Resilience of primary healthcare system across low- and middle-income countries during COVID-19 pandemic: a scoping review

Introduction Globally, the coronavirus disease 2019 (COVID-19) pandemic tested the resilience of the health system and its shock-absorbing capacity to continue offering healthcare services. The available evidences does not provide comprehensive insight into primary health care (PHC) system functioning across low- and middle- income countries (LMICs) during the pandemic. Therefore, the objective of this scoping review was to generate evidence on the resilience of PHC systems in LMICs during the COVID-19 pandemic. Methods A scoping review was carried out utilizing an iterative search strategy using the National Library of Medicine (NLM) and the WHO COVID-19 electronic databases. Data from the identified studies in LMICs were charted in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist in the first step. The analysis framework was adapted and modified using COVID-19 and health systems resilience framework developed by Sagan et al., Blanchet et al., and the WHO position paper on ‘Building health systems resilience for universal health coverage and health security during the COVID-19 pandemic and beyond’. A total of 26 documents were included on the basis of predefined eligibility criteria for our analysis. Results Our review explored data from 44 LMICs that implemented strategies at the PHC level during the COVID-19 pandemic. Most of the LMICs developed national guidelines on sexual, reproductive, maternal, newborn, child, and adolescent health (SRMNCAH). Most of the countries also transformed and reoriented PHC service delivery by introducing digital healthcare services to continue essential services. Task shifting, task sharing, and redeployment of retired staff were some frequently adopted health workforce strategies adopted by most of the countries. Only a few of the countries demonstrated the availability of necessary monetary resources to respond to the pandemic. Conclusions The functionality of the PHC system during the COVID-19 pandemic was demonstrated by a variety of resilience strategies across the six building blocks of the health system. To strengthen PHC resilience, we recommend strengthening community-based PHC, cross-sectoral collaboration, establishing surveillance systems, capacity building in financial risk planning, and investing in strengthening the digital healthcare system. Supplementary Information The online version contains supplementary material available at 10.1186/s12961-023-01031-4.


Introduction
Globally, the coronavirus disease 2019 (COVID-19) pandemic tested the resilience of health systems and their shock-absorbing capacity to continue healthcare service provision. In this regard, the role played by primary healthcare (PHC) is crucial, as it is the entry point in the health system. Investing in PHC to make it resilient to the crisis is thus a need that emerged during the COVID-19 pandemic [1]. Health systems resilience is defined as 'the capacity of health actors, institutions, and populations to prepare for and effectively respond to crises; maintain core functions when a crisis hits; and, informed by lessons learned during the crisis, reorganize if conditions require it' [2].
Developing and strengthening PHC resilience highlights a range of factors that are addressed in WHO's 13th General Programme of Work (2019-2023) [3]. This includes 'increasing and strengthening the capacity of PHC to sustain continuity in essential service delivery in the context of COVID-19 pandemic, moving from fragmentation to reintegration (where routine and emergencies services can be brought under one platform), working multisectoral and intersectoral, ensuring implementation and knowledge exchange and rethinking antifragility and resilience' [3].
The Astana Declaration on PHC in 2018 revitalized the significance of PHC to ensure that everyone from everywhere can enjoy the highest possible attainable standard of health [4]. PHC addresses the broader determinants of health and goes beyond providing healthcare for specific diseases and aims at whole-person care throughout the lifespan. The activities range from health promotion and prevention to treatment for common ailments. The Astana declaration reaffirmed the context of comprehensive PHC and presented three components; (i) primary care and essential public health functions as the core of integrated health services; (ii) empowered people and communities; and (iii) multisectoral policy and action [5].
Under PHC, the focus in many countries remained on the provision of maternal and child healthcare (MCH) services, health education, nutrition, safe water and sanitation, treatment of common diseases and injuries, immunization against infectious diseases, prevention, and control of locally endemic diseases [6]. The continuity of PHC healthcare services was in high demand during the COVID-19 pandemic. Thus, the need for a more resilient PHC infrastructure was recognized. As the COVID-19 crisis took a toll on health systems around the world in 2020, the entry point in the healthcare delivery system was shifted from PHC to hospitals [6]. This created intense pressure on already strained hospitals caring for sick patients, and thus the role of PHC got overlooked.
As the COVID-19 pandemic swept the world, the role and function of PHC varied greatly across the world. A lot of LMICs managed to continue the delivery of healthcare services during the COVID-19 pandemic with multiple challenges. For instance, India reported infrastructural issues in PHC with limited physical capacity [7]. The operation of outpatient services, specifically related to MCH, faced significant disruptions (P < 0.001) during the COVID-19 pandemic [7]. Despite good PHC infrastructure in Bangladesh, challenges were observed in the provision of quality PHC services during the initial phase of the COVID-19 pandemic [8]. Attendance in outpatient and inpatient units reduced substantially, alongside the proportion of fully immunized children dropping by 50% [8]. Likewise, the PHC system in Iran was also affected and led to reduced service utilization by midwives, physicians, dentists and mental health experts [9]. The reported challenges include insufficient knowledge of effective virus management and control strategies, inadequate use of strong PHC capacities, and potential to manage and control the COVID-19 crisis, resulting in reduced service utilization [9]. Like other countries, diagnostic tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were widely distributed in Brazil [10][11][12][13]. The issues were reported with the accessibility of diagnostic tests across varied population groups, alongside delays in testing results and reporting [14].
Pakistan demonstrated discontinuity in essential healthcare services during the early phase of the COVID-19 pandemic with the closure of PHC centres [15], with millions of children in Pakistan missing out on polio vaccination during the earlier phase of the pandemic [9]. The lockdown imposed by the COVID-19 pandemic led to serious disruptions in routine healthcare services at the outreach and facility levels [15]. At the grassroots level, door-to-door services by lady health workers (LHWs) were also affected due to the fear of contagion [15].
Some good examples of PHC reorientation emerged from high-income countries to respond to COVID-19, such as Europe reporting three models of PHC [16]: (i) 'Multi-disciplinary primary care teams for the emergency response. The activities included facility-based testing and triage, telephone-based triage, COVID-19 case tracing, home-based monitoring, and delivering a vaccine against COVID-19; (ii) PHC providers prioritizing vulnerable patients, this was inclusive of providing services to vulnerable people such as the provision of medicine to anyone with a prescription during lockdowns, minimum durations of prescriptions were introduced, etc., and (iii) Digital solutions to enhance the effectiveness of the PHC response to both COVID-19-and non-COVID-19-related care [16]. Activities included remote consultation, remote sick leave, electronic prescriptions, to mention a few.
Global evidence of the PHC system's functioning during the COVID-19 pandemic is continuing to evolve. Therefore, a need for collective evidence on how PHC demonstrated resilience during the COVID-19 pandemic in LMICs was addressed by synthesizing and documenting pieces of evidence on the resilience of PHC systems among resource-constrained countries. The overall objective of this scoping review was therefore to generate and synthesize evidence from LMICs on the resilience of PHC systems during the COVID-19 pandemic.

