Commentary
Understanding the lifetime determinants of television viewing David Bann,1 Peter Goldblatt,2 Rachel Cooper1 As societies change, so do the most apparent modifiable determinants of health. Since televisions first became commercially available earlier in the 20th century, they are now owned by the majority of households and increasing amounts of time are spent watching television. A growing body of evidence shows links between greater time spent watching television and increased risk of ill health.1 2 Despite its positive potential (eg, in information dissemination), watching television is typically sedentary, and is therefore likely to tip energy balance in favour of fat accumulation. In addition, it displaces time spent in health-benefiting behaviours, exposes users to food advertising, and may be done alongside other damaging behaviours such as snacking. There are therefore considerable potential public health benefits of reducing television viewing and replacing it with healthier pursuits. Understanding its determinants would aid this—the paper by Smith et al3 contributes to this by examining the childhood correlates of adult television viewing in the 1970 British birth cohort study. Smith et al found evidence that television viewing tracks from childhood (age 10) into adulthood (age 42), adding to the existing literature suggesting tracking of physical activity and diet.4 However, the strength of tracking observed may well have been influenced by the use of a relatively crude measure of childhood television viewing (which differed from the adult measure) and by the dichotomisation of both television viewing variables. Other factors at age 10 which were found to be associated with television viewing in adulthood included parental body mass index (BMI), own BMI and socioeconomic position, indicated by paternal occupational class; playing sports and gender did not appear to be significantly associated in multivariable models. This work reiterates the importance of intergenerational influences on health behaviours 1
MRC Unit for Lifelong Health and Ageing, London at UCL, UK; 2Institute of Health Equity University College London, London, UK Correspondence to Dr D Bann, MRC Unit for Lifelong Health and Ageing at UCL, London WC1B 5JU, UK; [email protected]
314
in adulthood,5 presents a useful step in beginning to identify early life determinants of television viewing, and helps suggest future research directions. Several factors in childhood and beyond may well have contributed to the association between childhood and adult television viewing presented by Smith et al. These include measures at birth and in early childhood ( parental occupational class at birth or age 5), later childhood (social, psychological and health-related factors, alternative leisure activities such as reading), adolescence (television viewing at age 16), and adulthood (occupation, income and BMI). Some of these clearly precede television viewing at age 10 and could therefore have been determinants of behaviour at both age 10 and in adulthood. Others lie on the pathway between the two variables and may have had a mediating effect on the association. The multivariate models presented by Smith et al hint at some of the possible pathways, but they were not explicitly tested or quantified, despite the availability of these data in the cohort analysed. Explicitly outlining a life course framework6 7 would have been useful to help conceptualise these pathways, and to help guide analyses and interpret findings. The rationale for examining childhood television viewing was clear, while the selection of other variables could have been further described, including the decision to omit potentially relevant variables collected in this cohort. Socioeconomic disadvantage earlier in life may be related to higher television viewing in adulthood, through a range of pathways including through links to childhood and adolescent television viewing, BMI across life, and continuity of socioeconomic disadvantage across life. Similarly, television viewing may track from childhood and adolescence to adulthood, and this could partly be explained by the tracking of socioeconomic disadvantage across life. Factors may also moderate the strength of tracking observed— tracking of physical activity has been found to be stronger in men than women.4 Of the variables Smith et al investigated, childhood socioeconomic position appeared to be most strongly associated with adult television viewing. This
suggests a need to better understand the means by which socioeconomic circumstances affect cultural capital, which ultimately affects health. As the detrimental effects for health of television viewing become increasingly apparent and are more widely disseminated, one may expect socioeconomic inequalities to widen, because those with more resources will be better placed to use this information to change their behaviour. When a health-impacting behaviour such as television viewing is found to be socioeconomically patterned, it provides the opportunity to develop interventions to reduce health inequalities. Interventions acting at the individual level are likely to be politically expedient (matching calls for ‘individual responsibility’) but have been found to widen inequalities,8 and can distract from the need to intervene on the up-steam causes9 10—the socioeconomic circumstances across life which help generate persisting unhealthy behaviours. As we begin to better understand the lifetime determinants of health-impacting behaviours, we should be mindful of potential age, cohort and period differences. Television viewing is currently highly prevalent in all age groups, but this will likely be replaced in the future by other behaviours—some which are now apparent (eg, electronic device use), and others which have yet to emerge. Epidemiological research should continue to investigate the consequences and determinants of these behaviours. Despite inevitable (and frustrating) delays this evidence can then be used to improve public health and its equity in an everchanging society. Contributors DB wrote the first draft; all authors contributed to its development and finalisation. Competing interests None. Provenance and peer review Commissioned; internally peer reviewed.
