Table 1.
Descriptive characteristics of analytic sample (N = 10 606) by fatigue at baseline
| Low fatiguea | Mid fatiguea | High fatiguea | |
|---|---|---|---|
| Baseline characteristics | Mean (s.d.) | Mean (s.d.) | Mean (s.d.) |
| Age (years) | 50.6 (16.3) | 51.7 (17.1) | 54.3 (17.4) |
| GHQ score (possible range 0–36) | 8.9 (3.6) | 11.5 (4.7) | 16.0 (7.0) |
| C-reactive protein | (%) | (%) | (%) |
| Low (<1 mg/L) | 44.8 | 37.2 | 31.3 |
| Mid (1–2.99 mg/L) | 37.9 | 38.5 | 37.3 |
| High (3.0–10.0 mg/L) | 17.3 | 24.3 | 31.5 |
| Gender | |||
| Male | 48.8 | 42.7 | 36.8 |
| Female | 51.2 | 57.3 | 63.3 |
| Ethnicity | |||
| White (British/Irish/other white) | 95.4 | 95.6 | 96.5 |
| Any other ethnicity | 3.8 | 3.9 | 3.2 |
| Missing | 0.8 | 0.5 | 0.3 |
| Somatic diagnoses (respiratory disease, cancer, cardiac disease, high blood pressure, diabetes) | |||
| No | 76.6 | 66.1 | 53.3 |
| Yes | 23.4 | 33.9 | 46.7 |
| Body mass index | |||
| <18.5 | 2.3 | 3.7 | 5.6 |
| 18.5–24.9 | 32.8 | 27.0 | 22.8 |
| 25.0–29.9 | 41.8 | 38.2 | 32.5 |
| 30–34.9 | 17.0 | 21.3 | 22.8 |
| >35 | 6.1 | 9.9 | 16.2 |
| Smoking status | |||
| Never | 55.2 | 52.0 | 45.5 |
| Ex | 27.2 | 27.6 | 29.8 |
| Current, ⩽10/day | 8.4 | 9.6 | 9.9 |
| Current, 11–20/day | 6.2 | 7.9 | 10.2 |
| Current, >20/day | 1.1 | 1.3 | 2.7 |
| Missing | 1.9 | 1.6 | 1.9 |
| Takes NSAIDs, corticosteroids or statins | |||
| No | 84.9 | 78.5 | 66.9 |
| Yes | 15.1 | 21.5 | 33.1 |
| Takes HRT or oral contraceptives | |||
| No | 94.0 | 94.5 | 94.4 |
| Yes | 6.0 | 5.5 | 5.6 |
| Anaemia (haemoglobin <12 g/L for women, <13 g/L for men) | |||
| No | 85.1 | 83.8 | 79.5 |
| Yes | 8.4 | 9.5 | 13.1 |
| Missing | 6.5 | 6.7 | 7.5 |
| Hypertension (⩾140 systolic, ⩾90 diastolic) | |||
| Normotensive untreated | 58.5 | 52.6 | 43.4 |
| Normotensive treated | 8.6 | 13.2 | 17.2 |
| Hypertensive | 4.1 | 4.2 | 4.3 |
| Missing | 28.9 | 30.0 | 35.1 |
| Glycated haemoglobin | |||
| Normal (<42 mmol/mol) | 85.1 | 81.3 | 73.8 |
| Prediabetes (42–47 mmol/mol) | 5.4 | 7.3 | 9.5 |
| Diabetes (⩾48 mmol/mol) | 3.1 | 5.2 | 9.3 |
| Missing | 6.4 | 6.3 | 7.5 |
GHQ, General Health Questionnaire.
a
Fatigue groups categorised as: low fatigue: a lot of energy ‘all’ or ‘most’ of the time; mid fatigue: a lot of energy ‘some’ of the time; high fatigue: a lot of energy ‘a little’ or ‘none’ of the time.