Effects of Quran Recitation on the Reduction of Preoperative Anxiety in Elective Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Anxiety is a common reaction among patients undergoing surgery. This study aim to assess effectiveness of Quran recitation on reducing the preoperative anxiety. Methods: A systematic review of the citations in the Medline, EMBASE, Cochrane Library, PsycInfo, Arab World Research Source and other relevant databases was performed to collect the data. Randomized clinical trials about the effect of Quran recitation on the reduction of preoperative anxiety in elective surgery were included without any Language and date restriction. Interventions with self-reading/self-recitation were excluded. The Cochran’s Q statistic and the (I 2 ) with 50 percent threshold was used for calculation of the heterogeneity and inconsistency index. Subgroup analysis was conducted based on the type of surgery. The funnel plot has been used to evaluate the possibility of the publication bias. Results:Twelve studies were included in the qualitative synthesis and nine studies included in the quantitative synthesis. Our meta-analysis showed a signicant reduction in the anxiety level with Quran recitation. The heterogeneity of the included studies was statistically signicant (Q=23.05, I 2 =65.29, P=0.003). The pooled effect size of the anxiety was d=−8.893; 95% CI=[−10.763 to −7.022] (P < 0.001). The subgroup analysis showed that Quran recitation has a benecial effect on reducing anxiety in both major and minor surgeries.There was no publication bias (t=0.907, P=0.39) in the studies. Conclusion: Quran recitation can be considered as a non-invasive and peaceful intervention to reduce preoperative anxiety in elective surgery.

Muslim countries, Arabic and Persian equivalents of search keywords were also searched. The rst round of the search was completed in December 2018 and was updated in January 2020 for any new eligible studies.

Inclusion Criteria
All possible randomized control trials (RCTs) on the effect of Quran recitation on the reduction of anxiety in elective surgery were included in this study. No language restriction was applied. Only studies in which the anxiety level was examined using the State-Trait Anxiety Inventory (STAI) checklist were included in this study.

Exclusion Criteria
Studies without a control group, without a pre-/post-test design, studies of poor quality according to quality assessment, studies using anxiety inventory tools other than the STAI, studies with different outcomes (such as depression) and studies involving the self-recitation of Quran by the patients themselves were excluded. Also studies involving Quran recitation along with its translation were excluded because the main aim of our study was assessment of the effect of listening to Quran voice in its original language.
Study selection and quality assessment All studies retrieved from databases were imported to EndNote X8 and duplicates eliminated. According to the inclusion and exclusion criteria, two authors (VZG & TKh) independently screened the studies for eligibility based on title and abstract. In the next stage, the remaining articles were examined by full text review. The quality of selected studies was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Randomized Controlled Trials (Table 1) [28]. Any disagreements were resolved through discussion. Two authors extracted data from studies using a data extraction form in Microsoft Excel 2013. The difference between end points with standard deviation (SD) was used for meta-analysis. To assess the heterogeneity, the Cochran's Q test and the inconsistency index (I 2 ) were applied. The I 2 statistical threshold value was indicated 50 percent. If I 2 is less than 50 percent, the Mantel-Haenszel xed effect size model should be used, and if I 2 is more than 50 percent or the p-value is less than 0.05, the random effect model should be used in order to calculate the effect size. Subgroup analysis carried out based on the type of surgery. The funnel plot and the Egger regression test were used to evaluate publication bias (p < 0.05 was considered as statistically signi cant publication bias). A Comprehensive Meta-Analysis (version 2) was employed for data analysis. A p-value of <0.05 was considered statistically signi cant.

