Table 1.

Overview of characteristics of included randomized trials

Characteristic	Summary measure
Study sample size
Median (range)	352 (37–27,830)
Year of publication (median, range)	Median 2005 (range 1968–2016)
Before 1980	3 (10%)
1981–1990	1 (3.3%)
1991–2000	6 (20%)
2001–2010	10 (33.3%)
2011–2016	10 (33.3%)
% Female participants
Median (range)	45.5% (0%–83.3%)
Average patient age (years)
# studies reporting mean/median	23
# with average age between <20	3 (13.0%)
# with average age between 20 and 40	13 (56.5%)
# with average age > 40	7 (30.5%)
Other population characteristics of note
# enrolling HIV patients	5 (17.2%)
# in prison populations	2 (6.9%)
# in population at risk of silicosis	3 (10.3%)
# in transplant patients	1 (3.5%)
Funding source
Industry	3 (10%)
Academic/government	15 (50%)
Mixed funding	1 (3.3%)
Not reported	11 (36.7%)