|Year : 2022 | Volume
| Issue : 2 | Page : 138-145
Tolerance and acceptance for unsedated diagnostic upper gastrointestinal endoscopy in Kaduna, North-West Nigeria
Husain Yahya1, Halima Umar2, Bulus Timothy Shekari3, Kalli Sani3, Muhammad Husain Yahya4
1 Department of Internal Medicine, Barau Dikko Teaching Hospital/Kaduna State University, Kaduna, Nigeria
2 Endoscopy Unit, Department of Internal Medicine, Barau Dikko Teaching Hospital, Kaduna, Nigeria
3 Department of Nursing Services, Barau Dikko Teaching Hospital, Kaduna, Nigeria
4 Department of Internal Medicine, Barau Dikko Teaching Hospital, Kaduna, Nigeria
|Date of Submission||09-Oct-2021|
|Date of Decision||05-Jan-2022|
|Date of Acceptance||06-Jan-2022|
|Date of Web Publication||23-Apr-2022|
Department of Internal Medicine, Barau Dikko Teaching Hospital, PO Box 9727, Kaduna
Source of Support: None, Conflict of Interest: None
Background: Upper gastrointestinal endoscopy (UGIE) using pharyngeal anesthesia, with or without sedation to improve tolerance and acceptance, is now standard practice but the unsedated examination is easier to perform, costs less and is associated with fewer complications. It is, therefore, attractive in resource-limited settings like sub-Saharan Africa but studies about tolerance and acceptance of unsedated UGIE there are limited. Objective: The objective of this study was to report the tolerance and acceptance of unsedated UGIE in a tertiary institution in Kaduna, Nigeria. Methods: Consecutive patients referred for diagnostic UGIE were requested to report the overall level of discomfort for the procedure on verbal and visual analogue scales and to indicate whether they would accept the procedure in the future. Their pulse rate, oxygen saturation and blood pressure were monitored. Results: Of 306 patients (mean age: 45.5 years, 39.2% <40 years, 57.5% of females), 51.3% reported no or mild discomfort and only 5.6% reported severe and intolerable discomfort. Overall, 232 (75.8%) tolerated the procedure well and 229 (79.5%) accepted to have the same procedure in the future. Patients <40 years and those with secondary/post-secondary education were significantly less likely to tolerate the procedure well than older patients (81.1% vs. 87.9%, P = 0.006) and those with lower education (72.7% vs. 86.2%, P = 0.032), respectively. 79.5% accepted to have the procedure in the future, with males significantly more so than females (86.9% vs. 74.4%, P = 0.019). Conclusion: Most patients undergoing unsedated diagnostic UGIE in Kaduna, Nigeria, tolerated the procedure well and accepted to have the same procedure in the future.
Keywords: Sub-Saharan Africa, tolerance and acceptance for endoscopy, unsedated endoscopy, upper gastrointestinal endoscopy
|How to cite this article:|
Yahya H, Umar H, Shekari BT, Sani K, Yahya MH. Tolerance and acceptance for unsedated diagnostic upper gastrointestinal endoscopy in Kaduna, North-West Nigeria. Niger Postgrad Med J 2022;29:138-45
|How to cite this URL:|
Yahya H, Umar H, Shekari BT, Sani K, Yahya MH. Tolerance and acceptance for unsedated diagnostic upper gastrointestinal endoscopy in Kaduna, North-West Nigeria. Niger Postgrad Med J [serial online] 2022 [cited 2022 May 22];29:138-45. Available from: https://www.npmj.org/text.asp?2022/29/2/138/343734
| Introduction|| |
Upper gastrointestinal endoscopy (UGIE) is now a widely performed procedure using flexible video endoscopes to evaluate and treat diseases of the oesophagus, stomach and first and second parts of the duodenum. Transoral examination is the standard means of accessing these structures but is associated with gagging, a reflex contraction of pharyngeal muscles, which prevents swallowing and causes retching, and is a major factor in the discomfort and poor tolerance of the procedure experienced by patients. To reduce gagging, pharyngeal anaesthesia with 10% lignocaine spray with or without sedation is used; transnasal endoscopy using ultrathin (4–6 mm diameter) endoscopes is associated with less gagging and is increasingly being offered to patients in many countries. Endoscopy using sedation with small doses of intravenous midazolam or diazepam improves tolerance and acceptability of the procedure but can lead to cardiorespiratory problems which account for almost half of complications associated with UGIE. Patients undergoing endoscopy under sedation require closer monitoring during the procedure and at least 30 min after and will need to be accompanied by another person to the procedure and back home and may not return to work on the same day. All these factors substantially increase the cost of the procedure in terms of materials, equipment, personnel, space and time; it is estimated that sedation for endoscopy is directly responsible for 30%–50% of the cost of the procedure, which, in resource-constrained settings like sub-Saharan Africa, can be a burden – we have estimated that in our facility, sedated examination increases the cost of an already highly subsidised cost of unsedated endoscopy (NGN15,000 or USD37) by a third.
