Table 2.

Summary of significant safety findings for COX-2 inhibitors versus placebo in patients with osteoarthritis

Outcomes	No. of participants Follow-up	Certainty of the evidence (GRADE)	Relative effect (95% CI) Risk ratio	Anticipated absolute effects
				Risk with placebo	Risk difference with COX-2 inhibitors
Treatment-related adverse events	7463	⊕⊕⊕⊕ HIGH	1.26 (1.09–1.46)	144 per 1000	37 more per 1000 (13 more to 66 more)
Upper gastrointestinal adverse events overall	23,974	⊕⊕⊕⊕ HIGH	1.19 (1.03–1.38)	29 per 1000	5 more per 1000 (1 more to 11 more)
Abdominal pain	9907	⊕⊕⊕⊕ HIGH	1.40 (1.08–1.80)	23 per 1000	9 more per 1000 (2 more to 19 more)
Hypertension	7360	⊕⊕⊕⊕ HIGH	1.45 (1.01–2.10)	27 per 1000	12 more per 1000 (0 fewer to 30 more)
Heart failure and edema	14,111	⊕⊕⊕⊕ HIGH	1.68 (1.22–2.31)	10 per 1000	7 more per 1000 (2 more to 14 more)

GRADE Working Group grades of evidence: High certainty we are very confident that the true effect lies close to that of the estimate of the effect; Moderate certainty we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different; Low certainty our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect; Very low certainty we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect

The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI)

CI confidence interval, COX-2 cyclooxygenase-2