Article Text
PDF
Abstract
Introduction The lifestyle and habit changes that have emerged as a result of quarantine measures may have had a negative impact on defecation habits. However, there is a lack of data on combined estimates of its occurrence and prevalence.
Methods and analysis We will conduct a systematic search for observational studies on PubMed/MEDLINE, Web of Science, Cochrane Library, EMBASE, CNKI, SinoMed, VIP China Science and Technology Journal database, Chinese Biomedical Databases and Wanfang Data. The search will include literature published from the inception of the databases to September 2022. Two authors will independently screen articles and extract data based on predefined inclusion and exclusion criteria. The risk of bias in the included studies will be evaluated using the Newcastle-Ottawa Scale for observational studies. Statistical analysis will be performed using Review Manager software V.5.4 and STATA V.16.0 software. Heterogeneity among studies will be assessed using the Q statistical test and I2 statistical tests. In case of significant heterogeneity, subgroup analysis and sensitivity analysis will be conducted to explore the source of heterogeneity. Sensitivity analyses will also be performed to assess the reliability of the study findings. If feasible, a meta-analysis will be conducted. Otherwise, a descriptive synthesis will be performed using a best-evidence synthesis approach. The primary outcome of interest will be the prevalence of constipation. The secondary outcomes will involve examining the association of risk factors. To evaluate potential publication bias, we will use both the Begg funnel plot and Egger’s weighted regression statistics. Furthermore, to accurately assess the quality of evidence for our primary outcome, we will employ the Grading of Recommendations Assessment, Development and Evaluation system.
Ethics and dissemination This systematic review protocol will only consider published studies available in databases and will not include individual patient data. Therefore, ethical approval is not required, and the findings will be published in a peer-reviewed journal.
PROSPER registration number CRD42022366176.
- COVID-19
- Functional bowel disorders
- Gastroduodenal disease
This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.
Statistics from Altmetric.com
STRENGTHS AND LIMITATIONS OF THIS STUDY
This study is a population-based observational study designed to summarise data on the prevalence and risk factors for constipation under closed management measures during the COVID-19 epidemic.
Potential bias in original studies in observational studies can be misleading.
The sample size and number of studies included may be insufficient.
The majority of the included studies are retrospective in design, which may introduce genetic bias.
The title and abstract screening, full-text review, data extraction and risk of bias assessment will be performed by two reviewers independently to minimise errors and potential bias in study selection.
Introduction
Background
Constipation is a common clinical condition in gastroenterological practice, estimated to affect up to 16% of the world’s population.1 It is characterised by infrequent and/or difficult bowel emptying, excessive straining, reduced bowel movements or a feeling of incomplete voiding, often accompanied by straining or a sensation of incomplete bowel movements.1 2 The occurrence of constipation is complex and multifactorial.3 It is closely related to age, gender and neurological disorders. Women have a higher prevalence rate of constipation than men, with a prevalence rate of 33.5% in people over 60 years of age.4 5 Additionally, constipation can be associated with a sedentary lifestyle or nature of work, low fibre intake, drug triggers, mood changes such as anxiety or depression, and reduced physical activity due to little or no exercise, as well as changes in lifestyle.1 6 7 Moreover, constipation may also result from lifestyle changes that occur or develop from other underlying diseases during isolation or confinement.
The COVID-19, caused by a novel coronavirus known as SARS-CoV-2, was declared a global pandemic on 11 March 2020, by the WHO.8 The disease has rapidly spread worldwide.9 In response to this public health crisis, the WHO has recommended maintaining physical distance between individuals as a preventive measure to curb the spread of infectious diseases.10 Consequently, many countries have implemented strict measures such as movement control orders, quarantine and social distancing to contain the transmission of the virus.10 However, while physical distancing helps protect against the spread of COVID-19, it can also have negative effects on both physical activity and mental health. The mandatory social self-isolation can disrupt people’s lifestyles and lead to the adoption of unhealthy habits, such as changes in eating habits (increased consumption of ultra-processed and refined foods, decreased intake of fruits, legumes and vegetables), reduced physical activity, sedentary behaviour and sleep disturbances.7 11 12 However, the COVID-19 pandemic has resulted in lifestyle changes and dietary adjustments, which may contribute to constipation.13 Measures such as isolation, limited outdoor activities and the closure of gyms and parks have led to a decrease in physical activity.14 This decline in physical activity has been associated with a reduction in gastrointestinal transit time. While exercise alone may not effectively alleviate constipation, research suggests that it could be a viable and effective treatment option for patients suffering from this condition. Moreover, patients have reported an improvement in their quality of life and a reduction in the severity of symptoms.15 A survey revealed that movement control orders have prohibited large gatherings and gatherings at all locations, resulting in constipation in over half of the patients due to prolonged inactivity.16 Prolonged shutdowns, fear of infection, lack of information and financial loss have had a detrimental impact on mental health, potentially leading to physical ailments like constipation and sleep disorders.17 Nevertheless, the precise impact of confinement during the COVID-19 pandemic on the likelihood of experiencing constipation in the general population remains uncertain. The objective of our study is to evaluate the occurrence of constipation and its associated factors during the lockdown period. The impact of COVID-19 confinement on the likelihood of experiencing constipation in the general population is not yet fully understood. Therefore, our study aimed to assess the incidence of constipation and identify the factors associated with it during the lockdown.
