Telehealth interventions for substance use disorders in low- and- middle income countries: A scoping review

The increasing prevalence and magnitude of harmful effects of substance use disorders (SUDs) in low- and middle-income countries (LMICs) make it imperative to embrace interventions which are acceptable, feasible, and effective in reducing this burden. Globally, the use of telehealth interventions is increasingly being explored as possible effective approaches in the management of SUDs. Using a scoping review of literature, this article summarizes and evaluates evidence for the acceptability, feasibility, and effectiveness of telehealth interventions for SUDs in LMICs. Searches were conducted in five bibliographic databases: PubMed, Psych INFO, Web of Science, Cumulative Index of Nursing and Allied Professionals and the Cochrane database of systematic review. Studies from LMICs which described a telehealth modality, identified at least one psychoactive substance use among participants, and methods that either compared outcomes using pre- and post-intervention data, treatment versus comparison groups, post-intervention data, behavioral or health outcome, and outcome of either acceptability, feasibility, and/or effectiveness were included. Data is presented in a narrative summary using charts, graphs, and tables. The search produced 39 articles across 14 countries which fulfilled our eligibility criteria over a period of 10 years (2010 to 2020). Research on this topic increased remarkably in the latter five years with the highest number of studies in 2019. The identified studies were heterogeneous in their methods and various telecommunication modalities were used to evaluate substance use disorder, with cigarette smoking as the most assessed. Most studies used quantitative methods. The highest number of included studies were from China and Brazil, and only two studies from Africa assessed telehealth interventions for SUDs. There has been an increasingly significant body of literature which evaluates telehealth interventions for SUDs in LMICs. Overall, telehealth interventions showed promising acceptability, feasibility, and effectiveness for SUDs. This article identifies gaps and strengths and suggests directions for future research.

