was to analyze the dominant factors affecting fatigue caused by soft-copy reading to identify a method for decreasing fatigue in clinical practice. Materials and Methods: Two types of fatigue-fatigue in the central nervous system and subjective visual fatigue-were evaluated using a critical fusion frequency test and a questionnaire administered to 17 male radiologists before and after soft-copy reading. Reading-induced fatigue was assumed to be affected by 20 hypothetical factors associated with personal characteristics, time required for reading, content or amount of reading, and the reading environment. We used multiple linear regression analysis with a variable selection method to detect the best combination of factors capable of expressing variations in each of the measured fatigue values. The effects of the detected (dominant) factors on fatigue were also examined based on coefficients of the dominant factors in multiple regression models. Results: Fatigue in the central nervous system decreased with a higher corrected visual acuity and a higher ambient illuminance in the reading room and was also affected by the type of monitor used. Visual fatigue was relieved when there was a larger difference in the brightness of the monitor and the surfaces surrounding the monitor and tended to be more severe when glasses rather than contact lenses were worn. Conclusions: Increasing the ambient illuminance, using an appropriate type of monitor, improving the corrected visual acuity, and using contact lenses rather than eyeglasses could help decrease reading-induced fatigue in male radiologists.