Background
Mental wellbeing has been defined as: “a dynamic state in which the individual is able to develop their potential, work productively and creatively, build strong and positive relationships with others and contribute to their community. It is enhanced when an individual is able to fulfil their personal and social goals and achieve a sense of purpose in society” [
1]. Individuals’ wellbeing is affected by a combination of distal and proximal factors. Thus, both good maternal health and nurturing parent–child relationships in the first few years of life have been associated with improved wellbeing across the life course [
2‐
5]. Equally, poor parenting, adverse childhood experiences and poverty have all been linked to poorer childhood, adolescent and adult health and wellbeing [
6‐
10]. As adults, proximal factors known to be strongly related to wellbeing include ecological measures such as deprivation, housing environments, green space access and community safety [
3,
11‐
13], as well as a variety of individual measures such as social integration and relationships, employment opportunities, attitudes and beliefs, education, and health status [
14‐
17].
Table 1
Relationship between life satisfaction and demographic, economic, health and behavioural factors stratified by deprivation tertile
All | | 5280 | 21.0 | 60.8 | 18.1 | | 5589 | 17.4 | 61.4 | 21.2 | | 4342 | 12.8 | 64.6 | 22.6 | | *** |
Age | 18-24 | 473 | 16.7 | 67.2 | 16.1 | *** | 375 | 14.7 | 63.2 | 22.1 | *** | 176 | 10.8 | 65.3 | 23.9 | 0.191 | 0.052 |
25-39 | 1271 | 20.1 | 58.1 | 21.8 | | 1050 | 13.2 | 62.4 | 24.4 | | 630 | 14.0 | 60.3 | 25.7 | | *** |
40-54 | 1180 | 24.3 | 58.8 | 16.9 | | 1170 | 19.1 | 60.9 | 20.0 | | 912 | 11.7 | 65.9 | 22.4 | | *** |
55-64 | 804 | 21.9 | 60.9 | 17.2 | | 935 | 19.3 | 57.5 | 23.2 | | 814 | 12.7 | 63.3 | 24.1 | | *** |
65 plus | 1552 | 20.2 | 62.5 | 17.3 | | 2059 | 18.2 | 62.6 | 19.2 | | 1810 | 13.1 | 66.1 | 20.8 | | *** |
Gender | Female | 3160 | 20.8 | 61.1 | 18.1 | 0.821 | 3335 | 17.3 | 61.8 | 20.9 | 0.741 | 2689 | 13.6 | 63.8 | 22.6 | 0.109 | *** |
Male | 2120 | 21.4 | 60.3 | 18.3 | | 2254 | 17.6 | 60.8 | 21.7 | | 1653 | 11.4 | 66.0 | 22.6 | | *** |
Employment | Employed | 1562 | 14.1 | 62.4 | 23.4 | *** | 2099 | 13.6 | 62.5 | 23.9 | *** | 1687 | 9.8 | 64.9 | 25.3 | *** | ** |
Unemployed | 1134 | 33.2 | 53.2 | 13.7 | | 651 | 29.0 | 56.4 | 14.6 | | 272 | 23.5 | 58.8 | 17.6 | | * |
FT Education | 111 | 16.2 | 60.4 | 23.4 | | 97 | 10.3 | 58.8 | 30.9 | | 45 | 6.7 | 60.0 | 33.3 | | 0.346 |
Domestic/other | 628 | 18.3 | 64.3 | 17.4 | | 363 | 19.3 | 60.9 | 19.8 | | 230 | 16.1 | 63.0 | 20.9 | | 0.615 |
Retired | 1845 | 20.7 | 63.0 | 16.4 | | 2379 | 17.6 | 62.0 | 20.5 | | 2108 | 13.5 | 65.5 | 21.0 | | *** |
Partner status | No Partner | 2466 | 25.5 | 59.9 | 14.5 | *** | 2162 | 23.0 | 59.1 | 17.9 | *** | 1346 | 18.0 | 62.8 | 19.2 | *** | *** |
Partner employed | 1244 | 14.4 | 62.6 | 23.0 | | 1755 | 12.3 | 62.7 | 25.0 | | 1562 | 9.7 | 65.4 | 24.9 | | ** |
Partner not employed | 1570 | 19.2 | 60.8 | 20.0 | | 1672 | 15.5 | 62.9 | 21.6 | | 1434 | 11.2 | 65.6 | 23.2 | | *** |
Ethnicity | White | 4665 | 22.1 | 60.7 | 17.2 | *** | 5353 | 17.4 | 61.6 | 20.9 | 0.106 | 4212 | 12.8 | 64.6 | 22.5 | 0.750 | *** |
South Asian | 427 | 12.2 | 59.0 | 28.8 | | 162 | 16.0 | 54.3 | 29.6 | | 90 | 8.9 | 64.4 | 26.7 | | 0.436 |
Black, mixed, other | 188 | 15.4 | 68.1 | 16.5 | | 74 | 17.6 | 58.1 | 24.3 | | 40 | 12.5 | 67.5 | 20.0 | | 0.554 |
Health status | Very good | 1175 | 8.7 | 60.8 | 30.6 | *** | 1433 | 7.8 | 57.6 | 34.6 | *** | 1297 | 5.9 | 64.2 | 29.9 | *** | ** |
Good | 1890 | 16.4 | 66.3 | 17.2 | | 2170 | 14.6 | 66.0 | 19.4 | | 1751 | 10.5 | 65.7 | 23.8 | | *** |
Fair | 1455 | 26.7 | 59.1 | 14.2 | | 1423 | 24.0 | 61.3 | 14.7 | | 1010 | 20.8 | 64.4 | 14.9 | | * |
Bad | 599 | 38.6 | 53.1 | 8.3 | | 450 | 34.7 | 54.2 | 11.1 | | 231 | 27.3 | 62.8 | 10.0 | | * |
Very bad | 161 | 49.7 | 40.4 | 9.9 | | 113 | 41.6 | 48.7 | 9.7 | | 53 | 39.6 | 54.7 | 5.7 | | 0.351 |
Smoking status | Never smoked | 2158 | 19.6 | 60.8 | 19.6 | *** | 2658 | 17.2 | 60.5 | 22.2 | *** | 2449 | 12.0 | 63.0 | 25.0 | *** | *** |