Introduction Substance use disorders (SUDs) are a growing public health concern of global significance with their impact cutting across all domains of life [1]. The 2021 world drug report of the United Nations Office on Drugs and Crime (UNODC) estimated that in 2019, 5.5% (275 million) of the global population (aged between 15 and 64 years) had used drugs and over 36 million people worldwide suffered from SUDs [2]. Using the World Bank country classification of low-and-middle income countries (LMICs) [3], increasing populations of people with the highest risk of substance use reside in LMICs and this is projected to increase by 40% in Africa by 2030 [4]. SUDs is one the world's leading causes of years lived with disability in LMICs and its resulting consequences pose major challenges to health systems globally, particularly to those in LMICs [5].
There is a huge treatment gap for SUDs globally with one in six people who receive treatment for SUDs and one in 11 and 18 people who receive treatment in Latin America and Africa respectively [6]. Generally, the treatment gap for SUDs ranges from 75% to 95% in LMICs with higher values reported in rural areas [5,7,8]. Whilst SUDs prevalence have increased across the world, existing evidence shows that over 80 to 85% of people with mental disorders in LMICs do not have access to appropriate mental healthcare especially the out of reach populations [5]. Arguably, there is an overlap between people who require treatment for SUDs and other mental disorders [9]. Nevertheless, the worsening problems of SUDs continue to compound the existing unmet mental health needs [5,9].
A considerable number of studies show that SUDs can be chronic, relapsing disorders with cycles of relapses and remissions [1]. The chronicity of SUDs suggests that an established care model which provides an integrated care system consisting of self-management and services is required to prevent relapse in individuals diagnosed with SUDs [10,11]. Several approaches that address recovery management, improve continuity of care, monitor periods of abstinence, and early intervention, encourage self-management, mutual aid, other recovery supports, and system-level interventions have been recommended in the management of SUDs [12]. The principal caregivers of affected individuals are they themselves. Therefore, it becomes pertinent to explore interventions with potentials for self-monitoring and self-management with favorable outcomes and reduced economic burden [13]. Present management approaches for SUDs usually involve a combination of behavioral therapy, brain stimulation techniques, pharmacological therapies, and the use of telecommunication technologies [1]. One strategy that has been recommended with favorable outcome in addressing the chronicity of SUDs and improving access to care especially for out of reach populations is telehealth [14]. Conventionally, telehealth interventions involve the use of communication technologies to deliver healthcare across a distance [15].
Emerging evidence shows that telehealth has the potential of reducing the existing treatment gap in LMICs in the diagnosis and management of people with mental disorders and SUDs. These interventions range from simple and easily accessible forms such as text messaging, and phone calls, to more advanced modalities such as virtual reality, videoconferencing and the use of innovative web-based platforms and mobile apps [16]. This form of healthcare intervention has been in existence for over half a century but it remains underutilized in several LMICs [17]. Several factors such as user barriers (awareness, level of education, availability of gadgets, affordability of resources, telehealth literacy), organizational, and program barriers are contributory to its limited use in LMICs [18]. On the other hand, telehealth interventions have been better endorsed and used in high income countries (HICs) with most studies assessing use of these interventions for substances such as alcohol use, cannabis, tobacco with limited use for opioid use disorder and methamphetamines [19][20][21][22]. These interventions have been shown to be effective in improving substance use outcomes and other outcomes such as quality of life [23,24]. Additionally, participants reported high satisfaction with use [25,26]. In LMICs there is limited use of digital interventions in SUDs treatment, for example, a systematic review on the use of digital interventions for mental health treatment and prevention identified only six studies who utilized telehealth interventions for SUDs out of the 49 articles [27]. An update of this review in 2021 identified seven articles on SUDs from LMICs [28]. Among the challenges cited with the use of telehealth interventions for SUDs treatment in LMICs include high rate of technology evolvement [29], limited access to internet and cost of airtime, lack or poor literacy skills needed to access these interventions, lack of non-verbal cues, high phone turnover, privacy, and litigation concerns [30][31][32].
Growing evidence demonstrates that remote management by means of telecommunications technology, offers a promising approach in improving accessibility and affordability of care of individuals with SUDs and has the prospect of facilitating self-monitoring and management of individuals with SUDs [33,34]. Several authors have examined feasibility, acceptability, and effectiveness of telehealth interventions for SUDs worldwide and have suggested different definitions for these. Overall, feasibility as a construct in public health practice takes into cognizance several aspects of intervention delivery. These include demand (is the intervention taken up?), implementation (can it be delivered as planned?), practicality (can it be delivered despite constraints, such as resources and time?). Feasibility incorporates acceptability, i.e how the recipients of (or those delivering) the intervention perceive and react to it [35].
There is a dearth of literature reviews on telehealth interventions for SUDs in LMICs. To address the gap of research on this topic, we conducted a scoping review of available literature on this subject to provide a preliminary overview to identify existing gaps from the available evidence, and to describe trends on this topic while addressing it from a broader perspective, unlike systematic review which develops critically appraised and synthesized results. Therefore, the objectives of this scoping review were to summarize literature evaluating the acceptability, feasibility, and effectiveness of telehealth interventions for SUDs in LMICs, to identify evidence gaps and proffer recommendations for future research.

Materials and methods
Following the conception of the topic, an exploratory search was carried out to determine the extent of literature on telehealth interventions for SUDs in LMICs, guided by formulation of the review question and identification of key concepts, search terms, phrase strategy and testing of the search strategy.

