Table 2.

Association of dental procedures with pyogenic vertebral osteomyelitis

	Hazard period	Control periodsa	ORb (95% CI)	p value
Main analysis
Exposure assessment period, 4 weeksc (n = 3599)	18 (663)	31 (1132)	0.81 (0.72-0.92)	< 0.001
Secondary analysisd
With antibiotic prophylaxis (n = 2737)	9 (250)	15 (410)	1.11 (0.93-1.32)	0.26
Without antibiotic prophylaxis (n = 3264)	14 (448)	27 (889)	0.72 (0.63-0.83)	< 0.001
Sensitivity analysis
Exposure assessment period, 8 weekse (n = 3222)	28 (909)	44 (1412)	0.81 (0.73-0.91)	< 0.001
Exposure assessment period, 12 weeksf (n = 2826)	34 (973)	53 (1492)	0.74 (0.66-0.84)	< 0.001
Invasive dental proceduresg (n = 1856)	4 (78)	8 (153)	0.94 (0.71-1.25)	0.67
Noninvasive dental proceduresg (n = 3407)	19 (634)	32 (1099)	0.80 (0.71-0.90)	< 0.001

Data are presented as % (n) unless noted otherwise.

^aPatients who underwent a dental procedure in at least one control period.

^bOR of exposure to dental procedures in the hazard period compared with the two control periods within the same individuals.

^cHazard period was 1 to 4 weeks and two control periods were 9 to 12 weeks and 17 to 20 weeks before the index date.

^dCategorizing the exposure depending on use of antibiotic prophylaxis.

^eHazard period was 1 to 8 weeks and two control periods were 17 to 24 weeks and 33 to 40 weeks before the index date.

^fHazard period was 1 to 12 weeks and two control periods were 25 to 36 weeks and 49 to 60 weeks before the index date.

^gClassifying the exposure according to whether the dental procedure was invasive or nonivasive.