Table 2.

Employment of NPs and PAs According to Physician and Practice Characteristics

Characteristic	Employment of NPs and PAs (%)	P
Physician
Specialty		< .01
Surgical oncology	28.7
Medical oncology	56.3
Radiation oncology	40.0
Sex		.02
Female	48.2
Male	37.1
Geographical location		.12
Metropolitan Detroit	43.5
Los Angeles County	37.2
Time in practice, years		< .01
≤ 10	48.8
10-20	41.8
> 20	33.5
Breast cancer specialization, % of all cases		< .01
< 25	34.6
25-50	40.1
> 50	57.0
Practice
University affiliation		< .01
Yes	54.2
No	32.2
No. of physicians in the practice		< .01
< 3	17.2
3-5	42.7
≥ 6	63.2

NOTE. P values obtained by χ² tests.

Abbreviations: NPs, nurse practitioners; PAs, physician assistants.