Protocol and registration
There was no formal registration of this scoping review with the international systematic review database (PROSPERO). As of the time of writing this manuscript, it was not a requirement for scoping reviews to be registered with PROSPERO. The Quality Assessment Tool for Studies with Diverse Designs (QATSDD) [36], was employed in assessing the quality of studies reviewed. Although, as of the time of writing, scoping reviews do not typically require quality assessment unlike systematic review which generally requires quality assessment of included studies [37].
The method used in this review adopted the framework developed by and Cochrane Library were used to search for articles published in English or translated to English to identify relevant studies. Different search engines were engaged and the initial database searches were conducted from September 30 to October 1, 2020 (S1 Data). Our searches spanned articles published from 2010 to time of search in 2020. A 10-year timeline was agreed upon by the authors because the use of digital intervention in LMICs gained prominence in the last decade.
The keywords used for the search in this review were "telehealth OR telepsychiatry OR telemedicine OR teleconsultation OR mobile health OR mhealth OR mobile phone OR web OR video conferencing OR SMS OR short message OR internet OR Substance use OR Substance use disorder OR substance abuse OR substance dependence OR addiction OR addict OR alcohol use disorder OR alcohol abuse OR alcohol dependence OR alcohol addiction OR tobacco OR cigarette OR smoking OR nicotine OR cannabis OR marijuana OR bhang OR Khat OR shisha OR heroin OR opioid OR injecting drug use OR people with injecting drug use OR PWID OR cocaine OR amphetamine OR methamphetamine OR Feasibility AND Effectiveness". (S1 Table) Manual extraction of relevant literature from the reference list of articles included in the review was done. This entailed consideration of relevant terms, dates, text words contained in the title, abstracts of retrieved papers and index terms. The PICOS (participants, intervention, context, outcomes, and study design) framework [41], was used to establish eligibility criteria.
Inclusion criteria. We included articles that examined at least one of the following outcomes such as acceptability, feasibility, effectiveness of telehealth interventions for substance use if: (a) the population examined or part of the population was from an LMICs as defined according to World Bank country classification (b) the article was an original research (c) there was evidence of substance use exposure, (d) articles were published in English or had an English translation available, (e) the studies was conducted among all age groups (f) studies used all designs quantitative, qualitative and/or mixed. (g) there was evidence of a substance use/SUDs related intervention outcome such as acceptability/ feasibility and/or effectiveness.
In this study, feasibility was defined in broad terms and included variables such as: ease of recruitment of participants, number of participants recruited in relation to targeted sample size, cost effectiveness, ease of delivery of the telehealth intervention, retention in the program follow up, and acceptability (perceived usefulness of the intervention, ratio of participants who dropped out/ requested to be removed from program, likability of the intervention and willingness to recommend intervention to others) [42][43][44][45][46]. For this review, articles that assessed 'Effectiveness' were those that described change in substance use following the intervention. Change in substance use was assessed through self-report, use of standardized tools or criteria and biochemical tests [44][45][46].
Exclusion criteria. Studies were excluded if: (a) they were conducted across LMIC and HICs and did not report LMIC specific results (b) they were review articles, dissertations, conference presentations or abstracts, case studies, commentaries, editorials, or grey literature (c) the full text articles were not available.
Stage 3: Literature selection. Following the search, all articles identified were exported to Mendeley reference manager where the initial removal of duplicates was done. Next, they were exported onto Rayyan (a software for screening and selecting studies for systematic and scoping reviews and detecting duplicates) [47], whereby, after further removal of duplicates, the abstracts and titles of retrieved articles were independently screened by two authors (M.O and F.J) based on the predetermined eligibility criteria for inclusion in the full text screening. A second screening of full text articles was also done independently by two other authors (S.K and R.K) and resulted in an 85% agreement. Disagreements during each stage of the screening were resolved through discussion and consensus. In instances where consensus could not be reached, a third author was invited to review. Screening of selected studies was performed between October 2, 2020 to March 30, 2021.
Stage 4: Charting the data. A comprehensive data extraction form was prepared in Microsoft Excel by the authors. The form was first piloted by F.J and S.K on ten articles to ensure consistency and necessary adjustments were made to the content thereafter. Data was extracted by all authors and the final form was entered by M.O and double checked by M.O and S.K for completeness and accuracy. The draft of the manuscript was written by M.O and discrepancies were resolved by discussion with S.K and F.J until consensus was achieved. The following data were extracted: author, year; country; modality of telehealth intervention; targeted substance; study design; sample size; study setting/population; measures of acceptability, feasibility, effectiveness, and other outcomes. After familiarization with the data, two authors (M.O and F.J) inductively identified seven specific themes from the data which were reviewed and affirmed by the other authors.
Stage 5: collating, summarizing, and reporting the results. A narrative account of the included articles was prepared to present patterns in telehealth interventions as acceptable/ feasible and/ or effective tools or not applicable in the reduction of SUDs in LMICs. The results have been summarized descriptively and defined by the authors to alleviate the narrative account and grouped into the following emergent themes: publication trends/ timing of publication, country of research, population and setting, research design, psychoactive substance of interest, telehealth modality utilized, measured outcome (S2 Table).