Objective
This study aimed to systematically review and conduct a meta-analysis on the prevalence of constipation and its associated factors during the COVID-19 lockdown period. The objective was to investigate the impact of the lockdown resulting from the COVID-19 pandemic on constipation rates.
Methods and analysis
Patient and public involvement
Patients and/or the general public will not be engaged in the process of designing, conducting, reporting or disseminating the findings of this research.
Type of studies
The types of studies considered for this research include cohort studies, case–control studies and cross-sectional studies.
Participants
The study includes all patients who experienced constipation or were present during the period of movement control order.
Date and language restrictions
There are no restrictions on language, publication status, geography or medical conditions. The study includes articles published from inception to November 2022.
Types of outcomes
The main outcome of interest is the prevalence or incidence of constipation during the COVID-19 lockdown period. This refers to the proportion or rate of individuals who experienced constipation.
Associated risk factors
The study also investigates the factors associated with the occurrence of constipation during the COVID-19 lockdown period. These factors may include dietary habits, level of physical activity, medication use, psychological distress and other relevant variables that can impact bowel movements.
This study aims to summarise and analyse existing literature to provide comprehensive information on the incidence of constipation and potential risk factors among individuals who experienced isolation or activity restrictions during this period. It is important to note that the specific results will be determined by the findings of the literature review and data analysis. Conclusions can only be drawn after the completion of the actual study.
Exclusion criteria: This study will exclude certain types of research, including animal experiments, short surveys and letters, editorials, comments, narrative reviews, case reports, and any secondary analyses of previously published data. The focus of the study will be on systematic reviews and original research articles.
Additionally, articles without full-text or with missing/unusable data will also be excluded.
Descriptive studies that do not report outcomes will not be included. Furthermore, studies that have been published repeatedly will be excluded from the analysis.
Search methods for the identification of studies
Data sources
The study will be conducted systematically from inception to November 2022 using multiple databases, including PubMed/MEDLINE, EMBASE, PsycINFO, Web of Science, Cochrane Library, China National Knowledge Internet (CNKI), WHO COVID-19 Database, Chinese Scientific and Technological Journal Database (VIP), China Science and Technology Journal Database, Chinese Biomedical Databases (CBM) and Wanfang Database (online supplemental appendix 1). There will be no restrictions on publication status, including preprint or peer-reviewed articles. Additionally, we will review the references of included studies and relevant systematic reviews and meta-analyses to identify potentially relevant studies. Manual searches will also be conducted to ensure the identification of any studies missed by electronic searches. Furthermore, we will search grey literature, such as regulatory data, unpublished trial data, government publications, policies and procedures, in addition to published peer-reviewed literature. This comprehensive approach aims to retrieve all relevant evidence, including those that may not be indexed in traditional bibliographic databases. In addition to electronic searches, manual searches will also be conducted to identify any studies that may have been missed. Grey literature, including regulatory data, unpublished trial data, government publications, policies and procedures, will be searched alongside published peer-reviewed literature. This comprehensive approach aims to ensure the retrieval of all relevant evidence, including those that may not be indexed in traditional bibliographic databases. Opengrey search will be used for this purpose. The search strategy for PubMed is adjusted according to the specific syntax for each database, as outlined in table 1.