However, widespread use of unsedated endoscopy depends on how patients tolerate the procedure, and are willing to accept the same procedure in the future. Tolerance and acceptance of unsedated endoscopy have been studied all over the world including Europe, North America and Asia,,,,,,,, but little is known about this in Africa. The main purpose of our study was to assess the tolerance of unsedated diagnostic UGIE referred to our unit and whether or not they would accept the same procedure in the future. As we provide unsedated endoscopy routinely, this will serve as an audit of the service we provide which will lead to its improvement.
| Methods|| |
This study was a cross-sectional study of patients referred to endoscopy unit of Barau Dikko Teaching Hospital, Kaduna, North-West Nigeria. Ethical approval for the study was obtained from the Health Research Ethics Committee of Kaduna State Ministry of Health – Protocol number: MOH/ADM/744/VOL 1/953; Date: 27 June 2020. The study was conducted between August 2020 and July 2021. We calculated that we would need to recruit at least 243 participants in the study using the formula for sample size for cross-sectional studies:
Our assumptions are as follows: n is the sample size, Z is the statistic corresponding to 95% level of confidence, which is fixed at 1.96, P (the estimated prevalence of tolerance for endoscopy −80.3% derived from Al-Atrakchi and d (precision set at 0.05). The sample size was calculated thus: N = 1.962 × 0.803 (1–0.803)/0.052 = 243.
Patients' recruitment and pre-procedure assessment
Consecutive patients referred for UGIE were included in the study if they gave written informed consent to the procedure and to the study, if they were at least 18 years old and if they did not have severe cardiorespiratory disease (New York Heart Association Class IV) as assessed before the procedure. Patients who required sedation for the procedure or did not tolerate the introduction of the endoscope into the stomach or had to have the endoscope removed during the procedure, before adequate examination of the stomach, were excluded from the study. Pre-procedure assessment and counselling were conducted for every patient. The pulse rate (PR) and peripheral oxygen saturation level (SPO2) were recorded using an AAA-battery operated pulse oximeter (Beijing Choice Electronic Tech. Co., Ltd), while systolic and diastolic blood pressures were measured using OMRON M2 Basic portable oscillometric blood pressure monitor (OMRON HEALTHCARE Co., Ltd, Kyoto, Japan). Patients' weight and height were measured using standard scales, the American Society of Anesthesiology (ASA) category determined and informed consent for the procedure and the study obtained.
Procedure and monitoring
Peroral diagnostic UGIE was performed by an experienced endoscopist in the standard position with Olympus GIF 140 (outer diameter of 9.8 mm) or GIF-H170 (9.2 mm) gastroscopes (Olympus Optical, Ltd., Tokyo, Japan) using a pharyngeal 10% lignocaine spray. Patients' PR and SPO2 were monitored at the beginning of the procedure and continuously throughout the procedure by a nurse who records the findings every 30 s and at the end. The highest PR and the lowest SPO2 at 2, 4, 6, 8 and 10 min were used for analysis. Systolic BP and diastolic BP were measured and recorded at 4-min intervals and at the end of the procedure. During the procedure, patients' relatives were allowed in the endoscopy room and encouragement and reassurance were continuously given the patient by the endoscopist, nurses and relatives. The procedure was considered complete when all parts of the stomach and the second part of the duodenum were examined, and incomplete if only the various parts of the stomach were adequately examined. Duration of the procedure (introduction of the endoscope into the mouth and removal) and timing of measurements were recorded using a smartphone clock application (Google LLC, Google Play Store).
