People living in deprived areas of the UK have poorer sleep quality than those in affluent areas, the first large-scale study of sleep across the population has found.

Black people reported the worst sleep overall, with the research finding both social deprivation and ethnicity affect sleep quality, irrespective of age, sex, personal wealth, employment and education.

In their findings, published in the journal Clocks & Sleep, the researchers said people living in deprived areas reported finding it harder to get up in the morning and were more likely to nap during the day and wake in the middle of the night.

Prof John Groeger, the lead researcher and head of Sleep Well Science at Nottingham Trent University, told the Guardian: “I’m hugely excited about this work and the implications of it.

“If sleep is really that different across the country as a result of where you live, then whole areas of people are not just going to be sleep disadvantaged, but the consequences are huge in terms of inequalities.”

Regular poor sleep can increase the risk of serious medical conditions, including obesity, heart disease and diabetes, and shorten life expectancy. Research has found it may contribute to mental health problems too.

“There are strong implications of sleeping badly – everything from being more likely to get a cold to mortalities being compromised. There are also educational outcomes – kids who sleep badly do less well in school. So this is a significant piece of work and sleep is worth thinking about seriously.”

The study, in collaboration with psychologists from the University of Roehampton, analysed data from about 500,000 people aged 40 to 69 from the UK Biobank, an online database of medical and lifestyle records of Britons.

They collated reports of sleep problems such as people sleeping for too long or too little for their age, waking in the night, waking too early, snoring, daytime sleepiness, and difficulty getting up in the morning.

Results showed almost a third of people in the study reported sleeping shorter (24.7%) or longer (7.7%) than the recommended sleep durations for those age groups, both of which are associated with increased risk of mortality.

The researchers also found white people (82.4%) considered it easier to get up in the morning compared with black people (74.4%), Asian people (73.5%) or people with mixed ethnicities (74.2%).

Groeger said although the study did not look into the causes of poor sleep in deprived areas, previous research had shown contributing factors to be overcrowding, noise, air and light pollution.

“We know a key factor is overcrowding, when you’ve got multiple people to a room or multiple people to a house,” he said. “What we’re saying is that if you look at the area that people live in, basically their postcode, that in and of itself, over and above income, over and above whether you’re single or married, old or young, has the biggest impact on your quality of sleep.”

He said the study showed the best sleepers were male, young, affluent, educated to degree level, living with others in the home they own, with a high income, multiple vehicles and a long-term job.

The team said those who were employed or retired reported having better sleep quality than those who were unemployed or unable to work.

The researchers used the data to create the problematic sleep index, a first-of-its-kind tool that combines all the sleep issues explored into a single measure that can be used in community healthcare settings to support those who have poor sleep quality.

“We could say these 100 postcodes in the country are more likely than not to have people sleeping poorly, and create a much more socially aware nuanced type of messaging around sleep,” Groeger said. “It also gives us the ability to estimate how good someone’s sleep is based on their age, sex, postcode and a few sleep related questions.”

He added that he hoped the findings could be used to launch more targeted educational programmes around sleep that explain the array of factors that can have an impact.

“It takes us away from this notion that ‘If I get my eight hours, I’m fine.’ That’s just absolute nonsense,” he said. “There is no magic number. The number is different for all of us. It’s different for us when we’re 20 to when we’re 60. The number is not just what’s important about sleep.”