Table 2.

Observed duration for each black hole using time-motion data and output from ANOVA.

“Black hole”	Time interval (minute), mean (SD)	Variation explained by clinical staff (%)	Variation explained by patient characteristicsa (%)
MAb room to MA log-in	0.73 (1.01)	11.6	35.1
MA log-off to exit	0.51 (1.39)	6.9	46.7
Physician entering examination room to log in	2.62 (1.61)	62.2	14.8
Physician log-off to exit	0.82 (1.29)	11.1	23
Physician exit to patient exit	2.72 (4.11)	39.1	17.5

^aPatient age, sex, race, and ethnicity.

^bMA: medical assistant.