Results
We identi ed 2381 articles from our systematic search for related literature. After removing duplicates, 986 articles were screened based on title and abstract.
Finally, 30 articles were assessed for eligibility. Some related articles were available with two different versions [29][30][31][32]. We excluded the version containing the less comprehensive data [29,32].. Some studies were also excluded because of the study methodology, for example because of assessing the effect of Quran recitation only after surgery [34], or the intervention was a combined model and it was not possible to separate the data for Quran recitation for example Quran recitation with aromatherapy [35] or Quran recitation with its translation [33]. Reasons for exclusion of the other studies from the review were: implementation of different assessment tools, different outcome measures, different publication types and not studying elective surgeries. After reviewing the full text of eligible studies, twelve RCTs were critically appraised. Finally, a total of twelve studies were included in the qualitative synthesis and nine studies were included for the quantitative synthesis [30,31,[36][37][38][39][40][41][42]. The ow diagram of the study is shown in the Figure 1.
The range of patient ages was 25 to 63 years old. All studies investigated the effect of Quran recitation on the reduction of anxiety in the elective surgeries. In eight studies (66.7%), the experimental group received only Quran recitation, whereas in three studies (25%), there were two experimental groups receiving Quran and music [30,38,41] and one study receiving Quran recitation and its translation [31]. All the studies were conducted in Iran, as all studies from other Arabic-speaking countries were eliminated in the study selection process as none of them studied elective surgeries. The characteristics of the sample and the level of anxiety before and after intervention are shown in Table 2.  (Table 3). Allocation blinding was unclear in most studies (75%). Blinding of participants was not possible due to the nature of study, as participants were aware of the intervention at the time, but in some studies, the researchers wore headphone when assessing patients in the intervention and control groups during the intervention period in order to reduce the risk of bias. In two of the studies, the outcome assessors were blinded to treatment assignment. In three studies, the outcome measure was described in a reliable way. Table 3. Results of critical appraisal of included studies Qualitative synthesis Instrument: In all of the studies the validated Persian version of the STAI was utilized as the outcome measure.
Quran recitation: In all of the studies except three [36,42,43], the Quran recitation was played for a duration of 20 minutes. The chapters (Surahs) Yusuf (Joseph) and Ar-Rahman (The Compassionate) were the most commonly used sections, and these were used in three studies. Most of the studies had two patient groups (intervention and control) but three studies included two interventions (one Quran recitation and the other music) with one control group. In these studies, 20 minutes of relaxing music was played to the second patient group.
Anxiety: In all of the studies, Quran recitation signi cantly reduced the level of anxiety in the intervention group. In the three studies that measured the effect of both music and Quran recitation as interventions, it was revealed that the impact of Quran recitation was larger than that of the music [30,38,41]. Four studies evaluated the levels of trait and state anxiety separately [36,39,42,43]. These studies showed a signi cant decrease in both the trait anxiety and state anxiety in intervention group. One study reported just the total anxiety level [44].
Vital signs and pain: Four studies evaluated the impact of Quran recitation and music on patients' vital signs [30,31,42,44]. The results of Mirbagher et al. and Shara show that Quran recitation had a signi cant effect on patients' breathing, blood pressure and pulse rate [30,44]. The study of Tayebi et al. showed a signi cant reduction in breathing and blood pressure but no signi cant reduction in pulse rate [42]. The results of Sha ei's study were in contradiction with those of Tayebi et al. in that breathing and blood pressure exhibited no signi cant changes while pulse rate reduced signi cantly after intervention [31]. Conversely, Asgari's study showed a signi cant pain reduction in patients undergoing abdominal surgeries [37].

Quantitative synthesis
In this review 9 studies were included comprising a total of 652 patients with elective surgeries who were pooled in the meta-analysis. Three studies were excluded from meta-analysis because the SD was not reported for the mean anxiety score [43,45] or only the total state and trait anxiety score was reported [44]. The intervention group was formed of 336 patients who listened to between 15 and 20 minutes of Quran recitation.
The mean anxiety score before and after intervention was used to calculate the pooled effect size. According to the results of the meta-analysis, Quran recitation had a positive effect on reducing anxiety in elective surgeries. Since the heterogeneity among included studies was statistically signi cant (Q=23.05, I 2 =65.29, P=0.003), a random effects model was used to calculate the pooled effect size. The pooled difference in means calculated using a random effects model for anxiety showed a statistically signi cant decrease in anxiety for the Quran recitation group (difference in means: −8.893; 95% CI: −10.763 to −7.022; P < 0.001). Figure 2 shows the forest plot of the combined effect size. Subgroup analysis was performed based on the type of surgery which was categorized into minor and major surgical procedures. The de nition of minor and major surgical procedures was based on prior literature [46]. Major surgeries included abdominal surgeries, elective general surgeries and cesarean section. Minor surgeries included endoscopy, angiography and cardiac catheterization. The subgroup analysis showed that Quran recitation has a bene cial effect on reducing anxiety in both major surgical procedures (difference in means: −8.327; 95% CI: −11.005 to −5.649; P < 0.001) and minor surgical procedures (difference in means: −9.877; 95% CI: −12.808 to −6.946; P < 0.001) (Figure 3).