Study design
To synthesize evidence from LMICs on the resilience of PHC systems during the COVID-19 pandemic, a scoping review was carried out. A comprehensive review of the literature on the PHC system's shock-absorbing capacity across LMICs is needed to understand how PHC operated during the COVID-19 pandemic. Therefore, a scoping review was deemed a reasonable review for this research. The study protocol was registered with Figshare on 22-12-2022 (https:// figsh are. com/ artic les/ prepr int/ Scopi ng_ Review_ proto col_ V3_ final_ docx/ 21763 673). The scoping review approach proposed by Arksey and O'Malley [17] was used as below.
Step 1: establish a scoping review question(s) What is the available evidence on the resilience of PHC systems during the COVID-19 pandemic in LMICs?

Step 2: identify relevant studies
The published literature was sought using the online search engines of the National Library of Medicine (NLM) and WHO COVID-19 research databases. The search terms were applied and adapted as appropriate to the syntax of each database. Key research terms composed of those obtained via subject headings of databases, for example, medical subject headings (MeSH). For the grey literature search, the WHO Institutional Repository for Information Sharing (IRIS), and Google Scholar were considered.
To map out the existing evidence related to the resilience of PHC in LMICs, a concentrated search strategy was used ( Table 1). The search strategy was carried out using search terms related to the 'concepts of interest' (resilience-enhancing strategy at the PHC level), 'context' (COVID-19 pandemic), and 'population' (LMICs). The search strategies for the selected peer-reviewed database remained similar; however, the concise search term was applied for the grey literature search to minimize duplication with electronic data search.

