AN EVALUATION OF THE LEVEL OF SKILL REQUIRED OF OPERATORS OF A COMPUTER-ASSISTED RADIOLOGIC TOTAL LUNG CAPACITY MEASUREMENT SYSTEM (RELIABILITY, VALIDITY)

This research was conducted to obtain information regarding the feasibility of using non-medical personnel to obtain measurements of radiologic total lung capacity (TLC). Operators from each of four groups (general undergraduates, nursing students, medical students, radiologists) differing in the amount of medical training and/or experience reading x-rays, performed each of two tasks. The first task was the measurement of radiologic TLC for a set of twenty x-rays. The second task consisted of tracing the outline of the anatomical structures that must be identified in the execution of the radiologic TLC measurement task. Data from the radiologic TLC measurement task were used to identify possible group differences in the reliability and validity of the measures. The reliability analyses were performed within the framework of Generalizability Theory. While the results are not conclusive, due to small sample sizes, the analyses suggest that group differences in reliability of the measures, if they exist, are small. The concurrent validity of the measures was assessed by obtaining, for each experience level, the correlation between the group mean radiologic TLC for a film set and the TLC for that patient, obtained from a body plethysmograph. Only small differences in the group correlation coefficients were observed. A liberal test of these differences indicated they were not statistically significant. Additionally, two experience level by film sets ANOVAs were performed to determine possible group differences in how well the actual magnitudes of the radiologic TLC measures approximated those obtained with the body plethysmograph. These analyses indicated that the magnitude of the differences between radiologic and plethysmographic TLC measures were smaller for the undergraduates than for the nursing students and radiologists. Lastly, a number of analyses of the anatomical structure tracings were performed. Few interpretable group differences were found.