Example: Arksey and O'Malley's Scoping Review on Informal Caregiving

This foundational work not only provides a comprehensive overview of the scoping review methodology but also serves as an illustrative example of how a scoping review can be effectively conducted.

Title: Scoping studies: towards a methodological framework

Authors: Hilary Arksey and Lisa O'Malley

Published In: International Journal of Social Research Methodology, 2005

Purpose: The primary aim of this scoping review was to map the existing literature on informal caregiving, identify the key concepts, types of evidence, and gaps in the research, and provide a clear framework for conducting scoping reviews.

Key Characteristics of the Review:

1. Broad Scope: The review aimed to cover a wide range of literature on informal caregiving, without restricting the scope to specific interventions or outcomes. This allowed for a comprehensive understanding of the topic.
2. Systematic Approach: The authors used a systematic method to search for and identify relevant studies. They defined clear research questions and criteria for including studies in the review.
3. No Quality Appraisal: Unlike systematic reviews, this scoping review did not include a detailed quality assessment of the individual studies. Instead, it focused on summarising the breadth and types of evidence available.
4. Diverse Evidence Types: The review included various types of evidence, such as quantitative studies, qualitative studies, and grey literature, to provide a holistic view of the research landscape.
5. Descriptive Summary: The findings were presented in a descriptive format, highlighting key themes, gaps, and the range of evidence available. The review also provided visual representations, such as tables and charts, to map the literature.

Key Findings:

• The review identified several key themes in the literature on informal caregiving, including the challenges faced by caregivers, the types of support needed, and the impact of caregiving on caregivers' health and well-being.
• It highlighted significant gaps in the research, such as the need for more studies on specific subgroups of caregivers and the long-term effects of caregiving.
• The review emphasised the importance of developing a clear methodological framework for conducting scoping reviews, outlining steps such as identifying the research question, searching for relevant studies, selecting studies for inclusion, charting the data, and summarising and reporting the results.

Impact:

This scoping review by Arksey and O'Malley has had a significant impact on the field of research methodology. It provided a foundational framework that has been widely adopted and cited by researchers conducting scoping reviews across various disciplines.

Summary:

This example demonstrates how a scoping review can be effectively used to map a broad field of research, identify key themes and gaps, and provide a comprehensive overview of the existing evidence. Arksey and O'Malley's work serves as a model for conducting scoping reviews and has contributed to the standardisation and development of this important methodological approach in evidence synthesis.

NIHR Example:

Recent Scoping review (from NIHR Journals library database 30/7/2024)

Webb EJD, King N, Howdon D, Carrol ED, Euden J, Howard P, et al. Evidence of quality of life for hospitalised patients with COVID-19: a scoping review

Funding: Health Technology Assessment programme (Health Technology Assessment, Published in May 2024) https://doi.org/10.3310/ATPR4281 https://www.journalslibrary.nihr.ac.uk/hta/published-articles/ATPR4281/#/abstract

Example: Systematic Review on Nicotine Replacement Therapy for Smoking Cessation

This review is a prime example of how systematic reviews can be used to summarise evidence from multiple studies to inform healthcare practice and policy.

Title: Nicotine replacement therapy for smoking cessation

Authors: Silagy, C., Lancaster, T., Stead, L., Mant, D., & Fowler, G.

Published In: Cochrane Database of Systematic Reviews, 2004

Purpose: The primary aim of this systematic review was to evaluate the effectiveness of various forms of nicotine replacement therapy (NRT), such as patches, gum, lozenges, inhalers, and nasal sprays, in helping people quit smoking.

Key Characteristics of the Review:

1. Comprehensive Literature Search: The review included a detailed and systematic search of multiple databases to identify randomised controlled trials (RCTs) that evaluated the effectiveness of NRT for smoking cessation. The search strategy was designed to be exhaustive to ensure all relevant studies were included.
2. Inclusion and Exclusion Criteria: Clear criteria were established for including studies in the review. Only RCTs that compared NRT to placebo or no treatment and reported on smoking cessation outcomes were included.
3. Quality Assessment: Each included study was assessed for quality and risk of bias using standardised criteria. This ensured that the findings of the review were based on high-quality evidence.
4. Data Extraction and Synthesis: Data from the included studies were systematically extracted and synthesised. The review used meta-analysis to combine data from multiple studies, providing a pooled estimate of the effectiveness of NRT.
5. Statistical Analysis: The review conducted meta-analyses using fixed-effect or random-effect models, depending on the level of heterogeneity among the studies. It also assessed publication bias and conducted sensitivity analyses.