The result of the endoscopy was discussed with patients by the endoscopist about 10 min after the procedure during which the pulse, BP and SPO2 were measured and recorded. The second part of a pretested questionnaire was then administered in English, with further explanations given in Hausa language, by an assistant not involved in the care of the patient. Patients were requested to report any problems they had during the procedure and to give an overall assessment of any discomfort they may have encountered during the procedure (no discomfort at all, mild discomfort, moderate discomfort but tolerable and severe discomfort and intolerable) and to rate that on a 0–10 color-coded Visual Analogue Scale (VAS) [adapted from Mulcahy et al., see Appendix]. Patients who reported no or mild discomfort, or moderate discomfort and a VAS score of 5 or less, were judged to have tolerated the procedure well, while patients with a VAS score of 6 or over or who reported severe discomfort during the procedure were considered to have poorly tolerated the procedure. Patients were then requested to indicate whether they would accept to have UGIE in the future in the same way should this be recommended by their physician; patients' responses were recorded as yes, no and maybe. Patients were also encouraged to explain their decision.
We analysed our data using IBM SPSS version 22 (Armonk, New York, USA, 2013. Descriptive statistics were obtained, and Chi-squared tests were used to assess the significance of differences and relationships between categorical variables, while independent-sample t-tests were used to assess the significance of differences between numerical variables. Post hoc tests were performed where appropriate. P < 0.05 was considered significant.
| Results|| |
Demography and basic characteristics of study participants
Of 317 patients who agreed to participate in the study, 9 were excluded because they did not tolerate the introduction of the endoscope (5 patients) or endoscope had to be withdrawn before all parts of the stomach were examined (4 patients) and eventually required sedation. [Table 1] shows a summary of demography and basic information of the 306 patients included in the study. The mean age of patients was 45.5 years, 39.2% were below the age of 40 and most (89.5%) were below the age of 65. Females constituted almost 60% of the patients. More than three-quarters of patients had a secondary or post-secondary education. Most of the patients neither smoked cigarette nor took alcohol on a regular basis. Almost half of the patients were of normal weight and almost all patients were in the ASA category 1. Most patients (88.9%) were having endoscopy for the first time. Dyspepsia was the predominant indication for the procedure which lasted from just under 3 min to over 15 min with a median of 6 min 15 s and completed in 92.2% of patients.
Tolerance for upper gastrointestinal endoscopy
Tolerance for endoscopy was assessed by patients' self-report of discomfort for the procedure and by a 0–10 VAS score. Just over half of the patients (51.3%) reported no or mild discomfort, while only 5.6% reported severe and intolerable discomfort. Three-quarters (75.8%) of patients were considered to have tolerated the procedure well. There was a very strong positive association between patients' self-report of discomfort of the procedure and VAS score (Cramer's V = 0.858, P = 0.000). Patients younger than 40 years were significantly less likely to tolerate the procedure well compared to those older (X2 = 5.462, P = 0.009). Furthermore, tolerance for the procedure was better in males compared to females although this did not reach statistical significance (80% vs. 72.7%, X2 = 0.063, P = 0.142) [Table 2]. The level of education also appeared to influence tolerance of the procedure as those who had only basic education (primary or Islamic education) significantly tolerated the procedure better compared with those who had higher education (secondary or post-secondary) (86.2% vs. 72.7%, X2 = 4.571, P = 0.032). Patients who took alcohol regularly tolerated the procedure better than those who did not although was not statistically significant (91.3% vs. 76%, X2 = 3.804, P = 0.149). Body weight did not have significant influence on tolerance for the procedure just like ASA category, previous endoscopy, or endoscope size. Patients who had the procedure completed were more likely to tolerate the procedure well than those in whom the procedure was not completed although this did not reach statistical significance. The mean duration of endoscopy was the same in those who tolerated the procedure well and those who did not (6.54 min vs. 6.46 min, 95% confidence interval [CI] – 0.44–0.61, P = 0.758).