Step 3: study selection and screening
The scoping review was conducted following the Joanna Briggs Institute (JBI) methodology [18]. The JBI population, concept, and context (PCC) mnemonic was used to develop the title, question, and inclusion and exclusion criteria. The PCC framework facilitated identifying the main concepts embedded in the research question and also informed the search strategy. The detailed inclusion and exclusion criteria are outlined in Table 2.
Article screening and selection were managed by the two researchers experienced in scoping review and health systems. The initial screening of the paper was carried out by reviewing the title first. If the title was considered appropriate, the second step was to review the abstract. If the abstract met the inclusion criteria, this was followed by reviewing the entire article and/or report.
Any identified discrepancies between the two researchers were resolved through discussion and involving the principal investigator (PI). We identified a total of 13,841 articles and reports from the NLM and WHO COVID-19 databases. Furthermore, a total of 73 records were identified through a grey literature search. Post-screening, 13, 442 articles were excluded as they did not fulfil the eligibility criteria. A total of 472 abstracts were assessed for screening. Out of these, 410 abstracts were classified ineligible. Therefore, a total of 62 papers and reports were included for full text review. Of these, 28 articles and reports were selected for analysis. Two papers were later dropped due to lack of consensus among the reviewers. Thus a total of 26 articles and reports were included in the final analysis (Fig. 1). The inter-reviewer agreement rate was 93%.
Step 4: data charting and analysis The Excel-based data extraction sheet comprised of 12 items including literature code, publication year, source and citation, title of the document, country, publication type, component of WHO building block/s addressed, targeted service, health setting(s), strategies adopted by the LMICs, main outcome/impact, and key recommendations/lessons learned (Table 3). One reviewer charted the relevant data and insights from the included studies using the developed instrument that served as our guideline, while the second reviewer ensured that the charting process was consistently applied. Once data was entered and finalized, the original data extraction sheet (Additional file 1) was transferred to a Word file (Table 7).

Analysis framework
Existing literature yields multiple approaches to assessing health systems' resilience [1,[19][20][21]. Hence, to obtain a holistic perspective on PHC system resilience across LMICs, a health systems approach was the best fit for our research question. The analysis framework for the scoping review was adapted and modified from the framework of COVID-19 and health systems resilience developed by Sagan et al. [22], Blanchet et al. [20], and the WHO position paper on 'Building health systems resilience for universal health coverage and health security during the COVID-19 pandemic and beyond' [21]. Our framework includes all six health systems' building blocks (governance, service delivery, health workforce, financing, information system, and supplies and equipment). Under each building block, a set of strategies is included. A total of 14 strategies were included. To operationally define these strategies, a description of the strategies was also added to bring transparency to our analysis in extracting the relevant information (Table 4).
The framework facilitated the exploration of resilienceenhancing strategies at the PHC level that were adopted by the LMICs during the COVID-19 pandemic. The analysis was carried out at two levels. Firstly, the findings were categorized using the WHO building blocks. Later, the findings were sorted into 'strategies and elements' across the building blocks, as guided by our framework (Table 4). To overcome the researcher's subjectivity in categorizing the findings, the second reviewer reviewed all the findings to validate the assortment, and a consensus was achieved in the team by engaging the third reviewer (Principal Investigator). Findings that were beyond the scope of PHC were excluded, and those that portray a health systems level with a strong possibility of supporting PHC were kept under the respective elements.
Step 5: synthesizing and reporting of findings The results were synthesized descriptively in the tabulated format using an Excel spreadsheet. The results were described in the narrative form by relevant themes (Additional file 2), as highlighted in the analysis framework. This includes a detailed description and charting of the                                 relevant data in specified categories for each of the six building blocks, as depicted in the analysis framework. Furthermore, the results were also tabulated and synthesized at the country level by selecting the key findings from the analysis using the WHO building blocks framework ( Table 5). The scoping review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) Checklist [23] (Table 8).

Patient and public involvement
There has been no patient or public involvement in the development of this protocol, neither in the scoping review itself.

Coordination, monitoring & quality control
The study has ensured quality control by adhering to the standard protocols for conducting the scoping review. This includes the use of the PRISMA-ScR checklist for reporting review findings. Furthermore, this review was undertaken by two well-experienced researchers with expertise in the scoping review. The reviewers were oriented on the conduct of the scoping review to ensure consistency in the data collection and analysis approach. In addition, throughout the review process (study selection, data extraction process, and data analysis) frequent debriefing meetings were carried out within the research team to ensure consensus among the team.

Characteristics of studies
Our findings encompassed a total of 26 studies and documents across 44 LMICs, which were published between the years 2020 and 2021. The included articles document any aspect related to the six health systems building blocks of PHC services (health services delivery, health workforce, governance, finance, supplies and equipment and information system) or the combination of these during the COVID-19 pandemic. The distribution of different types of publications in our analysis includes reports/updates (n = 13), journal articles (n = 8), policy briefs (n = 2), reviews (n = 2), and guidance documents (n = 1). The overall results were synthesized according to the WHO health systems building blocks framework (Additional file 2). The country-specific key findings are presented in Table 5.

Governance
In the context of our study, governance refers to the comprehensive management, leadership, and decision-making processes that guided the policies, strategies and operations of the PHC system during the COVID-19 pandemic.

