One hundred subjects were recruited from each “camp” of stethoscope wearers. We were unable to match the groups for age and sex. It was difficult, in fact, to find enough volunteers in the traditional group; however, after a concerted search in such places as retirement homes, nursing homes, golf courses and condos in Florida, a full complement was recruited.
The mean age of subjects in the traditional group was 67.4 (range 45–97, standard deviation [SD] 62) years and of those in the cool group 38.7 (range 24–50, SD 21) years. There were 81 men and 19 women in the traditional group and 59 men and 41 women in the cool group. The subjects included physicians, nurses, respiratory therapists, physiotherapists and medical students. There were no surgeons in either group because most of them were unable to find their old stethoscopes from medical school days.
The functional (F) position was defined as having the stethoscope's ear pieces in the examiner's external auditory canals and the head piece placed on the volunteer patient's chest. The cool or circumcervical (C) and the traditional (T) placements are illustrated in .
The time to transfer the stethoscope from the C or T positions to the F position was measured in seconds by stopwatch (Swiss Army Stopwatch, Model #3075). Each subject was asked to perform this manoeuvre 10 times. A research assistant measured the reaction times, and the mean time for each subject was used in the analysis.
It was anticipated that, because of differences in age between the 2 groups, the overall reaction time of the traditional group would be slower than that of the cool group. We attempted to include a crossover arm in the study whereby the traditional group would start from the C position and the cool group would start from the T position. We postulated that this element might reduce statistical confounding by age in our analysis. However, both groups adamantly refused to participate in this portion of the study, despite our offer of added inducements (see “Acknowledgements”).