Table 2.

Predictors of post-RP management strategy on multivariable analysis (observation as referent)

	ADT Alone		RT Alone		ADT & RT
	RRR (95% CI)	p-value	RRR (95% CI)	p-value	RRR (95% CI)	p-value
Age (per five years)	0.97 (0.92, 1.03)	0.33	0.88 (0.79, 0.98)	0.017	0.80 (0.75, 0.85)	<0.001‡
CCI
0	Ref.		Ref.		Ref.
1	0.85 (0.71, 1.03)	0.29	0.66 (0.48, 0.90)	0.024	0.79 (0.63, 0.99)	0.024
≥2	1.14 (0.78, 1.66)		0.81 (0.36, 1.85)		0.73 (0.42, 1.26)
Race
White	Ref.		Ref.		Ref.
Black	0.88 (0.72, 1.07)	0.20	0.88 (0.64, 1.22)	0.44	0.76 (0.59, 0.98)	0.033
Other	1.11 (0.77, 1.60)	0.56	1.02 (0.45, 2.29)	0.97	1.47 (0.97, 2.21)	0.068
Insurance
Private	Ref.		Ref.			Ref.
Medicare	1.10 (0.94, 1.30)	0.24	0.83 (0.60, 1.14)	0.26	1.03 (0.84, 1.28)	0.76
Medicaid	1.89 (1.36, 2.62)	<0.001	1.19 (0.63, 2.25)	0.59	1.02 (0.66, 1.58)	0.92‡
Other	1.21 (0.67, 2.16)	0.53	1.00 (0.38, 2.65)	1.00	1.38 (0.79, 2.41)	0.27
Uninsured	1.34 (0.83, 2.14)	0.23	1.63 (0.91, 2.92)	0.10	0.89 (0.53, 1.51)	0.67
Median income
<$38,000	Ref.		Ref.			Ref.
$38,000–$47,999	0.99 (0.82, 1.20)	0.062	0.74 (0.52, 1.06)	0.13	0.90 (0.69, 1.17)	0.94
$48,000–$62,999	0.84 (0.69, 1.02)		0.78 (0.55, 1.11)		0.93 (0.72, 1.21)
≥$63,000	0.85 (0.68, 1.06)		0.71 (0.50, 1.02)		0.96 (0.72, 1.26)
Urbanicity
Metropolitan	Ref.		Ref.		Ref.
Non-metropolitan	1.06 (0.86, 1.30)	0.61	0.76 (0.56, 1.05)	0.093	1.01 (0.80, 1.27)	0.95
Facility location
Northeast	Ref.		Ref.		Ref.
Midwest	1.82 (0.92, 3.58)	0.084	1.05 (0.64, 1.70)	0.86	1.13 (0.77, 1.68)	0.53
South	1.07 (0.63, 1.84)	0.79	1.22 (0.76, 1.95)	0.40	0.71 (0.47, 1.08)	0.11§
West	1.28 (0.68, 2.39)	0.45	0.75 (0.46, 1.23)	0.25	0.87 (0.56, 1.36)	0.54
Facility designation
Academic	Ref.		Ref.		Ref.
Non-academic	0.65 (0.51, 0.84)	0.001	1.29 (0.95, 1.76)	0.10†	0.93 (0.70, 1.23)	0.60‡
Facility case volume (per ten cases per year)	0.91 (0.68, 1.22)	0.53	0.58 (0.45, 0.75)	<0.001†	0.68 (0.60, 0.76)	<0.001
Year of diagnosis
2004	Ref.		Ref.		Ref.
2005	0.92 (0.63, 1.33)	0.95	0.98 (0.57, 1.67)	0.74	1.25 (0.75, 2.09)	<0.001‡§
2006	1.18 (0.82, 1.70)		0.61 (0.33, 1.15)		1.04 (0.65, 1.67)
2007	1.40 (0.98, 1.99)		0.78 (0.43, 1.42)		1.63 (1.05, 2.54)
2008	1.08 (0.75, 1.57)		0.78 (0.45, 1.32)		1.60 (1.03, 2.48)
2009	0.84 (0.58, 1.23)		0.65 (0.37, 1.15)		1.60 (1.03, 2.47)
2010	1.18 (0.81, 1.73)		0.99 (0.58, 1.68)		1.99 (1.27, 3.13)
2011	1.15 (0.80, 1.65)		0.81 (0.48, 1.38)		1.92 (1.19, 3.08)
2012	0.94 (0.64, 1.39)		0.86 (0.52, 1.43)		1.96 (1.26, 3.04)
2013	1.00 (0.67, 1.49)		0.80 (0.46, 1.38)		1.75 (1.11, 2.76)
2014	1.21 (0.81, 1.78)		0.78 (0.46, 1.31)		2.49 (1.60, 3.87)
PSA (per 5 ng/mL)	1.03 (1.02, 1.05)	<0.001	1.00 (0.97, 1.04)	0.89	1.01 (0.99, 1.04)	0.15
Grade group
1-2	Ref.		Ref.		Ref.
3	1.47 (1.21, 1.79)	<0.001	1.26 (0.92, 1.72)	0.97†	1.18 (0.94, 1.49)	0.003‡
4	1.74 (1.41, 2.15)		0.84 (0.56, 1.27)		1.22 (0.96, 1.57)
5	1.99 (1.62, 2.44)		1.11 (0.79, 1.54)		1.39 (1.12, 1.72)
Pathologic stage
T2	Ref.		Ref.		Ref.
T3a	1.40 (1.14, 1.72)	<0.001	1.67 (1.15, 2.42)	0.001	1.45 (1.14, 1.86)	<0.001‡§
T3b	1.69 (1.41, 2.02)		1.87 (1.33, 2.65)		2.29 (1.80, 2.91)
T4	1.99 (1.39, 2.85)		1.78 (0.84, 3.76)		2.73 (1.84, 4.04)
Surgical margins
Negative	Ref.		Ref.		Ref.
Positive	1.53 (1.34, 1.75)	<0.001	1.74 (1.37, 2.19)	<0.001	2.09 (1.74, 2.51)	<0.001‡
Number of positive LN (per one LN)	1.11 (1.07, 1.15)	<0.001	0.91 (0.80, 1.03)	0.14†	1.04 (0.99, 1.09)	0.097‡§
Number of negative LN (per five LN)	0.96 (0.91, 1.00)	0.052	0.99 (0.90, 1.08)	0.78	0.94 (0.89, 1.01)	0.078

p-values reported for CCI, income, year, grade group and stage derived from test for trend;

^†significant predictor of receipt of RT alone vs. ADT alone (p<0.05);

^‡significant predictor of receipt of ADT and RT vs. ADT alone (p<0.05);

^§significant predictor of receipt of ADT and RT vs. RT alone (p<0.05); ADT, androgen deprivation therapy; CCI, Charlson Comorbidity Index; CI, confidence interval; LN, lymph node; PSA, prostate-specific antigen; RRR, relative risk ratio; RT, radiation therapy