|Table 2: Tolerance and acceptance of non-sedated upper gastrointestinal endoscopy in 306 patients|
Click here to view
Acceptance of future endoscopy
Almost 80% of patients indicated they would accept to have the procedure in the future should this be required – they had used words such as 'absolutely', 'definitely', 'of course', 'sure', 'yes sir', 'in a hurry', 'I will do it again immediately', 'I will do it tomorrow', 'even 10x', 'God willing' or 'by God's grace'. Patients also accepted to have the procedure again with responses such as 'it's for my health', 'if there's a need', 'if it's necessary', 'if it's requested' or 'what can I do'? Patients were also surprised the procedure was not as difficult as they anticipated by responses such as 'the test was not difficult as I expected', 'if it goes the same way' or 'there's no pain'. About 7% of patients were not sure whether they would accept the procedure in the future. Some patients who declined a future procedure described it as the worst experiences of their lives or that they thought they were going to die. Overall, acceptance for the procedure was strongly related to patients' self-report of discomfort of the procedure, with 137/151 (90.7%) patients who reported no or minimal discomfort accepting to have the same procedure in the future compared to only 3/16 (18.8%) who reported severe discomfort (Cramer's V = 0.305, P = 000), or VAS for tolerance (Cramer's V = 0.424, P = 0.000). Acceptance was significantly higher amongst males than in females (113 [86.9%] vs. 131 [74.4%], x2 = 7.916, P = 0.019) but not age, educational level, body mass index, ASA category, previous endoscopy, endoscope size, procedure duration (6.57 min vs. 6.16 min, t = 1.253, P = 0.211) and procedure completion.
Pulse, oxygen saturation and systolic blood pressure
Overall, the PR of patients rose during the procedure and declined just before the end. There were no significant differences in mean PR between those who tolerated the procedure well and those who did not [Figure 1]a. The PR rose above 160 in only two patients during the entire procedure. Mild blood oxygen desaturation (SPO2 90% - 95%) during the procedure occurred in 35/306 (11.4%) of patients while severe desaturation (SPO2 < 90%) occurred in only 11/306 (3.6%) of patients. In most of these patients, desaturation was isolated, usually occurring within the first 2–4 min of the procedure and reverting to normal subsequently when asked to take deep breaths [Figure 1]b. Desaturation (SPO2 < 95%) was not significantly related to whether patients tolerated the procedure well or not at 2 min (Phi = 0.021, P = 0.710), 4 min (Phi = 0.018, P = 0.765), 6 min (Phi = 0.081, P = 0.299) or 8 min (Phi = 0.097, P = 0.442). The systolic BP rose slightly during the procedure and fell towards the end. There were no significant differences in systolic BP between those who tolerated the procedure and those who did not.
