|Results of trials with enhanced consent form intervensions|
|Standard control||Sample size||Understanding scores, %|
|Paris et al., 2010||Y||Simplified paper document with systematic readability improvement||Patients with stroke, DM, or OSAS||Simulated||115||67||69||NS|
|Y||Simplified paper document developed by a working group of clinical research nurse, IRB member, and healthy volunteer||Patients with stroke, DM, or OSAS||Simulated||114||67||69||NS|
|Campbell et al., 2008||N||Simplified text in booklet format with color. 7th grade reading level||Healthy volunteers||Simulated||146||64||85||<0.001|
|Walters and Hamrell, 2008||Y||Simplified paper document. 6th grade reading level||Healthy volunteers||Simulated||317||77||79||NS*|
|Paris et al., 2007||Y||Simplified paper document with systematic readability improvement||Healthy volunteers||Simulated||99||78||82||≤0.05|
|Y||Simplified paper document developed by a working group of clinical research nurse, IRB member, and healthy volunteer||Healthy volunteers||Simulated||101||78||83||≤0.017|
|Y||Simplified paper document developed by a working group and by systematic readability improvement||Healthy volunteers||Simulated||100||78||82||≤0.05|
|Campbell et al., 2004||Y||Simplified paper document with revised layout, text styling, and added pictures||Parents of pediatric patients||Simulated||119||47||53||NS|
|Agre and Rapkin, 2003||N||Simplified paper document presented in booklet form with summary section. 8th grade reading level||Patients with cancer and healthy volunteers||Real||221||69||70||NS|
|Coyne et al., 2003||Y°||Simplified paper document with revised text styling, page layout, and language. 7th grade reading level. Organized in Q/A format°||Patients with cancer||Real||207||69||72||NS‡|
|Dresden and Levitt, 2001||N||Simplified paper document with revised layout, text styling, and language||Patients in the E.R.||Simulated||100||72||88||<0.0001|
|Stiles et al., 2001||Y°||Simplified paper document with text styling and graphics°||Patients with mental illness and healthy volunteers||Simulated||227||81||81||NS|
|Bjorn et al., 1999||N||Leaflet used by pharmacology company with revised language, style and layout. Hypertension scenario||Healthy volunteers||Simulated||135||48||56||<.05|
|N||Leaflet used by pharmacology company with revised language, style and layout. Sterilization scenario||Healthy volunteers||Simulated||100||NA||NA||NS|
|Murphy et al., 1999||N||Simplified paper document. 6th grade reading level with text styling and illustrations||Women at risk for HIV||Simulated||141||70||83||0.0001|
|Davis et al., 1998||Y||Revised with patient input, readability improved from college to 7th grade level, shortened, booklet format, graphics||Patients and healthy volunteers||Simulated||183||56||58||NS|
|Rogers et al., 1998||Y°||Consent required to “opt out” of study, rather than “opt in”°||Recent mothers||Real||44||30||47||<0.02|
|Taub et al., 1987||Y||Simplified paper document. 7th grade reading level||Elderly volunteers||Real||235||68||70||NS|
|N||Standard or simplified paper document with “Letter Gothic”, enlarged font||Elderly volunteers||Real||235||71||65||NS*|
|N||Standard or simplified paper document with “Orator”, enlarged all-caps font||Elderly volunteers||Real||235||71||70||NS|
|Taub et al., 1986||Y||Simplified paper document. 7th grade reading level||Patients with heart disease||Real||188||71||74||NS|
|Epstein and Lasagna, 1969||Y||Simplified paper document. Shorter with succinct phrasing||Hospital Employees||Simulated||44||45||67||<.001|
Abbreviations: NA Not Available, NS Not Significant, DM diabetes mellitus, OSAS obstructive sleep apnea syndrome, HIV human immunodeficienc virus.
Bolded rows indicate trials included in the 2004 systematic review by Flory and Emanuel.
°Human proctor available for question/answer.
* Significant improvement reported for eldest cohorts.
‡ Understanding assessed within approximately 1 week.
Nishimura et al.
Nishimura et al. BMC Medical Ethics 2013 14:28 doi:10.1186/1472-6939-14-28