Table 1.
Baseline characteristics of study participants according to categories of the diet quality score
| All participants (n=592,571) | Low hPDI (Q1; n=148,143) | Intermediate hPDI (Q2-Q3; n=296,286) | High hPDI (Q4; n=148,142) | |
|---|---|---|---|---|
|
|
||||
| hPDI score, median [P25-P75] | 50 (47 to 54) | 45 (43–47) | 51 (49–52) | 56 (55–58) |
| Demographic characteristics | ||||
|
| ||||
| Age, years | 56 (44–65) | 52 (41–62) | 57 (45–66) | 57 (45–65) |
| ≥18–24 | 14,397 (2.4) | 5,146 (3.4) | 5,846 (2.0) | 3,405 (2.3) |
| 25–34 | 52,922 (8.9) | 16,535 (11.2) | 23,150 (7.8) | 13,237 (8.9) |
| 35–44 | 86,251 (14.6) | 26,907 (18.2) | 40,145 (13.5) | 19,199 (13.0) |
| 45–54 | 125,802 (21.2) | 34,890 (23.6) | 62,491 (21.1) | 28,421 (19.2) |
| 55–64 | 158,637 (26.8) | 34,279 (23.1) | 81,837 (27.6) | 42,521 (28.7) |
| ≥65 | 153,810 (26.0) | 30,215 (20.4) | 82,413 (27.8) | 41,182 (27.8) |
| Missing | 752 (0.1) | 171 (0.1) | 404 (0.1) | 177 (0.1) |
| Sex, No. (%) | ||||
| Male | 187,450 (31.6) | 58,199 (39.3) | 93,162 (31.4) | 36,089 (24.4) |
| Female | 404,126 (68.2) | 89,706 (60.5) | 202,605 (68.4) | 111,815 (75.5) |
| Prefer not to say | 995 (0.2) | 238 (0.2) | 519 (0.2) | 238 (0.2) |
| Raceε, No. (%), | ||||
| White | 568,770 (96.0) | 141,365 (95.4) | 284,804 (96.1) | 142,601 (96.3) |
| Black | 4,328 (0.7) | 1,466 (1.0) | 2,053 (0.7) | 809 (0.5) |
| Asian | 10,435 (1.8) | 2,954 (1.9) | 5,043 (1.7) | 2,438 (1.6) |
| Other | 7,228 (1.2) | 1,925 (1.3) | 3,463 (1.2) | 1,840 (1.2) |
| Missing | 1,810 (0.3) | 433 (0.3) | 923 (0.3) | 454 (0.3) |
| Country, No. (%) | ||||
| UK | 543,984 (91.8) | 135,360 (91.4) | 272,494 (92.0) | 136,130 (91.9) |
| US | 48,587 (8.2) | 12,783 (8.6) | 23,792 (8.0) | 12,012 (8.1) |
| Index of deprivation, No. (%)¶ | ||||
| Most deprived, decile 1 | 1,3416 (2.3) | 4,696 (3.1) | 6,163 (2.1) | 2,557 (1.7) |
| Least deprived, decile 10 | 103,608 (17.5) | 23,122 (15.6) | 53,652 (18.1) | 26,834 (18.1) |
| Missing | 40,759 (6.9) | 10,489 (7.1) | 20,249 (6.8) | 10,021 (6.8) |
| Population density, km2, No. (%)¶ | ||||
| <500 | 119,782 (20.2) | 28,139 (19.0) | 61,230 (20.7) | 30,413 (20.5) |
| 500–1,999 | 90,541 (15.3) | 23,631 (16.0) | 45,902 (15.5) | 21,008 (14.2) |
| 2,000 4,999 | 94,345 (15.9) | 24,813 (16.7) | 47,233 (15.9) | 22,299 (15.1) |
| ≥5,000 | 244,295 (41.2) | 60,156 (40.6) | 120,319 (40.6) | 63,820 (43.1) |
| Missing | 43,608 (7.4) | 11,404 (7.7) | 21,602 (7.3) | 10,602 (7.2) |
| Healthcare worker, yes, No. (%) | 41,141 (6.9) | 10,633 (2.3) | 20,183 (6.8) | 10,325 (7.0) |