|Figure 1: (a) Mean pulse rate of patients, (b) Mean blood oxygen saturation of patients|
Click here to view
| Discussion|| |
We found that most of our patients tolerated unsedated diagnostic UGIE well. Male patients tolerated the procedure slightly better than females, and older persons (aged 40 and above) significantly more than younger ones, but body weight, lack of experience with the procedure in the past, whether or not the procedure was completed and duration of the procedure had no significant effect on whether patients tolerated the procedure well. Patients with the most basic education tolerated the procedure significantly better than those who had a secondary or post-secondary education; exposure to negative comments about endoscopy, for example from the Internet, may have heightened their concern and apprehension about the procedure which translated to poorer tolerance. To the best of our knowledge, this is the first such study conducted in sub-Saharan Africa. In similar studies done in Europe and Asia using endoscopes with similar diameters, tolerance for unsedated endoscopy was also high. In an early study in the UK, Beavis et al. found 60% described their procedure as 'mildly unpleasant' with no one describing as 'very unpleasant' and therefore unbearable. In a large study of 2000 patients undergoing UGIE without sedation in Iraq, al-Atrakchi found 80.3% tolerated the procedure well. Farhadi et al. from Iran also found 79% of their patients tolerated the procedure well. Seventy-one per cent of patients (71%) who underwent unsedated endoscopy in one study in Spain tolerated the procedure well. Mulcahy et al. in another large study in the UK reported that, based on the evaluation of VAS scores, only 9% of their patients reported a severe level of discomfort during unsedated endoscopy with 69% reporting a moderate level of discomfort and 22% reporting very low levels; only about 27% of their patients reported they would request sedation in any future procedure, an indication of the high tolerance for the unsedated examination. Fisher et al. from the UK also found their patients tolerated unsedated endoscopy well, with only 12% reporting they would request sedation a future procedure. Factors which influenced tolerance for the procedure have been consistent across studies: older and male patients tolerated the procedure better than younger patients and females, respectively, similar to our findings.,,, Most of our patients were having endoscopy for the first time, unlike in other studies,, but there was no difference in tolerance of the procedure, compared to those with prior experience, a finding similar to Campo and Soma., The duration of the procedure did not influence tolerance of the procedure, too, a finding consistent with that of Yang et al.. In several studies,,,, thinner endoscopes (outer diameter ≤6 mm) were tolerated better and patients were more likely to accept future unsedated endoscopy, but there are concerns about the adequacy of examinations with these endoscopes. The diameter of our endoscopes (92 mm and 98 mm) did not make a difference in tolerance to the procedure undoubtedly because of the similarity of the sizes of the scopes. High levels of pre-endoscopy anxiety have been found to be associated with poor tolerance for the unsedated examination by Froehlich et al., Campo et al. and Yang et al. but not by Mulcahy et al. or Abraham et al. We did not assess patients' anxiety and apprehension about the procedure before endoscopy, so we do not know whether this had any influence in tolerance of the procedure. Behavioural techniques, information and counselling have been shown to alleviate anxiety and improve the tolerance of gastrointestinal endoscopy, although this needs not to be detailed..
We found a very high level of acceptance of a future similar procedure. Overall, acceptance was highly correlated with tolerance for the procedure. Gender was the only factor which significantly affected acceptability of a future procedure in our patients: male patients were more willing to do so than females. Similar studies from around the world have reported high acceptance of unsedated endoscopy.,, Our experience is that, although patients might be apprehensive before the procedure, and some had postponed having the examination for weeks and sometimes months, often discouraged by the experiences of relatives, friends or colleagues, patients were surprised that the procedure was not as uncomfortable as they thought; this likely contributed to the high acceptance of a future procedure we found and this was reflected in the comments they made. Patients' understanding of the health benefits of the procedure also played a major part and is consistent with reported patients' willingness to accept risks of a medication or a surgical procedure. We did not ask our patients whether they would prefer sedated endoscopy in the future, as we do not routinely use sedation in our unit as in the many centres in Nigeria, so we do not know whether this would have influenced their acceptance of the unsedated procedure, but other studies have shown most patients who tolerated unsedated endoscopy well do not request for sedation.,, Although sedated endoscopy is better tolerated by patients,,,, cardiorespiratory complications are higher and costs related to medications, consumables, personnel, equipment and space put a lot of strain on resources especially in countries like sub-Saharan Africa, where endoscopy services are limited and already face many daunting challenges. But even in resource-rich countries in many parts of Europe and Asia, where sedation practices vary, unsedated endoscopy is used for the majority of patients. Our findings also show that unsedated endoscopy is safe. Adverse cardiorespiratory changes were rare, milder and short lived similar to other reports.
