Descriptive characteristics of the study population and percentage of green space coverage within neighbouring buffer (radius=300 m) at baseline (n=3544)
| Number of subjects | Total months of follow-up | Coverage of green space (%) | ||||
| N (%) | Median (IQR) | Median (IQR) | Correlation coefficient | Median (IQR) | Correlation coefficient | |
| Overall subjects | 3544 (100%) | 133.32 (14.2) | 13.36 (29.1) | |||
| Demographics | ||||||
| Sex | ||||||
| Male | 1773 (50.0) | 137.2 (13.9) | 12.25 (29.1) | |||
| Female | 1771 (49.9) | 128.4 (9.2) | 14.16 (29.9) | |||
| Age (years) | 72.2 (5.0) | −0.25 | 0.01 | |||
| 65–70 | 1550 (43.8) | 135.0 (13.8)* | 13.13 (28.7) | |||
| 71–75 | 1111 (31.4) | 134.0 (13.0) | 13.21 (30.1) | |||
| 76–80 | 654 (18.4) | 127.7 (26.3) | 13.64 (31.1) | |||
| 81–85 | 181 (5.1) | 122.5 (51.3) | 13.13 (28.7) | |||
| ≥86 | 48 (1.3) | 110.6 (53.1) | 17.58 (35.0) | |||
| Marital status | ||||||
| Married | 2546 (71.9) | 135.3 (13.9)* | 12.85 (29.2) | |||
| Widowed | 849 (23.9) | 127.5 (8.0) | 14.16 (29.0) | |||
| Separated or divorced | 79 (2.2) | 128.7 (16.7) | 16.63 (37.7) | |||
| Single (never married) | 70 (2.0) | 126.9 (48.9) | 16.23 (30.7) | |||
| Years lived in Hong Kong | 52.7 (14.9) | −0.05* | −0.02 | |||
| Socioeconomics | ||||||
| Education Level | ||||||
| Not educated | 743 (20.9) | 128.4 (10.2)* | 16.07 (28.6) | |||
| Primary school not completed | 1164 (32.8) | 132.8 (14.2) | 13.60 (31.2) | |||
| Primary school graduated | 606 (17.2) | 134.0 (14.9) | 12.93 (31.9) | |||
| Secondary school | 679 (17.1) | 135.8 (14.6) | 11.46 (25.5) | |||
| University or above | 352 (9.9) | 135.8 (12.4) | 9.11 (23.8) | |||
| Socioeconomic ladder | ||||||
| Low (1–3) | 973 (27.4) | 134.4 (16.1) | 13.37 (30.3)† | |||
| Medium (4–6) | 2142 (60.5) | 132.9 (13.7) | 13.13 (29.2) | |||
| High (7–10) | 429 (12.1) | 133.4 (12.3) | 13.37 (27.5) | |||
| Lifestyle factors | ||||||
| Smoking | ||||||
| Non-smoker | 2259 (63.8) | 127.7 (11.8)* | 13.29 (28.5) | |||
| Past-smoker | 1046 (29.5) | 136.0 (24.3) | 13.37 (30.6) | |||
| Current-smoker | 239 (6.7) | 135.4 (23.4) | 14.16 (32.6) | |||
| Alcohol intake | ||||||
| Intake≤12 drinks during the past 12 months | 3069 (86.6) | 132.6 (13.6)† | 13.37 (29.3) | |||
| Intake>12 drinks during the past 12 months | 475 (13.4) | 137.2 (10.6) | 12.41 (27.2) | |||
| DQI-I | 64.45 (9.5) | 0.08* | −0.03† | |||
| PASE | 91.9 (43.0) | 0.14 | 0.01 | |||
| Health conditions | ||||||
| MMSE | 25.7 (3.6) | 0.11* | −0.13 | |||
| MCS | 55.5 (7.2) | −0.01 | 0.01 | |||
| Self-rated health | ||||||
| Very good | 335 (9.5) | 136.0 (14.5)* | 12.65 (29.8) | |||
| Good | 1354 (38.2) | 134.2 (14.3) | 12.65 (29.0) | |||
| Fair | 1607 (45.3) | 131.5 (13.3) | 14.48 (29.6) | |||
| Substandard | 220 (6.2) | 128.7 (12.3) | 12.29 (26.7) | |||
| Poor | 28 (0.8) | 127.2 (37.1) | 15.16 (31.6) | |||
| Environmental factors | ||||||
| Housing type | ||||||
| Private housing | 1521 (42.9) | 134.2 (13.5) | 12.65 (29.4) | |||
| Public housing | 2023 (57.1) | 132.6 (14.8) | 13.68 (29.7) | |||
| Highway proximity (m) | 138.9 (202.1) | −0.01 | 0.16* | |||
| PM2.5 concentration (µg/m3) | 32.4 (2.6) | −0.04† | −0.45* | |||
| Average building density (%) | 34.8 (9.8) | 0.01 | −0.65* | |||
| Absolute living height (m) | 112.9 (88.2) | −0.01 | 0.46* | |||
For categorical characteristics, the number of subjects n (% divided by the total N), the average follow-up duration and coverage of green space for each category are shown as median (IQR). For continuous variables, the average level of continuous variables for all subjects is presented as mean (SD) or median (IQR) if non-normal distribution was observed; their correlation with follow-up duration or coverage of green space is reported using Spearman's correlation coefficient.
*Difference between groups or correlation with a continuous variable is significant at the 0.01 level (two-tailed).
†Difference between groups or correlation with a continuous variable is significant at the 0.05 level (two-tailed).
DQI, Diet Quality Index-International; MCS, The mental component of SF-12; MMSE, Mini-Mental State Examination; PASE, Physical Activity Scale for the Elderly.