VAAY - Sleep Index

VAAY City Sleep Index

In this hectic world we inhabit, sleep is a sexy word - how much are you getting? How long did it last? How did you feel afterwards? Here at VAAY, we’re on a mission to help people slow down, relax and take care of their inner balance. We know that a good night’s rest is a vital element of a healthy, happy, life, but what’s the best way to go about it? To help us figure this out, we undertook a research project looking into all the different aspects which impact sleep quality.

In doing so, we realised that we could directly compare cultural night-time trends and sleeping disruptors from city to city to establish which people around the world are getting the best shuteye. The result is the City Sleep Index comparing 75 global cities. We hope that the results will highlight not only what contributes to a restful night, but which locations enjoy the most successful slumber to inspire others to follow their example.

To begin the study, we first created a shortlist of 75 prominent global cities with available and comparable data on the topic of sleep. Next, we consulted studies from the World Health Organisation, Harvard, The Sleep Foundation and more to determine nine factors which impact the quality of our sleep the most.

The study starts with mental well-being, looking at both mental health, and societal stress including data on anxiety in relation to the COVID-19 pandemic, which has impacted so many lives. Physical health is analysed next as levels of activity and obesity impact the quality of sleep, followed by the consumption of caffeine, nicotine and alcohol, which are all linked to poor rest.

Data for overwork, employment and finances were also collated, as anyone who has experienced money troubles can tell you, sleep is but a dream for those in difficult work or financial situations. Next we looked at chronic pain, a major contributor to loss of sleep, and environmental factors such as air, light and noise pollution, which can have long-term impacts on health and sleep.

Finally, since experts at the US National Sleep Foundation have advised adults to get at least seven hours (420 mins) of shuteye a night, we found the number of minutes that people sleep, as well as the percentage who undersleep according to this recommendation. The final results reveal which cities boast the best night’s sleep, and who could do a better job at bedtime.

Instructions for journalists

Each column in the below table is filterable, from highest to lowest and vice versa. Where a column is shown as a score out of 100, the higher, the better. Percentages and minutes are reflective of raw figures. The default ranking for the table is the Total column and the full methodology explaining how each factor was calculated can be found at the bottom of the page.