Adequate and effective leadership
Adequate and effective leadership plays a critical role in building a resilient health system during a crisis. Leaders in healthcare organizations and government agencies are responsible for strategic decisions to enable healthcare systems to withstand the challenges posed by the pandemic. Out of the 44 LMICs, only 16 countries (Bangladesh, Bhutan, Bosnia and Herzegovina, Ethiopia, India, Kenya, Morocco, Mozambique, Nepal, Nigeria, Rwanda, Sri Lanka, Thailand, Timor-Leste, Uganda and Zimbabwe) introduced guidelines and response strategies that reflected adequate and effective leadership during COVID-19 pandemic ( Table 6).
The Nigerian President approved and enacted the COVID-19 Health Protection Regulations in 2021. This law established a legal framework to protect public health and mitigate the spread of the COVID-19 pandemic within the country [24]. The national guidelines were introduced on maternal, newborn, and child health (MNCH) and family planning (FP) in Bangladesh, while countries such as Bhutan, India, Kenya, Mozambique, and a few other states also developed guidelines on MNCH with an element of reproductive component nested into it [24][25][26][27][28][29][30] (Table 5). In Timor-Leste, protocols for delivering antenatal care (ANC) and postpartum care in the context of the COVID-19 pandemic were developed and implemented [28]. Furthermore, since the announcement of the epidemic in China, the Moroccan government deployed an institutional and risk-based communication strategy without any COVID-19 cases notified in the country [31].

Coordination of activities across government departments and among key stakeholders
Coordination of activities across various departments in the government and key stakeholders ensures a comprehensive and coordinated response to the pandemic, including prevention, detection of cases and response efforts. However, evidence of coordination and collaboration across the different institutes and governmental organizations to tackle the crisis while maintaining essential healthcare services emerged only from 11 countries (Bangladesh, Ethiopia, Kenya, Morocco, Nigeria, North Macedonia, Rwanda, Senegal, Serbia, Timor-Lester and Ukraine) [1,8,24,28,[31][32][33] (Table 6). For instance, the Ethiopian Public Health Institute (EPHI) initiated a program called COVID -19 Plan Revitalization Movement, which aimed to bolster the response to the COVID-19 pandemic by raising public awareness through risk communication and community involvement . Another such example was from Morocco, where political commitment, organization and coordination of the response ensured the integration of all key stakeholders across all levels (central, regional and local) [31].  Similarly, in Nigeria, the key stakeholders inclusive of the National Primary Health Care Development Agency (NPHCDA) and other multisectoral partners collaborated to develop a plan for continuing and optimizing PHC services during the COVID-19 pandemic [33].

Financing
Adequate financial resources during a crisis allow for better management of resources. Our analysis focussed on two financing strategies to ensure resource mobilization during a public health crisis. These are explained next.

Ensure sufficient monetary resources in the system and flexibility to reallocate and inject extra funds into the system
In total, 8 out of 44 countries (Bhutan, India, Kyrgyzstan, Nigeria, North Macedonia, Senegal, Serbia and Ukraine) had adopted strategies to ensure the availability of necessary monetary resources to respond to the pandemic effectively and efficiently without compromising essential healthcare services (Table 6). For instance, to reduce the financial toll of the pandemic on poor households, Nigeria expanded the reach of the National Social Safety Nets Project (NASSP) and its regular cash transfer initiative [33]. Another strategy was the mobilization of private sector funding to supplement existing stock in Bhutan [34].
Flexibility to reallocate and inject extra funds into the system refers to the ability to adjust the allocation of resources in response to the COVID-19 crisis [19]. This involved reallocating resources from one area of the system to another or injecting additional funding to address emerging needs during the COVID-19 pandemic. In Senegal, the budget was allocated to the health system as part of a resilience package aimed at improving testing, treatment, tracing, and prevention measures, alongside enabling the recruitment of additional health workers [24].

Purchasing flexibility and reallocation of funding to meet changing needs
Nigeria was the only country that granted loans and waivers to pharmaceutical firms to encourage the development of vaccines against COVID-19 [33] (Table 5).

Health workforce
Having a strong, well-trained, and adequately deployed health workforce serves as the foundation to respond to the crisis.

