Rehearsal’s effect on recall and comprehension of orthodontic informed consent


Proper informed consent allows patients to take an active role in their own treatment decisions, and enhanced compliance might improve treatment outcomes. The objective of this research was to determine if handwritten rehearsal of core and custom consent items would increase short-term recall and comprehension.


A total of 90 patient-parent pairs were randomly assigned to 2 groups. After case presentation, each subject was provided 10 minutes to read a modified informed consent document. Group A received visual printouts containing the 4 core elements (root resorption, decalcification, pain, and relapse/retention) likely to be encountered by all patients and up to 4 custom elements (eg, impacted teeth, orthognathic surgery, or other case-specific treatment issues). Subjects identified and wrote what the image depicted and how it could affect treatment. Group B viewed a slideshow presentation on all 18 consent elements arranged from general to specific. All participants were interviewed, and each provided their sociodemographic data, as well as completed literacy, health literacy, and state anxiety questionnaires. The groups were compared for recall and comprehension through an analysis of covariance.


The rehearsal intervention significantly improved recall and comprehension of the core elements ( P = 0.001). Rehearsal also improved custom recall and comprehension, but not significantly. Group B performed significantly better on treatment questions ( P = 0.001). Overall, as anxiety increased, correct responses decreased.


The rehearsal group improved recall and comprehension of the core and custom elements of informed consent and proved a more efficient method than an audiovisual presentation to provide informed consent. It also improved meeting legal obligations.


  • Rehearsal- and audiovisual-based, chunked, best practices informed consent were compared.

  • The rehearsal method performed better for core and custom elements.

  • The best practices method performed better for treatment-based elements.

  • The rehearsal method shows promise as a more efficient method.

There are 2 main bases for dental practitioners to create and provide informed consent to their patients. First, proper informed consent allows patients to take an active role in their own treatment decisions. In order for patients to decide on their course of treatment, the options, risks, and benefits should be reasonably capable of being understood by them. Second, the protections that the practitioner anticipates to be provided, as a result of the informed consent doctrine, must be presented in such a fashion that the patient understands the material risks and is capable of making a decision about proceeding with the treatment.

Baird and Kiyak found that poor comprehension and recall among patients and their parents showed that current popular methods of orthodontic informed consent were insufficient. Comprehension and recall are also correlated with the parents’ education level and vocabulary. Anxiety, especially when too great, limits a patient’s ability to remember and understand new information. , To increase treatment success, understanding the planned treatment, as well as the risks of that treatment, is important.

Simply signing a document for legal purposes does not mean the patient understands treatment; therefore, the provider can still be liable for not properly informing the patient. Patients’ understanding of instructions increases compliance and improves treatment outcomes.

Depending on the legal jurisdiction, the claim for “lack of informed consent” is a claim that can be separate and independent from a claim of dental malpractice. Even if there is no negligence in the performance of the dental procedure, a lack of informed consent claim may be able to stand alone, as a separate tort. Thus, documenting that the patient is informed of the nature, extent, and risks of the procedure is an essential component of “Consent” documents signed by that patient or the patient’s parent/guardian.

Following the guidelines of the statute, the dental practitioner can greatly reduce their potential exposure for a lack of informed consent. The tort of lack of informed consent is established when (1) the physician fails to disclose to the patient and discuss the material risks and dangers inherently and potentially involved with respect to the proposed therapy, if any; (2) the unrevealed risks and dangers that should have been disclosed by the physician actually materialize and are the proximate cause of the injury to the patient; and (3) a reasonable person in the position of the patient would have decided against the therapy had the material risks and dangers inherent and incidental to treatment been disclosed to him or her before the therapy.

Recent studies demonstrate the current state of affairs and contemporary ways to address them. In a Scottish study, only 40% of orthodontic specialists had any evidence of consent regardless of how it was obtained. Despite widespread inadequate record keeping, it seems that informed consent can easily be incorporated into electronic dental records.

Increasing patient and parent comprehension includes simplifying the informed consent document. Many informed consent documents contain dental jargon and are written at a much higher reading level than what the mean national literacy level is for adults, which is estimated to be at the 7th to 9th grade.

One study showed that whether the information was given in a written, visual, or verbal form had no effect on information retention. Another study compared an audiovisual (AV) presentation to only verbal explanation. They found that the AV group had better comprehension, even in patients with lower education levels.

Modified informed consent (MIC) documents with larger font, improved readability, and processability used in a surgical study were more effective than the original written form. A modified orthodontic consent form, with similar improvements and the 18 elements found in the American Association of Orthodontists (AAO) form, combined with a slideshow demonstrated improved recall for patients and parents/guardians when compared with the standard AAO informed consent document.

Short-term memory may limit the number of novel items presented to 7 ± 2 according to previous research. How to “package” the 18 elements to improve comprehension was examined in a follow-up study by Carr et al. These investigators used “chunking,” grouping similar items together. Chunks presented at the beginning or end of the slideshow were understood better than the items in the middle when presenting more than 7 items, consistent with the learning theories of “primacy” and “recency.” The best practice was found to be the procedures reported by Carr et al —MIC and a customized slideshow with chunking, which was ordered from general to specific issues.

In addition to focusing on how the materials are presented, evaluating the process of memory acquisition should be considered. Patient and parents involvement in creating mind maps (visual representations of central and associated concepts and ideas) related to orthodontic treatment combined with an AV presentation improved information retention in the short and long term.

