AJPH PERSPECTIVES The Nurses’ Health Study and the Australian Longitudinal Study on Women’s Health: Providing Infrastructure for Public Health Research The Nurses’ Health Study (NHS) and the Australian Longitudinal Study on Women’s Health (ALSWH) are examples of the tremendous investment in longitudinal studies and how they not only provide short-term returns for their original purposes, but also how they grow and mature to provide substantive infrastructure for public health research that provides information returns for many decades and across generations.
BACKGROUND AND BEGINNINGS The ALSWH arose from the 1989 Australian National Women’s Health Policy, which recommended research into the health of Australian women.1 The remit was to establish a longitudinal study that took a social view of health, and that would inform health policy. The study, funded by the Australian Government was established in 1995 following a competitive tender process. The overall aim is to examine social, psychological, physical, and environmental factors that determine good health, and those that cause ill-health, in women across the life course, with particular emphasis on
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their use of health services. The study is led by investigators from the Universities of Newcastle and Queensland, but is a national resource that, so far, has been used by almost 800 researchers. In planning the study, we examined several other well-established cohort studies to develop recruitment, data collection, and retention strategies, and to inform the development of our surveys. The NHS established in 1976 in the United States was a primary source of information and inspiration.2 The NHS, with more than 122 000 women initially recruited, was a beacon. But we knew we would not have resources to sustain a study with so many participants. So, to span a wide age range, we chose to recruit as many women as we could afford in three five-year age cohorts. The youngest cohort was born in 1973 to 1978 and so was aged 18 to 23 years when ALSWH started in 1996 (18 years being the youngest age at which participants could consent to the study without needing parental consent); the midaged cohort, born in 1946 to 1951, was aged 45 to 50 years; and the oldest cohort was born in 1921 to 1926 and aged 70 to 75 years. Between 12 000 and 14 000 women were initially recruited in each cohort. The age
groups were chosen so that most women began their participation in the ALSWH before the occurrence of major events such as first pregnancy, menopause, retirement, or death of partner. By comparison, the original NHS participants were born between 1921 and 1946, spanning the ages of the two older ALSWH cohorts, but including all ages in between. While the NHS was originally designed as a prospective study to gain information on the effects of the oral contraceptive pill, it has been broadened to investigate risk factors for cancer and cardiovascular disease, as well as a range of other public health issues. By contrast, a major initial focus for the ALSWH was the appropriateness of health services to meet women’s needs, but that too has expanded. As with the NHS, ALSWH aims to provide data that aids in understanding the origins of health and disease, and to inform effective social strategies and health
care delivery. Both studies include repeated measures of exposures and outcomes over time, allowing the associations between changes in risk factors and changes in health to be assessed. Both studies also link survey data to health records, providing detailed information on health service use and outcomes.3,4
RECRUITMENT AND RETENTION NHS researchers were remarkably successful in recruiting participants using a series of mailings. For ALSWH, we used a similar three-stage mailing protocol based on the methods described by Dillman.5 The initial NHS cohort was recruited from married nurses registered with the American Nurses Association in the 11 most populous States. By contrast, ALSWH aimed to recruit nationally representative samples of women from all walks of life. To achieve this, for the sampling frame we used the database of the Australian universal health insurance scheme, now called Medicare Australia, which includes all residents of Australia. To obtain reliable estimates for women living outside the major urban centers, we deliberately oversampled women in rural and remote areas. For ALSWH we also employed some of the retention strategies employed by the
ABOUT THE AUTHORS Annette J. Dobson is with the School of Public Health, The University of Queensland, Brisbane, Australia. Julie E. Byles is with the Centre for Generational Health and Ageing, The University of Newcastle, Newcastle, Austrialia. Wendy J. Brown is with the School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane. Correspondence should be sent to Annette J. Dobson, Professor of Biostatistics, School of Public Health, The University of Queensland, Herston, Queensland 4006 Australia (e-mail: [email protected]. au). Reprints can be ordered at http://www.ajph.org by clicking the “Reprints” link. This editorial was accepted June 22, 2016. doi: 10.2105/AJPH.2016.303352
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NHS, such as asking women to provide the name and address of a relative (usually their mother) or a close friend, who would always know where the woman was if we lost touch with her. This approach has proven particularly helpful with the youngest cohort who have been more mobile than the women in their mothers’ and grandmothers’ generations.
