Table 3.

Association of microscope use with operating room times in elective spine surgery patients.

	Non-microscope Mean ± SD	Microscope Mean ± SD	Bivariate linear regression		Multivariate linear regression*
			Beta†	p	Beta†	p
Preoperative room time (minutes)**	44.8 ± 31.0	45.3 ± 17.4	+0.6	0.635	+2.9	0.013
Operative time (minutes)**	127.9 ± 83.0	121.8 ± 80.9	−6.1	0.062	+13.2	<0.001
Postoperative room time (minutes)**	18.0 ± 12.0	16.6 ± 9.9	−1.4	0.004	−0.7	0.110
Total room time (minutes)**	183.9 ± 97.4	180.3 ± 95.5	−3.6	0.346	+18.6	<0.001

SD = standard deviation. Bolding indicates statistical significance (p < 0.05).

^*Each line represents a separate multivariate analysis for each variable in order to give an adjusted unstandardized beta coefficient and p-value by controlling for all demographics, comorbidities, and operative characteristics found in Table 1 and Table 2.

^**Operating room times were only simultaneously available for 8,210 patients, of which 701 (8.4%) underwent surgery with an operating microscope.

^†Unstandardized beta coefficient represents unit change in the outcome variable if the predictor variable is positive. For example, a statistically significant coefficient of +13.2 for operative time means that on average, microscope use is associated with an increase in operative time of 13.2 minutes.