A recent study showed that writing notes by hand increases memory and ability to understand information. Visual attention is commonly restricted to precisely the point where the pen touches the paper during handwriting. Increasing participation of the patient can also increase memory and learning. Rehearsal can prevent the loss of information from short-term memory and can lead to long-term consolidation of the material. Overall, active participation in the process increases retention better than passive reception of that information.

This study compared best practices presented by Carr et al with a technique that incorporated greater patient interaction and rehearsal, emphasized the most important elements pertaining to each specific patient, and required the subject’s acknowledgment of the element’s impact. The new informed consent methods were evaluated for recall and comprehension immediately after the consultation. Our objective was to determine if handwritten rehearsal of core and custom consent items would increase short-term recall and comprehension.

Material and methods

The research protocol was reviewed and approved by an institutional review board (2017B0330). Subjects were recruited as a convenience sample from new patients at a graduate orthodontic clinic by a research assistant during the orthodontic records appointment or by telephone. A sample size of 45 per group was determined based on power analysis calculations from a previous study by Carr et al with a nondirectional alpha = 0.05, and a standard deviation = 16.8. This would yield a power of 0.80.

A total of 90 parent-patient pairs agreed to participate in the study. The inclusion criteria were as follows: patients aged 11 through 18 years, patients with no previous orthodontic treatment or no siblings currently in treatment or completing treatment in the past 5 years, both patient and parent able to communicate in English, and both patient and parent did not have any developmental disabilities or urgent medical conditions. Patients were accompanied by a parent or guardian who could consent to participation and had legal guardianship for at least 1 year. A total of 45 parent-patient pairs were allocated at random via a random number generator to 1 of 2 groups.

MIC developed by Kang et al and containing the 18 informed consent elements ( Fig 1 ) was given to the subjects in group A to read for up to 10 minutes after their consultation was completed. The MIC was written at a 7th grade reading level, contained little, if any, medical or dental jargon, had a larger font size, and well-proportioned white space ( Fig 2 ).

Fig 1
Eighteen orthodontic informed consent elements.

Fig 2
( A-C ) Modified informed consent document (copyright 2008, The Ohio State University).

The subjects in group A also received printed images illustrating each of the 4 core informed consent elements. The 4 “core” elements (and their percentage prevalence among treated patients in the literature) were root resorption (66%), , discomfort (95%), cavities and decalcification (96%), and retention or relapse (66%). , In addition, up to 4 customized visual consent elements chosen by the orthodontist (eg, impacted teeth, orthognathic surgery, or other case-specific treatment issues) that applied specifically to this patient’s treatment were identified. Remaining elements not included in core and custom were considered general and as a group comprised domain 1 for analysis. Subjects wrote on the image what the picture displayed and described the prevention or impact the risk posed.

Group B subjects instead watched a slideshow as prepared by Carr et al explaining all 18 elements but “chunked” from general to specific and with the “core” elements followed by the “custom” elements at the end. The elements were also designated as either responsibility, risk, or treatment related (domain 2 for analysis). Both groups were then interviewed and had their answers recorded by a trained research assistant using an open-ended script of questions.

The questions were developed and validated previously to analyze recall, the ability to provide specific pieces of information, and comprehension, the ability to understand and apply information. The script contained 4 rephrased recall questions to analyze subject reliability. The research assistant administered the reading portion of the Wide Range Achievement Test 3 (WRAT3) to all subjects. The Rapid Estimate of Adult Literacy in Medicine Short Form (REALM-SF) was administered to the parents/guardians, and the Rapid Estimate of Adolescent Literacy in Medicine Short Form (REALM-TeenS) was administered to the patients. The Steinberger State-Trait Anxiety Index—6-item form (STAI-6) was given to parents/guardians and patients to determine state anxiety after the interview. All of the instruments used in this study have been shown to be valid and reliable measures for the age groups in this study. A self-administered questionnaire focused on sociodemographic information was also completed by each subject. A gift card was given to each patient for participation.

The research assistant transcribed all interviews and deidentified the entries and scored the literacy tests. The calibrated orthodontist was blinded to any identifying information and scored each interview using the established codebook by Kang et al.

Statistical analysis

Data were entered on a spreadsheet (Microsoft Office Excel, Redmont, Wash) and analyzed with statistical software (SAS, Cady, NC). Simple kappa statistics and 95% confidence intervals (CIs)were used to determine intrarater and interrater reliability as well as for internal reliability of the subjects with 4 rephrased concept questions. Between-group differences in sociodemographic data, REALM-SF or REALM-TeenS scores, WRAT 3 scores, and STAI-6 scores were analyzed using the Wilcoxon signed rank test. The Fisher exact test was used to evaluate sex differences.

An analysis of covariance (ANCOVA) was used to assess the following differences between groups A and B for: mean percent of on-target responses for overall recall and comprehension; the domains of treatment, risk, and responsibility; and the relationship of the subjects of informed consent. This covariate analysis was performed with STAI-6 scores and ethnicity as covariates. A similar method to evaluate the differences between the core, custom, and general elements was performed.

A Bonferroni-corrected t test was used to resolve significant effects that had more than 1 degree of freedom.


Interrater reliability was used to determine the reproducibility for coding the interview data and was “excellent” (κ = 0.88; 95% CI 0.65-1.00). Intrarater reliability for coding the interviews was “excellent” (κ = 1.00). Internal reliability ( Table I ) for all subjects was “moderate to substantial” for 3 of the 4 questions with kappa scores ranging from 0.44 to 0.67. The question examining ankylosis had “fair” reliability with a kappa score of 0.22.

Apr 19, 2021 | Posted by in Orthodontics | Comments Off on Rehearsal’s effect on recall and comprehension of orthodontic informed consent

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