Appropriate level and distribution of human resources
Ensuring adequate level and distribution of the health workforce remained a popular area of intervention among the LMICs during the COVID-19 pandemic. The evidence from 13 countries (Bangladesh, Bhutan, Brazil, Congo, India, Kenya, Malawi, Myanmar, Nepal, Pakistan, South Africa, Sri Lanka and Sudan) demonstrated a wide range of measures implemented to ensure sufficient stock of front-line healthcare workers to manage the influx of patients with COVID-19 (Table 6).
In Brazil, specialists were relocated to PHC centres to facilitate access for pregnant women [34]. Similarly, Congo redeployed health personnel from departments with low patient load to Reproductive, Maternal, Neonatal, Child, and Adolescent Health (RMNCAH) departments [34]. India also redeployed additional nursing staff to PHC centres from other facilities [34], while Kenya redeployed staff within and between facilities [25]. In Pakistan, inactive women doctors were mobilized to deliver RMNCAH services through virtual platforms in collaboration with the private health sector [34].

Motivated and well-supported workforce
Healthcare workers were under extreme mental and physical duress during the COVID-19 pandemic, and thus it was essential to provide them with adequate psychological support and to prevent burnout. A total of 16 countries (Albania, Bangladesh, Bosnia and Herzegovina, Bulgaria, Kenya, Kyrgyzstan, Morocco, Nepal, Nigeria, Russian Federation, South Africa, Sudan, Tajikistan, Uganda, Ukraine and Yemen) [1,25,28,31,34,35] documented coping strategies for healthcare personnel ( Table 6). The most frequently documented strategy was the provision of psychosocial support and counselling services to facilitate the health workforce to cope with the pandemic [34].

Recruitment and capacity building of the health workforce
A total of 21 LMICs (Bangladesh, Bhutan, Bolivia, Brazil, Congo, Ethiopia, India, Kenya, Malawi, Maldives, Myanmar, Nepal, Nigeria, Pakistan, Senegal, Sri Lanka, Sudan, Tajikistan, Thailand, Uganda and Yemen) had documented evidence on recruitment and capacity building of their healthcare workers during the pandemic (Table 6). It was crucial to enhance the capacity of the health workforce through training and preparing healthcare workers to cope with the increased work burden during the pandemic [1,8,24,25,28,30,31,[34][35][36][37][38][39]. One interesting finding that emerged during the synthesis of evidence was the use of digital technology to train healthcare workers. For instance, in Ethiopia, a mobile learning platform was introduced that utilized an interactive text message and voice response application for training the healthcare personnel on sexual reproductive, maternal, neonatal, child, and adolescent health (SRMNCAH) services during the COVID-19 pandemic [34]. Some LMICs also invested in training medical staff and postgraduate students to provide emergency obstetric care, family planning and antenatal care services [25,26,28,30,33,34,38,40]. India expedited recruitment and filled existing staff vacancies amid the COVID-19 pandemic [38]. The involvement of community health workers (CHWs) and community health volunteers (CHVs) and their training across various PHC activities such as infection prevention and control in Yemen [34], training of Rohingya refugees (who worked as CHVs) in immunizations, management of non-communicable diseases, and maternal and child health support [37], and activities including preventing the spread of rumours and misinformation in the community by India [37] was evident in the review.

Service delivery
Provision of safe and effective and quality healthcare services to individuals and communities while reorganizing the PHC infrastructure remains the hallmark of a resilient health system.

Absorptive, adoptive and transformative capacity
In 35 countries, evidence related to the three essential resilience capacities (1. absorptive, 2. adoptive, 3. transformative) of PHC systems was discussed ( Table 6). The absorptive capacity refers to 'the capacity of the healthcare system to respond to the pandemic while continuing to deliver the same level of basic healthcare services' [41]. The example includes the development of contingency plans in Bhutan to ensure the provision of essential healthcare services and the activation of micro-plans for health facilities [28]. In Kenya, specific policies were implemented to guarantee uninterrupted essential care for expectant and nursing women [25]. The adoptive capacity of health is defined as 'the adaptation to the shock (COVID-19 pandemic) and continue providing the same level of healthcare services with fewer or different resources' [41]. The transformative capacity refers to 'the ability of the health system to reorient and transform its functions in response to the shocks' [41]. Examples of the later two categories include the strengthening of referral and transport mechanisms in Bolivia, India and Sri Lanka [28,34]. Furthermore, in India, health facilities at all levels (block, district and state) were mapped, and healthcare service delivery was restructured to cater to both COVID-19 and non-COVID-19 care needs [42].
Transformation of service delivery was also evident with the use of digital platforms across multiple countries. The use of WhatsApp, Viber, hotlines, and telemedicine for providing maternal, child, reproductive, and adolescent health services were used in Bolivia and Bangladesh [34]. Refer to Table 5 (service delivery domain) with specific examples illustrating three different capacities while coping with the COVID-19 pandemic.