Ex occasional | 257 | 18.3 | 68.1 | 13.6 | | 267 | 22.1 | 62.2 | 15.7 | | 191 | 13.1 | 71.2 | 15.7 | | 0.142 |
Ex daily | 794 | 17.6 | 64.4 | 18.0 | | 1138 | 13.8 | 67.0 | 19.2 | | 872 | 11.0 | 68.9 | 20.1 | | ** |
Occasional | 131 | 16.8 | 60.3 | 22.9 | | 140 | 17.1 | 58.6 | 24.3 | | 95 | 15.8 | 71.6 | 12.6 | | 0.206 |
Daily | 1940 | 24.7 | 58.5 | 16.8 | | 1386 | 19.8 | 58.4 | 21.7 | | 735 | 16.9 | 62.4 | 20.7 | | *** |
Exercise days/week | 6 to 7 | 941 | 12.0 | 56.7 | 31.2 | *** | 1290 | 10.4 | 57.4 | 32.2 | *** | 965 | 8.9 | 56.1 | 35.0 | *** | 0.145 |
3 to 5 | 1138 | 14.6 | 65.1 | 20.3 | | 1388 | 12.2 | 63.0 | 24.9 | | 1103 | 8.2 | 66.1 | 25.7 | | *** |
1 to 2 | 785 | 20.9 | 63.7 | 15.4 | | 965 | 17.8 | 66.5 | 15.6 | | 842 | 13.8 | 68.8 | 17.5 | | ** |
None | 2416 | 27.6 | 59.4 | 12.9 | | 1946 | 25.6 | 60.3 | 14.1 | | 1432 | 18.3 | 66.9 | 14.8 | | *** |
Alcohol consumption category | Lower risk | 1433 | 16.8 | 63.4 | 19.7 | *** | 2051 | 13.0 | 63.8 | 23.2 | *** | 1890 | 10.6 | 66.6 | 22.8 | ** | *** |
Abstainer | 2884 | 22.2 | 59.8 | 17.9 | | 2435 | 19.7 | 59.2 | 21.1 | | 1662 | 14.9 | 62.3 | 22.8 | | *** |
Not usual drinker | 395 | 21.0 | 60.3 | 18.7 | | 467 | 22.3 | 62.7 | 15.0 | | 301 | 15.9 | 60.8 | 23.3 | | * |
Increasing risk | 417 | 23.7 | 61.4 | 14.9 | | 518 | 18.5 | 60.8 | 20.7 | | 418 | 10.5 | 69.1 | 20.3 | | *** |
| Higher risk | 151 | 31.1 | 54.3 | 14.6 | | 118 | 22.0 | 60.2 | 17.8 | | 71 | 18.3 | 57.7 | 23.9 | | 0.152 |
Table 2
Relationship between mental wellbeing and demographic, economic, health and behavioural factors stratified by deprivation tertile
All | 5280 | 21.0 | 60.8 | 18.1 | | 5589 | 17.4 | 61.4 | 21.2 | | 4342 | 12.8 | 64.6 | 22.6 | | *** |
Age | 18-24 | 473 | 16.7 | 67.2 | 16.1 | *** | 375 | 14.7 | 63.2 | 22.1 | *** | 176 | 10.8 | 65.3 | 23.9 | 0.191 | 0.052 |
25-39 | 1271 | 20.1 | 58.1 | 21.8 | | 1050 | 13.2 | 62.4 | 24.4 | | 630 | 14.0 | 60.3 | 25.7 | | *** |
40-54 | 1180 | 24.3 | 58.8 | 16.9 | | 1170 | 19.1 | 60.9 | 20.0 | | 912 | 11.7 | 65.9 | 22.4 | | *** |
55-64 | 804 | 21.9 | 60.9 | 17.2 | | 935 | 19.3 | 57.5 | 23.2 | | 814 | 12.7 | 63.3 | 24.1 | | *** |
65 plus | 1552 | 20.2 | 62.5 | 17.3 | | 2059 | 18.2 | 62.6 | 19.2 | | 1810 | 13.1 | 66.1 | 20.8 | | *** |
Gender | Female | 3160 | 20.8 | 61.1 | 18.1 | 0.821 | 3335 | 17.3 | 61.8 | 20.9 | 0.741 | 2689 | 13.6 | 63.8 | 22.6 | 0.109 | *** |
Male | 2120 | 21.4 | 60.3 | 18.3 | | 2254 | 17.6 | 60.8 | 21.7 | | 1653 | 11.4 | 66.0 | 22.6 | | *** |
Employment | Employed | 1562 | 14.1 | 62.4 | 23.4 | *** | 2099 | 13.6 | 62.5 | 23.9 | *** | 1687 | 9.8 | 64.9 | 25.3 | *** | ** |
Unemployed | 1134 | 33.2 | 53.2 | 13.7 | | 651 | 29.0 | 56.4 | 14.6 | | 272 | 23.5 | 58.8 | 17.6 | | |
FT Education | 111 | 16.2 | 60.4 | 23.4 | | 97 | 10.3 | 58.8 | 30.9 | | 45 | 6.7 | 60.0 | 33.3 | | 0.346 |
Domestic/other | 628 | 18.3 | 64.3 | 17.4 | | 363 | 19.3 | 60.9 | 19.8 | | 230 | 16.1 | 63.0 | 20.9 | | 0.615 |
Retired | 1845 | 20.7 | 63.0 | 16.4 | | 2379 | 17.6 | 62.0 | 20.5 | | 2108 | 13.5 | 65.5 | 21.0 | | *** |
Partner status | No Partner | 2466 | 25.5 | 59.9 | 14.5 | *** | 2162 | 23.0 | 59.1 | 17.9 | *** | 1346 | 18.0 | 62.8 | 19.2 | *** | *** |
| Partner employed | 1244 | 14.4 | 62.6 | 23.0 | | 1755 | 12.3 | 62.7 | 25.0 | | 1562 | 9.7 | 65.4 | 24.9 | | ** |
| Partner not employed | 1570 | 19.2 | 60.8 | 20.0 | | 1672 | 15.5 | 62.9 | 21.6 | | 1434 | 11.2 | 65.6 | 23.2 | | *** |
Ethnicity | White | 4665 | 22.1 | 60.7 | 17.2 | *** | 5353 | 17.4 | 61.6 | 20.9 | 0.106 | 4212 | 12.8 | 64.6 | 22.5 | 0.750 | *** |
South Asian | 427 | 12.2 | 59.0 | 28.8 | | 162 | 16.0 | 54.3 | 29.6 | | 90 | 8.9 | 64.4 | 26.7 | | 0.436 |
Black, mixed, other | 188 | 15.4 | 68.1 | 16.5 | | 74 | 17.6 | 58.1 | 24.3 | | 40 | 12.5 | 67.5 | 20.0 | | 0.554 |
Health status | Very good | 1175 | 8.7 | 60.8 | 30.6 | *** | 1433 | 7.8 | 57.6 | 34.6 | *** | 1297 | 5.9 | 64.2 | 29.9 | *** | ** |
Good | 1890 | 16.4 | 66.3 | 17.2 | | 2170 | 14.6 | 66.0 | 19.4 | | 1751 | 10.5 | 65.7 | 23.8 | | *** |
Fair | 1455 | 26.7 | 59.1 | 14.2 | | 1423 | 24.0 | 61.3 | 14.7 | | 1010 | 20.8 | 64.4 | 14.9 | | |
