To give an informed consent to any medical procedure, patients need to have adequate knowledge about the nature and risks of the procedure. It is the physicians' duty to provide this information and to ensure that the patients are fully informed. However, it is very challenging to obtain informed consent.1 Generally, it is difficult for patients to understand anesthesia because it is rather intangible and metaphysical, unlike their surgeries such as tumor resection, which are easily imaginable. Insufficient understanding of anesthesia can potentially incite legal conflict over the validity of informed consent.2 Although it would be ideal to obtain a patient's consent with full understanding of the risks and benefits of anesthesia, it is impractical because anesthesiologists often do not have sufficient time to explain anesthesia until the patient can fully comprehend it. Several studies have shown that video-assisted patient education, in comparison with an interview alone or an interview plus a brochure, has mixed results on patient's knowledge regarding the anesthesia procedures and preoperative anxiety. Reasons for these conflicting results may include variability in clinical venue, complexity of surgery, and specific features of the video.3–6 Some patients may refuse to participate in video-assisted patient education because they do not want to see medical interventions on video and may panic if they are forced to do so.3
To solve these problems, we designed an interactive animated video that provides a basic explanation—including the risks, benefits, and alternatives—of anesthetic procedures.a Our animation video is intended to help patients understand anesthesia, to help anesthesiologists understand what their patients do not understand, and to make the preanesthetic interview effective and efficient. It is not intended as a substitute for the preanesthetic interview by the anesthesiologist.
There are several possible advantages to our interactive animation video over a conventional photographic video. First, the animation video is easier to edit or modify with computer software. Clinical practice is ever changing, and the contents of the explanation must always reflect this changing practice. It is not necessary to employ actors and camera crew to modify an animation video. Second, animation video may be more acceptable to patients who do not want to view realistic medical interventions.3 Third, animation video can visually highlight the important points better than can a photographic video, and patients can easily understand the point of the video image. Fourth, our interactive video can serve as proof that patients understand the explanation of anesthesia. It is impossible to know whether patients understand the explanation of anesthesia with a pamphlet or conventional video. We asked patients scheduled for cancer surgery to view this animation video in the ward the day before surgery. We hypothesized that this video would improve patient understanding of anesthesia, reduce anxiety, and shorten the interview time.
Approval of the ethics committee of Teikyo University and written informed consent from the patients were obtained. The study was conducted as a prospective randomized, controlled trial from August 2008 to February 2009. All patients scheduled for cancer surgery (including diagnostic biopsy) under general or combined general and epidural anesthesia, who were admitted to the ward at least 1 day before surgery in Teikyo University Hospital, were considered for enrollment in the trial. Patients were excluded if they would require a third party to complete the consent process (patients younger than 20 years, patients who did not adequately understand Japanese, and those with mental impairment). Ambulatory surgical patients were also excluded. Patients were approached for enrollment in the trial before the preanesthetic interview the day before surgery.
All patients who agreed to participate in the study were asked to complete the State–Trait Anxiety Inventory (STAI)7 before the preanesthetic interview. The STAI is a general tool to assess anxiety levels, and this questionnaire is designed to assess an individual's momentary or situational anxiety. It consists of 20 statements, each with 4 answers, producing a score between 20 and 80. A higher score reflects higher anxiety. We used the STAI in a well-established and validated Japanese translation.8 Patients were also asked to complete a knowledge questionnaire before the interview conducted by the anesthesiologist (Appendix 1, see Supplemental Digital Content 1, https://links.lww.com/AA/A237). The knowledge questionnaire was intended to evaluate the patients' knowledge of the purpose, procedural details, and the potential complications of anesthesia. The questions asked were adopted from similar studies.4,5,9,10 Patients were then randomly assigned to the video group or the no-video group. The allocation sequence was generated by a random number table. Patients in the video group were asked to watch the short interactive animation video in the ward. The video was shown to the patient using a touch-screen laptop PC with monitor and headphones. After brief instruction, the patient was left alone with this video for at least 30 minutes. All patients were allowed to repeat any part of the video as many times as they wanted.
After the video session, the patients were visited by a board-certified anesthesiologist who performed a preanesthetic interview and risk assessment. Patients in the no-video group were visited by a board-certified anesthesiologist who performed a routine preanesthetic interview and risk assessment as usual. The standard format of the interview consists of confirmation of the surgery, medical history, medication, physical examination, explanation of anesthesia method, and common and patient-specific complications, as well as a question-and-answer session in the no-video group. In the video group, anesthesia method and common complications were explained on the animation video. The anesthesiologist conducted the rest of the interview described above. This video was operated on a touch-screen laptop PC with headphones. An animation character playing the role of a female anesthesiologist explained some of the important aspects of anesthetic procedures in plain Japanese language with a female voice (Appendix 2, see Supplemental Digital Content 2, https://links.lww.com/AA/A238). This video comprised several brief sections. Each section lasted from 1 to 2 minutes. In the video, the animation character first discussed the role of anesthesiologists during surgery, gave nil per os (NPO) instructions, and then explained the rationale for the NPO instructions, usual general or combined general and epidural anesthesia procedures, and postoperative recovery. There was a questionnaire at the end of every section to examine the patients' understanding of anesthesia. This was also intended to serve as a legal document to prove that patients understood the explanation of anesthesia and gave informed consent (Appendix 3, see Supplemental Digital Content 3, https://links.lww.com/AA/A239). The summary of patients' answers is shown in Appendix 4 (see Supplemental Digital Content 4, https://links.lww.com/AA/A240). Before the preanesthetic interview, anesthesiologists knew whether patients watched the video, and whether they correctly answered the questions. During the interview, the anesthesiologists could explain in detail what patients did not understand. We measured the interview time. The interview time was defined as the time from the beginning of an anesthesiologist seeing the patients in their rooms in the ward to when the anesthesiologist left the room. The interview time was recorded by the primary investigator (AK). On the day of surgery the patients were asked again to complete the STAI form and a knowledge questionnaire in the ward before leaving for the operating room (Fig. 1). We determined our sample sizes to be large enough to detect a difference in interview time more than 5 minutes with >80% possibility.11
The data were analyzed with Microsoft Excel 2007 (Microsoft, Redmond, WA). If not otherwise stated, mean ± SD (95% confidence interval [CI]) is displayed. The data on the effects of short interactive animation video were log-transformed and were analyzed with a generalized pivotal approach.12 Ninety-five percent confidence intervals of relative effectiveness were determined by a modified signed log-likelihood ratio approach.13 Nominal data were analyzed with χ2 test. P value <0.05 was considered significant.