An essential package of healthcare services
Our evidence synthesis revealed that 17 out of 44 countries (Bangladesh, Botswana, Brazil, Ghana, India, Kenya, Liberia, Malawi, Maldives, Myanmar, Nepal, Nigeria, Sierra Leone, South Africa, Uganda, Yemen and Zimbabwe) implemented measures to ensure the delivery of essential public health services during COVID-19 (Table 6). This encompassed strategies that aimed to develop a package of services that was adequately resourced, organized and distributed by identifying vulnerable population groups (ensuring that appropriate data are collected) and ensured adequate access to services and evidence of continuing essential public health functions (including health education and awareness).
Uganda conducted community outreach activities for adolescents on sexual and reproductive health (SRH), HIV counselling and testing, ANC, contraception, condom distribution, and human papillomavirus immunization [34]. Brazil implemented an elderly health home record book to record personal, social, and family data, health conditions, health behaviours and vulnerabilities, and guidance on self-care [34].

Evidence of services related to COVID-19 pandemic
A total of 20 countries (Albania, Bangladesh, Bolivia, Cameroon, Ethiopia, Ghana, India, Indonesia, Kenya, Maldives, Morocco, Mozambique, Myanmar, Nigeria, Rwanda, South Africa, Sudan, Tajikistan, Timor-Leste and Uganda) reported evidence of measures taken by LMICs to provide services for COVID-19 testing, isolation and quarantine (Table 6). In Albania, PHC providers assisted public health surveillance teams with contact tracing [1]. In India, several measures were instituted, such as the introduction of standard operating procedures for screening, triage, and isolation for suspected maternal and newborn COVID-19 cases [34]. Furthermore, antenatal care services for pregnant women were offered at quarantine centres in Myanmar [34] (Table 5).

Ability to deliver services safely
Alongside ensuring the continuity of essential healthcare services to the population during COVID-19, patient and health worker safety is also crucial.
The evidence of safe delivery of services emerged from 21 countries during our review. This includes Bhutan, Bolivia, Botswana, Cameroon, Ethiopia, Ghana, India, Indonesia, Kenya, Malawi, Morocco, Myanmar, Nepal, Nigeria, Pakistan, South Africa, Sri Lanka, Tajikistan, Uganda, Yemen and Zimbabwe [24-26, 28, 30, 34, 35] (Table 6). For instance, in Bolivia, prenatal and PNC visits were scheduled to reduce the number of women in close contact at health facilities [34]. In Sri Lanka, while treating children under 5 years of age at the primary care level, infection prevention and control measures were followed [28]. (Table 5).

Information system
The adaptations in the information system for timely data collection and evidence-based decisions drive the public health response during a crisis (Table 5).

Surveillance and timely generation of data during the COVID-19 pandemic
Surveillance played a critical role in facilitating the identification of COVID-19 cases, tracking the spread of the virus and informing public health interventions to control the outbreak [26,30,32,[42][43][44]. Surveillance measures were evident in 11 out of 44 countries, including Bangladesh, Bolivia, Ethiopia, Ghana, India, Malawi, Maldives, Nepal, Nigeria, South Africa and Uganda (Table 6). India managed the pandemic utilizing an integrated disease surveillance system [42]. Bolivia coordinated with RedBol12 and the National Sexually Transmitted Infection/HIV/AIDS program to support surveillance, information and referral centres [34]. In Nigeria, case-based digital surveillance from health facilities was carried out through the Surveillance Outbreak Response Management and Analysis System [43]. Similarly, South Africa developed COVID Connect and COVID Alert South Africa app notification systems for COVID-19 management [43] (Table 5). Furthermore, in the Maldives, monitoring of service data and digitization of maternal and child health records assisted in harmonizing real-time monitoring [28].

Effective information (communication) systems and flows
Evidence from 17 out of 44 countries (Bangladesh, Bhutan, Cameroon, Congo, Ethiopia, Ghana, Kenya, Malawi, Maldives, Morocco, Mozambique, Nigeria, Pakistan, South Africa, Sri Lanka, Uganda and Yemen) demonstrated measures to facilitate the effective flow of information across different institutions (Table 6). For instance, in Morocco, multiple awareness-raising spots on preventive measures have been produced and distributed continuously to raise awareness to avoid the risk of contamination [31]. Similarly, in Cameroon, broadcast, print and social media campaigns were utilized to raise awareness of the reopening of health facilities for routine healthcare services [34].

