Lifetime physical activity in postmenopausal Caucasian and Chinese-Canadian women
ABSTRACT Physical activity is recognized as a modifiable lifestyle risk factor that may prevent breast cancer. The aim of this cross-sectional study was to compare the physical activity patterns in two populations with different risks for breast cancer. We collected physical activity information from two groups of postmenopausal Canadian women with substantially different risks of developing breast cancer - Caucasians (N=372) and recent Chinese migrants from urban China (N=352). The frequency, duration, and intensity of occupational, household, and recreational activities were measured throughout the lifetime using the interviewer-administered Lifetime Total Physical Activity Questionnaire. Compared with Caucasians, Chinese migrants reported lower average total physical activity over their lifetime and for each age period (0-21, 21-29, 30-39, 40-49, and ≥50 years). Compared with Caucasians, Chinese migrants reported greater lifetime occupational activity, but lower levels of lifetime activity for both household and recreation activity. Among Chinese migrants, reported levels of occupational, household, and recreational activities were all greater in migrants from Mainland China than in migrants from Hong Kong. In conclusion, our results show that total activity was greater amongst Caucasians than Chinese migrants, suggesting that the lower breast cancer risk in urban Chinese women is not likely to be explained by greater total physical activity.
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ABSTRACT: Recent efforts to more fully understand the mechanisms through which work and family experiences and their cross-over effects influence well-being have stimulated the development of integrative models of the work-family interface. This line of research is represented by the model which Frone, Russell, and Cooper (1992) tested with a sample of U.S. employees. In the current study, we examine the cross-cultural generalizability of this model among married Hong Kong employees. Results of the analyses suggest that many of the relationships among work and family constructs are similar across the two cultures, but that the nature and effects of the cross-over between family and work domains on overall employee well-being may differ. That is, life satisfaction of Hong Kong employees is influenced primarily by work-family conflict, while that of American employees is influenced primarily by family-work conflict. Limitations of the study and implications of the findings for assisting employees integrate their work and family responsibilities as a source of competitive advantage are discussed.Journal of Management 01/1999; 25(4):491-511. DOI:10.1177/014920639902500402 · 6.86 Impact Factor
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ABSTRACT: To review (1) the epidemiological literature on physical activity and the risk of breast cancer, examining the effect of the different parameters of activity and effect modification within different population subgroups; and (2) the biological mechanisms whereby physical activity may influence the risk of breast cancer. A review of all published literature to September 2007 was conducted using online databases; 34 case-control and 28 cohort studies were included. The impact of the different parameters of physical activity on the association between activity and the risk of breast cancer was examined by considering the type of activity performed, the timing of activity over the life course and the intensity of activity. Effect modification of this association by menopausal status, body mass index (BMI), racial group, family history of breast cancer, hormone receptor status, energy intake and parity were also considered. Evidence for a risk reduction associated with increased physical activity was found in 47 (76%) of 62 studies included in this review with an average risk decrease of 25-30%. A dose-response effect existed in 28 of 33 studies. Stronger decreases in risk were observed for recreational activity, lifetime or later life activity, vigorous activity, among postmenopausal women, women with normal BMI, non-white racial groups, those with hormone receptor negative tumours, women without a family history of breast cancer and parous women. The effect of physical activity on the risk of breast cancer is stronger in specific population subgroups and for certain parameters of activity that need to be further explored in future intervention trials.British journal of sports medicine 06/2008; 42(8):636-47. DOI:10.1136/bjsm.2006.029132 · 4.17 Impact Factor
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ABSTRACT: To develop and test the intra-rater reliability of an interview-administered questionnaire that assesses lifetime patterns of total physical activity including occupational, household, and exercise/sports activities. The questionnaire was developed and pretested using cognitive interviewing techniques on a sample of women with and without previous breast cancer diagnoses. A pilot study was conducted with 115 women who were interviewed twice, 6 to 8 wk apart by interviewers trained in cognitive interviewing methods. Respondents used recall calendars to record their education, occupations, life events, and physical activity patterns before the interviews. Interviewers helped respondents recall their lifetime exposures, including their occupational, household, and exercise/sports activities, using these calendars and memory-probing strategies. Activity levels were estimated as the average number of hours of activity per week over different time periods. Means and correlation coefficients were estimated and compared for the two time periods. The questionnaire was found to be highly reliable. The test-retest correlations for hours per week spent in total lifetime physical activity was 0.74, for lifetime occupational activity was 0.87, for household activity was 0.77, and for exercise/sports activities was 0.72. This is the first questionnaire to measure lifetime physical activity by collecting data on each type of physical activity separately over lifetime and by measuring frequency, intensity, and duration of each activity. It is also the first physical activity questionnaire to be developed, refined, and administered using cognitive-based methods employed in survey research. Respondents were able to reliably recall their lifetime physical activity patterns. This instrument can be used for any disease outcome for which physical activity may be a risk factor.Medicine & Science in Sports & Exercise 02/1998; 30(2):266-74. DOI:10.1097/00005768-199802000-00015 · 4.46 Impact Factor