Our study has some limitations. We did not assess pre-procedural anxiety, so we do not know whether this had any influence on tolerance of the procedure for our patients. Furthermore, we did not assess what specific part of the examination (intubation, rest of examination) was associated with the most difficulty for patients. Lastly, the procedure was performed by one experienced endoscopist; our study could not assess what differing operator experience or skill might have had on tolerance and, therefore, acceptance for the procedure. These are areas that can be explored in a future study.
| Conclusion|| |
We found most patients undergoing unsedated UGIE in Kaduna, Nigeria, tolerated the procedure well. Male patients and older persons tolerated the procedure better than females and younger patients, respectively, and patients with no or basic formal education tolerated it better those with a higher education. Most patients accepted to have a similar procedure, with males more likely to do so than females. Although we did not assess patients' anxiety before the procedure, we believe the pre-procedural explanation and counselling and constant encouragement given to patients by staff and patients' relatives during the procedure contributed to the high tolerance and acceptance we observed. We also found that unsedated endoscopy is safe. This should serve as further assurance to us and others who do not use sedation for upper endoscopy routinely. A study is underway assessing patients' satisfaction with the service we provide.
The administrative and technical support provided by Nazifi Hassan is highly appreciated.
Financial support and sponsorship
Personal resources of authors.
Conflicts of interest
There are no conflicts of interest.
| Appendix|| |
| References|| |
Haycork A, Cohen J, Saunders PB, Cotton PB, Williams CB. Cotton and William's Practical Gastrointestinal Endoscopy: The Fundamentals. 7th
ed. Chichester: Wiley Blackwell; 2014.
Campo R, Brullet E, Montserrat A, Calvet X, Rivero E, Brotons C. Topical pharyngeal anesthesia improves tolerance of upper gastrointestinal endoscopy: A randomized double-blind study. Endoscopy 1995;27:659-64.
Parker C, Alexandridis E, Plevris J, O'Hara J, Panter S. Transnasal endoscopy: No gagging no panic! Frontline Gastroenterol 2016;7:246-56.
Eisen GM, Baron TH, Dominitz JA, Faigel DO, Goldstein JL, Johanson JF, et al.
Complications of upper GI endoscopy. Gastrointest Endosc 2000;55:784-93.
Waring JP, Baron TH, Hirota WK, Goldstein JL, Jacobson BC, Leighton JA, et al.
Guidelines for conscious sedation and monitoring during gastrointestinal endoscopy. Gastrointest Endosc 2003;58:317-22.
Mokhashi MS, Hawes RH. Struggling toward easier endoscopy. Gastrointest Endosc 1998;48:432-40.
Beavis AK, La Brooy S, Misiewicz JJ. Evaluation of one-visit endoscopic clinic for patients with dyspepsia. Br Med J 1979;1:1387-9.
Fisher NC, Bailey S, Gibson JA. A prospective, randomized control trial of sedation vs. no sedation in outpatient diagnostic upper gastrointestinal endoscopy. Endoscopy 1998;30:21-4.
Campo R, Brullet E, Montserrat A, Calvet X, Moix J, Rué M, et al.
Identification of factors that influence tolerance of upper gastrointestinal endoscopy. Eur J Gastroenterol Hepatol 1999;11:201-4.
Mulcahy HE, Kelly P, Banks MR, Connor P, Patchet SE, Farthing MJ, et al.
Factors associated with tolerance to, and discomfort with, unsedated diagnostic gastroscopy. Scand J Gastroenterol 2001;36:1352-7.
Abraham N, Barkun A, Larocque M, Fallone C, Mayrand S, Baffis V, et al.
Predicting which patients can undergo upper endoscopy comfortably without conscious sedation. Gastrointest Endosc 2002;56:180-9.
al-Atrakchi HA. Upper gastrointestinal endoscopy without sedation: A prospective study of 2000 examinations. Gastrointest Endosc 1989;35:79-81.
Farhadi A, Fields JZ, Hoseini SH. The assessment of esophagoduodenoscopy tolerance: A prospective study of 300 cases. Diagn Ther Endosc 2001;7:141-7.