#	City	Country										Total
1	Amsterdam	Netherlands	100	94.1	67.9	95.8	99	54.3	86.2	435	31	100
2	Auckland	New Zealand	88.1	84.4	73.3	77.7	97.1	71.1	97.5	437	29	96.2
3	Glasgow	UK	85.7	88.8	76.2	85.2	95.3	57.3	90.5	433	31	88.6
4	Liverpool	UK	83.8	88.4	76.2	83.3	96.9	57.3	90.9	433	31	87.5
5	Stockholm	Sweden	91.3	95	69.3	89.7	86.4	62.5	93.2	430	33	84.3
6	Dublin	Ireland	90	91.7	73.4	85.8	88.4	66.6	88.9	431	32	83.4
7	Dresden	Germany	92.9	89.3	54.6	100	98.5	53.3	96.3	425	38	82.2
8	Munich	Germany	91.6	88.8	54.6	97.8	98.2	53.3	98.9	425	38	81.5
9	Bern	Switzerland	97.3	95.9	51.3	91.1	98.4	50.9	99.6	425	36	81.2
10	Bremen	Germany	92.2	90.1	54.6	99	94.8	53.3	98.8	425	38	80.5
11	Ottawa	Canada	77.1	91.7	70.8	90.6	89.6	74	88.4	428	32	79.4
13	Manchester	UK	83.8	88.6	76.2	75.4	97.6	57.3	86.9	433	31	79.3
12	Sydney	Australia	79	91	76.6	68.4	91.6	81	93.9	433	31	79.3
14	Melbourne	Australia	76.9	91.5	76.6	71	91.5	81	92.1	433	31	79
15	Dusseldorf	Germany	90.2	88.5	54.6	99.4	96.5	53.3	96.3	425	38	78.8
16	Cologne	Germany	90.2	89	54.6	98.5	94.2	53.3	98.9	425	38	78.5
17	Graz	Austria	96.7	93.4	55.3	96.6	90.2	62.5	93	427	38	77.8
18	Stuttgart	Germany	91.5	89	54.6	99.5	98.5	53.3	90.9	425	38	77
19	Oslo	Norway	87.5	92	64.8	94.5	90.5	54	91.6	427	36	77
20	Leipzig	Germany	92.9	89.4	54.6	98.3	92.5	53.3	96.5	425	38	76.7
21	Helsinki	Finland	81.9	96.1	50	93.1	93.3	54.4	87.2	435	30	76.4
22	Portland	USA	59.4	90	76	77.8	84.5	67.3	92.7	443	30	74.9
23	Zurich	Switzerland	96.5	95.2	51.3	81	100	50.9	100	425	36	74.6
24	Hamburg	Germany	91.9	90.4	54.6	95.2	95.7	53.3	92.4	425	38	73.5
25	Oklahoma City	USA	56.3	72	78.9	86.2	94.2	66.3	89.5	437	34	72.8
26	Minneapolis	USA	65.1	88.4	76.1	74	90.3	71.1	87.4	435	28	72.2
27	London	UK	83.8	90.3	76.2	71.7	95	57.3	81.7	433	31	71.1
28	Frankfurt (am Main)	Germany	89.9	88.9	54.6	98.4	96.3	53.3	86.7	425	38	70.6
29	Brussels	Belgium	86.8	91.4	64.6	92.9	87.4	56.6	80.2	432	34	70.6
30	Berlin	Germany	92.7	91.2	54.6	92.5	90.8	53.3	94	425	38	69.5
31	Vienna	Austria	92.8	94.1	55.3	97	82.8	62.5	90.9	427	38	69.2
32	Budapest	Hungary	82.6	88.9	77.3	88.1	91.1	64	87.9	418	39	67.6
33	Denver	USA	60.1	93.2	75.9	74.4	87	68.1	88.9	432	28	67
34	Copenhagen	Denmark	94.5	93.9	63.4	99.5	89.9	50	91	402	34	66.8
35	Seattle	USA	60.1	90.9	82.4	68.8	89.5	67	87.9	430	29	64.4
36	Austin	USA	65.6	77.9	80.3	76.4	95.2	70	83.1	424	30	64
37	Vancouver	Canada	68.9	90.9	70.8	84.2	78.3	74	89.9	428	32	63.1
39	Calgary	Canada	66.6	91.1	70.8	91.5	76.9	74	81.2	428	32	59.8
38	St. Louis	USA	62.3	79.1	74.6	84.6	89.2	66.9	82.6	435	37	59.8
40	Geneva	Switzerland	93.5	95	51.3	87.7	86.6	50.9	87.5	425	36	58.7
41	Phoenix	USA	62.4	86.7	80.6	79	89.2	65.6	81.3	428	34	58.5
42	Louisville	USA	58.6	50	75.3	88.4	95.8	63.8	81.9	432	36	56.6
43	Washington	USA	66.3	91.6	70.4	69.5	91.5	72.1	89.1	430	36	56.5
44	Indianapolis	USA	56.7	78.1	75.8	82.1	86.1	66.5	82.9	432	35	53.6
45	San Francisco	USA	65.6	90.7	81.2	57.3	84.5	69.1	85.3	431	29	53.4
46	Barcelona	Spain	79.5	93.2	65	97.2	78.1	62.5	77.5	422	37	53.1
47	Milan	Italy	89.4	91.1	73.2	90.3	83	51.1	77	419	40	53.1
48	Houston	USA	65.6	78	80.3	68.4	89.6	70	82	430	34	53
49	Atlanta	USA	66.4	79.2	81.4	68.6	92.5	68.1	85.6	425	37	52.1
50	Toronto	Canada	77.1	91	70.8	76.7	77.6	74	77.7	428	32	51.9
51	Paris	France	88.1	95.5	63.3	82	80.7	66.6	69.7	430	35	50.8
52	Memphis	USA	58.5	73	76.2	87.7	84.3	66.6	80.7	431	38	50.5
53	Cleveland	USA	63.2	79.8	77.1	77.5	79.9	67.2	84.6	431	36	49.6
54	Cape Town	South Africa	84	88.9	87.5	60.9	50	96.5	94.4	424	34	46.3
55	Madrid	Spain	81.6	93.4	65	92.4	78	62.5	70.9	422	37	45.8
56	Hong Kong	Hong Kong	79.4	100	100	58.2	90.6	80.8	73.3	411	42	44.8
57	Boston	USA	69.3	88.9	79.1	66	72.7	69.2	86.6	429	35	43.8
58	Chicago	USA	74	85.9	78.5	69	76	67.9	75.9	425	33	40.9
59	Lisbon	Portugal	64.1	89	68.6	86.2	80	54.1	84.8	418	37	40.1
60	New Orleans	USA	72.5	62.5	73.5	83	79.4	66.8	84.6	423	41	39.8
61	Miami	USA	57.9	82.1	77.8	67.8	82.7	65	87.2	418	33	39.1
62	Bangkok	Thailand	86.6	97.2	88.2	59.7	92.1	87.2	75.6	412	49	39
64	New York	USA	64	85.9	81.8	67.9	71.6	67.6	82.7	423	34	36.4
63	Kuala Lumpur	Malaysia	77.1	93.2	98.1	55.3	92.1	100	83.4	402	51	36.4
65	Philadelphia	USA	65.5	85	77.7	71.8	77.8	65.4	79.6	427	41	33.8
66	Singapore	Singapore	75	95.9	97.6	54.5	99.5	85.3	68.2	408	48	33.1
67	Honolulu	USA	62.7	90.4	78.3	70.5	79.9	71.1	92.9	413	45	32.3
68	Dubai	UAE	93.3	86.8	81.5	52.2	98.1	74.6	50	415	43	20.2
69	Detroit	USA	63.9	83.2	76.1	64.8	69.1	69.4	83.6	418	42	17
70	Buenos Aires	Argentina	75.4	86.9	70.9	57.3	72.9	84.3	73	413	37	15.3
71	Seoul	South Korea	96.2	96.2	85.3	58.3	95.2	74.9	70.3	393	56	14.7
72	Las Vegas	USA	51.7	85.1	71.3	84.1	72	66.7	85.7	393	39	12.3
73	Los Angeles	USA	65.6	90.7	81.2	50	70.9	69.1	73.6	415	35	11.5
74	Tokyo	Japan	73.7	96.4	78.2	59.5	98.7	68.1	83.5	388	61	2.3
75	Sao Paulo	Brazil	50	88.1	73.4	70.2	66.1	83.7	74.2	408	42	1

