Table 1. Cohort Characteristics From a Sample of UK Biobank Participants Wearing Accelerometersa.
| Incident dementia (n = 414) | No incident dementia (n = 49 427) | |
|---|---|---|
| Age, median (IQR), y | 71 (68 to 74) | 67 (64 to 70) |
| Sex, No. (%) | ||
| Female | 187 (45.2) | 27 053 (54.7) |
| Male | 227 (54.8) | 22 374 (45.3) |
| Education (college or higher), No. (%) | 167 (40.3) | 20 578 (41.6) |
| Townsend Deprivation Index, median (IQR)b | −2.6 (−4.0 to 0.1) | −2.7 (−3.9 to −0.6) |
| Ethnicity, No. (%)c | ||
| Asian | 3 (0.7) | 365 (0.7) |
| Black | 2 (0.5) | 139 (0.3) |
| Multiethnicd | 1 (0.2) | 146 (0.3) |
| Othere | 4 (1.0) | 197 (0.4) |
| White | 404 (97.6) | 48 580 (98.3) |
| APOE ε4 allele status, No. (%) | ||
| 1 allele | 171 (41.3) | 11 651 (23.6) |
| 2 alleles | 39 (9.4) | 1068 (2.2) |
| Body mass index, median (IQR)f | 26.2 (23.7 to 29.3) | 26.2 (23.8 to 29.0) |
| Smoking status, No. (%) | ||
| Current | 23 (5.6) | 2680 (5.4) |
| Former | 193 (46.6) | 19 855 (40.2) |
| Never | 198 (47.8) | 26 892 (54.4) |
| Alcohol consumption, No. (%)g | ||
| Excessive | 113 (27.3) | 14 923 (30.2) |
| Moderate | 187 (45.2) | 23 082 (46.7) |
| Never | 114 (27.5) | 11 422 (23.1) |
| Chronic condition present, No. (%)h | 194 (46.9) | 18 380 (37.2) |
| Self-reported health, No. (%) | ||
| Excellent | 61 (14.7) | 10 741 (21.7) |
| Good | 233 (56.3) | 30 494 (61.7) |
| Fair | 91 (22.0) | 7183 (14.5) |
| Poor | 29 (7.0) | 1009 (2.0) |
| Had depression, No. (%)i | 91 (22.0) | 8655 (17.5) |
| Adherence to a healthy diet, No. (%)j | 230 (55.6) | 28 550 (57.8) |
| Sedentary behavior, median (IQR), h/d | 9.7 (8.4 to 11.1) | 9.3 (8.1 to 10.4) |
| Sedentary bouts, median (IQR) | ||
| Frequency, bouts/d | 17.8 (15.3 to 40.9) | 17.5 (15.3 to 42.7) |
| Mean length, h/d | 0.5 (0.2 to 0.7) | 0.5 (0.2 to 0.6) |
| Maximum length, h/dk | 2.0 (1.5 to 2.5) | 1.9 (1.4 to 2.4) |
| Moderate to vigorous physical activity, median (IQR), h/d | 0.4 (0.1 to 0.8) | 0.5 (0.3 to 1.0) |
The accelerometer data were collected during a follow-up substudy (additional details appear in the Methods section). The demographic data were collected at the baseline visit (the data appear by sedentary behavior quartile in eTable 2 in Supplement 1).
A measure of socioeconomic status calculated using unemployment rate, no car ownership, no home ownership, and household overcrowding, which were obtained from census data. These variables were combined to create a single composite score, which was then standardized to have a mean of 0 and an SD of 1. Higher scores indicate higher levels of socioeconomic deprivation, whereas lower scores represent lower levels.
Obtained from self-report using a set of sequential branching questions with fixed categories.
The UK Biobank used the term mixed for participants who self-identified as multiethnic in their assessment.
Provided as a possible answer choice.
Calculated as weight in kilograms divided by height in meters squared.
Categories were determined using the methods of Lourida et al.13 Moderate defined as greater than 0 g/d to 14 g/d or less for women and greater than 0 g/d to 28 g/d or less for men.
Based on physician diagnosis of vascular or heart disease (eg, prior myocardial infarction, angina, or stroke or current high blood pressure), diabetes, or cancer.
Self-reported at baseline.
Determined using the methods of Lourida et al13 and was considered a diet that included at least 4 of the following 7 categories: (1) 3 or more servings/d of fruit; (2) 3 or more servings/d of vegetables; (3) 2 or more servings/wk of fish; (4) 1.5 servings/wk or less of unprocessed red meats; (5) 1 serving/wk or less of processed meats; (6) 3 or more servings/d of whole grains; and (7) 1.5 servings/d or less of refined grains.
Calculated as the mean of the daily maximum bout lengths.