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Did COVID-19 pandemic improve our sleep?

Millions infected, people locked at home, media full of catastrophic news, economic crisis coming… We found out that our sleep habits did actually improve during the pandemic, read on to see how.

Remember how it all began? We started hearing strange news about a new disease in the media. There were reports from remote countries about increasing numbers of cases, including fatalities. Something that grabs everyone’s attention, but few people take it too seriously. Then it appears in your country. A few hundred cases get diagnosed, media start spreading disastrous scenarios, the government gets serious about it and takes radical measures. Public places are closed, kids can’t go to school and, in some countries, people can’t leave their homes at all. Businesses stop working, people are getting worried about their jobs and mortgages. How does the situation influence our sleep habits?

The Italian story

  • Lockdown restrictions have significantly impacted sleep patterns
  • Italian citizens go to bed later and sleep longer
  • Sleep habits during workdays get closer to weekend values

We analyzed the recent sleep records from our users to see how such a situation affected their sleep. We have a database of 35 million records from the users who decided to share their sleep data with us. This is a unique source of information about population-wide sleep habits and we have already published several articles revealing surprising findings on our sleep.

The image below nicely summarizes the entire story. The chart shows the average wake up time in Italy during the last four months (Jan-Apr 2020). The gray line represents expected values, based on observations from previous years. The blue line depicts the actual average values this year. We chose Italy because it was one of the first countries where the epidemic erupted after China, and we have a sufficient amount of data from there (33468 records from 754 users this year).

The first cases of COVID-19 were detected on January 31. On February 21, several municipalities (about 50000 people) were locked down. The measures were being gradually expanded, until they reached the entire country on March 9. The restrictions were further toughened up during the following two weeks, up to March 21.

We can clearly see that the wake-up hour shifts as the restrictions expand, peaking at about 40 minutes later wake-up, compared to previous years. The difference is getting smaller recently, as some restrictions are being eased.

There is a similar impact on other sleep statistics too – people go to bed about 20 minutes later and sleep 20 longer. The times change only a little for weekends and sleep habits during workdays get closer to the weekend values.

We also tried to find out how people perceive the shift in their sleep subjectively. We evaluated the overall rating of the sleep, as well as the frequency of the tags like #stress, #alcohol, or #sport, attached to sleep records. Unfortunately, only a small part of the users provides this kind of input consistently, so the results were not conclusive and there was no clear change during the lockdown.

Shift towards the natural rhythm

  • People in locked-down countries tend to return to their natural sleeping rhythms
  • People in countries without lockdowns did not change their sleeping habits

Although people are under great pressure these days, it looks like their sleep habits have actually improved. As we explained in earlier posts (The World is Sleep Deprived, On Social Jetlag), most people sleep less than they should, and they often must wake up at a time that does not agree with their natural disposition. When given an opportunity, like weekend or holiday, their sleep habits shift immediately towards their natural needs. We can observe the very same phenomenon during lockdown when most people can structure the day with more freedom.

The very same pattern as in Italy occurs in every country that implements a strict lockdown policy (USA, Germany, Russia, Czechia, etc, etc). What is most astonishing, even the actual times (20 minutes longer sleep, 20 minutes later sleep onset, 40 minutes later wake up) are very similar in all the countries. It looks like we have the first large-scale experiment in history, showing how much today’s sleep habits have departed from the normal and what happens when people have an opportunity to sleep naturally.

On the other hand, some countries, such as Sweden, Japan, or Korea, implemented more liberal policies – children keep going to schools, most businesses remain open, people are not locked at home. We did not observe any change in sleep habits in these countries, as most people probably retained their regular daily schedule.

New York drilldown

  • One third of NY population had dramatically changed their sleep habits for the better

Let’s move to the state of New York. It is a relatively small area, heavily hit by the epidemic. Furthermore, it has the highest density of our users in the entire world, hence providing enough data for subgroup analysis.

Not everyone has an opportunity to sleep freely during the pandemic. Some people still need to attend their jobs personally, and heroic medical workers maybe do not sleep at all these days. Besides, some people were able to sleep satisfactorily even before the lockdown, so there is no reason for them to change their habits.

Our data show that there is no significant subgroup that sleeps significantly less after lockdown. The obvious exceptions, such as doctors and medical staff, either form too small groups to be statistically significant, or they just have better things to do these days than to track their sleep. About 2/3 of people changed their sleep habits only a little – measured by the standard deviation from previous years, and 1/3 changed them dramatically. They wake up more than 50 minutes later or sleep more than 30 minutes longer. These are the poor hard-workers who have been trading their healthy sleep for professional achievements for a long time.

There are also dramatic differences related to age. People around 20 changed their habits the most. They sleep 25 minutes longer and wake up 80 minutes later on average. On the other hand, our users above 65 did not change their habits at all.

As for inter-gender differences, males in our dataset slept consistently less and went to bed earlier than females. However, after lockdown was implemented, their habits shifted by about the same amount of time.

Conclusion

Despite all its unfortunate impacts, this crisis demonstrated how many of us systematically neglect our sleep and how our sleep habits change when we have a chance to adjust our schedule according to our natural disposition. If we only learn this bit and pay more attention to our sleep hygiene when all this is over, we may live longer and prosper.

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