METHODOLOGY

The Sleep Index compares and analyses the conditions for sleeping quality in 75 cities around the world. The cities were chosen for being some of the most well-known global metropolises, as well as for their availability of extensive and comparable data. The study consists of nine factors that contribute to the overall quality of a person's sleep:

Mental Wellbeing (Score)
Physical Health (Score)
Caffeine, Nicotine and Alcohol Consumption (Score)
Overwork + Commute (Score)
Employment and Finances (Score)
Chronic Pain (Score)
Environment (Score)
Sleep Duration (Minutes)
Undersleep (%)

The methods used to find each factor are described in detail below. All of the information collected is based on the latest data available.

SCORING

In cases where a factor consisted of one or more indicators, these were scored and averaged. The equation for scores is as follows:

z-Score = x - mean(X)Standard deviation(X)in short x - μσ

For columns where a low value is better, for example, a low amount of Caffeine, Nicotine and Alcohol Consumption, the score is inverted such that it is attributed a higher score:

z-Scoreinverted = -1*x - mean(X)Standard deviation(X) in short -1 *x - μσ

Where present for a factor, scores are normalised such that 50 equals the lowest value in the final dataset and 100 the highest value in the final dataset. Therefore, the higher the score, the better the city ranks for that factor in comparison to the other cities in the index. The equation for normalization is as follows:

score = (100-50) *x - min(X)max(X) - min(X)+50

FACTORS

Mental Wellbeing Score

The combined rates of mental health disorders and societal stress in a city. The higher the score, the better the mental wellbeing of residents. Mental health and stress are recognised to have significant impacts on sleep quality and can lead to sleep deprivation.

Mental health

Chronic sleep problems have been reported as high as four times more prevalent in people with mental health disorders than the general population, and are more prevalent in people living with conditions like anxiety, depression and bipolar disorder.¹ Prevalence of depression among the general population. Country-level data. Source: World Health Organisation (WHO) - Global Health Observatory (GHO), 2016.

