Table 4.

Results From Regression Analyses of Cost of Care 3 to 24 Months After Diagnosis, With or Without Receiving at Least One Tumor Marker Test During the 2 Years After Diagnosis

Factor	% Increase (+) or Decrease (−) in Total Cost of Care*	95% CI
Receipt of at least one tumor marker test†
No (reference)
Yes	+29.4‡	+26.6 to +32.2
Age (years)
Mean age at diagnosis§	−1.7‡	−1.8 to −1.5
Year
Diagnosis year§	+5.4‡	+4.9 to +5.9
Comorbidity
Klabunde Index§	+55.7‡	+51.7 to +59.7
Race (v white)
African American	−0.1	−3.1 to +6.2
American Indian/Alaskan native	−13.9	−33.4 to +5.5
Asian/Pacific Islander	−23.1‡	−27.8 to −18.3
Hispanic	−6.9‖	−11.8 to −2.0
Other/unknown	−23.7‖	−35.5 to −12.0
Tumor stage (v stage 1)
2	+18.1‡	+15.5 to 20.7
3	+64.3‡	+56.3 to +72.3
Estrogen receptor status (v negative)
Positive	−18.4‡	−21.5 to −15.2
Borderline	−4.8	−28.8 to +19.1
Unknown	−9.3	−22.7 to +4.2
Progesterone receptor status (v negative)
Positive	−2.9‖	−5.7 to −0.0
Borderline	+1.6	−9.8 to +13.1
Unknown	−17.9‖	−29.8 to −6.1
Geographic region (v San Francisco)
Connecticut	−2.4	−8.9 to +4.1
Detroit	+15.8‡	+8.2 to +23.5
Hawaii	−12.9‖	−22.5 to −3.2
Iowa	−28.6‡	−33.7 to −23.6
New Mexico	−17.5‡	−24.9 to −10.3
Seattle	−12.1‡	−17.9 to −6.2
Utah	−27.0‡	−33.1 to −20.9
Atlanta	−11.9‖	−18.7 to −5.2
San Jose	+3.6	−4.9 to +12.0
Los Angeles	+1.4	−5.1 to +7.9
Rural Georgia	−10.7	−29.3 to +7.8
Greater California	−7.3‖	−12.7 to −1.9
Kentucky	−27.8‡	−32.7 to −23.0
Louisiana	−15.4‡	−21.2 to −9.6
New Jersey	−4.7	−10.3 to +0.8
Urban/rural status (v large metropolitan area with 1M+ population)
Metropolitan (250,000+)	−2.0	−4.8 to +0.8
Large urban (20,000+)	−3.5	−8.0 to +0.9
Small urban (2,500+)	−7.1‖	−11.5 to −2.7
Rural (< 2,500)	−8.2‖	−16.1 to −0.3

^*Analyzed using the natural log transformation (70 participants not included because of no costs).

^†During the 2 years after diagnosis, excluding the 2 months immediately after diagnosis.

^‡P < .001, two-sided t test.

^§Analyzed as a continuous variable.

^‖P < .05, two-sided t test.