Bad | 599 | 38.6 | 53.1 | 8.3 | | 450 | 34.7 | 54.2 | 11.1 | | 231 | 27.3 | 62.8 | 10.0 | | |
Very bad | 161 | 49.7 | 40.4 | 9.9 | | 113 | 41.6 | 48.7 | 9.7 | | 53 | 39.6 | 54.7 | 5.7 | | 0.351 |
Smoking status | Never smoked | 2158 | 19.6 | 60.8 | 19.6 | *** | 2658 | 17.2 | 60.5 | 22.2 | *** | 2449 | 12.0 | 63.0 | 25.0 | *** | *** |
Ex occasional | 257 | 18.3 | 68.1 | 13.6 | | 267 | 22.1 | 62.2 | 15.7 | | 191 | 13.1 | 71.2 | 15.7 | | 0.142 |
Ex daily | 794 | 17.6 | 64.4 | 18.0 | | 1138 | 13.8 | 67.0 | 19.2 | | 872 | 11.0 | 68.9 | 20.1 | | ** |
Occasional | 131 | 16.8 | 60.3 | 22.9 | | 140 | 17.1 | 58.6 | 24.3 | | 95 | 15.8 | 71.6 | 12.6 | | 0.206 |
Daily | 1940 | 24.7 | 58.5 | 16.8 | | 1386 | 19.8 | 58.4 | 21.7 | | 735 | 16.9 | 62.4 | 20.7 | | *** |
Exercise days/week | 6 to 7 | 941 | 12.0 | 56.7 | 31.2 | *** | 1290 | 10.4 | 57.4 | 32.2 | *** | 965 | 8.9 | 56.1 | 35.0 | *** | 0.145 |
3 to 5 | 1138 | 14.6 | 65.1 | 20.3 | | 1388 | 12.2 | 63.0 | 24.9 | | 1103 | 8.2 | 66.1 | 25.7 | | *** |
1 to 2 | 785 | 20.9 | 63.7 | 15.4 | | 965 | 17.8 | 66.5 | 15.6 | | 842 | 13.8 | 68.8 | 17.5 | | ** |
None | 2416 | 27.6 | 59.4 | 12.9 | | 1946 | 25.6 | 60.3 | 14.1 | | 1432 | 18.3 | 66.9 | 14.8 | | *** |
Alcohol consumption category | Lower risk | 1433 | 16.8 | 63.4 | 19.7 | *** | 2051 | 13.0 | 63.8 | 23.2 | *** | 1890 | 10.6 | 66.6 | 22.8 | ** | *** |
Abstainer | 2884 | 22.2 | 59.8 | 17.9 | | 2435 | 19.7 | 59.2 | 21.1 | | 1662 | 14.9 | 62.3 | 22.8 | | *** |
Not usual drinker | 395 | 21.0 | 60.3 | 18.7 | | 467 | 22.3 | 62.7 | 15.0 | | 301 | 15.9 | 60.8 | 23.3 | | |
Increasing risk | 417 | 23.7 | 61.4 | 14.9 | | 518 | 18.5 | 60.8 | 20.7 | | 418 | 10.5 | 69.1 | 20.3 | | *** |
| Higher risk | 151 | 31.1 | 54.3 | 14.6 | | 118 | 22.0 | 60.2 | 17.8 | | 71 | 18.3 | 57.7 | 23.9 | | 0.152 |
Table 3
Adjusted odds for low or high life satisfaction compared with moderate levels by deprivation strata
Age | 18-24 (Ref) | | | | | | | | | | | | | | | | | | |
25-39 | 0.93 | 0.68-1.28 | ns | 0.93 | 0.71-1.21 | ns | 1.02 | 0.66-1.58 | ns | 0.83 | 0.62-1.11 | ns | 0.96 | 0.50-1.86 | ns | 0.94 | 0.62-1.40 | ns |
40-54 | 0.98 | 0.71-13.5 | ns | 0.94 | 0.71-1.25 | ns | 1.30 | 0.85-1.99 | ns | 0.68 | 0.51-0.92 | | 0.66 | 0.34-1.27 | ns | 0.95 | 0.64-1.41 | ns |
55-64 | 0.59 | 0.40-0.86 | ** | 1.13 | 0.81-1.57 | ns | 0.68 | 0.43-1.09 | ns | 1.06 | 0.77-1.44 | ns | 1.00 | 0.51-1.96 | ns | 1.17 | 0.77-1.78 | ns |
65 plus | 0.47 | 0.28-0.79 | ** | 1.43 | 0.94-2.17 | ns | 0.68 | 0.38-1.20 | ns | 1.12 | 0.77-1.61 | ns | 0.71 | 0.34-1.51 | ns | 1.41 | 0.89-2.22 | ns |
Employment | Employed (Ref) | | | | | | | | | | | | | | | | | | |
Unemployed | 1.71 | 1.34-2.19 | *** | 1.10 | 0.88-1.37 | ns | 2.07 | 1.58-2.72 | *** | 1.13 | 0.88-1.44 | ns | 1.62 | 1.09-2.42 | | 1.09 | 0.78-1.53 | ns |
FT Education | 0.73 | 0.37-1.45 | ns | 0.83 | 0.50-1.38 | ns | 1.11 | 0.48-2.56 | ns | 1.49 | 0.91-2.43 | ns | 0.47 | 0.10-2.20 | ns | 0.61 | 0.30-1.26 | ns |
Domestic/other | 2.00 | 1.51-2.65 | *** | 1.53 | 1.21-1.92 | *** | 1.65 | 1.15-2.35 | | 1.07 | 0.82-1.40 | ns | 1.45 | 0.89-2.38 | ns | 1.34 | 0.98-1.82 | ns |
Retired | 1.09 | 0.71-1.67 | ns | 1.26 | 0.90-1.77 | ns | 1.05 | 0.68-1.60 | ns | 1.38 | 1.06-1.79 | | 0.78 | 0.49-1.22 | ns | 1.23 | 0.93-1.61 | ns |
Partner status & employment Ethnicity | No Partner (Ref) | | | | | | | | | | | | | | | | | | |
Partner employed | 0.52 | 0.41-0.67 | *** | 1.27 | 1.05-1.53 | | 0.54 | 0.42-0.69 | *** | 1.49 | 1.25-1.78 | *** | 0.57 | 0.41-0.78 | ** | 1.13 | 0.92-1.38 | ns |
Partner not employed | 0.79 | 0.65-0.95 | | 1.27 | 1.09-1.49 | ** | 0.72 | 0.59-0.89 | *** | 1.39 | 1.20-1.62 | *** | 0.72 | 0.55-0.95 | | 1.28 | 1.08-1.52 | ** |
White (Ref) | | | | | | | | | | | | | | | | | | |
South Asian | 0.97 | 0.68-1.38 | ns | 1.19 | 0.92-1.54 | ns | 1.05 | 0.62-1.80 | ns | 0.90 | 0.61-1.33 | ns | 1.37 | 0.64-2.93 | ns | 1.00 | 0.62-1.61 | ns |
Black, mixed, other | 1.40 | 0.94-2.08 | ns | 0.70 | 0.47-1.06 | ns | 1.57 | 0.77-3.22 | ns | 0.72 | 0.40-1.28 | ns | 0.31 | 0.04-2.32 | ns | 1.39 | 0.72-2.69 | ns |
Health status | Very good (Ref) | | | | | | | | | | | | | | | | | | |