To cite Bann D, Goldblatt P, Cooper R. J Epidemiol Community Health 2015;69:314–315. Published Online First 24 September 2014
▸ http://dx.doi.org/10.1136/jech-2014-204365 J Epidemiol Community Health 2015;69:314–315. doi:10.1136/jech-2014-204879
Bann D, et al. J Epidemiol Community Health April 2015 Vol 69 No 4
Commentary REFERENCES 1
2
3
Thorp AA, Owen N, Neuhaus M, et al. Sedentary behaviors and subsequent health outcomes in adults: a systematic review of longitudinal studies, 1996–2011. Am J Prev Med 2011;41:207–15. Wennberg P, Gustafsson PE, Howard B, et al. Television viewing over the life course and the metabolic syndrome in mid-adulthood: a longitudinal population-based study. J Epidemiol Community Health 2014;68:928–33. Smith L, Gardner B, Hamer M. Childhood correlates of adult TV viewing time: a 32 year follow-up of the 1970 British Cohort Study. J Epidemiol Community Health 2015;69:309–13.
4
5
6
7
Craigie AM, Lake AA, Kelly SA, et al. Tracking of obesity-related behaviours from childhood to adulthood: a systematic review. Maturitas 2011;70:266–84. Cooper R, Hypponen E, Berry D, et al. Associations between parental and offspring adiposity up to midlife: the contribution of adult lifestyle factors in the 1958 British Birth Cohort Study. Am J Clin Nutr 2010;92:946–53. Ben-Shlomo Y, Kuh D. A life course approach to chronic disease epidemiology: conceptual models, empirical challenges and interdisciplinary perspectives. Int J Epidemiol 2002;31:285–93. Power C, Kuh D, Morton S. From developmental origins of adult disease to life course research on
Bann D, et al. J Epidemiol Community Health April 2015 Vol 69 No 4
8
9
10
adult disease and aging: insights from Birth Cohort Studies. Annu Rev Public Health 2013;34:7–28. Lorenc T, Petticrew M, Welch V, et al. What types of interventions generate inequalities? Evidence from systematic reviews. J Epidemiol Community Health 2013;67:190–3. Giesinger I, Goldblatt P, Howden-Chapman P, et al. Association of socioeconomic position with smoking and mortality: the contribution of early life circumstances in the 1946 birth cohort. J Epidemiol Community Health 2013;68:275–9. Katikireddi SV, Higgins M, Smith KE, et al. Health inequalities: the need to move beyond bad behaviours. J Epidemiol Community Health 2013;67:715–16.
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Copyright of Journal of Epidemiology & Community Health is the property of BMJ Publishing Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
Understanding the lifetime determinants of television viewing David Bann,1 Peter Goldblatt,2 Rachel Cooper1 As societies change, so do the most apparent modifiable determinants of health. Since televisions first became commercially available earlier in the 20th century, they are now owned by the majority of households and increasing amounts of time are spent watching television. A growing body of evidence shows links between greater time spent watching television and increased risk of ill health.1 2 Despite its positive potential (eg, in information dissemination), watching television is typically sedentary, and is therefore likely to tip energy balance in favour of fat accumulation. In addition, it displaces time spent in health-benefiting behaviours, exposes users to food advertising, and may be done alongside other damaging behaviours such as snacking. There are therefore considerable potential public health benefits of reducing television viewing and replacing it with healthier pursuits. Understanding its determinants would aid this—the paper by Smith et al3 contributes to this by examining the childhood correlates of adult television viewing in the 1970 British birth cohort study. Smith et al found evidence that television viewing tracks from childhood (age 10) into adulthood (age 42), adding to the existing literature suggesting tracking of physical activity and diet.4 However, the strength of tracking observed may well have been influenced by the use of a relatively crude measure of childhood television viewing (which differed from the adult measure) and by the dichotomisation of both television viewing variables. Other factors at age 10 which were found to be associated with television viewing in adulthood included parental body mass index (BMI), own BMI and socioeconomic position, indicated by paternal occupational class; playing sports and gender did not appear to be significantly associated in multivariable models. This work reiterates the importance of intergenerational influences on health behaviours 1
MRC Unit for Lifelong Health and Ageing, London at UCL, UK; 2Institute of Health Equity University College London, London, UK Correspondence to Dr D Bann, MRC Unit for Lifelong Health and Ageing at UCL, London WC1B 5JU, UK; [email protected]
314
