Abstract
Background
The main objective of this review is to assess the effects of non-pharmaceutical therapies such as cognitive-behavioral therapies, sleep hygiene and behavioral therapies, exercise, and complementary and alternative medicine (CAM) on sleep quality in patients with substance abuse (SA).
Methods
Randomized controlled trials (RCTs) will be retrievaled by a systematic computerized search in the following online databases: PubMed, Cochrane Central Register of Controlled Trials, MEDLINE, Clinicaltrial.gov, EMBASE, CNKI, Wanfang, VIP and CBM, with no language restrictions. We plan to use network meta-analysis with a frequentist approach to compare the efficacy of non-pharmaceutical therapies (cognitive-behavioral therapies for insomnia (CBTI), sleep hygiene and behavioral therapies, exercise, and CAM) in sleep quality with substance abuse (SA). The primary outcome is “sleep quality”, secondary outcomes are “depression”, “anxiety”, “cognition related to sleep”, “the consumption of psychoactive substances” and “frequency of adverse effects”. Bias in individual studies will be assessed using the revised Cochrane risk of bias tool RoB2.0 (2019 revised version). The certainty of evidence across all outcomes will be evaluated using the CINeMA (Confidence in Network Meta-Analysis) framework. The systematic review and network meta-analysis will be presented according to the PRISMA for Network Meta-Analyses (PRISMA-NMA) guideline.
Discussion
This systematic review and network meta-analysis will provide a synthesis of the currently available evidence on the comparative efficacy of various non-pharmacological therapies for sleep quality in patients with substance abuse and offer a reference for clinicians to help make evidence-based treatment decisions.
Systematic review registration
The protocol has been registered at the International Prospective Register of Systematic Reviews (PROSPERO; registration number: CRD42019130984).
Introduction
Substance abuse (SA) is the abuse of alcohol, cigarettes, illegal drugs, and/or prescribed medications. The accessibility and precise harm of these three factors make their harm difficult to ignore. SA contributes to affecting the sleep quality which makes a difficulty in initiating or maintaining sleep or impaired daytime functioning.1234-5 Insomnia is associated with numerous adverse outcomes in SA group, such as insufficient happiness, low quality of life, low occupational function, more negative emotions, and poor physical and mental health.678-9 Numerous epidemiological studies have suggested that the increased prevalence of insomnia among individuals with SA results in a greater prevalence of addictive comorbidities.910111213-14
Currently, the main treatments recommended for sleep quality in individuals with substance abuse are non-pharmaceutical and pharmaceutical treatments. Pharmaceutical treatments include benzodiazepines as well as new non-benzodiazepine drugs, which can shorten the latency to fall asleep and prolong total sleep time but also affect normal sleep physiology and cause adverse reactions to make substance dependence worse.15,16 Non-pharmaceutical therapies can reduce sleep onset latency and wake after sleep onset and improve sleep efficiency and quality and include strategies, such as cognitive-behavioral therapies for insomnia(CBTI), sleep hygiene and behavioral therapies, exercise, and CAM2,10,1718-19 to reduce substance dependence and adverse reactions. Therefore, the application of non-pharmacological therapies in sleep disorders is receiving increasing attention. CBTI is designed to alter thoughts, beliefs, and attitudes about sleep to exact change on an observable behavior.1920-21 Sleep hygiene involves maintaining a consistent sleep schedule of arising and going to bed, sleeping as long as necessary to feel refreshed upon awakening, avoiding stimuli near bedtime, such as television, and relaxing before bedtime.22,23 Regular exercise, but not within several hours of bedtime, can improve sleep quality, and randomized controlled trials (RCTs) have been conducted to assess the benefits of exercise for smokers’ symptoms, such as fatigue and diminished mobility of sleep disturbances.13,24 Complementary and alternative medicine (CAM) is a group of varied medical and health care systems, therapeutic methods and products that include techniques, such as acupuncture, yoga, and Taiji; most of these therapies focus on negative thought patterns and redirecting irrational emotions and are commonly used by adults with chronic medical conditions linked to insomnia.2526-27
A large number of non-pharmaceutical therapies can be proposed, but comparative effectiveness assessing the effect of one intervention compared to other therapies are equivocal. Comparative effectiveness is not yet sufficient to understand the most effective intervention measures for SA insomnia. Many studies have been hampered by investigating a single comparison and a limited number of effectiveness comparisons.2829-30 Despite numerous recent meta-analyses and extensive reviews, no therapeutic guidelines for non-pharmaceutical therapies have been published based on fewer multiple comparisons and comparative effectiveness data, which limits clinical decision-making. In this study, network meta-analysis (NMA) will be used to synthesize data across multiple comparisons, which will provide a measure of comparative effectiveness by fitting a single statistical model to a connected network of interventions.3132-33
Methods
Overview
Before initiating this project, a search in relevant databases (including the International Prospective Register of Systematic Reviews (PROSPERO)) was conducted and revealed no prior or ongoing systematic reviews of this subject. This systematic review protocol has been reported according to the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) guidelines.3435-36 This protocol was published in the PROSPERO database (CRD42019130984). The systematic review and NMA itself will be presented according to the PRISMA Extension Statement for the Reporting of Systematic Reviews Incorporating Network Meta-analyses of Health Care Interventions. In addition, we will follow the PRISMA flow diagram (2020) to conduct this study (Figure 1).