Supplies and equipment PPE and other essential supplies and equipment for PHC service delivery
The provision of PPE and other essential supplies and equipment for PHC service delivery was documented by 22 out of 44 LMICs (Table 6). Evidence from Kenya, Maldives, Pakistan, and Sri Lanka revealed the availability of PPE being ensured in PHC facilities [24,28,[45][46][47][48] to safeguard the continuity of health services [36]. The LMICS including Cameroon, Ethiopia, Maldives, Myanmar, Morocco, Nepal, Nigeria, South Africa, and Yemen documented measures to ensure the availability of essential medicines, equipment, and supplies at the facility level during the COVID-19 pandemic [24,28,31,34,43]. This includes strengthening the supply chain and procurement of RMNCAH commodities in Ethiopia [34], as well as the mobilization of equipment and supplies for emergency obstetric and newborn care (EmONC) care and personal hygiene in Sri Lanka [28]. In addition, a monitoring dashboard was developed in Nigeria to ensure appropriate distribution and availability of contraceptive supplies [34], while in Nepal the supply of FP commodities was increased at the PHC level through collaborations with private organizations and non-governmental organizations (NGOs) [34].

Discussion
The unprecedented challenge posed by the COVID-19 pandemic was responded to by a variety of measures adopted by 44 LMICs around the world to continue uninterrupted healthcare services at the PHC level. To our knowledge, this scoping review is the first of its kind in consolidating the existing evidence across resource-constrained settings on the capacity of the PHC system during the COVID-19 pandemic by using the WHO's six-building blocks framework. Despite being faced with significant challenges, such as limited funding, workforce shortages, weak and poor governance, and weak health systems, our review demonstrated that several LMICS implemented innovative strategies and transformed the PHC infrastructure to maintain the delivery of PHC services, showcasing their ability to be resilient in times of crises.
Our review identified commonalities among countries in their response to fight the pandemic and initiation of public health measures that fall under the larger ambit of PHC. In general, the majority of LMICs implemented measures and strategies across the domains of governance, service delivery, and health workforce. The role of governance and leadership to coordinate the PHC response system during the pandemic has emerged during our review. The governing bodies of LMICs unequivocally prioritized healthcare services for SRMNCH during the COVID-19 pandemic over other services [28]. The response was led by the central and local health governing bodies that introduced nationallevel guidelines and protocols for SRMNCAH in multiple countries including Bangladesh, Bhutan, India, Kenya, and Mozambique, among others [8,24,26,28,29]. The measures introduced at the central and local governance trickled down to the service delivery level, which exhibited the shock absorptive capacities of LMICs to respond to the pandemic while continuing to deliver essential healthcare. For example, in Kenya, special guidelines were enacted to ensure that pregnant and breastfeeding women continued to receive the requisite care without any disruption [30]. Likewise, India continued offering both non-COVID-19 and COVID-19-related health services by decentralizing essential healthcare services [42]. (Table 5). Countries including Bolivia, India, and Sri Lanka strengthened referral systems and transportation facilities [28,34], with evidence of emergency referral transport systems established for women, children and adolescents as reported from these countries. (Table 5). Contingency planning remains a crucial process in being prepared with needed resources in the pre-disaster phase. We found an evidence of contingency planning only in Bhutan, which involved ensuring the provision of essential healthcare services and the development of micro-plans for service provision at health facilities [28] (Table 5). LMICs also adopted innovative and technologically driven strategies to reorient their PHC services during the COVID-19 pandemic; their approach towards using and integrating digital options, however, varied across multiple countries. Nigeria utilized a surveillance outbreak response management and analysis system to support case-based digital surveillance [43], while Bolivia took the opportunity of the digital platform to build health workers' capacity [34]. The use of the WONDER App (mobile application) in India was unique to tracking high-risk pregnancies and continuity of care [34] (Table 5). Furthermore, the use of WhatsApp and other telemedicine for providing maternal, child, reproductive and adolescent health services was documented in Bolivia and Bangladesh [34]. Additionally, examples of the use of digital technologies kept flourishing in LMICs amidst the COVID-19 pandemic. Some highincome countries such as China and South Korea reported the use of artificial intelligence to develop faster and more accurate COVID-19 diagnostic tests and to analyse large amounts of data to identify patterns and predict the spread of the virus [49]. Though transforming the PHC service delivery with digital options are appreciated, what is important is to also investigate how well the quality of healthcare services was ensured and whether countries were able to sustain the digital options in PHC service delivery. These, however, remain beyond the scope of our work.
Our review also exhibited that several countries grappled with a shortage of healthcare workers, which made it even more challenging for healthcare systems to cope with the influx of patients, resulting in long wait times, delayed care, and in some cases, inadequate care [1,24,30]. To address this challenge, many countries recruited and trained additional health workers and provided incentive pay to retain and motivate them [1,24,30,31,35] (Table 5). The mobilization of CHWs and their capacity building was also evident in a few of the countries (Nigeria, Malawi, Bangladesh, Yemen, India) to offer services for COVID-19 and other essential healthcare services. A similar approach was documented in developed countries such as Germany, where HCWs were incentivized using bonus payments and rewards during the COVID-19 pandemic. Though monetary incentives have a strong influence on health workers' motivation and retention [49], resource-constrained countries must plan sustainable financing schemes for health worker retention in the longer run.
To build resilient health systems, it is crucial not only to maintain essential services, but also to ensure that COVID-19 cases can be managed at the PHC level. Our scoping review revealed that despite facing numerous challenges, most LMICs developed sophisticated systems for screening, triaging and diagnosing COVID-19 at the PHC level while maintaining the provision of essential services [1,34]. Our findings are consistent with those of Haldane et al., who documented measures adopted by countries including active surveillance, testing, contact tracing, use of innovative and digital solutions, and preservation of PHC services by supporting CHWs for outreach services [49].
Our review of the 44 LMICs revealed that Nigeria and India were the only countries that exhibited evidence of resilience measures across all six health systems building blocks (Table 6). With the emergence of the COVID-19 pandemic, the Nigerian President signed the law for COVID-19 Health Protection Regulations 2021 to safeguard the population's wellbeing by enforcing mandatory compliance with facility protocols [24]. Under this law, a designated space or holding bay was established at all facility levels (primary, secondary and tertiary) for the initial triage of individuals suspected to have COVID-19 [24,34]. The National PHC Development Agency collaborated with multisectoral partners and donors to develop a plan for continuing and optimizing PHC services that could be scaled up and sustained over time [33]. Additionally, the Nigerian government recruited, trained and incentivized healthcare workers to continue the provision of essential services [34].
Our analysis revealed that only a few of the lowresource countries struggled to address the healthcare financing measures for the continued delivery of PHC services amidst the COVID-19 pandemic [24,28]. Noteworthy to mention is the budget allocation to the health system in Senegal (part of the resilience package for diagnostic and treatment services for COVID-19), the launch of an insurance package for the health workforce in India, and the purchasing flexibility and duty waivers to pharmaceutical companies in Nigeria for vaccine development [24,28] (Table 5).