Search results
Our search in five electronic databases identified a total of 2513 articles through PubMed (1978), Psych INFO via EBSCOhost (128), Web of Science (108), Cumulative Index of Nursing and Allied Professionals via EBSCOhost (CINAHL) (60), and Cochrane Library (239). A total of 301 duplicated articles were excluded and 2212 articles underwent title and abstract screening. A total of 2085 publications which did not meet the inclusion and exclusion criteria were excluded and 127 full-text articles were retained. Following full text review, 39 articles were included in the data extraction (Fig 1).
This method of research was conducted on the basis of a predetermined protocol in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) standards for scoping reviews [48] (S1 PRISMA Checklist).

General characteristics of included studies
Original peer reviewed articles that examined the topic have progressively increased in the last 10 years with 37 articles (94.9%) published in the last 5 years of this review (2016-2020). The year 2019 had the highest frequency of identified publications, n = 12 (30.8%).    [74], Korea [75], South Africa [77], and Kenya [80] had one article each (Fig 3).

Population and settings
The age range of participants in the included studies was 12-87 years [63,68]. Across studies identified, four focused on children and adolescents [55, 63,74,78], and two had 15 and 17 years as their lower age limit [61,65]. Two studies were on only male patients [53,62], one on parents of adolescents [66], and one on smoking fathers, non-smoking mothers, and exposure of their newborns to secondhand smoking (SHS) [54]. Our review identified a heterogeneous distribution of participants across studies. Participants cut across individuals in the community who were dependent on psychoactive substances and indicated a willingness to quit, oil workers, night club patrons, families, and children and adolescents. Consequently, settings spanned across workplace [75], general population [16,45,46

Study design and sample size
The selected articles in this review used quantitative, qualitative, and mixed methods. Most studies primarily used quantitative methods (n = 30). Sample sizes for individuals ranged from 40 to 23054 [62,72]. One study was done prior to implementation of the intervention to assess the willingness to use a mobile phone application for smoking cessation [61]. Four studies used qualitative methods [58, 66,77,81]. Two studies reported an ecological momentary assessment (EMA) approach to examine psychoactive substance and exposure to social and environmental cues [52,67]. Secondary data analysis was used in three identified studies [67,78,82].

Telehealth modality utilized
Studies included in this review used either one or a combination of telehealth interventions such as SMS, telephone calls, web-based cessation programs, mobile applications, web-based surveys, emails, virtual reality, hybrid phone counselling, and /or one-on-one consultations. Eleven studies used short message system (SMS) [46,[49][50][51]54,57,59,68,75,77,81], and twelve studies incorporated web based mobile interventions programs [44,55,56,64,65,68,69,[72][73][74]78,79]. Nine of the articles used mobile apps such as "smoker face"," WeChat", "What-sApp", and S-health [16,44,59,60,62,63,67,80,82]. A considerable number of studies utilized telephone communication [13,53,64,66,75,76], and some studies applied hybrid forms in delivering the interventions [13,64,68,70,75]. Psychotherapy and pharmacological interventions were used in addition to telehealth intervention in some studies [44,79,80]. The telehealth modalities were delivered via digital platforms and face to face consultations. Feedback from the telehealth modalities utilized were majorly asynchronous and engaged the services of medical students, trained counselors, healthcare providers, and researchers were employed for the delivery of the respective interventions. Of the 31 quantitative studies, twenty-nine publications clearly stated how the intervention was administered. Two studies were majorly automated messages [49,64]. Two others did not report who delivered the intervention [13,50] and one did not implement the intervention on participants [61]. Five studies clearly reported that trained counsellors in substance cessation treatments were engaged to deliver the intervention [53,54,65,68,70]. A heterogenous spread of physicians and allied professionals such as clinicians with masters/ degree in nursing/ doctoral degree in clinical psychology/ medical degree and trained in mental disorders/ occupational nurse with over 10 years' experience provided face to face consultations in three studies [44, 75,80], and one was delivered by medical students [63].
Although the heterogeneity of the frequency and duration of sessions made it difficult to combine, varying durations of sessions which ranged between 5mins to 60mins across studies were recorded in our review [65,72]. The number of sessions of the telehealth interventions conducted ranged between 1 to 42 sessions usually at baseline and at predefined times in the program [16,68]. Eight authors conducted one session each in the course of their study [63,[68][69][70][71]74,79,80]. Three sessions were recorded by Bedendo and colleagues [68], and daily interactions for 4 weeks was reported in a study by Liang and colleagues [60].

