Table 2.

Study quality

Author, year	Representativeness (sampling)	Selection of comparison group	Comparability of cohortsa	Outcome follow-upb
No comparison
Reichert (2004)26	0	N/A	N/A	0
Del Fiol et al. (2006)29	0	N/A	N/A	N/A
Oppenheim et al. (2009)36	0	N/A	N/A	N/A
Comparison with non-IB resource
Cimino et al. (2003)25	0	N/Ac	N/A	N/A
Rosenbloom et al. (2005)27	1	1	1 (RCT)	1
Chen et al. (2006)28	0	N/Ac	N/A	N/A
Cimino (2007)32	0	N/Ac	N/A	N/A
Hunt et al. (2013)39	0	N/Ac	N/A	N/A
Hyun et al. (2013)40	0	N/Ac	N/A	N/A
Borbolla et al. (2014)41	0	N/Ac	N/A	N/A
Comparison with alternate IB implementation
Maviglia et al. (2006)30	0	1	1 (RCT)	0
Cimino et al. (2007)31	0	1	0	1
Cimino and Borovtsov (2008)33	0	0	0	1
Del Fiol et al. (2008)34	0	1	1 (RCT)	1
Cimino (2009)35	0	N/Ac	N/A	N/A
Del Fiol et al. (2010)37	0	1	0	N/A
Cimino et al. (2013)38	0	0	0	N/A

NA = not applicable (no separate comparison group or no follow-up period).

^aComparability of cohorts could be demonstrated through randomized group assignment or by statistical adjustment for baseline characteristics; no studies reported the latter approach.

^bWe also appraised the quality of outcome assessment. All studies reported log file data on infobutton usage, which we coded as an objective, blinded measurement. Several studies also reported self-report measures of impact on patient care and satisfaction (see Table 1).

^cCompared usage of different resources among the same group of potential users, thus providing comparison results without a separate comparison group.