Strengths and limitations
To the best of our knowledge, this is the first scoping review that has described the resilience of the LMICs' PHC systems during the COVID-19 pandemic. The use of the WHO health systems building blocks framework integrated with other resilience frameworks facilitated in collating and compiling the overall resilience-enhancing activities (Additional file 3). The challenges encountered during the conduct of the scoping review included: (i) reporting of measures and interventions at the health systems level rather than at the PHC level, which led to discussions in our team to sort and segregate measures specific to the PHC level; (ii) overlapping elements across the building blocks framework leading to duplication of results in a few areas, which led us to revisit the framework and take another look at the analysis; and (iii) the results synthesized and recommendations emerging from our review are based on the findings obtained. Therefore, any resilience measures by LMICs in our review could have been potentially missed in the case that it was not documented (Additional file 4).
The 44 countries that were included in our analysis represent diversified healthcare systems, with a mix of public and private healthcare actors and limited resources with a wide range of contextual factors that may have potentially affected countries' approaches to fight against the COVID-19 pandemic. Understanding the contextual challenges (pre-pandemic as well as during the pandemic) experienced by these territories is instrumental in understanding the resilience measures that we were trying to synthesize. However, during data extraction, it was realized that not all countries reported challenges and limitations specific to the strategies and measures to continue to deliver PHC services. Hence, this limited our approach to documenting country-specific challenges. Some of the common challenges that were reported for 17 out of 44 countries included in our review (Bolivia, Brazil, Kazakhstan, Tajikistan, Pakistan, Sudan, Yemen, Democratic Republic of Congo, Ethiopia, Nigeria, South Africa, Uganda, Bangladesh, India, Myanmar, Nepal and Timor-Leste) include disrupted information systems, balancing the secondary and tertiary care services in hospitals with PHC services, limited transport to women and children, and re-purposing health workers to COVID-19, to mention a few [34].
A critical insight into country-specific contextual factors was thus beyond the scope of this review, as we primarily assessed the resilience strategies adopted by countries for the PHC system amidst the COVID-19 pandemic. How countries' approaches were challenged and restricted by contextual factors require a next level of analysis.

Annexure
See Tables 7 and 8     Data charting process 10 Describe the methods of charting data from the included sources of evidence (e.g. calibrated forms or forms that have been tested by the team before their use, and whether data charting was done independently or in duplicate) and any processes for obtaining and confirming data from investigators 4 Data items 11 List and define all variables for which data were sought and any assumptions and simplifications made