Supplemental material
Search strategy used in PubMed
Selection process of included studies
The retrieved literature is imported into EndNote V.X9 for further analysis. Duplicate records will be eliminated using the software. EndNote software will also be used to manage the records effectively. Two reviewers will carefully assess the abstracts and titles of the studies based on predefined inclusion and exclusion criteria. The full-text reports of eligible studies will be thoroughly examined to confirm their eligibility, while reasons for excluding ineligible studies will be documented. The selection process will be visually depicted in a Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) flow diagram (figure 1). Any disagreements between the reviewers will be addressed and resolved through discussion with a third reviewer.
The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) 2009 flow diagram of studies identified.
Data extraction and management
The data extraction process will be carried out by two authors using a preconceived, piloted and standardised Excel table. In case of any discrepancies, they will be resolved through discussion or consultation with a third review author. The relevant information to be extracted will be done independently:
General characteristics: date of publication, title, retrospective or prospective design, first author’s name, country of origin, email address, country in which the study was conducted.
Study methods: study design, single centre or multicentre, number of multicentre recruiting centres, start and end dates of the study, need for ethical approval/access to the study, source of study funding, possible conflicts of interest of study authors, potential for reporting other biases, methods used to prevent and address missing data.
Patient characteristics: age (mean with SD, range), gender, occupation, race/ethnicity, inclusion and exclusion criteria, participant recruitment method, number of participants, clusters (number of clusters and mean size of each cluster), intracluster (or intraclass) correlation coefficient, and International Standard Classification of Occupations.
Outcomes: Prevalence or incidence of constipation, data on risk factors associated with constipation, name of outcome, measurement tool, method of aggregation, timing of outcome measurement, adverse outcomes.
Between-group outcomes will include risk ratio (95% CI), OR (95% CI), mean difference (95% CI), standardised mean difference (95% CI), other effect measures and main conclusions of the study authors. The final extracted data will be exported to Stata V.26 for meta-analysis.
Dealing with missing data
If the full text cannot be retrieved from the database, a broader search will be conducted in other sources. If the full text is still unavailable, the author of the document will be contacted to obtain the necessary data. References will be excluded if the full text cannot be found after an extensive search, no response from the author is received, or if the author cannot be contacted.
Assessment of risk of bias of included studies
The Newcastle-Ottawa Scale (NOS) is a valuable tool used to evaluate the risk of bias in observational studies.18 However, it is important to note that the inter-rater reliability of the NOS can vary, ranging from fair to high, depending on the specific types of observational studies being assessed and the individual raters involved. Furthermore, it is crucial to consider that the lack of comprehensive reporting of methodological details in published articles can potentially impact the accuracy of the risk of bias assessment.19
Strategy for data synthesis
RevMan V.5.4 and Stata V.26 software (StataCorp) will be used for statistical analysis. The reported risk factors for constipation will be calculated using OR values and 95% CIs. If the CIs of the OR do not include 1, it is considered statistically significant. The risk factors and prevalence of interest in each study will be extracted using the OR and 95% CI. The OR will be used to explore potential risk factors and will be considered statistically significant at 1 and p<0.05 when the OR and 95% CI are not equal. Prevalence estimates will be converted to prevalence percentages and their respective SEs will be calculated. All prevalence estimates will be reported with their 95% CIs. To minimise the impact of studies with very small or very large prevalence estimates on the overall estimate, the study-specific prevalence variances will be stabilised using the Freeman-Tukey double inverse sine transformation before combining the data with the random effects meta-analysis model. Prevalence will be recalculated for each study to confirm the numerator and denominator and adjusted as necessary.20
Meta-analyses will be conducted in cases of low heterogeneity or if sources are available, even if there is high heterogeneity. If a meta-analysis cannot be conducted, a systematic narrative synthesis will be performed.
Heterogeneity assessment
Heterogeneity will be evaluated using a χ² test on Cochrane’s Q statistic, and the I² statistic will be used to measure inconsistency among studies. The I² statistic represents the percentage of variation in effect estimates attributed to heterogeneity rather than sampling error. I² values of 25%, 50% and 75% are considered to indicate low, moderate and high heterogeneity, respectively. If statistical heterogeneity is low (p>0.1 or I²<50%), the data will be combined using a fixed-effects model. If statistical heterogeneity is high (p<0.1 or I²>50%, with I² values exceeding 75%), it will indicate the presence of considerable heterogeneity. In such cases, sensitivity analysis and subgroup analysis will be conducted to explore potential causes.
If a meta-analysis cannot be performed due to significant heterogeneity between study groups (I²>75%), a vote-counting method validated and recommended by Cochrane will be used as an alternative synthesis method.