Yang M, Lu LL, Zhao M, Liu J, Li QL, Li Q, et al
. Associations of anxiety with discomfort and tolerance in Chinese patients undergoing esophagogastroduodenoscopy. PLoS One 2019;14:e0212180.
Pourhoseingholi MA, Vahedi M, Rahimzadeh M. Sample size calculation in medical studies. Gastroenterol Hepatol Bed Bench 2013;6:14-7.
Froehlich F, Schwizer W, Thorens J, Köhler M, Gonvers JJ, Fried M. Conscious sedation for gastroscopy: Patient tolerance and cardiorespiratory parameters. Gastroenterology 1995;108:697-704.
Soma Y, Saito H, Kishibe T, Takahashi T, Tanaka H, Munakata A. Evaluation of topical pharyngeal anesthesia for upper endoscopy including factors associated with patient tolerance. Gastrointest Endosc 2001;53:14-8.
Zaman A, Hapke R, Sahagun G, Katon RM. Unsedated peroral endoscopy with a video ultrathin endoscope: Patient acceptance, tolerance, and diagnostic accuracy. Am J Gastroenterol 1998;93:1260-3.
Mulcahy HE, Riches A, Kiely M, Farthing MJ, Fairclough PD. A prospective controlled trial of an ultrathin versus a conventional endoscope in unsedated upper gastrointestinal endoscopy. Endoscopy 2001;33:311-6.
Garcia RT, Cello JP, Nguyen MH, Rogers SJ, Rodas A, Trinh HN, et al.
Unsedated ultrathin EGD is well tolerated when compared with conventional sedated EGD: A multicenter randomized controlled trial. Gastroenterol 2003;125:1606-12.
Sorbi D, Gostout CJ, Henry J, Lindor KD. Unsedated small-caliber esophagogastroduodenoscopy (EGD) versus conventional EGD: A comparative study. Gastroenterology 1999;117:1301-7.
Sorbi D, Chak A. Unsedated EGD. Gastrointest Endosc 2003;58:102-10.
Wilson JF, Moore RW, Randolph S, Hanson BJ. Behavioral preparation of patients for gastrointestinal endoscopy: Information, relaxation, and coping style. J Human Stress 1982;8:13-23.
van Zuuren FJ, Grypdonck M, Crevits E, Vande Walle C, Defloor T. The effect of an information brochure on patients undergoing gastrointestinal endoscopy: A randomized controlled study. Patient Educ Couns 2006;64:173-82.
Levy N, Landmann L, Stermer E, Erdreich M, Beny A, Meisels R. Does a detailed explanation prior to gastroscopy reduce the patient's anxiety? Endoscopy 1989;21:263-5.
Kauf TL, Mohamed AF, Hauber AB, Fetzer D, Ahmad A. Patients' willingness to accept the risks and benefits of new treatments for chronic hepatitis C virus infection. Patient 2012;5:265-78.
Reed SD, Fairchild AO, Johnson FR, Gonzalez JM, Mentz RJ, Krucoff MW, et al.
Patients' willingness to accept mitral valve procedure-associated risks varies across severity of heart failure symptoms. Circ Cardiovasc Interv 2019;12:e008051.
Nwokediuko SC, Obienu O. Sedation practices for routine diagnostic upper gastrointestinal endoscopy in Nigeria. World J Gastrointest Endosc 2012;4:260-5.
Ristikankare M, Hartikainen J, Heikkinen M, Julkunen R. Is routine sedation or topical pharyngeal anesthesia beneficial during upper endoscopy? Gastrointest Endosc 2004;60:686-94.
Perl D, Leddin D, Bizos D, Veitch A, N'Dow J, Bush-Goddard S, et al.
Endoscopic capacity in West Africa. Afr Health Sci 2016;16:329-38.
Ladas SD, Satake Y, Mostafa I, Morse J. Sedation practices for gastrointestinal endoscopy in Europe, North America, Asia, Africa and Australia. Digestion 2010;82:74-6.
[Table 1], [Table 2]