Discussion
This meta-analysis was conducted to understand if listening to Quran recitation is effective in the management of anxiety before elective surgery. All possible RCTs on the effect of listening to the Quran recitation before the elective surgeries on reducing the anxiety were included in the analysis. The results revealed that listening to the Quran recitation before surgery leads to a signi cant reduction in anxiety, as measured using the STAI. This nding is consistent with the results of a previous meta-analyses nding a reduction of anxiety from listening to music [47,48]. This also ful lls the Quranic verses as stated: The Quran is healing for those who perceive its meaning (Quran: 10:57; 17:82). The Quran is known as the ultimate source of guidance for Muslims, a book that contains the divine knowledge, and its instructions are su cient for guidance of the men [49].
In our study, the quality of 58% of included studies was moderate. Nevertheless, less than half of studies reported the details about the randomization procedure used for assignment of participants and in the rest of studies it was unclear. In half of the studies, both true randomization and allocation concealment were unclear. Only one of the studies declared that those delivering treatment were blind to treatment assignment.Blindness declaration for outcomes assessors was reported by two studies. However, in all of the studies an appropriate statistical analysis was used. There was no selection bias in any of the studies.
According to a study by El-shahat and colleagues, the level of preoperative anxiety varies between minor and major surgical procedures and this rate is higher in the major ones [50]. They recommend psychological counseling at hospitals to help patients for anxiety reduction. The results of our study showed that Quran recitation has a signi cant effect on reducing preoperative anxiety in both major and minor elective surgeries. Other studies have con rmed the positive effect of various interventions such as music, information therapy and education on reducing anxiety before major and minor surgeries [51][52][53].
It should be emphasized that although both interventions (Quran and music) have a positive effect on anxiety reduction, the studies indicate that the effect of Quran recitation on anxiety reduction is higher than that of music [30,38,41]. But to reach the certainty in this regard, more studies need to be conducted.
The evidence reveals that Quran recitation has been used as a non-medical method for different purposes, especially for psychological issues in researches. An investigation on the effect of reading the Quran on controlling stress has shown that reading the Quran leads to a signi cant decrease in the stress level among 16-20 year olds [54]. In addition, Quran recitation itself or even listening to Quran recitation has a positive effect on the mental health by decreasing the risk of depression and anxiety-related disorders among caregivers [55], as well as hospitalized patients. It was also found that learning life skills through a Quranic approach is more effective in the reduction of students' depression [24].. This means that the intervention of the Quran in any form of reading, perception and listening may be effective in improving health and wellbeing. However, the outcomes of a study about the relationship between Quran recitation and post-operative abdominal pain showed no signi cant relationship [56].
As emphasized by Kaleem and Ahmed, there is a relationship between religious belief and anxiety [57]. Therefore, it is possible that presence of religious belief modulates the effect of listening to Quran recitation. From this, the clinical recommendation may need to take culture into account, and as such the use of Quran recitation before elective surgery can be recommended in Islamic countries to reduce patient anxiety.
In this review, although the included studies were from an Islamic country, their ndings did not address the likely relationship between religious beliefs and the positive effect of Quran recitation on anxiety. Additional studies are needed to evaluate the interaction between the differing religious beliefs and the effect of Quran recitation on the anxiety.
The main limitation of the current study was the lack of access to some Arabic Databases to search local language studies. Nevertheless, the current study utilized Google Scholar and Arab World Research Source with regard to Arabic language studies, in addition to international databases. The small sample size may also be considered a limitation of this meta-analysis. The source of heterogeneity could not be identi ed due to insu cient studies.
One of the strengths of this review was that a validated questionnaire was used to assess the effectiveness of the intervention of all studies. Homogeneity was observed in majority of the studies in terms of the duration of Quran recitation, representing another strength of this study.

Conclusion
Quran recitation has a signi cant effect on decreasing the anxiety among Muslim patients undergoing elective surgery. Sound of Quran as a non-invasive and peaceful intervention can be supported and advocated by the ndings of this study. However, due to the importance of evidence-based decision making in medical science, further studies in different populations especially in non-believers and non-Muslim communities are still needed to achieve certainty.