DALYs (Disability Adjusted Life Years) from anxiety and depressive disorders. Country-level data, with US cities using state-level data. Source: Institute for Health Metrics and Evaluation (IHME) - Global Burden of Disease Study, 2017.

Societal Stress

The emergence of the Covid-19 pandemic has resulted in heightened concerns about public and personal health, as well as measures implemented to control the spread of the virus.

COVID-related stress: Country-level survey data on anxiety and psychological stress related to the spread of the pandemic and the conditions that have arisen as a result of the spread. Source: COVIDiStress Global Survey. Results as of August, 2020.

Divorce rates can be seen as a measure of societal stress resulting from the breakdown of the family unit.

Divorce rate: Crude divorce rates at a regional level. Source: Sub-national and national vital statistics departments, latest available data.

Physical Health Score

The combined rates of obesity, physical inactivity and the number of gyms available in a city. The higher the score, the better the physical health of residents. Research has found that physical activity positively impacts sleep quality in young and older groups,² while other studies have found that obesity is associated with an increased prevalence of sleep apnea, potentially causing sleeping problems that reduce sleep quality and duration.³

A lack of adequate sleep has also been suggested to be a contributing factor to a growth in obesity, with most studies finding an association in inadequate sleep and weight gain among children.⁴

Obesity rates: Crude adult obesity rates at national level, US cities use state-level data. Source: World Health Organisation – Global Health Observatory, 2016; Robert Wood Johnson Foundation - State of Childhood Obesity report (adult rates), 2019.

Physical inactivity rates: Prevalence of adult inactivity at national level, US cities use state-level data. Source: World Health Organisation – Global Health Observatory, 2016; Center for Disease Control – Physical Activity database, 2018.

Number of gyms: Quantity of gyms and fitness centres in a city as a proportion of the city population. Search terms ‘leisure=fitness_centre’ and ‘leisure=sports_centre’. Source: OSM Overpass API, data as of August, 2020.

Caffeine, Nicotine and Alcohol Consumption Score

The combined indexes for the intakes of caffeine, nicotine and alcohol in a city. The higher the score, the less stimulants consumed by residents. Certain dietary intake is known to adversely impact sleep quality and duration. These include excess levels of caffeine⁵, nicotine⁶ and alcohol⁷ consumption – especially in the leadup before bed.

Caffeine consumption: Country-level kg per capita consumption of coffee, as well as kg per capita consumption of tea. Source: International Coffee Organization – Trade Statistics database, 2019; US Food and Agriculture Organization – FAOSTAT, 2019.

Nicotine consumption: Smoking prevalence rates and cigarette consumption per capita. Data used is at a country level, US cities use state-level data. Source: World Health Organisation – Global Health Observatory, 2016; Center for Disease Control –State Tobacco Activities Tracking and Evaluation (STATE) System, 2018.

Alcohol consumption: Alcohol consumption in litres per capita. Data used is at a country level, US cities use state-level data. Source: World Health Organisation – Global Health Observatory, 2016; National Institute on Alcohol Abuse and Alcoholism – Surveillance Report, 2018.

Overwork + Commute Score

The percentage of the population working over 48 hours combined with the average commuting time in a city. The lower the score, the more hours a city puts into work and commute.

Percent of the population working over 48 hours: Country level data, US cities use state-level data. Source: International Labour Organisation – ILOSTAT, 2019; Bureau of Labor Statistics, 2018. Commuting time: City level average minutes commuting one-way. Source: US Census – American Fact Finder, 2019; INRIX – Global Traffic Scorecard, 2019; Numbeo, 2020; Various media sources.

Employment and Finances Score

The combined unemployment rate and monthly living costs in a city. The higher the score, the less financial and career stress experienced by residents. Financial and career stress is a factor which contributes to heightened stress and, by extension, a loss of sleep, with research showing that money worries correlate with sleep problems in older people.⁸

Unemployment rate: Harmonised unemployment figures for June, 2020. Metropolitan crude rates taken where available, otherwise regional data was used. In rare cases national data was used. Source: vital statistics departments, latest available data; International Monetary Fund - World Economic Outlook, 2020.

