4 Title & Abstract Screening in Covidence

Why Screening Matters

Before we can analyze anything, we need to identify which studies are actually relevant to our research question. This starts with screening, a process of filtering thousands of search results down to the small set of studies that meet our inclusion criteria.

We use Covidence, a platform built specifically for systematic reviews. In this step, you’ll read the title and abstract of each study and decide whether it might be eligible. If so, we include it for full-text review.

This process may seem repetitive—but it’s one of the most important stages. Every strong meta-analysis depends on careful, consistent screening.

Your Job: Scan, Decide, Repeat

In the title & abstract screening phase, your job is to quickly ask:

• Is this study about pregnancy?

• Does it examine exposure to PM₂.₅ (or ambient air pollution)?

• Is it a human study (not animal or lab-based)?

• Does it take place in an LMIC or global south setting?

If you answer yes to most of these, vote Include.

If you’re unsure—include it. It’s better to flag something for a second look than to accidentally leave out a valuable paper.

Include If:

• The title or abstract mentions PM₂.₅, air pollution, or fine particulate matter

• It involves pregnant women or birth outcomes

• It takes place in Africa, Asia, Latin America, or other LMICs

• It appears to report health outcomes (e.g., preterm birth, stillbirth, low birth weight)

Exclude If:

• It is a lab, animal, or in vitro study

• The focus is indoor air pollution only (e.g., cookstove interventions), unless PM₂.₅ is measured

• It’s about postnatal or childhood outcomes only

• There is no mention of air pollution or PM₂.₅

• It is a conference abstract, editorial, or review with no original data

Tips for Screening in Covidence

• Keep it quick: You’re not making final decisions – just flagging papers that might be relevant.

• Use CTRL+F (or CMD+F on Mac) to find keywords like PM2.5, pregnancy, birth, Africa, etc.

• Don’t overthink it: If in doubt, vote Include—someone else will double-check it.

Each study is screened independently by two people. If you and your partner disagree, a third reviewer will resolve the conflict.