Table 3.

The equations and criteria for the algorithm

Algorithms	Equation	Criteria
ROR	ROR= (a×d) / (b×c)	lower limit of the 95% CI > 1 and a ≥ 3
	95%CI = eln(ROR)±1.96 × (1/a+1/b+1/c+1/d)∧0.5
PRR	PRR= [a×(c + d)] / [c×(a + b)]	PRR ≥ 2, χ2 ≥ 4, and a ≥ 3
	χ2= [(a×d − b×c)2]×(a + b + c + d) /[(a + b)×(c + d)×(a + c)×(b + d)]

ROR, reporting odds ratio; PRR, proportional reporting ratio; CI, confidence interval; χ², chi-squared