Table 2.
Characteristics of the study population (n = 12,589 observations) stratified by season
| Characteristics | Overall | N | Winter | N | Spring | N | Summer | N | Autumn | N | P value* |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Median (IQR) | Median (IQR) | Median (IQR) | Median (IQR) | Median (IQR) | |||||||
| Age (years) | 66.3 (59.4–73.7) | 12,589 | 66.3 (59.8–73.5) | 3239 | 66.5 (58.8 to 74.1) | 3951 | 67.3 (59.7–74.5) | 2868 | 64.7 (59.3–72.5) | 2531 | < 0.01 |
| Physical activity (z score MET-hours/week)a | − 0.22 (− 0.77 to 0.58) | 10,412 | − 0.19 (− 0.75 to 0.55) | 2643 | − 0.26 (− 0.78 to 0.48) | 3301 | − 0.23 (− 0.78 to 0.56) | 2388 | − 0.11 (− 0.77 to 0.78) | 2080 | < 0.01 |
| BMI | 26.5 (24.3–29.1) | 12,397 | 26.3 (24.2–29.0) | 3204 | 26.6 (24.3–29.3) | 3882 | 26.4 (24.2–29.0) | 2820 | 26.4 (24.3–29.1) | 2491 | 0.04 |
| Energy intake (kilocalories/day) | 1996 (1653–2392) | 12,589 | 2001 (1671–2396) | 3239 | 1984 (1654–2391) | 3951 | 1982 (1625–2371) | 2868 | 2021 (1657–2416) | 2531 | 0.06 |
| Diet quality score | 7 (5–8) | 12,589 | 7 (6–8) | 3239 | 7 (5–8) | 3951 | 7 (5–8) | 2868 | 7 (6–8) | 2531 | 0.63 |
| N | % | N | % | N | % | N | % | N | % | ||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Sex | |||||||||||
| Men | 5306 | 42.1 | 1391 | 43.0 | 1679 | 42.5 | 1181 | 41.18 | 1055 | 41.7 | 0.50 |
| Women | 7283 | 57.9 | 1848 | 57.0 | 2272 | 57.5 | 1687 | 58.82 | 1476 | 58.3 | |
| Education | |||||||||||
| Primary | 1695 | 13.6 | 410 | 12.8 | 550 | 14.0 | 409 | 14.35 | 326 | 13.0 | < 0.01 |
| Lower | 5189 | 41.6 | 1370 | 42.6 | 1553 | 39.7 | 1196 | 41.96 | 1070 | 42.8 | |
| Intermediate | 3626 | 29.0 | 911 | 28.4 | 1128 | 28.8 | 828 | 29.05 | 759 | 30.4 | |
| Higher | 1968 | 15.8 | 521 | 16.2 | 685 | 17.5 | 417 | 14.63 | 345 | 13.8 | |
| Smoking status | |||||||||||
| Never | 4031 | 32.1 | 1046 | 32.5 | 1261 | 32.0 | 908 | 31.76 | 816 | 32.5 | 0.42 |
| Ever | 5879 | 46.9 | 1537 | 47.8 | 1855 | 47.0 | 1345 | 47.04 | 1142 | 45.4 | |
| Current | 2626 | 21.0 | 635 | 19.7 | 829 | 21.0 | 606 | 21.20 | 556 | 22.1 | |
| Prevalent diseasesb | |||||||||||
| Yes | 2155 | 17.1 | 590 | 18.2 | 692 | 17.5 | 476 | 16.60 | 397 | 15.7 | 0.06 |
| No | 10434 | 82.9 | 2649 | 81.8 | 3259 | 82.5 | 2392 | 83.40 | 2134 | 84.3 | |
Bold values are considered statistically significant (P < 0.05)
Some characteristics do not sum up, because table is based on non-imputed data
BMI body mass index, MET metabolic equivalent of task
*P value of population differences between seasons estimated using Kruskal–Wallis test for continuous variables, and Chi-square test for categorical variables
aPhysical activity is based on non-imputed data, because (imputed) standardized values of physical activity were used for the analyses
bPrevalent diseases include stroke, myocardial infarction (MI), diabetes mellitus type 2 (T2DM), and cancer