PRISMA 2020 Flow Diagram of Study Selection Process. This Diagram Systematically Outlines the Identification, Screening, Eligibility Assessment, and Inclusion of Studies for the Systematic Review and Network Meta-Analysis. the Flow Chart Documents: 1. The Number of Records Identified Through Database Searching (eg, CENTRAL, Medline, Embase) and Additional Sources. 2. The Process of Duplicate Removal, Title/Abstract Screening, and Full-Text Assessment. 3. Specific Reasons for Exclusion at the Full-Text Review Stage (eg, Ineligible Study Design, Incomplete Data, Unclear Outcome) 4. The Final Number of Studies Included in Qualitative Synthesis and Quantitative Meta-Analysis. The Diagram Follows the Standardized PRISMA 2020 Template to Ensure Transparent Reporting of Study Selection. Final Numbers May Vary Slightly Depending on Data Availability for Specific Outcome Measures. (Source: Page MJ, et al BMJ 2021;372: n71. doi: 10.1136/bmj.n71.).
Search Strategy and Study Selection
All literature (public publications, internal information, and ongoing publications) on non-pharmaceutical therapies of insomnia with no restrictions on language or publishing status will be included. We will apply a search strategy according to the Cochrane Handbook for Systematic Reviews of Interventions (version 5.1.0) and will constitute insomnia, non-pharmaceutical therapies, and random.
For searching in electronic databases, we will use the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, EMBASE, CNKI, Wanfang, VIP and CBM (1980-2024). Literature is limited to the period after 1980 because it was the time when RCTs began to be promoted, and electronic databases began to be fully developed. For searching other resources, we will review the reference lists of the identified trials to identify further relevant trials. In addition, we will search online trial registries, such as ClinicalTrials.gov, European Medicines Agency (www.ema.europa.eu/ema/), the World Health Organization International Clinical Trials Registry Platform (www.who.int/ictrp), the Food and Drug Administration (www.fda.gov), as well as pharmaceutical company sources for ongoing or unpublished trials.
Criteria for Considering Studies for This Review
Types of Studies
We will include RCTs comparing non-pharmaceutical therapies with pharmaceutical therapies and/or placebo as oral therapy for treating insomnia in individuals with SA. The drugs taken orally generally refer to western medicine, Chinese patent medicine or Chinese herbal decoction. RCTs are the “gold standard” for evaluating the effectiveness of interventions in the field of healthcare. We value the quality of the included literature, so we only consider including RCTs strictly executed according to CONSORT. The studies we include should use randomized allocation when grouping. We will exclude controlled clinical trials, cluster-randomized trials, and cross-over trials to minimize sources of heterogeneity. The language included in the research report can be English or Chinese to achieve database complementarity and reduce publication bias.