Measured outcomes
Adherence to treatment was assessed in all the 31 quantitative studies identified and rates of adherence to protocol ranged from 45% to 100% [53,71]. Higher adherence rates of 74.6% to 100% were seen for cessation of smoking among participants [59,71]. Increased adherence rates were seen with the usage of WhatsApp, text messages, web based and mobile applications. One study reported poor agreement between mobile application, multiple substances assessed and laboratory findings [67].
Our review identified four qualitative studies [58, 66,77,81]. Generally, there was an overall high interest in those with intention to quit among participants. Findings from the focus group discussions and in-depth interviews demonstrated that the majority of participants wanted to quit smoking but did not have a plan, some wanted more digital reminders but all the participants found the intervention to be helpful [58,81]. Some authors reported no significant differences before and after the intervention [53, 65,80]. However, only a few authors reported poor agreement between the type of mobile application used, substance assessed and laboratory findings as well as poor outcomes seen with high drop-out rates, low post intervention rates, no significant reduction in the substance use [13,45,46,53,54,67,73,74,78].

Discussion
This scoping review aimed to provide an overview of literature examining the acceptability, feasibility, and effectiveness of telehealth interventions in the management of SUDs in LMICs and to highlight areas of gaps in research on this subject.
Overall, our review identified seven main themes. Our findings show that considerable work has been done on the treatment of SUDs using telehealth interventions globally but with only a few studies from LMICs and fewer yet from Africa. The earliest identified study was in 2012 [49], and research on this topic has progressively increased over the last 10 years with the highest number of studies seen in 2019 as at the time of data extraction. This suggests that more clinicians and researchers in LMICs are realizing the role of telehealth interventions in addressing SUDs and are embracing this innovative method of healthcare delivery and this can also be related to increase in availability and use of information technology in recent years [65,69,79,83,84]. However, in the face of the importance of this subject and the existing evidence from HIC, there is a paucity of research in LMICs [46,85]. Amongst the 14 countries represented in this review, China and Brazil have the highest number of studies. A plausible explanation for this may be because China has the highest mobile phone and internet users in the world with an estimated number of 1.02 billion internet users as of January 2022 [86]. Similarly, Brazil has experienced an increasing internet user in the last decade with over 140 million and 167.7 million number of users on the web (with the latter equivalent to 77.87 percent of the country's population) as of 2018 and 2022 respectively. The smartphone, which was one of the most commonly used devices as of 2021, among approximately 75.6% of the Brazilian population (within the 18-55-year-old age group) [87], may also be contributory.
Plausible factors for few or no entries of some LMICs include: factors such as limited/ no internet access to telecommunication technology especially in rural areas, internet illiteracy, worsening poverty levels and paucity of research from sub-Saharan Africa [5,7,43]. Arguably, the consequences of limited/ no resources or poor prioritization for research in SUDs cessation programs in some LMICs may explain the paucity of data. For example, a country like Nigeria with the highest number of internet users in Africa estimated at 109 million as of January 2022, was not represented in our review [86]. These suggest that telehealth interventions may be implemented for SUDs in LMICs but may go unreported or unpublished.