Affordability: Monthly living costs as a share of household income, after tax. A basket of estimated monthly costs includes: basic utilities costs, groceries, internet connection, leisure activities, clothes, and eating out. Source: OECD – Employment Database, 2018; Numbeo – Cost of Living Index, 2020.

Chronic Pain Score

The impact of chronic pain on the health of inhabitants. The higher the score, the less chronic pain experienced by residents. Chronic pain is understood to have a cyclic relationship with sleep: chronic pain is a major contributor to loss of sleep, and a lack of proper sleep produces fatigue and increases sensitivity to pain.⁹ Global disease studies have reported high levels of chronic pain burden in developed countries (although not exclusively).

Research points to a connection between ageing populations (Italy, Germany and Denmark, for example) and an increase in the burden of non-communicable diseases, as these are understood to increase rapidly with age.¹⁰ It is possible that due to this, countries with a younger population structure will tend to score better in this factor.

Prevalence and impact of chronic pain: Disability Adjusted Life Years (DALYs) resulting from: Back and neck pain; Osteoarthritis; Rheumatoid Arthritis; Migraines and headaches disorders; and Gout. Country-level data, with US cities using state-level data. Source: World Health Organisation — Global Health Observatory, 2016; Institute for Health Metrics and Evaluation (IHME) - Global Burden of Disease Study, 2017.

Environment Score

The combined rates of air, light and noise pollution. The higher the score, the less pollution. Environmental pollution can have significant impacts on the ability to receive adequate sleep duration and quality. The World Health Organisation has warned against the short and long-term effects of excessive environmental background noise (eg. from cars, trains and planes) at night on health and sleep.¹¹

Other research has suggested that light pollution can, among other things, interrupt natural rhythms in the body and delay the release of sleep-inducing hormones¹². Asthma, which can be triggered by exposure to ozone (O3), can seriously impede sleep for sufferers¹³, while other research has suggested a link between exposure to particle pollution in the air (PM2.5/PM10) and sleep apnea (snoring)¹⁴.

Air pollution: Annual median particulate matter (PM2.5/PM10) pollution, and annual median ground-level or tropospheric ozone (O3) pollution at a city level. Sources: AQICN – Air Quality Index historical database, 2019; World Health Organisation – Global Ambient Air Quality Database, 2018.

Light pollution: Average annual night radiance at a metropolitan level, and percent of the urban population exposed to very high artificial night sky light in microcandelas per square metre (>3000 μcd/m2) at a country level. US cities use city-level data. Source: Radiance Light Trends light pollution map, 2016; National Oceanic and Atmospheric Administration - VIIRS Day/Night Band Nighttime Lights, 2018; Falchi, et. al. ‘The new world atlas of artificial night sky brightness’, Science Advances, 2016 (DOI: 10.1126/sciadv.1600377).

Noise pollution: Percent of population exposed to excessive night-time noise (Lnight ≥50dB) and overall background noise population, as well as severity of hearing loss at a city level. Sources: European Environment Agency – noise exposure database, 2019; US Park Service – sound map, 2019; Mimi – World Hearing Index, 2017; Numbeo – pollution index, 2020.

Sleep Duration (minutes)

The average duration of sleep experienced by inhabitants. Sleep researchers advise people to receive a minimum number of hours sleep in order to reduce the likelihood of sleep deprivation. Experts at the US National Sleep Foundation have advised adults receive a minimum of at least seven hours (420 mins) of sleep a night.¹⁵

Mean sleep duration in minutes, per night. Duration estimates modelled using country-level data, with US cities adjusted using county-level data. Sources: OECD Time Use Survey, 2020; “A global quantification of “normal” sleep schedules using smartphone data”, Science Advances journal (DOI: 10.1126/sciadv.1501705), 2016; Economist/Sleep Cycle country sleep study, 2018; Fitbit country sleep duration study, 2019; Jawbone – USA circadian rhythm study, 2014

% Undersleep

The percentage of the adult population getting inadequate sleep on any given night.

US cities employ official county-level data on percent of adults receiving under seven hours of sleep. National figures are modeled estimates from various country-level data sources. Sources: Center for Disease Control, 2019; Sleep Cycle, 2020; Financial TImes, 2018; Barmer – Doctor Report, 2018; YouGov.au, 2018; Aviva sleep study, 2016