Types of Participants
Adults aged 18 years or older will be included. There will be no limits in terms of sex, ethnicity, race, or severity of insomnia. Trials that meet the following criteria will be included: 1) participants are adults (ie, aged 18 years or older) of either sex; 2) uses a diagnosis or significant symptoms of insomnia according to any standardized diagnostic criteria (the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition 37 and the International Classification of Sleep Disorders, Third Edition 38 ); 3) includes participants with concurrent problems of SA, such as the use of alcohol, illegal drugs, cigarettes, and/or prescribed medications; 4) participants have undergone treatment of either CBTI, sleep hygiene and behavioral therapies, exercise, or CAM; 5) includes at least one other comparator group; 6) reports sleep quality as an outcome.
Types of Interventions
Trials evaluating all forms of non-pharmaceutical therapies, including CBTI, sleep hygiene and behavioral therapies, regular exercise, and CAM will be included in the review, regardless of the number of times patients underwent the intervention or the length of the intervention period. CBTI is designed to alter thoughts, beliefs, and attitudes about sleep to exact change on an observable behavior. Sleep hygiene involves maintaining a consistent sleep schedule of arising and going to bed, sleeping as long as necessary to feel refreshed upon awakening. CAM is a broad category that includes many non-pharmacological therapies, such as acupuncture, Tai Chi, and yoga. The non-pharmacological therapies that may be involved in this study are shown in Table 1.
Possible Non-Pharmacological Therapies Involved in This Study.
Types of Outcome Measures
Primary Outcome
1. Sleep Quality
Pittsburgh Sleep Quality Index
The Pittsburgh sleep quality index (PSQI) is an internationally established tool that is used to evaluate patients’ sleep quality. The scale includes seven dimensions, which consist of subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, sleeping medication, and daytime dysfunction. Each factor has a score of 0 to 3, with a total score of 21 points. The score correlates adversely with sleep quality which a higher score means the sleep quality is worse. A global score greater than 5 are classified as ‘poor sleepers’, while a score of 5 or less are classified as “good sleepers”.
Athens Insomnia Scale
Athens Insomnia Scale (AIS) was designed by the Ohio State University School of Medicine in 1985, with a total of 8 items, each rated on a scale of 0, 1, 2, and 3, from no sleep disorder to severe. A total score of < 4 indicates no sleep disorders, 4-6 indicates sleep disorders, and > 6 indicates insomnia. The self-testing results of this scale are accurate and easy to use, making it a recognized standard scale for evaluating insomnia in the international medical community.
Self-Rating Sleep Scale
Self-Rating Sleep Scale (SRSS) has 10 items in total, each item is scored on 5 levels (1-5), and the total score is the sum of the scores for each item. The higher the rating, the more severe the sleep problem. This scale has a minimum score of 10 (indicating no sleep problems) and a maximum score of 50 (indicating the most severe).
Epworth Sleepiness Scale
Epworth Sleepiness Scale (ESS) was developed by Professor Murray Johns from Epworth Hospital in Australia. It consists of 8 items, with each item rated on a scale of 0, 1, 2, and 3 from no drowsiness to severe drowsiness. A total score of over 6 indicates drowsiness, over 10 indicates extreme drowsiness, and over 16 indicates dangerous drowsiness. This scale has accurate judgment and strong self-testing ability at home, making it one of the most practical drowsiness scales internationally recognized.
Insomnia Severity Index
The Insomnia Severity Index (ISI) is a tool used to assess and evaluate insomnia symptoms in individuals with insomnia within the past 2 weeks. It consists of 7 items, with each item scoring 0-4 points. The higher the score, the more severe the insomnia. The ISI scale is easily influenced by emotional factors such as anxiety and depression in patients.
Secondary Outcomes
Depression
Beck Depression Inventory
The Beck depression inventory (BDI) is a valid self-assessment index to measure depression severity. It consists of 13 items, which are divided into a score of 0 to 3; 0 to 4 indicates no depression, 5 to 7 shows mild depression, 8 to 15 indicates moderate depression, and 16 points or more is considered severe depression.
Self-Rating Depression Scale
Self-rating depression Scale (SDS) is a self-assessment scale consisting of 20 items divided into 4 levels. It is easy to use and can intuitively reflect the subjective feelings of depressed patients and their changes during treatment. Mainly suitable for adults with depressive symptoms, including outpatient and inpatient patients. SDS is not effective for people with lower levels of education or slightly lower levels of intelligence.