Good | 1.29 | 0.98-1.70 | ns | 0.48 | 0.40-0.57 | *** | 1.23 | 0.92-1.65 | ns | 0.50 | 0.43-0.58 | *** | 1.55 | 1.06-2.27 | | 0.43 | 0.37-0.51 | *** |
Fair | 2.43 | 1.83-3.24 | *** | 0.41 | 0.34-0.50 | *** | 2.25 | 1.66-3.06 | *** | 0.39 | 0.33-0.48 | *** | 3.32 | 2.24-4.93 | *** | 0.27 | 0.22-0.33 | *** |
Bad | 5.23 | 3.76-7.27 | *** | 0.38 | 0.28-0.51 | *** | 4.92 | 3.45-7.03 | *** | 0.22 | 0.16-0.31 | *** | 6.78 | 4.12-11.14 | *** | 0.26 | 0.18-0.38 | *** |
Very bad | 10.32 | 6.59-16.17 | *** | 0.38 | 0.22-0.68 | ** | 10.77 | 6.43-18.04 | *** | 0.40 | 0.22-0.74 | ** | 7.57 | 3.69-15.52 | *** | 0.09 | 0.03-0.25 | *** |
Smoking status | Never smoked (Ref) | | | | | | | | | | | | | | | | | | |
Ex occasional | 0.69 | 0.43-1.09 | ns | 1.06 | 0.79-1.44 | ns | 1.14 | 0.74-1.75 | ns | 0.97 | 0.72-1.30 | ns | 0.90 | 0.49-1.67 | ns | 0.84 | 0.60-1.17 | ns |
Ex daily | 1.22 | 0.95-1.57 | ns | 1.05 | 0.85-1.28 | ns | 1.30 | 1.02-1.65 | | 1.13 | 0.97-1.33 | ns | 1.50 | 1.12-2.00 | ** | 1.14 | 0.96-1.36 | ns |
Occasional | 2.26 | 1.40-3.64 | ** | 1.35 | 0.87-2.10 | ns | 1.20 | 0.69-2.10 | ns | 1.06 | 0.71-1.57 | ns | 2.30 | 1.22-4.31 | | 0.97 | 0.61-1.56 | ns |
Daily | 1.19 | 0.98-1.44 | ns | 0.91 | 0.77-1.08 | ns | 1.38 | 1.11-1.72 | ** | 0.95 | 0.81-1.12 | ns | 1.43 | 1.06-1.93 | | 0.88 | 0.72-1.07 | ns |
Exercise days/week | 6 to 7 (Ref) | | | | | | | | | | | | | | | | | | |
3 to 5 | 0.95 | 0.71-1.27 | ns | 0.68 | 0.56-0.83 | *** | 0.71 | 0.53-0.95 | | 0.78 | 0.66-0.93 | ** | 1.10 | 0.76-1.58 | ns | 0.91 | 0.75-1.10 | ns |
1 to 2 | 0.97 | 0.71-1.32 | ns | 0.46 | 0.36-0.58 | *** | 0.94 | 0.71-1.26 | ns | 0.61 | 0.50-0.74 | *** | 1.08 | 0.74-1.57 | ns | 0.82 | 0.66-1.00 | |
None | 1.30 | 1.01-1.67 | | 0.66 | 0.55-0.80 | *** | 1.15 | 0.90-1.48 | ns | 0.80 | 0.67-0.95 | | 1.13 | 0.80-1.58 | ns | 0.89 | 0.73-1.08 | ns |
Alcohol consumption category | Lower risk (Ref) | | | | | | | | | | | | | | | | | | |
Abstainer | 1.30 | 1.05-1.60 | | 1.05 | 0.90-1.24 | ns | 1.03 | 0.84-1.28 | ns | 1.01 | 0.87-1.16 | ns | 0.94 | 0.72-1.22 | ns | 1.06 | 0.91-1.24 | ns |
Not usual drinker | 1.51 | 1.09-2.08 | | 0.94 | 0.71-1.25 | ns | 0.99 | 0.70-1.41 | ns | 1.15 | 0.92-1.45 | ns | 1.04 | 0.67-1.61 | ns | 1.00 | 0.76-1.31 | ns |
Increasing risk | 1.56 | 1.14-2.14 | ** | 0.81 | 0.61-1.07 | ns | 1.27 | 0.92-1.74 | ns | 0.90 | 0.72-1.13 | ns | 0.98 | 0.65-1.48 | ns | 1.00 | 0.79-1.27 | ns |
| Higher risk | 1.93 | 1.25-2.98 | ** | 0.88 | 0.55-1.43 | ns | 1.22 | 0.69-2.16 | ns | 0.92 | 0.59-1.45 | ns | 1.64 | 0.76-3.53 | ns | 1.25 | 0.73-2.15 | ns |
Table 4
Adjusted odds for low or high mental wellbeing compared with moderate levels by deprivation strata
Age | 18-24 (Ref) | | | | | | | | | | | | | | | | | | |
25-39 | 1.42 | 1.05-1.93 | | 1.63 | 1.20-2.22 | ** | 0.92 | 0.63-1.34 | ns | 1.24 | 0.89-1.72 | ns | 1.53 | 0.85-2.77 | ns | 1.34 | 0.85-2.11 | ns |
40-54 | 1.16 | 0.85-1.58 | ns | 1.50 | 1.09-2.08 | | 1.18 | 0.82-1.70 | ns | 1.17 | 0.84-1.63 | ns | 1.01 | 0.56-1.82 | ns | 1.09 | 0.70-1.70 | ns |
55-64 | 0.80 | 0.56-1.15 | ns | 2.05 | 1.42-2.96 | *** | 1.25 | 0.85-1.84 | ns | 1.52 | 1.06-2.18 | | 0.89 | 0.48-1.64 | ns | 1.33 | 0.84-2.13 | ns |
65 plus | 0.67 | 0.42-1.06 | ns | 3.15 | 1.94-5.11 | *** | 1.17 | 0.74-1.87 | ns | 1.21 | 0.80-1.84 | ns | 0.58 | 0.30-1.14 | ns | 1.32 | 0.79-2.19 | ns |
Employment | Employed (Ref) | | | | | | | | | | | | | | | | | | |
Unemployed | 1.51 | 1.21-1.89 | *** | 0.89 | 0.71-1.13 | ns | 1.27 | 0.99-1.63 | ns | 0.87 | 0.67-1.15 | ns | 1.24 | 0.86-1.80 | ns | 1.03 | 0.72-1.49 | ns |
FT Education | 1.32 | 0.74-2.36 | ns | 1.27 | 0.76-2.12 | ns | 0.80 | 0.38-1.68 | ns | 1.53 | 0.90-2.59 | ns | 0.74 | 0.20-2.73 | ns | 1.49 | 0.72-3.07 | ns |
Domestic/other | 1.02 | 0.78-1.34 | ns | 0.74 | 0.57-0.96 | | 1.28 | 0.93-1.74 | ns | 0.84 | 0.63-1.13 | ns | 1.33 | 0.88-2.00 | ns | 0.82 | 0.57-1.17 | ns |
Retired | 1.17 | 0.80-1.70 | ns | 0.59 | 0.40-0.86 | ** | 0.68 | 0.49-0.95 | | 1.27 | 0.95-1.69 | ns | 1.20 | 0.80-1.79 | ns | 0.93 | 0.69-1.26 | ns |
Partner status & employment Ethnicity | No Partner (Ref) | | | | | | | | | | | | | | | | | | |