Age
Majority of included literature were among adults with only four studies with their foci on children and adolescents [55, 63,74,78]. Existential evidence is indicative of young adults as the fastest growing users of psychoactive substances across the world and an increasingly faster rate of substance use among individuals aged 40 years and above compared to younger populations [88]. Findings from our review suggest that adolescents can easily be motivated to abstain from psychoactive substances using telehealth applications [64,74]. Most people who start smoking in early adolescence are usually curious, fascinated by the practice and influenced by peer pressure [63,74], an intervention acceptable to peers in this population would have increased likelihood of favorable outcome. Considering that children and adolescents are in a phase in life when appearance is of great importance, therefore in mitigating SUDs, innovations which utilizes appearance as a telehealth tool as a school-based program will help to reduce the number of adolescents who eventually develop SUDs [74].

Population setting
Our review shows that engaging the use of telehealth interventions early in primary care is feasible and effective in addressing SUDs in healthcare facilities evidenced by several studies in this review. Its flexibility enables its use in the workplace, nightclubs, schools and among families with promising results. In the assessment of SHS among smoking fathers, non-smoking mothers and their newborn in a parental program, Yu and colleagues reported increased abstinence rates and success in the reduction to exposure to smoke [54]. SUD is a public health problem which affects the individual, the family and society [1], consequently, SUD cessation programs which target the family and establish structures that protect children and adolescents in such environments should be encouraged. The majority of the reviewed studies assessed participants in urban settings, this underscores the need to promote telehealth interventions for hard-to-reach populations. The use of technology which provides opportunities for cost effective, improved healthcare and reaching underserved populations and prioritization for such programs should be encouraged in LMICs.

Study design
Studies differed in interventions and approaches across different domains (sample size, settings, participants, and modalities). The bulk of studies identified in this review used quantitative study design and the majority were randomized controlled trials (RCTs). Identified articles assessed interventions at individual and group levels and majority of studies examined interventions and comparison groups which added weight to such studies. Our review suggests that preliminary results were acceptable, feasible and effective. Mechanisms which contributed to significant findings had a diverse spread and studies which utilized eclectic approaches may require subsequent replication across settings to ascertain positive outcomes of telehealth interventions in the management of SUDs [54,69]. Findings from the qualitative studies show that the majority of participants enjoyed the sessions but they reported that they did not like the counseling sessions being recorded and similar reports were noted by the facilitators who felt recording the session hindered ease of participation. Overall, small sample size, insufficient power to definitively test the intervention, possible bias from self-reporting, absence of a comparison group, lack of regular follow-up, problems with technology, and high attrition rates, were some of the methodological limitations identified in our review [46,64,65,68,69,72,73].

Psychoactive substance
Selected studies in this review assessed telehealth interventions for tobacco, alcohol, cannabis, opioids, cocaine, methamphetamine, MDMA, inhalants, hallucinogen, sedatives, and other psychoactive substances. A great proportion of the included studies examined telehealth interventions with regards to cigarette smoking, possibly because tobacco use is a major cause of disease burden and one of the top five preventable causes of death [89]. Studies which assessed multiple psychoactive substances recommended careful interpretation of results and caution in the adoption of results [65,67]. Overall, our review highlighted substantial reduction in psychoactive substances with telehealth interventions.