Key Findings:

• The review found that all forms of NRT (patch, gum, lozenges, inhalers, and nasal sprays) significantly increased the likelihood of quitting smoking compared to placebo or no treatment.
• The pooled analysis showed that the use of NRT doubled the chances of successful smoking cessation.
• The effectiveness of NRT was consistent across different forms and doses, and it was effective regardless of the level of additional behavioural support provided.

Impact:

This systematic review provided robust evidence supporting the use of NRT for smoking cessation. It has informed clinical guidelines and public health policies worldwide, promoting the widespread use of NRT as a first-line treatment for people attempting to quit smoking.

Summary:

This Cochrane systematic review is a classic example of how systematic reviews can be used to rigorously evaluate the effectiveness of healthcare interventions. By combining evidence from multiple high-quality studies, the review provided clear and reliable conclusions about the benefits of NRT for smoking cessation, which have had a significant impact on clinical practice and policy.

NIHR example:

Recent systematic review and meta analysis (from NIHR Journals library database 30/7/2024)

Caldwell DM, Davies SR, Thorn JC, Palmer JC, Caro P, Hetrick SE, et al. School-based interventions to prevent anxiety, depression and conduct disorder in children and young people: a systematic review and network meta-analysis. Public Health Res 2021;9(8)

Funding: Public Health Research programme (Public Health Research Volume: 9, Issue: 8, Published in August 2021) https://doi.org/10.3310/phr09080 https://www.journalslibrary.nihr.ac.uk/phr/phr09080/#/abstract

Example: The Global Burden of Disease Study

This large-scale synthesis of evidence integrates data from multiple sources to provide a comprehensive picture of global health, identifying key health challenges and informing policy decisions worldwide.

Title: Global Burden of Disease Study 2017

Published In: The Lancet, 2018

Purpose: The primary aim of the Global Burden of Disease (GBD) Study is to provide a comprehensive assessment of the health status of populations around the world. It quantifies the burden of diseases, injuries, and risk factors by age, sex, and geography over time.

Key Characteristics of the Review:

1. Comprehensive Scope: The GBD study covers a wide range of diseases, injuries, and risk factors across all countries. It synthesises data from numerous sources, including health surveys, administrative records, vital registration data, and epidemiological studies.
2. Systematic Data Collection: The study uses systematic methods to collect and harmonise data from various sources. This includes detailed and standardised protocols for data extraction, ensuring consistency and comparability across different data sets.
3. Quality Assessment: Rigorous methods are applied to assess the quality of data sources. This includes evaluating the completeness, accuracy, and consistency of data, and adjusting for biases and missing data where necessary.
4. Advanced Statistical Methods: The GBD study employs advanced statistical techniques, including meta-analysis and modelling, to estimate the burden of diseases and risk factors. This allows for the synthesis of data from diverse sources and the estimation of health metrics such as years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life years (DALYs).
5. Interactive Data Visualisation: The findings of the GBD study are presented through interactive data visualisations and detailed reports. This makes the complex data accessible to a wide audience, including policymakers, researchers, and the general public.

Key Findings:

• The GBD study provides detailed estimates of the burden of various diseases and risk factors globally, regionally, and nationally.
• It identifies leading causes of mortality and morbidity, such as ischemic heart disease, stroke, lower respiratory infections, and neonatal disorders.
• The study highlights the impact of key risk factors, including smoking, high blood pressure, high blood sugar, and obesity, on global health.
• It reveals trends over time, showing how the burden of diseases and risk factors has changed and identifying emerging health challenges.

Impact:

The GBD study has had a profound impact on global health research and policy. It provides crucial data for setting health priorities, allocating resources, and designing interventions to address the most pressing health challenges. Governments, international organizations, and researchers use the findings of the GBD study to inform health policies and strategies aimed at improving population health.

Summary:

The Global Burden of Disease study exemplifies the power of evidence synthesis to integrate data from multiple sources and provide a comprehensive assessment of global health. By systematically collecting, evaluating, and analysing vast amounts of data, the GBD study offers valuable insights into the burden of diseases and risk factors, guiding efforts to improve health outcomes worldwide. This large-scale evidence synthesis project demonstrates how combining diverse evidence can lead to a deeper understanding of complex health issues and inform effective health policies.