Partner employed | 0.68 | 0.55-0.85 | *** | 1.26 | 1.02-1.55 | | 0.57 | 0.46-0.70 | *** | 1.20 | 0.99-1.45 | ns | 0.54 | 0.41-0.72 | *** | 1.07 | 0.85-1.34 | ns |
Partner not employed | 0.83 | 0.70-0.98 | | 1.22 | 1.02-1.46 | | 0.69 | 0.58-0.82 | *** | 1.06 | 0.89-1.26 | ns | 0.69 | 0.55-0.86 | ** | 1.12 | 0.92-1.36 | ns |
White (Ref) | | | | | | | | | | | | | | | | | | |
South Asian | 0.61 | 0.43-0.86 | ** | 1.74 | 1.33-2.29 | *** | 1.02 | 0.64-1.64 | ns | 1.75 | 1.19-2.57 | ** | 0.63 | 0.29-1.36 | ns | 1.00 | 0.60-1.67 | ns |
Black, mixed, other | 0.59 | 0.38-0.91 | | 0.88 | 0.57-1.34 | ns | 1.34 | 0.69-2.60 | ns | 1.12 | 0.62-2.02 | ns | 0.84 | 0.32-2.24 | ns | 0.83 | 0.37-1.87 | ns |
Health status | Very good (Ref) | | | | | | | | | | | | | | | | | | |
Good | 1.69 | 1.32-2.16 | *** | 0.54 | 0.45-0.65 | *** | 1.46 | 1.15-1.86 | ** | 0.50 | 0.43-0.59 | *** | 1.78 | 1.33-2.38 | *** | 0.84 | 0.70-1.00 | |
Fair | 2.90 | 2.23-3.76 | *** | 0.54 | 0.43-0.67 | *** | 2.32 | 1.80-2.99 | *** | 0.43 | 0.35-0.53 | *** | 3.40 | 2.50-4.64 | *** | 0.57 | 0.45-0.72 | *** |
Bad | 4.47 | 3.30-6.04 | *** | 0.39 | 0.27-0.55 | *** | 3.31 | 2.42-4.54 | *** | 0.40 | 0.28-0.56 | *** | 4.22 | 2.77-6.44 | *** | 0.45 | 0.28-0.73 | ** |
Very bad | 7.09 | 4.65-10.81 | *** | 0.60 | 0.34-1.08 | ns | 4.35 | 2.71-6.96 | *** | 0.39 | 0.20-0.77 | ** | 6.92 | 3.63-13.16 | *** | 0.29 | 0.09-0.96 | |
Smoking status | Never smoked (Ref) | | | | | | | | | | | | | | | | | | |
Ex occasional | 0.80 | 0.56-1.14 | ns | 0.63 | 0.43-0.94 | | 1.27 | 0.91-1.77 | ns | 0.68 | 0.47-0.98 | | 1.00 | 0.63-1.59 | ns | 0.58 | 0.38-0.88 | |
Ex daily | 0.73 | 0.58-0.92 | ** | 0.97 | 0.77-1.22 | ns | 0.68 | 0.55-0.84 | *** | 0.83 | 0.69-1.00 | | 0.80 | 0.62-1.04 | ns | 0.78 | 0.63-0.95 | |
Occasional | 0.66 | 0.39-1.09 | ns | 1.28 | 0.82-2.01 | ns | 0.96 | 0.59-1.57 | ns | 1.18 | 0.77-1.80 | ns | 1.16 | 0.64-2.10 | ns | 0.44 | 0.23-0.82 | |
Daily | 0.93 | 0.79-1.11 | ns | 1.05 | 0.88-1.27 | ns | 0.98 | 0.81-1.18 | ns | 1.17 | 0.99-1.40 | ns | 1.14 | 0.89-1.47 | ns | 0.89 | 0.72-1.11 | ns |
Exercise days/week | 6 to 7 (Ref) | | | | | | | | | | | | | | | | | | |
3 to 5 | 1.20 | 0.91-1.57 | ns | 0.51 | 0.41-0.63 | *** | 1.13 | 0.88-1.45 | ns | 0.69 | 0.58-0.82 | *** | 0.80 | 0.58-1.10 | ns | 0.62 | 0.51-0.75 | *** |
1 to 2 | 1.67 | 1.26-2.20 | *** | 0.40 | 0.31-0.52 | *** | 1.46 | 1.13-1.88 | ** | 0.42 | 0.34-0.52 | *** | 1.18 | 0.86-1.60 | ns | 0.41 | 0.33-0.52 | *** |
None | 1.67 | 1.31-2.12 | *** | 0.42 | 0.34-0.51 | *** | 1.80 | 1.44-2.26 | *** | 0.48 | 0.40-0.59 | *** | 1.20 | 0.90-1.60 | ns | 0.40 | 0.33-0.50 | *** |
Alcoholconsumption category | Lower risk (Ref) | | | | | | | | | | | | | | | | | | |
Abstainer | 1.19 | 0.99-1.42 | ns | 1.02 | 0.85-1.22 | ns | 1.22 | 1.02-1.46 | | 1.13 | 0.96-1.32 | ns | 1.18 | 0.95-1.48 | ns | 1.22 | 1.03-1.46 | |
Not usual drinker | 1.15 | 0.85-1.55 | ns | 1.09 | 0.81-1.48 | ns | 1.63 | 1.25-2.13 | *** | 0.69 | 0.51-0.91 | | 1.43 | 0.99-2.05 | ns | 1.14 | 0.84-1.55 | ns |
Increasing risk | 1.31 | 0.98-1.74 | ns | 0.77 | 0.56-1.06 | ns | 1.52 | 1.16-2.01 | ** | 0.88 | 0.69-1.14 | ns | 0.97 | 0.68-1.39 | ns | 0.87 | 0.67-1.15 | ns |
| Higher risk | 1.49 | 0.99-2.26 | ns | 0.94 | 0.57-1.56 | ns | 1.53 | 0.93-2.52 | ns | 0.79 | 0.47-1.32 | ns | 1.62 | 0.82-3.17 | ns | 1.19 | 0.66-2.15 | ns |
National and international policy makers are seeking effective and economic ways of improving population wellbeing [
18,
19]. Work on social determinants has identified the negative impact of inequitable societies on wellbeing [
20‐
22]; although debate continues on the most appropriate definitions and mechanisms for its measurement [
23,
24]. The UK government has implemented a number of policy measures to make wellbeing, along with reductions in health inequalities, pan-governmental objectives [
3,
25,
26] including introducing subjective wellbeing questions into national household surveys [
