Table 4.

Patient-level Factors and Surgeon Case Volume Associated with Number of Procedures per Case

	Unadjusted Patient Level	Adjusted Patient Level	Adjusted Patient and Surgeon Levels
	IRR (SE) 95% CI	IRR (SE) 95% CI	IRR (SE) 95% CI
Female	#.95 (.004) .95–.96	#.95 (.004) .95–.96	# .95 (.004) .94–.96
Race/ethnicity
White	Reference	##Reference	Reference
Black	1.00 (.010) .99–1.02	1.01 (.010) .99–1.03	1.02 (.010) 1.00–1.04
Hispanic	.99 (.008) .98–1.01	.98 (.008) .96–1.0	.99 (.009) .97–1.01
Other	1.02 (.011) 1.00–1.03	.99 (.011) .97–1.02	1.00 (.012) .98–1.03
Expected primary payer
Medicare	##Reference	##Reference	Reference
Medicaid	.93 (.017) .90–.97	.99 (.019) .95–1.02	1.00 (.020) .96–1.04
Private insurance	1.00 (.005) 1.00–1.01	1.03 (.008) 1.01–1.04	1.01 (.008) 1.00–1.03
Other	.97 (.011) .95–.99	1.00 (.013) .97–1.02	1.01 (.013) .98–1.03
Hospital	1.00 (.004) .99–1.01	1.01 (.004) 1.00–1.01	#1.02 (.006) 1.01–1.03
Nasal surgery	#.98 (.004) .97–.98	#.97 (.004) .96–.98	#.96 (.005) .96–.97
Image guidance	#1.21 (.008) 1.19–1.22	#1.18 (.008) 1.17–1.20	#1.21 (.010) 1.19–1.23
Surgeon case volume			#1.002 (.0001) 1.00–1.00
Surgeon-specific random effects variance			0.17 (0.0034) .16–.18

IRR Incidence rate ratio

SE Standard error

Models were adjusted for study year.

^#P<0.05 for comparison

^##P < 0.05 for comparison across entire group