Table 2.

Incidence rate ratios for the association between tendon rupture and current systemic fluoroquinolone and co-amoxiclav exposure

Tendon rupture	Exposed cases/total	Exposed controls/total	Crude IRR	Adjusted IRR	Adjusted p value
Any tendon rupture
Fluoroquinolones	111/4836	236/18,356	1.79 (1.41–2.27)	1.61 (1.25–2.09)	< 0.001
Co-amoxiclav	98/4836	314/18,356	1.15 (0.90–1.45)	1.02 (0.79–1.31)	0.900
Achilles tendon rupture
Fluoroquinolones	67/1577	82/6007	3.50 (2.45–5.02)	3.14 (2.11–4.65)	< 0.001
Co-amoxiclav	38/1577	114/6007	1.19 (0.81–1.77)	1.00 (0.64–1.57)	0.989
Biceps tendon rupture
Fluoroquinolones	20/1316	62/4946	1.19 (0.71–2.00)	1.07 (0.61–1.89)	0.804
Co-amoxiclav	23/1316	74/4946	1.16 (0.72–1.88)	1.01 (0.61–1.66)	0.978
Other tendon rupture
Fluoroquinolones	24/1943	92/7403	0.94 (0.59–1.50)	0.82 (0.50–1.35)	0.439
Co-amoxiclav	37/1943	126/7403	1.09 (0.75–1.60)	1.01 (0.68–1.50)	0.946

Model adjusted for exact age, body mass index, Charlson co-morbidity score, hypothyroidism, hyperparathyroidism, smoking status, oral and injectable corticosteroid therapy, statin therapy and prior history of tendon rupture

IRR incidence rate ratio