Subgroup analysis
Subgroup analysis is a valuable tool in identifying potential sources of heterogeneity in a study. In this particular study, the subgroup analysis will focus on four variables: country or region, diagnostic criteria for constipation, age and sex.
Country or region
Variations in healthcare systems, cultural practices and environmental factors across different countries or regions can have an impact on the prevalence, diagnosis and treatment of constipation. By analysing the data separately for each country or region, it may be possible to identify patterns or differences that contribute to the heterogeneity observed in the study results.
Diagnostic criteria for constipation
There are various diagnostic criteria available for constipation, such as the Rome criteria and the Bristol Stool Chart. These criteria may differ in terms of their sensitivity and specificity in identifying constipation, which can influence the study findings. By analysing the data separately for each diagnostic criterion, it may be possible to determine which criteria are most effective in accurately identifying constipation.
Age
The prevalence, diagnosis and treatment of constipation may vary by age. While constipation is more common among older adults, it can occur at any age. Therefore, analysing the data separately for different age groups can help identify potential differences.
Sex
Constipation is more commonly reported by women than men, although the exact reasons for this disparity are not fully understood. By examining the data separately for men and women, it may be possible to determine if there are specific gender-related variations in the prevalence, diagnosis and treatment of constipation.
Sensitivity analyses
To evaluate the robustness of our findings, sensitivity analyses will be conducted. We will remove each included study individually and assess the remaining overall estimates of delirium prevalence and risk factors.
Publication bias assessment
If the total number of included studies is equal to or greater than 10, we will assess publication bias using funnel plots and Egger’s test. A p<0.10 will be considered indicative of statistically significant publication bias.
Quality control of the systematic review and meta-analysis
The quality of evidence for each outcome will be evaluated using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) method. The GRADE approach to grading the certainty of evidence is based on a system of four levels: high, moderate, low and very low. Reviewers will classify the evidence as high certainty, moderate certainty, low certainty or very low certainty based on these results.
Assessment of reviewer agreement
We will evaluate the inter-rater agreement among reviewers for study inclusion, data extraction and study quality assessment using Cohen’s kappa statistics. Kappa statistics will classify the level of agreement into three categories: moderate agreement (0.41–0.60), substantial agreement (0.61–0.80) and almost perfect agreement (0.81–1.00).21
Ethics and dissemination
The findings of the study will be disseminated through peer-reviewed journals, and national and international conference presentations.
Discussion
This systematic review and meta-analysis aim to provide a comprehensive summary of the prevalence and risk factors associated with constipation during COVID-19 control measures across different countries and regions worldwide. By investigating the potential risk factors, we hope to identify high-risk populations that could benefit from early interventions. It is important to note that the impact of COVID-19 on people’s lives may persist in the future. However, our analysis has certain limitations. First, the varying definitions of constipation used in COVID-19 (with or without systematic screening tools) may have influenced our findings. Additionally, in some cases, the symptoms of constipation may resolve once individuals resume their prelockdown physical activity and habits. Lastly, we did not consider psychological comorbidities, which have increased during the pandemic and could be confounding factors. Overall, there is a lack of comprehensive reviews that fully explore the incidence of constipation in relation to COVID-19. To enhance our comprehension of the association between COVID-19 and constipation rates and to encourage preventive measures at both individual and population levels, we will undertake a comprehensive review and meta-analysis. This study aims to provide an up-to-date overview of the incidence of constipation during COVID-19 lockdowns, considering the latest literature. The majority of relevant studies are expected to be derived from cohort studies, cross-sectional studies, case–control studies and self-controlled case series designs. Nonetheless, we will conduct a systematic review and meta-analysis using the available evidence to investigate the immediate, intermediate and long-term effects of COVID-19 on the population.
Ethics statements
Patient consent for publication
Supplementary materials
Supplementary Data
This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.
Footnotes
Correction notice This article has been corrected since it was published. The funding statement has been corrected.
Contributors JJZ conceived this study and wrote the manuscript. SG and RS developed the search strategy. JJZ, SG and RS provided methodological advice. SY revised the manuscript. All authors have reviewed this protocol and approved the final manuscript.
Funding This research was funded by Central Guidance for Local Projects (NO.2022ZYD0101); National Natural Science Foundation of Sichuan Province (NO.2023NSFSC0696); National Natural Science Foundation of China (NO.82004487) and National Natural Science Foundation of China (NO.82374604).
Competing interests None declared.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.
Provenance and peer review Not commissioned; externally peer reviewed.
Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.