Table 2

Results of trials with enhanced consent form intervensions
Standard control Sample size Understanding scores, %
Source Intervention Population Scenario Control Intervention P Value
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 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 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 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

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