in adulthood,5 presents a useful step in beginning to identify early life determinants of television viewing, and helps suggest future research directions. Several factors in childhood and beyond may well have contributed to the association between childhood and adult television viewing presented by Smith et al. These include measures at birth and in early childhood ( parental occupational class at birth or age 5), later childhood (social, psychological and health-related factors, alternative leisure activities such as reading), adolescence (television viewing at age 16), and adulthood (occupation, income and BMI). Some of these clearly precede television viewing at age 10 and could therefore have been determinants of behaviour at both age 10 and in adulthood. Others lie on the pathway between the two variables and may have had a mediating effect on the association. The multivariate models presented by Smith et al hint at some of the possible pathways, but they were not explicitly tested or quantified, despite the availability of these data in the cohort analysed. Explicitly outlining a life course framework6 7 would have been useful to help conceptualise these pathways, and to help guide analyses and interpret findings. The rationale for examining childhood television viewing was clear, while the selection of other variables could have been further described, including the decision to omit potentially relevant variables collected in this cohort. Socioeconomic disadvantage earlier in life may be related to higher television viewing in adulthood, through a range of pathways including through links to childhood and adolescent television viewing, BMI across life, and continuity of socioeconomic disadvantage across life. Similarly, television viewing may track from childhood and adolescence to adulthood, and this could partly be explained by the tracking of socioeconomic disadvantage across life. Factors may also moderate the strength of tracking observed— tracking of physical activity has been found to be stronger in men than women.4 Of the variables Smith et al investigated, childhood socioeconomic position appeared to be most strongly associated with adult television viewing. This
suggests a need to better understand the means by which socioeconomic circumstances affect cultural capital, which ultimately affects health. As the detrimental effects for health of television viewing become increasingly apparent and are more widely disseminated, one may expect socioeconomic inequalities to widen, because those with more resources will be better placed to use this information to change their behaviour. When a health-impacting behaviour such as television viewing is found to be socioeconomically patterned, it provides the opportunity to develop interventions to reduce health inequalities. Interventions acting at the individual level are likely to be politically expedient (matching calls for ‘individual responsibility’) but have been found to widen inequalities,8 and can distract from the need to intervene on the up-steam causes9 10—the socioeconomic circumstances across life which help generate persisting unhealthy behaviours. As we begin to better understand the lifetime determinants of health-impacting behaviours, we should be mindful of potential age, cohort and period differences. Television viewing is currently highly prevalent in all age groups, but this will likely be replaced in the future by other behaviours—some which are now apparent (eg, electronic device use), and others which have yet to emerge. Epidemiological research should continue to investigate the consequences and determinants of these behaviours. Despite inevitable (and frustrating) delays this evidence can then be used to improve public health and its equity in an everchanging society. Contributors DB wrote the first draft; all authors contributed to its development and finalisation. Competing interests None. Provenance and peer review Commissioned; internally peer reviewed.
To cite Bann D, Goldblatt P, Cooper R. J Epidemiol Community Health 2015;69:314–315. Published Online First 24 September 2014
▸ http://dx.doi.org/10.1136/jech-2014-204365 J Epidemiol Community Health 2015;69:314–315. doi:10.1136/jech-2014-204879
Bann D, et al. J Epidemiol Community Health April 2015 Vol 69 No 4
Commentary REFERENCES 1
2
3
Thorp AA, Owen N, Neuhaus M, et al. Sedentary behaviors and subsequent health outcomes in adults: a systematic review of longitudinal studies, 1996–2011. Am J Prev Med 2011;41:207–15. Wennberg P, Gustafsson PE, Howard B, et al. Television viewing over the life course and the metabolic syndrome in mid-adulthood: a longitudinal population-based study. J Epidemiol Community Health 2014;68:928–33. Smith L, Gardner B, Hamer M. Childhood correlates of adult TV viewing time: a 32 year follow-up of the 1970 British Cohort Study. J Epidemiol Community Health 2015;69:309–13.
4
5
6
7
Craigie AM, Lake AA, Kelly SA, et al. Tracking of obesity-related behaviours from childhood to adulthood: a systematic review. Maturitas 2011;70:266–84. Cooper R, Hypponen E, Berry D, et al. Associations between parental and offspring adiposity up to midlife: the contribution of adult lifestyle factors in the 1958 British Birth Cohort Study. Am J Clin Nutr 2010;92:946–53. Ben-Shlomo Y, Kuh D. A life course approach to chronic disease epidemiology: conceptual models, empirical challenges and interdisciplinary perspectives. Int J Epidemiol 2002;31:285–93. Power C, Kuh D, Morton S. From developmental origins of adult disease to life course research on
Bann D, et al. J Epidemiol Community Health April 2015 Vol 69 No 4
8
9
10
adult disease and aging: insights from Birth Cohort Studies. Annu Rev Public Health 2013;34:7–28. Lorenc T, Petticrew M, Welch V, et al. What types of interventions generate inequalities? Evidence from systematic reviews. J Epidemiol Community Health 2013;67:190–3. Giesinger I, Goldblatt P, Howden-Chapman P, et al. Association of socioeconomic position with smoking and mortality: the contribution of early life circumstances in the 1946 birth cohort. J Epidemiol Community Health 2013;68:275–9. Katikireddi SV, Higgins M, Smith KE, et al. Health inequalities: the need to move beyond bad behaviours. J Epidemiol Community Health 2013;67:715–16.
315
Copyright of Journal of Epidemiology & Community Health is the property of BMJ Publishing Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