Telehealth modality/measured outcomes
Mobile phone text messages are an affordable and effective way of overcoming resource barriers in LMICs, they have the potential of reaching a wide range of people, those in hard-toreach areas and people who prefer non-face to face consultations and reducing stigma [44, 70,79]. This may explain why most studies in this review utilized SMS as the telehealth intervention of interest. Several studies found text messages to be affordable and feasible mobile health intervention modalities with promising effectiveness in several of the studies reviewed [51,56,58,82]. Mobile applications were demonstrated to be effective in reducing stigma and surmounting barriers to accessing treatment in LMICs [45, 79,80]. An innovative approach with promising effectiveness in addressing the barriers encountered in resource constrained settings is web-based information modality [28,56,69,90,91]. This form of telehealth intervention can be harnessed to provide information and health care services which targets reduction in SUDs and treatment strategies across a wide population of people [65,68,69,70], although, some authors reported high rates of attrition using this method [64,72,73]. Studies conducted among students in high schools and colleges which used a particular facial aging apps ("smoker face") reported this intervention as acceptable [63,78]. Participants stated their preference for this app and described it as interesting [63,78]. The engaging nature and practicality of the app may be plausible reasons for its recommendation by participants. In evaluating the outcome of included studies, a great number of these studies demonstrated acceptability and feasibility as favorable outcomes and a considerable number showed promising effectiveness of telehealth interventions in the management of SUDs. However, not all authors found mobile apps and other telehealth modalities to be acceptable in the management of SUDs [46, 65,67]. Cultural practices, existing preconceptions, confidentiality, and privacy issues were possible explanations for the poor acceptability of mobile health interventions [18,54,61,65]. Furthermore, lack of incentives, poor internet literacy, and limited or lack of internet connections especially in the rural areas were some of the factors identified as barriers to feasibility and effectiveness by participants [18,61,64,72,81].

Strengths and limitations
The strengths for this scoping review include being one of the few that have examined outcomes of telehealth intervention for SUD treatment in LMICs, use of a transparent and reproducible process which states the search strategy, data sources, and data extraction. Our findings show that a great number of articles have been published on SUDs but only a small proportion of publications screened in comparison to the total number of selected articles assessed telehealth interventions as possible feasible, acceptable, and effective tools for SUDs in LMICs.
In addition to the above, our scoping review identified several limitations which include the exclusion of grey literature and evaluation of bibliographic databases and journals published in the English language, this may have resulted in relevant articles published in other languages to be overlooked. Additionally, not all authors we contacted for the full text of their studies responded. The study populations of the included studies examined circumscribed populations, and sample sizes which may make it difficult to generalize results. Our review aimed to provide an overview of literature published on telehealth interventions and SUDs and to identify gaps in research. Consequently, it is likely that the heterogeneity of methods used across studies may have affected the results reported.

Conclusions
The present scoping review adds to the body of knowledge, provides a summary of findings on application of telehealth interventions in SUDs treatment in LMICs and underscores gaps in research and areas of emphasis. These findings can guide subsequent research and interventions geared at reduction of SUDs to improve outcomes. The increasingly innovative mobile health technology can provide opportunities for underserved populations. Existing evidence suggests its potentials in the reduction of SUDs if appropriately implemented. The evidence base is growing, although there is a gap of knowledge in literature examining the effect of telehealth interventions in the reduction of SUDs in LMICs. Therefore, it is difficult to draw a firm conclusion on its effectiveness. Future studies with larger scale randomized studies are required to evaluate the effectiveness of telehealth interventions for individuals with SUDs in LMICs.
Our recommendations include provision of resources and enabling conditions for telecommunication technology to thrive as an interventional health care tool in resource poor settings, prioritizing research in SUDs cessation programs and promoting publications of such activities. Future research is recommended on populations with larger sample size, longer follow up and replication of these methods across different populations to determine if telehealth interventions are as effective as some preliminary studies suggest. We also recommend that other unexplored outcomes of telehealth intervention such as issues around privacy, confidentiality, and cultural applicability of these methods of service delivery in LMICs should be addressed in subsequent research. Considering that adolescents are a significant proportion of those who use psychoactive substances [68], we recommend more research in this population with regards to SUDs. The incorporation of smoking/ substance use cessation programs into school programs should be supported. In addition, SUDs cessation programs using telehealth targeting children and parents should be considered as focus for future observational studies and in the establishment of favorable policies.