Comprehensive Assessment of Quality of Life and Physical Activity

The validated WHOQOL-BREF (Hong Kong version) was used to measure QOL [1 , 21 (link)]. It consists of 24 items to assess perception of quality of life in four domains, including physical health, psychological, social relationships and environment, and two items on overall QOL and general health. The domain scores were transformed into a linear scale between 0 and 100 following the scoring guidelines [1 ]. A higher score indicated a better QOL. Physical activities were assessed by the International Physical Activity Questionnaire short form (IPAQ-SF) which is adequately reliable and valid in a Chinese population [22 ]. Walking, moderate-intensity and vigorous-intensity activities were assessed. The total MET-minutes/week was calculated for each participant. Metabolic Equivalent of Task (MET) is the energy cost of physical activities [23 (link)]. Physical activity levels were categorized as low, moderate and high, based on the criteria listed on the IPAQ guidelines [22 ]. People have to answer all questions on number of days in a week and daily time performing walking, moderate and vigorous activities in order to calculate their total MET and identify their physical activity levels. Those who were unable or refused to answer all these questions were removed from the analysis according to the IPAQ guidelines [22 ]. Smoking, alcohol drinking, and vegetable and fruit intakes were also assessed. For practicing low fat, low salt and low sugar diets, respondents could choose “never (1)”, “seldom (2)”, “sometimes (3)” and “always (4)”. Seven questions on satisfaction with the neighborhood environment with a five-point Likert scale (1: very unsatisfied; 5: very satisfied) were used to evaluate air quality, ventilation, drinking water quality, noise condition, lighting condition, environmental hygiene, and environmental protection and recycling. Six questions on satisfaction with open spaces including greening, parks and gardens, recreation and sports facilities, promenade, rest areas and pedestalization were also assessed using the same Likert scale. Socio-demographic profiles of the residents were also assessed.
Test-retest reliability of the questionnaire had been tested with 64 subjects before implementation of the main study. All question items showed a Cohen’s kappa value ranged from 0.50–1.00 or an intraclass correlation coefficient value ranged from 0.55–1.00, which indicated that the reliability of the questionnaire was fair to excellent.