Table 1

Summary of stepwise selection of regressors

Step	Effect entered*	Effect removed†	Score χ2‡	P value§
1	Needle size<20 G		9.19	<0.01
2	Nerves		8.37	<0.01
3	Obesity		7.93	<0.01
4	Repeated Lesions¶		4.32	0.04
5	RFA type (binary)		7.26	<0.01
6		Needle size<20 G		0.70
7	Depression		4.39	0.04
8	Opioids (binary)		4.41	0.04
9	Previous knee surgery		2.94	0.09
10	Disability/worker’s compensation**		2.76	0.10
11		Nerves		0.17
12	Age		2.08	0.15
13		Age		0.15

*Multivariable logistic regression analysis performed with significance levels of 0.15.
†Regressors with p>0.15.
‡χ2 statistic generated from a score test.
§P value compares levels of the regressor with respect to the logit of a positive outcome.
¶Designates more than one lesion at a different location for a single nerve target.
**For active duty personnel, includes the military equivalent (medical board evaluation).
G, gauge; RFA, radiofrequency ablation.