Table 1

Age-adjusted characteristics of the study population at 2001 baseline by rotating night shift duration

Duration of rotating night shift work (years)0<22–5.96–9.9>10
Proportion of sample (%)292724119
Age, years*47.05±4.6046.64±4.7346.22±4.7046.27±4.5847.22±4.28
Body mass index, kg/m225.66±4.8925.85±4.9826.22±5.0926.76±5.3027.21±5.33
Physical activity, MET-hours/week†19.22±21.6619.47±21.5520.33±22.6620.35±22.7320.15±22.96
Alcohol intake, g/day3.87±7.044.07±7.284.14±7.303.98±7.343.52±6.64
Alternate Health Eating Index‡47.82±10.6947.74±10.7847.91±10.6347.68±10.8147.14±10.72
Sleep, ≤6 hours over a 24-hour period, %2527313340
First degree relative history of melanoma, %1111121212
Red or blonde hair, %2020202017
Moles, ≥10 on lower legs, %1515141413
Artificial tanning, ≥6 times/year at ages 25–35, %33333
Time spent in sun, ≥5 hours/week at ages 25–35, %4343444445
Severe sunburns, ≥6 at ages 15–20, %910111011
Skin sensitivity to burning,§ %4241414141
Annual UV-B flux at residence, ≥ 145 R-B units,¶ %2623211916
Sleep not usually adequate, %4648515257
Sleepy ≥4 days/week, %1112121314
Snore most nights, %1415171819
Restless legs syndrome22222
Current smoker, %78101012
Married, %8282797675
In top 20 per cent of economic ladder,** %121211109
Oral contraceptive use, ≥8 years, %2222222222
Current use of postmenopausal hormones,†† %6664646259
  • Values are means±SD or percentages and are standardised to the age distribution of the study population.

  • *Value is not age-adjusted.

  • †Metabolic equivalents from recreational and leisure-time activities.

  • ‡Score of 0–100 measuring adherence to a dietary pattern most predictive of disease risk.

  • §Skin reaction after two or more hours in the sun without sunscreen on a bright sunny day during childhood and adolescence (none/some redness, burn, painful/blistering burn).

  • ¶Measured in Robertson-Berger units (count×10−4).

  • **Self-reported economic status compared to others.

  • ††Calculated among postmenopausal women only.

  • MET, metabolic equivalent.