Systematic review and meta-analysis: An introduction

Programa de doctorado que propone la actividad

Biodiversidad, Funcionamiento y Gestión de Ecosistemas

Persona de contacto

Arantza Aldezabal Roteta

• Teléfono: 94 601 2617
• Email: arantza.aldezabal@ehu.eus

Breve descripción de la actividad

Introduction and rationale for the course

Every year there are more and more ecological articles published. This accumulation of knowledge is vital but also presents a series of problems. First, it is increasingly hard to maintain a good knowledge of the literature on a given topic. Second, there are now so many papers on that providing a general answer about almost any question is challenging.

Systematic review and meta-analysis can help with this. We can use these methods to compile and synthesise large bodies of literature providing general answers to many ecological questions. These methods can play a major role in synthesising evidence enabling researchers, policymakers, and practitioners to make decisions informed by scientific evidence. Meta-analyses are also amongst the most widely read and highly cited papers in ecology.

This course will provide students with an introduction to these powerful methods and hands-on experience of using a variety of different methodologies needed to carry out a meta-analysis.

We will aim to make the course as relevant and interesting as possible for the students, so we will send out some pre-course questionnaires to learn about the topics that students are studying/interested in as well as what their previous experience of statistical analysis is. We will use this to prepare case studies based on students' interests.

Course objectives/Learning outcomes

By the end of the course students will be able to:

1. Identify and formulate questions suitable for a systematic review
2. Understand the importance of conducting a thorough literature search
3. Understand how to select studies to use in a systematic review
4. Evaluate studies to assess their robustness
5. Extract data from articles
6. Analyse the data they extract from studies
7. Explore heterogeneity in study results
8. Develop ideas for their own project

Requirements for students

• Some previous experience of statistics would be helpful, particularly in using R.
• It is vital students have a laptop they can use for the practical sessions.

Course structure

Anticipated time needed: 3 days (15 hours)

The structure of each session and estimated time needed are given below.

Instructors

Philip Anthony Martin, Basque Centre for Climate Change (BC3).

Ecólogo aplicado cuyo trabajo cuantifica el impacto de los seres humanos en los ecosistemas naturales y ayuda a identificar las mejores soluciones a los problemas ambientales. Gran parte de su trabajo utiliza métodos de síntesis de evidencia, como la revisión sistemática y el meta-análisis y ha trabajado en 15 publicaciones diferentes utilizando estos métodos. Actualmente, forma parte del equipo de Jorge Curiel, donde utiliza diferentes métodos de síntesis de evidencia para investigar los impactos de los cambios en la precipitación y los incendios en la biodiversidad del suelo en los bosques.

Céline Moreaux, Basque Centre for Climate Change (BC3).

Ecóloga, actualmente trabaja sobre los efectos globales y locales de las estrategias de gestión forestal en la salud y el funcionamiento de los bosques y el suelo. Tiene formación en macroecología, economía ambiental y gestión de recursos naturales por la Universidad de Copenhague (Dinamarca). Actualmente dirige una revisión a gran escala de meta-análisis (umbrella review) sobre los efectos de la gestión forestal en la salud de los bosques.

Day 1 (04/10/2023)

Start time: 10:00 am

Session 1: What are systematic reviews and meta-analyses? (~30 mins, 10:00-10:30) We will provide a general overview of systematic reviews and meta-analyses, why they are important, and what kind of questions they can answer. In this section we will also give brief details of the kinds of data and statistics used in a meta-analysis.

Session 2: Defining the scope and questions for a systematic review (~30 mins talk, ~30 mins practical session; 10:30-11:30)

• Talk: We will identify topics that are suitable for systematic reviews and meta- analyses and provide detail on how to structure questions following best- practice.
• Practical session: Students will think of questions that they could answer using a meta-analysis which they will then get feedback on. They will learn to identify relevant elements of their research questions and to assess the scope of their reviews, depending on the comprehensiveness and specificity of their questions.

Coffee break (11:30-12:00)

Session 3: Searching for papers (~30 min talk, ~60 mins practical session, 12:00-13:30)

• Talk: We will identify best practice when searching for scientific literature including the use of synonyms, use of 2oolean search terms, the available range of databases and the implications of including grey literature in searches.
• Practical session: Students will design their own search terms in small groups. We will test the ability of students’ searches to retrieve important references to measure how comprehensive they are.

Lunch break (13:30-15:00)

Session 4: Selecting studies to use (~30 mins talk, ~60 mins practical session, 15:00- 16:30)

• Talk: We will discuss the importance of inclusion criteria when carrying out a systematic review.
• Practical session: Students will screen a series of papers using an online platform. We will test the agreement between different students.

Day 2 (5/10/2023)

Start time: 10 :00am

Session 5: Critical Appraisal of Studies (30 mins talk, 60 mins practical session; 10:00- 11:30)

• Talk: We will discuss the importance of assessing the quality of studies and how to do this, using a critical appraisal protocol for evidence syntheses.
• Practical session: Students will work in groups to assess the quality of a selected case study.

Coffee break (11:30-12:00)

Session 6: Data extraction (~20 mins talk, 70 minutes practical session; 12:00-13:30)

• Talk: We will introduce the concept of data extraction from studies and discuss how to do this.
• Practical session: Students will work in groups to extract data from a study.

Lunch break (13:30-14:30)

Session 7: Effect Sizes (~20 mins talk, 40 mins practical session; 14:30-15:30)

• Talk: We will introduce the concept of effect sizes and their importance in meta- analysis.
• Practical session: Students will calculate effect sizes using data from studies

Session 8: Running your first meta-analysis (~30 mins talk, 60 mins practical session; 15:30-17:00)

• Talk: We will provide details of how to use meta-analysis to calculate mean effect sizes using a variety of different methods in R.
• Practical session: Students will use R and the package metafor to calculate mean effect sizes, interpret them, and produce some figures to display the results.

Day 3 (6/10/2023)

Start time: 10:00 am

Session 9: More complex meta-analysis (~30 mins talk, 60 mins practical session; 10:00-11:30)

• Talk: In this session we will discuss some more complex methodologies needed to perform a meta-analysis using ecological data such as multi-level models, data imputation, and testing for biases.
• Practical session: Students will use R to run multilevel models, impute missing data, and assess the impacts of various biases on meta-analysis results.

Coffee break (11:30-12:00)

Session 10: Exploring variability (~30 mins talk, 60 mins practical session; 12:00-13:30)

• Talk: In this session we will discuss the importance of exploring variability between studies using techniques such as subgroup analysis and metaregression.
• Practical session: Students will use R to run subgroup analyses and metaregressions, interpret the results, and plot some figures to display these.

Lunch break (13:30-14:30)

Session 11: Project development and brainstorming (14:30-16:30)

This session will focus on the interests of the students and any potential projects they may wish to develop. We will provide feedback on project ideas and help to guide the initial stages of potential projects.

Idioma

Inglés y Castellano

Calendario

4, 5 y 6 de Octubre de 2023: 5 horas por día (total 15 horas)

Lugar de impartición

UPV/EHU- Facultad de Ciencia y Tecnología. Leioa