27]. While providing a national measure of self-reported life satisfaction and wellbeing, to date this work has not examined how risk and protective factors for poor wellbeing vary with deprivation. Moreover, large studies on such issues elsewhere are scarce. Relatively little is also known about how policies aimed at reducing health inequalities may differentially impact on wellbeing in richer and poorer communities. However, such data are critical to ensure that existing public health services (e.g. alcohol, tobacco control, exercise initiatives) and policy specifically developed to improve wellbeing can, and does, reduce inequalities.
Here, we employ a simple but widely used scale of life satisfaction (LS) as a proxy for aspects of wellbeing such as happiness and pleasure [
28] and, for mental wellbeing (MWB), an established shortened version of the Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS) [
29]. Using these two different measures, LS and MWB, we examine their relationships with demographics, employment and health status. We explore how other public health priorities (here, alcohol, tobacco and exercise) are associated with low, moderate and high wellbeing. Importantly, we measure how such relationships differ between deprived, middle and affluent communities. Finally, we discuss how understanding the risk and protective factors associated with different levels of wellbeing can be used to increase LS and MWB in general and reduce inequalities in wellbeing.
Methods
The study was undertaken across the North West of England; a European region with a population of 6,897,905 (2009 [
30]) which includes a mix of affluent, deprived, urban and rural communities [
31]. Survey sample size was calculated to provide estimates of LS and MWB at a sub-regional geography corresponding with local health authority areas (n = 24). The target sample was 18,500 individuals aged 16 years and over. Ethical approval was obtained from Liverpool John Moores University.
Households were selected for inclusion using a clustered random sample approach. The national Post Office Address File (a database containing all known UK addresses and postcodes) was employed as the sampling frame and lower super output areas (LSOAs) were the primary sampling units. LSOAs are standard geographical areas in England that contain approximately 1,500 residents [
32]. Each LSOA has an average measure of deprivation routinely calculated across residents based on the Index of Multiple Deprivation (IMD). The IMD is a composite measure that includes 38 indicators relating to health, economic and educational status [
33]. LSOAs within each health area were labelled by national quintile of IMD and a random selection of LSOAs was made for each quintile based on their proportion within the health area. Households were randomly selected within each specific LSOA resulting in a total of 30,884 households. At the point of visit, the household resident aged ≥16 years who was next to have their birthday was selected to participate in the survey. However, for this analysis of adult LS and MWB, only those aged ≥18 years are included. For the purpose of this study IMD quintile for respondents’ LSOA of residence was used as an ecological measure of respondents’ deprivation.
The survey was piloted and data collected between 1 April and 30 June 2009. Sampling times ranged from 9.00 am to 8.00 pm and sampling was undertaken on weekdays and weekends to ensure those in daytime employment or education were included. Trained researchers attempted a maximum of four visits to each selected household; after which another household was selected at random from the same cluster. Of all households selected 60.1 % participated.
Data were collected using a structured questionnaire containing 44 questions covering relationships, health, lifestyle behaviours and key demographics such as age, gender, ethnicity and postcode of residence (a full list of data items is published elsewhere [
34]). Researchers explained the purpose of the survey, its confidential and anonymous nature and introduced the hand-held computer assisted self-interviewing (CASI) devices as the mechanism for data collection [
35]. Where required (e.g. with some elderly respondents) researchers provided assistance with using the devices. The final sample size was 18,560.