Hamilton Depression Scale
Hamilton Depression Scale (HAMD) was developed by Hamilton in 1960 and is the most commonly used scale for assessing depression in clinical practice. This scale has three versions: 17 items, 21 items, and 24 items. This scale is jointly assessed by two trained assessors for HAMD in patients, usually through conversation and observation. After the assessment is completed, the two assessors independently score each other.
Anxiety
Beck Anxiety Inventory
The Beck anxiety inventory (BAI) is used to assess the degree of anxiety. A total of 21 items are scored from 1 to 4, with 15 to 25 points indicating mild anxiety, 26 to 35 points indicating moderate anxiety, and 36 points considered severe anxiety.
Self-Rating Anxiety Scale
Self-Rating Anxiety Scale (SAS) consists of 20 items that reflect subjective feelings of anxiety, with each item graded into four levels based on the frequency of symptom occurrence. Suitable for adults with anxiety symptoms. Scoring criteria: A score below 50 is considered normal, a score between 50-59 is considered mild anxiety, a score between 60-69 is considered moderate anxiety, and a score above 69 is considered severe anxiety.
Hamilton Anxiety Scale
The Hamilton Anxiety Scale (HAMA) was developed by Hamilton in 1959 and is one of the commonly used scales in psychiatric clinical practice, particularly suitable for assessing the severity of anxiety symptoms. The total score is the sum of all items, which is 0-56 points. A total score exceeding 29 points may indicate severe anxiety; 29-22 points, with obvious anxiety; 21-15 points, there must be anxiety; 14-7 points, there may be anxiety; Less than points, no anxiety. Generally, the cut-off value is 14 points for the total score of HAMA 14 items.
Generalized Anxiety Disorder 7
The total score range of the Generalized Anxiety Disorder 7 (GAD-7) is 0-21 points. 0-4 is classified as clinically insignificant anxiety; 5-9 points are mild; 10-14 is classified as moderate; Exceeding 15 points is considered severe. When used as an auxiliary diagnosis for anxiety symptoms, the cut-off value for GAD-7 is 10.
Hospital Anxiety and Depression Scale
The Hospital Anxiety and Depression Scale (HADS) is mainly used for screening anxiety and depression among patients in general hospitals. HADS consists of 14 items, with 7 items assessing depression and 7 items assessing anxiety. There are a total of 6 reverse questioning items, 5 on the depression scale and 1 on the anxiety scale. In the project, A represents the anxiety scale and D represents the depression scale. Each item is rated on a scale of 0-3 out of 4, as follows: 0 indicates no symptoms. A score of 1 indicates a perceived mild symptom that has no impact on the subject, or a mild impact. A score of 2 indicates self-awareness of the symptom, which has a certain impact on the examinee. A score of 3 indicates a conscious presence of the symptom, with severe frequency and intensity, which has a serious impact on the examinee.
Cognition Related to Sleep
Dysfunctional Beliefs and Attitudes About Sleep Scale Version 16
The Dysfunctional Beliefs and Attitudes about Sleep Scale version 16 (DBAS-16) is used to evaluate the relationships between insomnia and psychological constructs, such as anxiety and depression. There are 16 items in the index, which are divided into four factors: (1) consequences of insomnia; (2) worry about sleep; (3) sleep expectations; and (4) medication. A scale of 1-5 is used to analyze the above criteria from “strongly disagree” to “strongly agree”. The score is positively correlated with the reasonableness of sleep beliefs and attitudes.
The Consumption of Psychoactive Substances
CRAFFT Scale
The consumption of psychoactive substances is evaluated using the CRAFFT scale, which consists of two parts: three questions on alcohol, marijuana/hashish, and other illicit drug consumption in the last 12 months and six questions on problems related to the consumption of these substances.
Frequency of Adverse Effects
We divided the frequency of adverse effects (AEs), where possible, into immediate post-treatment, medium-term (3 to 12 months), and long-term (more than 12 months).
Data Collection and Analysis
A summary table of the studies included will be provided. Authors will independently extract the following data from each trial using EpiData 3.1 (ver. 270108, the EpiData Association): (1) basic information of the article, such as first author, year, language, country of publication, and article title; (2) population characteristics, such as diagnostic criteria, baseline severity of sleep quality, depression status, age, and number of participants; (3) study baseline, including the number of study groups and centers, sample size, sex ratio, age, and course; (4) interventions of the observation and the control groups and the type, frequency, and duration of interventions; (5) outcomes measures used and results, such as sleep quality and duration; (6) AEs associated with interventions; and (7) methodological quality and risk of bias.
