TABLE 6.

Descriptive statistics of the log concentrations of the vegetables with L. monocytogenes by the type of product, the process degree, the period of publication, and the geographical origin of the studies^a

Qualitative variable	Modality	No. of studies	Mean	SD	2.5th percentile	Median	97.5th percentile
Type of product	Leafy salads	38	−3.36 A	1.42 A	−5.99 A	−3.41 A	−0.17 A
	Sprouts	12	−3.09 B	1.55 B	−5.88 B	−3.17 B	0.74 B
	Other vegetables	115	−3.43 B	1.55 B	−6.10 B	−3.53 B	0.69 B
Process degree	Unprocessed	91	−3.40	1.47	−6.01	−3.48	0.11
	Minimally processed	74	−3.37	1.53	−6.03	−3.47	0.57
Period of publication	1988-1999	80	−2.79 C	1.53 C	−5.30 C	−2.93 C	1.49 C
	2000-2005	85	−3.94 D	1.31 D	−6.34 D	−3.97 D	−1.23 D
Geographical origin	North America	33	−3.73	1.39	−6.32	−3.78	−0.80
	Europe	95	−3.45	1.50	−6.05	−3.53	0.30
	Other countries	97	−3.07	1.38	−5.67	−3.12	−0.13

^aFor each variable, significant differences at the 95% credible interval between modalities are indicated by different letters. Results are expressed as log viable L. monocytogenes organisms per gram unless otherwise indicated.