NIHR Example:

Recent Evidence synthesis (from NIHR Journals library database 30/7/2024)

Kingsbury SR, Smith LK, Czoski Murray CJ, Pinedo-Villanueva R, Judge A, West R, et al. Safety of disinvestment in mid- to late-term follow-up post primary hip and knee replacement: the UK SAFE evidence synthesis and recommendations. Health Soc Care Deliv Res 2022;10(16)

Funding: Health and Social Care Delivery Research (HSDR) Programme (Health and Social Care Delivery Research Volume: 10, Issue: 16, Published in June 2022) https://doi.org/10.3310/KODQ0769 https://www.journalslibrary.nihr.ac.uk/hsdr/KODQ0769/#/abstract

Example: Meta-Analysis on Psychological Interventions for PTSD

This meta-analysis combined data from multiple studies to evaluate the effectiveness of different types of psychological therapies for PTSD.

Title: A multidimensional meta-analysis of psychotherapy for PTSD

Authors: R. Bradley, J. Greene, E. Russ, L. Dutra, and D. Westen

Published In: American Journal of Psychiatry, 2005

Purpose: The primary aim of this meta-analysis was to evaluate the efficacy of various psychological interventions for the treatment of post-traumatic stress disorder (PTSD). The study sought to determine which types of psychotherapy were most effective in reducing PTSD symptoms.

Key Characteristics of the Meta-Analysis:

1. Comprehensive Literature Search: The researchers conducted an extensive search of multiple databases to identify relevant randomised controlled trials (RCTs) and controlled clinical trials (CCTs) that evaluated psychological treatments for PTSD.
2. Inclusion and Exclusion Criteria: Clear criteria were established for including studies in the meta-analysis. Only studies that provided data on PTSD symptom outcomes and employed a control group were included.
3. Quality Assessment: The included studies were assessed for methodological quality, and only high-quality studies were included in the final analysis. This ensured the reliability and validity of the meta-analysis findings.
4. Data Extraction and Coding: Data on study characteristics, treatment types, and PTSD outcomes were systematically extracted and coded. This included details such as sample size, type of intervention, duration of treatment, and outcome measures.
5. Statistical Analysis: The meta-analysis used statistical techniques to combine the results of individual studies. This involved calculating effect sizes for each study and using random-effects models to account for variability between studies.

Key Findings:

• The meta-analysis found that psychological interventions, particularly cognitive-behavioural therapy (CBT), were effective in reducing PTSD symptoms.
• CBT showed the largest effect sizes, indicating it was the most effective treatment compared to other psychological interventions.
• Other effective treatments included eye movement desensitisation and reprocessing (EMDR) and stress inoculation training (SIT), although their effect sizes were smaller than those for CBT.
• The findings supported the use of psychological therapies as a first-line treatment for PTSD, with CBT being the most recommended approach.

Impact:

This meta-analysis provided robust evidence supporting the efficacy of psychological interventions, especially CBT, for treating PTSD. It has influenced clinical guidelines and practice, promoting the use of evidence-based psychological therapies for individuals with PTSD. The study has been widely cited and used as a reference for developing treatment protocols and informing clinical decision-making.

Summary:

This meta-analysis by Bradley et al. is a prime example of how meta-analytic techniques can be used to synthesise data from multiple studies and provide evidence on the effectiveness of different treatments. By combining data from numerous high-quality studies, the meta-analysis offered clear and reliable conclusions about the efficacy of psychological interventions for PTSD. This study has had a significant impact on the field of mental health, guiding treatment recommendations and improving outcomes for individuals with PTSD.

NIHR Example:

Recent Meta analysis (from NIHR Journals library database 30/7/2024)

A systematic review with mixed treatment comparisons meta analysis of anti-depressant treatment for adults with chronic pain

Funding: NIHR Health Technology Assessment Programme, 2024 https://www.fundingawards.nihr.ac.uk/award/NIHR128782

Example: Realist Review on the Delivery of Health Services

This review exemplifies how the realist approach can be used to understand how and why complex interventions work (or don't work) in different contexts.

Title: Realist review – a new method of systematic review designed for complex policy interventions

Authors: Ray Pawson, Trisha Greenhalgh, Gill Harvey, Kieran Walshe

Published In: Journal of Health Services Research & Policy, 2005

Purpose: The primary aim of this realist review was to develop and refine a theoretical framework that explains how health services delivery interventions work, for whom, and under what circumstances. The focus was on understanding the mechanisms that generate outcomes in different contexts.

