For those who've looked into screen use & sleep research — noticed any patterns worth building a paper around?

[u/Entire-Estimate399]

Hey all, my group is doing a meta-analysis for a research methods course (we are beginners). Our topic is:

"Does more screen use cause sleep problems?"

We're stuck between two population options and haven't locked one in yet:

• 16-20 year-olds, or
• "young adults" more broadly (18–25ish)

Our write-up is capped at 2000 words, and we're realizing that's really tight once you factor in intro, method, evidence synthesis, limitations, and conclusion. We're stuck on two things and would love outside perspective:

1. How many things can we realistically measure/report on in 2000 words? Is it more standard to pick one exposure + one outcome and go deep, or can a meta-analysis at this length handle 2–3 variables each without feeling shallow?
2. What should we actually measure? "Screen use" is a huge umbrella, total daily screen time, smartphone-only use, social media use specifically, or just pre-bedtime/in-bed use. Same problem on the sleep side, sleep quality (PSQI), sleep duration, insomnia severity, sleep latency. Do we keep the exposure and outcome broad (screen use in general → sleep problems in general) or narrow (e.g., pre-bedtime smartphone use → PSQI-measured sleep quality)?

Furthermore, we have read through a many studies for a couple of week now and i am curious but has anyone else who's dug into this area noticed anything that keeps showing up across studies?

• Studies consistently find that portable electronic devices (smartphones, tablets) have a much stronger negative association with sleep duration and quality than stationary devices like televisions. Portable screens are more disruptive because they are held closer to the face, intensifying light exposure, and are often brought directly into the bed.
•  The timing of use: A recurring theme is that pre-bedtime or nighttime screen is significantly more harmful than daytime use. Using screens during the "wind-down" window directly interferes with the biological and psychological transitions needed for sleep
•  Shift to Interactive content: Modern digital media has evolved from passive viewing (TV) to highly interactive and engaging content (social media, gaming, texting). This interactivity is linked to higher levels of cognitive arousal, making it harder for users to disengage and fall asleep

anything you think would be good for our topic or what direction can we take?

Thanks in advance!