Of the 262 eligible patients, 217 patients consented to participate in this study. Of these, 6 patients withdrew after the preanesthetic interview and had to be excluded, because of the time constraints to complete the 14-point-scale questionnaires on the day of surgery. There was no significant difference in age, gender, education, ASA classification, types of surgery, and previous experience of anesthesia. There was no difference in the baseline anxiety and knowledge between the groups (Table 1). There was also no difference in anxiety between the 2 groups. The interview time was 34.4% shorter in the video group (video group, 12.2 ± 5.3 minutes vs. no-video group, 18.6 ± 6.4 minutes; 95% CI for the percentage reduction in time: 32.7% to 44.3%). Knowledge of anesthesia on the day of surgery was 11.6% better in the video group (score, 12.5 ± 1.4 vs. no-video group score, 11.2 ± 1.7; 95% CI for the percentage increase in knowledge, 8.5% to 13.9%) (Table 2).
Our interactive animation video significantly shortened the interview time. In a preanesthetic interview, descriptions of anesthetic procedures may be classified as generic, or specifically directed according to the needs of an individual patient. A generic explanation is identical for all surgical patients. It appeared that time was saved because the patients demonstrated their knowledge through use of the interactive video, and these topics covered in the video did not need to be reiterated by the anesthesiologist. By offering the information in advance, the preoperative interview became more effective and efficient. Shortening interview time while maintaining the same quality can result in medical cost reduction.14 One previous study showed that the preanesthetic interview time of the video group was longer than that of the no-video group. The authors explained that the patients who watched the video became aware of more issues related to anesthesia, and that this awareness led to more detailed questions.3 We speculate that the interactiveness of our video prevented this from happening. Our patients were allowed to repeat any part of the video in the study. The anesthesiologist had the opportunity to review the patient's responses to the questionnaire before the interview, and restrict his or her explanations to areas that the patient did not understand. We have demonstrated that this more focused approach can make the preanesthetic interview more time efficient. Various media tools, including pamphlets and videotapes, have been used in conjunction with the preanesthetic interview, and have shown results suggesting better recall of information.10
In our study, knowledge improvement after the preanesthetic interview was greater in the video group than in the no-video group, consistent with results from previous investigations.3,4,6,10,15 The effect of information provided during the consent process on anxiety is controversial. There has been a belief that the provision of extra information, particularly about risks and complications, may exaggerate patients' anxiety.16 There are some reports regarding relief of anxiety by providing detailed information.17 Previous studies have shown that there is no significant change in anxiety levels after additional written information is provided to the patients.18–20 Luck et al. demonstrated that preoperative video information was effective for reducing anxiety in patients undergoing colonoscopy.15 However, the cause of anxiety might have been different between our study and that of Luck et al. Colonoscopy does not require general anesthesia, whereas our patients have to have both anesthesia and surgery for cancer. Our patients might well worry about their surgery and cancer prognosis rather than anesthesia, and our animation video explains only anesthesia. Concerns about anesthesia might be a relatively small part of their anxiety, particularly for patients who are going to have major surgery.3,21,22 Our interactive animation video was not designed to reduce surgical anxiety.
There are several limitations in this study. The first limitation is failure to double-blind patients and anesthesiologists.3 However, our study was designed to mimic the way our interactive animation video is used in a real clinical setting. Therefore, our results are valid when our video is actually used. The second limitation is the possibility of families' help when patients answered questions, although patients were asked to do the test by themselves. The third limitation is the difference in interview style. This interactive animation video explained only general anesthesia. Anesthesiologists could save time if they spent more time explaining anesthesia than performing patient preoperative assessment. Our short interactive animation video helps patients understand anesthesia and reduces anesthesiologists' interview time.
Name: Akihito Kakinuma, MD.
Contribution: Study design, conduct study, data analysis, manuscript preparation.
Name: Hirokazu Nagatani, MD.
Contribution: Manuscript preparation.
Name: Hiroshi Otake, MD, MBA.
Contribution: Manuscript preparation.
Name: Ju Mizuno, MD, PhD.
Contribution: Manuscript preparation.
Name: Yoshinori Nakata, MD, MBA.
Contribution: Study design, manuscript preparation.
a Kakinuma A, Sawa T, Komatsu T, Yuji K, Kami M, Nakata Y. Effects of short interactive animation video on preanesthetic anxiety, knowledge and interview time. Anesth Analg 2009;108:S108
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