Data will be synthesized descriptively. Two researchers (JBY, ZJC) will independently conduct the study selection and data extraction processes. The titles and abstracts of all the studies searched will be reviewed for relevance, and full texts of the eligible studies will be evaluated for final inclusion. If there is any missing information, the lead author will be contacted to request further details. Any disagreements arising from this process will be resolved by the involvement of a third reviewer (TJQ).
Assessment of the Risk of Bias in the Included Studies
We will use the revised Cochrane risk of bias tool for randomized trials (2019) to evaluate the quality of reviews. Five domains of each study will be assessed: (1) bias in randomization process, (2) bias from established intervention measures, (3) bias in outcome measurement, (4) bias caused by missing outcome data, (5) bias in selective reporting results. Two authors will independently assess the studies by scoring each criterion as “Y” (yes), “PY” (probably yes), “PN” (probably no), “N” (no), “NI” (not involved) or “NA” (not applicable). Inconsistent results will be resolved by a third researcher who will reassess the studies.
Assessment of Reporting Biases
Reporting bias will be assessed through a two-pronged approach:
Visual analysis: Contour-enhanced funnel plots will be generated when ≥10 studies are available for a given outcome. These plots will demarcate regions of statistical significance (p = 0.05 and p = 0.01 contours) to differentiate publication bias from heterogeneity-related asymmetry.
Statistical testing: For pairwise comparisons with ≥10 trials, we will perform Egger's weighted linear regression test (α=0.1) to quantify funnel plot asymmetry. In network meta-analyses, comparison-adjusted funnel plots will be analyzed using the extended Egger's regression method, which accounts for multiple intervention comparisons through a multivariate meta-regression framework.
All analyses will be conducted using STATA v22.0 (network meta module) and R v4.3.2 (netmeta package), with results interpreted in the context of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) certainty assessment.
Statistical Analysis
We will perform NMA by Stata 18 using the ‘mvmeta’ command and the graph theory framework using the netmeta package in R to calculate network meta-analyses within a frequentist framework. We will perform NMA using a random-effects model for primary outcomes within a frequentist setting, assuming equal heterogeneity across all comparisons, and we will account for correlations induced by multi-arm studies. Results of the meta-analysis and NMA will be applied where reasonable and presented as relative summary effect sizes (MD, SMD, or RR) for each possible pair of treatments. We will present a contributions matrix to indicate the weighting of direct evidence contributions to each NMA effect size, which will also be used to evaluate the confidence in the overall evidence. We will illustrate the contribution of each design to the NMA effect size using net heat plots.
If sufficient studies are available, we will perform network subgroup analyses for the primary efficacy outcome using age (patients aged over 65 years vs patients aged 18 to 65 years) as a possible source of inconsistency or heterogeneity. Results from the NMA will be presented as a summary SMD for other pairs of treatments. If a sufficient number of studies per comparison are identified, we will carry out a sensitivity analysis of the primary outcomes that include trials with a low risk of bias across all domains. Moreover, we will perform a sensitivity analysis to assess the robustness of the results if imputations have been applied. Where possible, measures of uncertainty will be reported in the form of 95% confidence intervals and 95% prediction intervals. Should NMA prove methodologically inappropriate due to network sparsity or significant inconsistency (p < 0.05), we will proceed to pairwise meta-analyses using DerSimonian-Laird random-effects models with Hartung-Knapp-Sidik-Jonkman variance adjustment for comparisons involving ≤5 studies, complemented by sensitivity analyses excluding high-risk trials (ROB 2.0 score ≥4). In scenarios precluding quantitative synthesis, evidence will be synthesized through PRISMA-compliant narrative methods incorporating evidence maps, semi-quantitative classification per NIH BEST criteria (biological plausibility, effect direction consistency, risk-benefit profile), and SWiM-guided reporting with explicit weighting of findings by methodological rigor. All analytical modes will undergo cross-validation via leave-one-out sensitivity testing and Rücker's side-splitting assessment to quantify small-study effects, with final interpretation derived through triangulation of quantitative and qualitative findings to ensure methodological robustness across evidence syntheses.
