Sample demographics and bias analysis.
| Sociodemographic characteristics | Included sample | Excluded sample | Comparison | |
| (n=4481) | (n=2959) | P value | ||
| Age at survey | Mean, SD | 47 (0.6) | 47 (0.7) | 0.072 |
| Sex (female) | % (N) | 52% (2347) | 50% (1483) | 0.060 |
| Married | % (N) | |||
| Unmarried | 19% (836) | 20% (553) | <0.001* | |
| Divorced, separated or widowed | 15% (691) | 18% (520) | ||
| Married or in civil partnership | 66% (2954) | 62% (1747) | ||
| Highest educational attainment | % (N) | <0.001* | ||
| No formal qualifications | 25% (1132) | 32% (917) | ||
| GCSE or equivalent | 32% (1430) | 30% (869) | ||
| A level or equivalent | 6% (253) | 6% (164) | ||
| Undergraduate degree or equivalent | 31% (1407) | 27% (765) | ||
| Higher degree | 6% (259) | 5% (143) | ||
| Occupation type | % (N) | <0.001* | ||
| No occupation | 8% (377) | 12% (291) | ||
| Sitting | 51% (2274) | 47% (1108) | ||
| Standing | 14% (629) | 14% (324) | ||
| Physical work | 22% (1001) | 23% (547) | ||
| Heavy manual work | 5% (200) | 4% (94) | ||
| Health status and behaviours | ||||
| Disability status (EU-SILC) | % (N) | <0.001* | ||
| No EU-SILC longstanding health condition | 85% (3811) | 80% (2379) | ||
| EU-SILC classification, disability to some extent | 10% (456) | 12% (342) | ||
| EU-SILC classification, severely hampered | 5% (214) | 8% (236) | ||
| Psychological distress (abbreviated Malaise Scale) | % (N) | <0.001* | ||
| High malaise (4+) | 17% (768) | 21% (520) | ||
| Alcohol consumption (weekly units) | % (N) | <0.001* | ||
| None | 10% (438) | 12% (360) | ||
| Occasional (<14) | 68% (3033) | 63% (1827) | ||
| Regular, risky (>14) | 23% (1010) | 25% (726) | ||
| Smoker status | % (N) | <0.001* | ||
| Never | 50% (2260) | 44% (1310) | ||
| Ex-smoker | 32% (1446) | 32% (933) | ||
| Less than daily | 5% (215) | 6% (175) | ||
| Daily | 12% (560) | 18% (541) | ||
| BMI | Mean, SD | 28.4 (5.6) | 29.0 (6.2) | <0.001* |
In the Excluded sample group, results were not available for all. The percentages in this column are based on varying total numbers.
*Significant differences between included and excluded sample characteristics presented at the level ɑ≤0.05 as indicated by t tests and Pearson’s χ2 test.
BMI, body mass index; EU-SILC, EU-Statistics on Income and Living Conditions.