MWB was measured using the Short Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS). This is a shortened seven-item alternative to the full version of WEMWBS which uses a series of Likert-style items asking people to describe their experience of feelings and thoughts over the last two weeks: 1) I’ve been feeling optimistic about the future; 2) I’ve been feeling useful; 3) I’ve been feeling relaxed; 4) I’ve been dealing with problems well; 5) I’ve been thinking clearly; 6) I’ve been feeling close to other people; 7) I’ve been able to make my own mind up about people [
29]. Responses are scored (none of the time = 1; rarely = 2; some of the time = 3; often = 4; all the time = 5) and summed to provide a total score for each respondent. The SEMWBS has been validated against the full WEMWBS [
29] and been used to measure wellbeing in UK national household surveys [
36].
LS was measured using the single item question: “All things considered, how satisfied are you with your life as a whole nowadays on a scale of 1 to 10 where one is extremely dissatisfied and 10 is extremely satisfied” [
37]. This is a well-established measure that is widely used in global (e.g. World Values Survey [
38]), European (e.g. European Social Survey [
37]); and UK (e.g. British Social Attitudes Survey [
28]) population surveys. Across surveys that use this question, average LS values for UK populations have been relatively consistent. Some variations in the wording and scale of single item LS questions are used in other social surveys, yet results produced are generally similar [
28].
For the purposes of analyses respondents were categorised for MWB into moderate (mean +/− one standard deviation (SD) range 23–32), low (below one SD from the mean) and high (above one SD from the mean). LS was categorised into low (scored 1–5), moderate (6–8) and high (9–10).
Employment was categorised as employed (including full-time, part-time and self- employed), unemployed (including seeking work, not seeking work for reasons of disability), retired, and domestic/other (of which those engaged in domestic duties accounted for 77.4 %). Individuals were also categorised according to whether they had a partner (here, in a long term meaningful relationship) and, if so, if that person was employed. Ethnicity was recorded using standard UK ethnic group categories [
39]; however due to small numbers of some ethnic minorities it was only possible to categorise ethnicity into three groups: White, South Asian and Other (of Other, 44.4 % were Black). For health status we used a standard self-assessed five point scale from very good to very bad health (“How is your health in general? Would you say it is…”) [
40]. Smoking status categorised people into five categories; never smokers, ex-occasional smokers, ex-daily smokers, current occasional smokers and current daily smokers. Exercise was measured by asking participants “In the past week, on how many days have you accumulated at least 30 minutes of moderate intensity physical activity such as brisk walking, cycling, sport, exercise, and active recreation? (do not include physical activity that may be part of your job or usual role activities)” [
41].
For alcohol consumption, participants were asked “In general, how often do you drink alcoholic drinks” (response categories: never, monthly or less, once or twice a week, three or four days a week, daily or almost daily, don’t know/refused) followed by a question asking drinkers how many of a range of drink types they had consumed in the last week. Individuals who reported never drinking were categorised as abstainers and those that reported drinking monthly or less were categorised as not usual drinkers. All other drinkers were categorised based on the amount of alcohol they reported to have consumed in the past week according to UK Department of Health categories. Thus, lower risk drinkers were, for females, those that drank ≤14 units (standards UK drinks; 1 unit = 8 grams of pure alcohol) per week and, for males, ≤21 units per week. Increasing risk drinkers were those that consumed 15 to 35 units (females) and 22 to 50 units (males) per week and higher risk drinkers were those that consumed >35 (female) and >50 units (males) per week [
42]. To ensure that drinking reported over the past week was representative of typical drinking behaviour, individuals were asked if last week’s drinking was higher, lower or about typical for their alcohol consumption. Only those who stated that their past weeks’ alcohol consumption was typical were included in the analysis. Those individuals not providing an age (n = 286), not answering both LS and MWB questions (n = 383) and not providing answers to all other general health, smoking or exercise questions (n = 294) were excluded from analyses.
The final sample contained 15,228 individuals who had provided answers across all variables included in analyses (82 % of all those completing the survey). Statistics utilised chi-squared for bivariate exploration of LS and MWB across the entire dataset. Sample size did not permit robust analyses within each deprivation quintile. Therefore, to examine associations with LS and MWB at different levels of deprivation the dataset was split into tertiles (affluent, n = 4346; middle, n = 5598; deprived, n = 5284). Sample sizes vary slightly between tertiles as the catchment of each was matched to national IMD ranges for quintiles 1&2, 3&4 and 5 respectively. For each tertile, multinomial logistic regression (MLR [
43]) was used to identify independent relationships between LS / MWB and demographic, employment and lifestyle factors. Moderate LS / MWB was used as the reference category in order to quantify odds of low or high LS / MWB. All analyses were undertaken in PASW (Predictive Analytics Software) v18.0.
Discussion
Our study is one of the largest examining LS and MWB in the UK to date. Consistent with research elsewhere [
15,
44], data show strong relationships between a composite measure of deprivation and low LS and MWB as well as reduced levels of high LS and MWB (Tables
1 &
2). However, while studies have largely examined risk and protective factors for low LS and MWB across the entire deprivation spectrum, here we have looked at such factors within different derivation strata and treated the transition from moderate LS and MWB to low or high levels as separate outcomes.
Our results identify different factors impacting on LS and MWB in different deprivation strata and different risk and protective factors for low or high LS and MWB (cv moderate levels). For example, a recent UK survey [
27] found a U shape relationship between age and lower LS scores with the nadir for LS at 45–49 years. Here, in equivalent bivariate analyses we identified peaks in low LS at age 40–54 years in both deprived and middle tertiles but at age 55–64 years in the most affluent. Moreover after correcting for other factors, the impact of age on odds of low LS was only significant in the most deprived tertile where low LS decreased with increasing age (Table
3). Equally, in the same tertile high MWB increased significantly with age (Table
4). In deprived communities, a concentration of low LS in younger age groups may relate to individuals having more adverse childhood experiences, less access to material resources and lower aspirations for achieving life goals such as meaningful careers and personal wealth [
45]. This should be considered a contributory factor in their increased risk of anti-social behaviour and violence [
46]. Such effects have been identified as underlying drivers of recent disturbances in the UK involving primarily youths from the most deprived communities [
47].
