Table 1.

Contributing factors of patients’ self-assessed stress

Parameter	OR	95% CI	P value
Study phase
Other	1.00	–
Phase I	1.18	0.55 to 2.52	0.009
Phase II	0.29	0.10 to 0.90	0.032
Phase III	0.52	0.22 to 1.24	0.404
Uninsured medical expenses	1.23	1.03 to 1.46	0.026
Time consumption	2.35	1.62 to 3.41	<0.0001
Tests in trials	0.64	0.42 to 0.97	0.035