Are the Relationships of Physical Activity and Television Viewing Time With Mortality Robust to Confounding? A Study, Utilizing E-Values, From the Melbourne Collaborative Cohort Study

Kwan, BPM; Lynch, BM; Edbrooke, L; Hodge, A; Swain, CTV

Author(s): Kwan, BPM; Lynch, BM; Edbrooke, L; Hodge, A; Swain, CTV;
Details: Publication Year 2024-11-01,Volume 21,Issue #11,Page 1105-1113
Journal Title: Journal of Physical Activity & Health
Publication Type: Research article
Abstract: BACKGROUND: Physical activity and sedentary behavior are associated with health outcomes. However, evidence may be affected by confounding bias. This study aimed to examine the relationships of physical activity and television (TV) viewing time with all-cause, cardiovascular, and cancer mortality in a cohort of Australian adults, and determine the robustness of these relationships to residual and unmeasured confounding. METHODS: Data from 27,317 Melbourne Collaborative Cohort Study participants (mean age = 66) were used. Physical activity was assessed using the International Physical Activity Questionnaire-Short Form and categorized as insufficient, sufficient, or more than sufficient. TV viewing time was categorized as low, moderate, or high. Multivariable Cox regression models were used to evaluate associations of interest. E-values were calculated to assess the strength of unmeasured confounders required to negate the observed results. RESULTS: For highest versus lowest physical activity category, the hazard ratio was 0.67 (95% confidence interval, 0.56-0.81) for all-cause mortality; E-values ranged between 1.79 and 2.44. Results were similar for cardiovascular mortality; however, hazard ratios were lower (0.72; 95% confidence interval, 0.51-1.01) and E-values much smaller (1.00-2.12) for cancer mortality. For highest versus lowest TV viewing time category, the hazard ratio was 1.08 (1.01-1.15) for all-cause mortality; E-values ranged between 1.00 and 1.37. Results were similar for cardiovascular and cancer mortality. CONCLUSIONS: Physical activity and TV viewing time were associated with mortality. The robustness to unmeasured/residual confounding was moderate for physical activity (all-cause and cardiovascular mortality), but weaker for physical activity (cancer mortality) and TV viewing time in this study of Australian adults.
Publisher: Human Kinetics
Keywords: Humans; Male; Female; *Television; *Sedentary Behavior; Middle Aged; *Neoplasms/mortality; Aged; *Cardiovascular Diseases/mortality; Exercise; Australia/epidemiology; Proportional Hazards Models; Surveys and Questionnaires; Time Factors; Confounding Factors, Epidemiologic; Cohort Studies; Mortality; Adult; Motor Activity; biostatistics; epidemiology; public health
Department(s): Health Services Research
Publisher's Version: https://doi.org/10.1123/jpah.2024-0218
Terms of Use/Rights Notice: Refer to copyright notice on published article.

Creation Date: 2024-11-28 06:25:38

Last Modified: 2024-11-28 06:29:09