Table 6.
Results of trials with multiple study groups receiving different intervention types to improve patient comprehension in informed consent
| Source | Study country |
N | Mean patient age (and range if specified) |
Patients’ education |
Procedure | Intervention | Elements of patient comprehension assessed |
Comprehension assessment tool |
Timing of patient comprehension assessment relative to informed consent consultation* |
Risk of bias for patient comprehension outcome† |
Results | Group favored‡ |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Johnson et al. (2011) | USA | 151 | 67 y | Mean education in years: 13 | Total knee arthroplasty | Group 1: control (standardized informed consent using iMedConsent web-based tool plus customized written handout) Group 2: same as control plus a standard video from the American Academy of Orthopedic Surgeons (audiovisual intervention) Group 3: same as group 2 plus a “formal education session” (further details not provided) with a nurse coordinator/ educator additionally reviewing risks, benefits, and expectations of total knee arthroplasty (multicomponent intervention) |
Risks, benefits, alternatives, general knowledge about procedure | 14-item multiple choice questionnaire | Immediately and delayed | High risk of bias | Control: immediate score 10.1 out of 14 (SD 2.4), day of surgery score 10.2 out of 14 (SD 2.3), 6-week post op score 10.5 out of 14 (SD 1.7) Group 2: immediate score 10.8 out of 14 (SD 1.6), day of surgery score 10.3 out of 14 (SD 1.8), 6-week post-op score 10.2 out of 14 (SD 2.7) Group 3: immediate score 11.1 out of 14 (SD 1.5), day of surgery score 11.0 out of 14 (SD 1.2), 6-week post-op score 10.4 out of 14 (SD 2.2) P values 0.11 (immediate), 0.08 (day of surgery), 0.80 (6-weeks post-op) |
None |
| Shukla et al. (2012) | USA | 100 | 74 y | Not specified | Cataract surgery | Group 1: control (conventional resident-administered verbal consent) Group 2: conventional verbal consent plus 2nd grade reading level written information sheet (written intervention) Group 3: conventional verbal consent plus 8th grade reading level written information sheet (written intervention) Group 4: conventional verbal consent plus a 13-minute video from the American Academy of Ophthalmology (audiovisual intervention) |
Risks, benefits, alternatives, general knowledge about procedure | 12-item multiple choice questionnaire | Not specified | High risk of bias | Group 2: mean score 10.8 out of 12 (SD 1.29) vs. 7.68 out of 12 (SD 2.80) control, P = 0.000 Group 3: 9.08 out of 12 (SD 1.60) vs. 7.68 out of 12 (SD 2.80) control, P > 0.05 Group 4 mean score 10.56 out of 12 (SD 1.44) vs. 7.68 out of 12 (SD 2.80) control, P = 0.000 No statistically significant difference between Group 2 and Group 4, P > 0.05 |
Group 4 and group 2 > control |
| Bennett et al. (2009) | USA | 99 | Not specified | Not specified | Imaging-guided spinal epidural steroid, nerve root, and facet joint injections | Group 1: control (standard informed consent which includes “a conversational description of the 12 key points of consent and home-care with the patients given the opportunity to read and sign the printed procedure informed consent document”) Group 2: “teach-the-teacher group” i.e. standard informed consent then participants had to repeat back the 12 key points without error to the physician before informed consent was complete (verbal discussion with teach-back intervention) Group 3: standard informed consent plus participants viewed a set of diagrams illustrating the 12 key points before signing the informed consent form (audiovisual intervention) |
Risks, benefits, general knowledge about procedure | 6-item multiple choice questionnaire with some "circle all that apply" questions (read aloud to any patient with difficulty reading) | Not specified | High risk of bias | Control: 5.5 out of 10 Group 2: 7.4 out of 10 Group 3: 7.3 out of 10 P ≤ 0.05 for each intervention group compared to control |
Group 2 and group 3 > control |
| Cornoiu et al. (2011) | Australia | 61 | 44.2 y (range 20 - 74) | Average grade level: 10.4 | Knee arthroscopy | Group 1: control (standardized verbal consent with a trained resident using a checklist and script based on author consensus of average risk for complications based on literature review plus information about desired information from a focus group of patients who had previously undergone knee arthroscopy) Group 2: 1-page written information at an 8th grade level, without pictures, developed using the same score information as the verbal script, in place of standardized verbal consent (written intervention) Group 3: multimedia education module (pilot tested and revised) covering the same core information as the verbal and the written groups with voice, text, photographs, and 3D computer animations in place of standardized verbal consent, patients could control progression through the module (interactive digital intervention) |
Risks | 10-item questionnaire | Immediately and delayed | High risk of bias | Control: correct answers on immediate testing 88% (SD 14%) Group 2: correct answers on immediate testing 76% (SD 28%) Group 3: correct answers on immediate testing 98% (SD 5%) and answered a higher proportion of questions correctly “at all stages” P < 0.05 |
Group 3 > group 2 and control |
| Goldberger et al. (2011) | USA | 63 | 61 y | 62.3% college or above | Diagnostic cardiac electrophysiology | Group 1: control (standard text read verbatim by physician then questions answered) Group 2: participants given a booklet (no other details provided) then had the opportunity to ask the physician questions (written intervention) Group 3: video narrator read same text as that contained in the booklet then participants had the opportunity to ask the physician questions (audiovisual intervention) |
Risks, general knowledge about procedure | 4 multiple choice questions and patients asked to recall potential complications | Immediately | High risk of bias | Control: mean score: 6 (SD 2) Group 2: mean score 4 (SD 2) Group 3: mean score 5 (SD 2) P = 0.11 |
None |
*
Immediately: within 1 hour of informed consent consultation; delayed: more than 24 hours after informed consent consultation
†
Assessed using the Cochrane Risk of Bias 2.0 tool, see Table 7 for details
‡
If a study reported an improvement in patient comprehension on a single item or multiple items of the comprehension assessment but if overall score did not improve, we considered neither or no group to be favored