Key Characteristics of the Review:

1. Theory-Driven Approach: The review was driven by the aim to develop and test theoretical frameworks or explanations. It sought to understand the underlying mechanisms of interventions and how they interact with various contexts to produce outcomes.
2. Iterative Process: The review followed an iterative process of searching for evidence, extracting data, and refining theories. This cyclical approach allowed the reviewers to continually refine their understanding and explanations.
3. Context-Mechanism-Outcome (CMO) Configurations: The review focused on identifying CMO configurations, which are key to realist reviews. This involves understanding the contexts in which interventions are implemented, the mechanisms through which they operate, and the outcomes they produce.
4. Diverse Evidence Sources: The review included a wide range of evidence types, including qualitative studies, quantitative studies, policy documents, and grey literature, to develop a comprehensive understanding of the interventions.
5. Explanatory Focus: Unlike traditional systematic reviews that primarily focus on effectiveness, the realist review aimed to explain how and why interventions work, emphasising the importance of context and mechanism.

Key Findings:

• The review identified various mechanisms through which health service delivery interventions achieve their outcomes, such as changes in professional behaviour, patient engagement, and organisational change.
• It highlighted the importance of context, showing that the success of interventions often depends on factors like the organisational culture, the resources available, and the specific needs of the patient population.
• The review provided a refined theoretical framework that can be used by policymakers and practitioners to design and implement more effective health service delivery interventions by considering the key mechanisms and contexts identified.

Impact:

This realist review by Pawson and colleagues has significantly contributed to the field of health services research and policy. It has provided valuable insights into the complexity of health interventions and has helped to establish realist review as a robust method for synthesising evidence on complex interventions.

Summary:

This example demonstrates how a realist review can be effectively used to understand the complexity of health service delivery interventions. By focusing on the underlying mechanisms and contexts, this approach provides deeper insights into how interventions work and can inform more effective policy and practice decisions. The work of Pawson et al. has been influential in promoting the use of realist reviews in various fields, particularly for evaluating complex social and health interventions.

NIHR Example:

Recent Realist Review (from NIHR journals library database 30/7/2024)

Maben J, Taylor C, Jagosh J, Carrieri D, Briscoe S, Klepacz N & Mattick K. Causes and solutions to workplace psychological ill-health for nurses, midwives and paramedics: the Care Under Pressure 2 realist review. Health and Social Care Delivery 2024;12(9)

Funding: Health and Social Care Delivery Research (HSDR) Programme (Health and Social Care Delivery Research Volume: 12, Issue: 9, Published in April 2024) https://doi.org/10.3310/TWDU4109 https://www.journalslibrary.nihr.ac.uk/hsdr/TWDU4109/#/abstract

Example: Rapid Review on Personal Protective Equipment (PPE) for COVID-19

This rapid review was conducted to provide timely and evidence-based guidance on PPE use to healthcare workers and policymakers during the early stages of the pandemic.

Title: Rational use of personal protective equipment (PPE) for coronavirus disease (COVID-19): interim guidance

Organization: World Health Organization (WHO)

Published In: WHO interim guidance documents, 2020

Purpose: The primary aim of this rapid review was to synthesize the best available evidence on the use of personal protective equipment (PPE) to prevent the transmission of COVID-19 among healthcare workers and the general public. The review sought to provide immediate, evidence-based recommendations in response to the urgent need for guidance during the pandemic.

Key Characteristics of the Review:

1. Expedited Process: The review was conducted rapidly, within a matter of weeks, to provide timely guidance. This involved streamlined processes for literature search, selection, and synthesis.
2. Focused Scope: The review focused specifically on the effectiveness of various types of PPE (masks, gloves, gowns, face shields) in preventing COVID-19 transmission. This narrow focus helped to expedite the review process.
3. Comprehensive Search Strategy: Despite the rapid nature of the review, a comprehensive search strategy was employed to identify relevant studies. This included searching multiple databases, preprints, and grey literature to capture the most recent and relevant evidence.
4. Inclusion and Exclusion Criteria: Clear criteria were established to include studies that provided data on PPE effectiveness, particularly in the context of COVID-19 and other respiratory infections.
5. Quality Assessment: A rapid yet rigorous assessment of the methodological quality of included studies was conducted to ensure the reliability of the evidence.
6. Synthesis and Recommendations: The evidence was synthesised quickly to produce actionable recommendations. The findings were summarised, and practical guidance was provided based on the best available evidence.