Expected Outcome
As this is a protocol, no empirical results are available. In the final review, study selection will be summarized via a PRISMA flow diagram, and included study characteristics (eg, participant demographics, intervention details, and sleep quality measures) will be tabulated. For the primary outcome (sleep quality), NMA will generate league tables presenting standardized mean differences (SMDs) with 95% credible intervals (CrIs) for all intervention comparisons, alongside rank probabilities (SUCRA values) to estimate treatment hierarchies. Pairwise meta-analyses will supplement direct comparisons where data permit. Secondary outcomes and subgroup analyses will be reported similarly if feasible.
Risk of bias (assessed via RoB2.0) and evidence certainty (GRADE for NMA) will be evaluated graphically and narratively. Sensitivity analyses will test robustness by excluding high-bias studies or adjusting for heterogeneity. All methods align with the priori statistical plan detailed in this protocol.
Discussion
This systematic review will provide an overview of the current state of evidence concerning the effects of non-pharmaceutical therapies on insomnia in people with SA. The primary outcomes analyzed will provide evidence on the benefits (ie, duration and perceived quality of sleep) of the interventions. Secondary outcomes will provide information on sleep-related constructs and the relationships between insomnia and psychological constructs. In addition, the consumption of psychoactive substances and other adverse outcomes will be evaluated. Furthermore, gaps in the literature will be identified, and recommendations for future avenues of research will be offered. Strengths of this review include searching in multiple databases according to the interdisciplinary nature of the subject, the systematic approach, including screening, data extraction, and quality assessment by two independent reviewers, and transparent reporting according to guidelines.
At present, the recommended intervention for insomnia in people with SA are non-pharmaceutical therapies, however, there is an excess of non-pharmaceutical therapy interventions to make clinical decisions.3940-41 In addition, there are currently no clear recommendation guidelines or expert consensus for non-drug therapies. Given the importance of sleep disturbances in people with SA, this systematic review aims to accelerate the consolidation of evidence, such that it provides decision-makers (ie, patients, healthcare professionals, and policymakers) with high-quality evidence to facilitate decisions on whether and how to implement non-pharmaceutical therapies, such as CBTI, sleep hygiene, relaxation training traditional and alternative medicine for insomnia in people with SA.
Because of the complexity of defining SA, we may analyze the included literature by subgroup according to substances, such as alcohol, illegal drugs, and cigarettes. Moreover, psychiatrists will be asked for their opinions on SA during the inclusion and analysis of studies. Through search strategy, a preliminary search has performed to find that a large number of clinical studies focused on non-pharmaceutical therapies on sleep in individuals with SA.2,5,28,42,43 However, it is uncertain whether there will be a sufficient number of studies that meet the criteria to allow network analysis to be performed. If there is a sufficient number of high-quality studies, network analysis will be performed. However, if not, a meta-analysis of pairwise comparisons or a descriptive analysis will be performed.
In conclusion, this study will review non-pharmaceutical intervention options and propose recommendations regarding the comparative effectiveness of therapies for sleep quality in individuals with SA.
Footnotes
Author Contributions
(I) Conception and design: WY Pei, GH Wen, P Zhou; (II) Registered Research Scheme: JQ T, JC Zeng, BY Jiao, GF Qian; (III) Manuscript writing: All authors; (IV) Final approval of manuscript: All authors.
Funding
The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The study was supported by (I) Traditional Chinese Medicine Bureau of Guangdong Provine (20211128, 20211365); (II) Guangzhou Science and Technology Project (No.202102010505; 202201011103); (III) Natural Science Foundation of Guangdong Province (No.2022A1515010729); (IV) Key R&D Program of Guangdong Province (No.2020B1111120001); (V) Sanming Project of Medicine in Shenzhen nanshan (No.SZSM202103010); (VI) National Natural Science Fund for Distinguished Young Scholars (Grant No. 82205247); (VII) Bao'an District Traditional Chinese Medicine Clinical Special Project (No.2023ZYYLCZX-4).
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Data Availability Statement
The dataset generated and analysed during the current study is available from the corresponding author on reasonable request.