|
| ||||
| Lifestyle characteristics | ||||
|
| ||||
| Smoking status, No (%) | ||||
| Never | 475,347 (81.9) | 113,165 (79.0) | 238,192 (81.9) | 123,990 (84.6) |
| Former | 87,901 (15.1) | 22,683 (15.8) | 44,771 (15.4) | 20,447 (13.9) |
| Current | 17,401 (3.0) | 7,402 (5.2) | 7,837 (2.6) | 2,162 (1.5) |
| Physical activity | ||||
| < 1 day/week | 106,294 (17.9) | 37,258 (25.2) | 50,713 (17.1) | 18,323 (12.4) |
| 1–2 days/week | 224,606 (37.9) | 59,325 (40.0) | 113,749 (38.4) | 51,532 (34.8) |
| 3–4 days/week | 143,548 (24.2) | 30,009 (20.3) | 73,601 (24.8) | 39,938 (27.0) |
| ≥ 5 days/week | 117,007 (19.7) | 21,164 (14.3) | 57,701 (19.5) | 38,142 (25.7) |
| Missing | 1,116 (0.2) | 387 (0.3) | 522 (0.2) | 207 (0.1) |
| Body mass index, Kg/m2 | 25.1 (22.6–28.7) | 26.6 (23.6–30.7) | 25.2 (22.7–28.5 | 24.0 (21.8–26.9) |
| <18.5 | 12,004 (2.0) | 2,680 (1.8) | 5,540 (1.9) | 3,784 (2.6) |
| 18.5–24.9 | 277,536 (46.8) | 52,109 (35.2) | 138,503 (46.7) | 86,924 (58.7) |
| 25–29.9 | 189,197 (31.9) | 51,517 (34.8) | 97,919 (33.0) | 39,761 (26.8) |
| ≥30 | 113,056 (19.1) | 41,655 (28.1) | 53,909 (18.2) | 17,492 (11.8) |
| Missing | 778 (0.1) | 182 (0.1) | 415 (0.1) | 181 (0.1) |
| Mask wearing, No (%)† | ||||
| Most of the time / always | 437,782 (73.9) | 113,202 (76.4) | 218,402 (73.7) | 106,178 (71.6) |
| Never / sometimes | 152,551 (25.7) | 34,240 (23.1) | 76,809 (25.9) | 41,502 (28.0) |
| Missing | 2,238 (0.4) | 701 (0.5) | 1,075 (0.4) | 462 (0.3) |
|
| ||||
| Clinical history, yes, No. (%) | ||||
|
| ||||
| Diabetes | 20,058 (3.4) | 6,079 (4.1) | 10,158 (3.4) | 3,821 (2.6) |
| Heart disease | 20,376 (3.4) | 5,200 (3.5) | 10,660 (3.6) | 4,516 (3.0) |
| Cancer | 6,559 (1.9) | 1,643 (1.8) | 3,348 (1.9) | 1,568 (1.8) |
| Lung disease | 62,999 (10.6) | 17,534 (11.8) | 31,227 (10.5) | 14,238 (9.6) |
| Kidney disease | 5,134 (0.9) | 1,492 (1.0) | 2,594 (0.9) | 1,048 (0.7) |
Values are median (P25-P75) for continuous variables; numbers and (percentages) for categorical variables.
ε
Race was self-reported by the participants.
¶
Index of deprivation and population density were generated using zipcode or postcode information linked with census track data. Country-specific deprivation indices were generated (supplement).
†
Mask wearing information was collapsed into two categories: participants who wore masks ‘none of the time or sometimes’, and those who reported wearing masks ‘most of time/ always’.
*
hPDI ranges from 0 to 70, with higher scores indicating higher adherence to a healthy plant-based diet.