As with other studies we found poorer LS in those who are unemployed [
27], with our results confirming unemployment (cv employment) as a predictor of low LS across all deprivation strata (Table
3). In contrast, for MWB this was only the case in the most deprived tertile (Table
4). LS is more closely related to general happiness and pleasure; both of which may rapidly reduce with unemployment at any level of affluence [
48]. MWB (through SWEMWBS) includes specific elements such as dealing with problems, thinking clearly, being close to others and, making up one’s own mind about things. These factors may be more resilient to changes in employment status, especially if unemployment benefit/compensation is available and where there is family support [
49]. In fact, being in a meaningful relationship with a partner was strongly related to better LS and MWB outcomes across all deprivation strata. While this is consistent with other studies [
27] our results also identified that the employment status of the partner had no discernible effects on outcomes (Tables
3 &
4).
Better LS and MWB are related to improved health status as both a cause and a consequence [
50]. Associations between health and LS here were such that those with very bad health (in deprived and middle tertiles) had odds of low LS more than ten times higher than individuals in very good health (10.32 and 10.77 respectively; Table
3). Equivalent odds for MWB were 7.09 and 4.35 for deprived and middle tertiles respectively. High LS and MWB (cv moderate) were also strongly related to health in all tertiles (Tables
3 &
4). However, the impact of health on LS is strongly moderated by levels of deprivation. Thus, among those with self-assessed very bad health, movement from the most deprived to most affluent tertile represents a reduction in low LS membership of 21.9 % (from 54.0 % to 32.1 %). Our results suggest that LS and MWB will benefit from health-increasing measures and vice versa. However, in order to reduce inequalities such actions need to focus disproportionately on deprived communities. The strong relationship between health and both LS and MWB may partly explain the strength of public opinion on changes to health service provision. More work is required to better understand how perceived security of access to health treatment impacts on LS and MWB [
51].
As well as health status, increasing deprivation was associated with lower LS and MWB within most independent variables studied here. However, no such relationships were seen in South Asian respondents (Tables
1 &
2). Whether South Asian communities benefit through stronger community ties, family relationships, cultural or individual protective factors against low LS and MWB remains unclear [
52‐
54]. A better understanding of the protective factors present in South Asian communities should help identify mechanisms for improving wellbeing in the broader population as well as specifically in deprived communities [
55].
For tobacco, public health policy has frequently been challenged on the basis that changes in legislation to improve health would reduce access to pleasure. In 2004 the Secretary of State for Health (UK) resisted changes to smoking legislation as ‘people from these lower socioeconomic categories have very few pleasures in life and one of them they regard as smoking’ [
56]. In this study, there was no suggestion that smoking was linked to improved LS (cv never smoked; Table
3). Interestingly low MWB was less likely in ex-daily smokers (deprived and middle tertiles) than even those that had never smoked (Table
4). However, the causality in relationships between smoking and MWB are still unclear and individuals with good MWB are likely to have sufficient determination to quit. Equally however, our results are consistent with no fall in MWB as a result of quitting. Elsewhere, individuals who successfully quit smoking have been found to have significantly improved well-being compared with individuals who continue to smoke [
57].
Drinking within government weekly guidelines for alcohol consumption was associated with lower risks of low LS, but only in the most deprived tertile (Table
3). Here, although there were minor differences from abstainers, increasing and higher risk drinkers showed the highest risks of low LS (Table
3), supporting previous studies identifying strong relationships between alcohol use and LS [
58,
59]. Alcohol consumption is frequently used as a form of self-medication for stress with such users often increasing consumption levels as they develop greater tolerance [
60]. Consequently, higher risk drinking may be a result as well as a cause of poorer LS [
58]. Importantly, the risks of alcohol-related diseases associated with any specific level of consumption appear to be higher in poorer communities [
61]. Our results suggest that the impact of alcohol on LS may also be stronger in poorest communities. Lower risk drinking was protective against low MWB in the middle tertile (Table
4); even compared to not usual drinkers and abstainers [
62]. As community engagement is related to MWB, more work is needed to identify whether non-drinkers can successfully engage in UK communities where socialising can be based around alcohol consumption [
63].
Exercise had one of the most wide-ranging impacts on both LS and MWB (Tables
3 &
4). Importantly, higher levels of exercise were protective against low MWB in the deprived tertile but not in the affluent. The UK Chief Medical Officers released advice on exercise levels for different age groups and a series of initiatives have been established to encourage uptake (e.g. change4life, Physical Exercise Responsibility Deal) [
64]. Other policy changes have also placed public health leadership within local authorities with responsibility for cycling, public- and school-based sports facilities, and parks and green space access and security [
25]. With a strong evidence base to support causal relationships [
65], this study suggests that physical exercise may be particularly beneficial for wellbeing in deprived communities and may be an important element in addressing wellbeing inequalities.
Although this is one of the largest studies of LS and MWB in the UK to date, it has a number of limitations. Using residential address as the sampling unit meant that an individual compliance rate and therefore sample representativeness could not be calculated. However, CASI and stratified residence sampling were used to improve compliance with approximately two thirds of all residences identified in the initial sample participating in the survey. Moreover, while we have no nationally comparable measures for MWB, a recent national survey using a version of the LS scale employed here [
27] reported an average LS score of 7.4 (cv 7.57 here). SWEMWBS has not been extensively used in the general population and requires further validation to better understand the precise nature of the metric and its relationship with population mental health. For deprivation, individuals were assigned to quintiles based on their LSOA of residence. While this ecological technique is widely used it can mask individual-level differences within each LSOA. Moreover, despite a large sample size there were insufficient individuals from ethnic minorities to examine the LS and MWB characteristics of smaller ethnic groups. Using a cross-sectional survey we were not able to identify causal relationships but only associations between wellbeing, life satisfaction and deprivation, health and lifestyle factors. This is a limitation in the application of the findings to the development and implementation of measures to improve wellbeing. However, our cross-sectional data still identifies the characteristics of communities and individuals most likely to suffer from poor wellbeing; and thus where interventions and longitudinal studies may best be targeted. Finally, although we have examined how relationships between LS/MWB and behaviour (e.g. smoking and alcohol use) differ with deprivation our study was not able to identify if motivations for such behaviours also vary. Thus, in some communities, more than others, substance use may function as a coping strategy. Behaviours such as alcohol consumption and smoking may themselves be the result of early life or environmental stressors but examining such issues was not possible in this study [
66].
Competing interests
The author(s) declare that they have no competing interests.
Authors’ contributions
MAB directed the study, analysed the data and wrote the manuscript. HL and KH analysed data and co-wrote the manuscript. LD contributed to the data collection, study methodology and edited the manuscript. JS and CP contributed to literature review and manuscript editing. All authors read and approved the final manuscript.