Table 2.

Numeric Estimates of Verbal Probability Terms

Verbal probability term	Number of studies	Average numeric estimate, random effects model (%)	95% CI (%)	Minimum sample average (%)*	Maximum sample average (%)*	Range of individual estimates (%)†
Rare(ly)	7	10.00	[7.99, 12.01]	7.0	21	0–80
Rare-severe event	3	10.06	[5.45, 14.68]	6.3	34.8	–
Rare-mild event	3	14.14	[7.88, 20.40]	9.6	39.3	–
Uncommon	4	17.64	[13.19, 22.09]	13.3	22.9	0–90
Unlikely	6	17.71	[14.86, 20.55]	13.3	27	0–85
Common-severe event	3	43.08	[40.27, 45.88]	41.9	45.6	–
Possible(ly)	6	43.28	[36.66, 49.89]	36.9	62	–
Common-mild event	3	50.47	[45.59, 55.34]	48	58	–
Common	6	58.73	[50.40, 67.06]	34.2	70.5	10–100
Very common	3	60.10	[42.36, 77.85]	38.5	71.6	5–100
Probable(ly)	5	69.87	[67.07, 72.67]	66	73.9	20–100
Likely	6	71.87	[69.90, 73.84]	66	94	–
Usual(ly)	3	75.38	[71.53, 79.23]	72	78	–
Very likely	3	84.30	[79.43, 89.17]	75.2	93	20–100

Table includes terms studied in 3 or more studies in which sufficient information was reported for the meta-analysis

*All 19 studies reported an average estimate; minimum is the lowest of these averages, and maximum is the highest

†Only 4 studies reported ranges of estimates provided by individual participants within the study. This column reflects the range across all 4 studies