Key Findings:

• The review found strong evidence supporting the use of masks, particularly N95 respirators, in preventing the transmission of COVID-19 among healthcare workers.
• It recommended the use of surgical masks for the general public and healthcare workers when N95 respirators were not available.
• The review highlighted the importance of other PPE, such as gloves, gowns, and face shields, in providing additional protection, especially in healthcare settings.
• It emphasised the need for proper training and protocols for PPE use to maximise effectiveness.

Impact:

This rapid review provided critical, evidence-based guidance on PPE use at a time when such information was urgently needed. The WHO’s recommendations were widely disseminated and adopted by healthcare facilities and governments worldwide, helping to protect healthcare workers and the public from COVID-19. The rapid review process allowed for the timely translation of research findings into practical guidelines, which was crucial during the fast-evolving pandemic situation.

Summary:

This example demonstrates how a rapid review can be effectively used to provide timely and evidence-based guidance in urgent situations. By focusing on a specific and immediate need, employing expedited yet rigorous methods, and synthesising the best available evidence, the WHO was able to offer practical recommendations on PPE use that had a significant impact on global health during the COVID-19 pandemic.

NIHR Example:

Recent Rapid Review (from NIHR journals library database 30/7/2024)

Westwood M, Armstrong N, Krijkamp E, Perry M, Noake C, Tsiachristas A & Corro-Ramos I. A cloud-based medical device for predicting cardiac risk in suspected coronary artery disease: a rapid review and conceptual economic model. Health Technol Assess 2024;28(31)

Funding: Health Technology Assessment programme (Health Technology Assessment Volume: 28, Issue: 31, Published in July 2024) https://doi.org/10.3310/WYGC4096 https://www.journalslibrary.nihr.ac.uk/hta/WYGC4096/#/plain-language-summary

Example: Umbrella review on the impact of the Covid 19 pandemic on cancer care

A well-cited umbrella review was conducted to synthesize the fragmented evidence that emerged during the pandemic regarding its impact on cancer services..

Title: An umbrella review of systematic reviews on the impact of the COVID-19 pandemic on cancer prevention and management, and patient needs

Authors: Taulant Muka, Joshua J X Li, Sahar J Farahani, John P A Loannidis

Published In: Elife, 2023

Purpose: An umbrella review was undertaken to summarise the findings from systematic reviews on impact of the COVID-19 pandemic on cancer treatment modification, delays, and cancellations; delays or cancellations in screening and diagnosis; psychosocial well-being, financial distress, and use of telemedicine as well as on other aspects of cancer care.

Key Characteristics of the Review:

1. Broad Scope: What was the multi-dimensional impact of the COVID-19 pandemic on all aspects of cancer care, including prevention, diagnosis, treatment, and patient psychosocial well-being?
2. "Studies" Included: Included dozens of existing systematic reviews and meta-analyses that had been published rapidly during and immediately after the pandemic. Each of these reviews focused on a narrower topic (e.g., one review on screening delays, another on treatment modifications, another on telemedicine use).
3. Synthesis Goal: To consolidate the evidence from these separate reviews to give a holistic national picture of the disruption.

Key Findings:

• Treatment Disruption: There was consistent evidence across reviews of significant delays and cancellations in cancer treatment (e.g., a 50% reduction in breast and cervical cancer screening).
• Psychosocial Impact: Evidence was consistent in suggesting the psychosocial well-being of patients deteriorated, and they experienced financial distress.
• Evidence Quality: The umbrella review highlighted a crucial finding: most of the included systematic reviews were based on primary observational studies judged to be at medium or high risk of bias.

Impact:

The results served as a clear directive to the NHS and policymakers: not only was the pandemic disruptive, but the evidence base used to justify early policy responses (treatment modifications) was often of low quality, underscoring the urgent need for robust, high-quality primary research and systematic monitoring moving forward.

Summary:

This example illustrates perfectly why umbrella reviews are needed: a broad, urgent question required synthesizing fragmented evidence of varying quality to create a clear, actionable summary for healthcare leaders.

NIHR Example:

Interventions for primary prevention of cardiovascular disease: An umbrella review of systematic reviews

Uthman OA, Al-Khudairy L, Nduka C, Court R, Enderby J, Anjorin S, et al.

Funding: Health Technology Assessment programme  (Health Technol Assess 2025;29(37):19–44) https://www.journalslibrary.nihr.ac.uk/hta/published-articles/GJTR5006