SURVEY CONTENT Both the ALSWH and the NHS share a focus on women’s health, defined broadly. The initial surveys of ALSWH focused on medical conditions and symptoms, physical and emotional well-being, health behavior, use and satisfaction with health services; time use and social roles; weight and physical activity; self-image and satisfaction with life; violence against women; life stages and key events. Initially, we intended to ask similar questions to the NHS to allow comparisons between the two surveys; however, we also needed to use questions that would allow us to compare our data with other Australian surveys. ALSWH does have many similar questions to the NHS, for example in relation to body shape and size, and in
relation to sitting and standing at work. Of particular importance for ALSWH has been the methodology for the collection and analysis of dietary data pioneered by Willett.6
EVOLUTION AND IMPACTS Both studies have expanded by recruiting new cohorts. NHS II started in 1989 enrolling female nurses aged 25 to 42 years, NHS3 started in 2010 with both female and male nurses aged 19 to 45 years, and the Growing Up Today Study (GUTS) involves the children of the NHS II cohort. ALSWH has recruited a new cohort born in 1989 to 1995 and is currently collecting data for the Mothers and Their Children study, which involves mothers from the 1973 to 1978 cohort and their children. For both NHS3 and the ALSWH 1989 to 1995 cohort, the Internet was used for recruitment and data collection. While NHS started collecting blood samples in 1989 to 1990, ALSWH is only piloting the collection of biological samples in 2016. Data from both studies are made available openly to other researchers, and collaboration is actively encouraged.
Two of the NHS researchers have close links with the University of Queensland and have provided ongoing advice. Chris Bain worked with the NHS team in the late 1970s and early 1980s before returning to his alma mater. He was a source of advice about managing surveys and large data sets. Later, Graham Colditz, another University of Queensland medical graduate, went to Harvard and became a key member of the NHS team. On his regular visits to Brisbane he has given us valuable advice on analysis of weight gain in women, validation of self-reported diagnoses using hospital and other records, and a range of other issues.
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The Feminine Mystique, though not feminist in nature, NHS proposed an assertive and opportune research agenda aimed at reducing the burden of NCDs among women. For the past 40 years, the cohort of more than 100 000 North American nurses have
CONTRIBUTORS All authors contributed equally to this editorial.
ACKNOWLEDGMENTS The Australian Longitudinal Study on Women’s Health is funded by the Australian Government Department of Health.
REFERENCES 1. Lee C, Dobson AJ, Brown WJ, et al. Cohort profile: the Australian Longitudinal Study on Women’s Health. Int J Epidemiol. 2005;34:987–991. 2. Belanger CF, Hennekens CH, Rosner B, Speizer FE. The Nurses’ Health Study. Am J Nurs. 1978;78(6):1039–1040.
PUBLIC HEALTH INFRASTRUCTURE Just as the NHS contributed to the establishment of dietary and physical activity guidelines and regulations, findings from ALSWH provided much of the evidence for the Australian Government’s 2010 National Women’s Health Policy.7 Thus, both studies have had a profound effect on knowledge of women’s health, methodology for longitudinal studies, and relevant health policies.
Long-Term Cohort Studies in Brazil: On the Tracks of the Nurses’ Health Study and Beyond Epidemiological studies need sound and socially relevant questions, as well as timely health needs. When it comes to noncommunicable diseases (NCDs), the Nurses’ Health Study (NHS) has it all. Launched on the 13th anniversary of Betty Friedan’s book
Annette J. Dobson, PhD Julie E. Byles, PhD Wendy J. Brown, PhD
provided an extraordinary empirical base for testing hypotheses on
3. Colditz GA, Martin P, Stampfer MJ, et al. 1986). Validation of questionnaire information on risk factors and disease outcomes in a prospective cohort study of women. Am J Epidemiol. 1986;123(5):894–900. 4. Dobson AJ, Hockey R, Brown WJ, et al. Cohort profile update: Australian Longitudinal Study on Women’s Health. Int J Epidemiol. 2015;44(5):1547, 1547a–1547f. 5. Dillman DA. Mail and Telephone Surveys: The Total Design Method. New York, NY: Wiley; 1978. 6. Willett WC. Nutritional Epidemiology. 2nd ed. New York, NY: Oxford University Press; 1998. 7. Australian Government Department of Health and Ageing. National Women’s Health Policy 2010. Canberra, Australia: Commonwealth of Australia, 2010.
various risk factors for women’s health. Taking advantage of the rapid increase in obesity prevalence in the United States at that time, the study was able to estimate the impact of concurrent rapid shifts in diet and activity levels on weight gain, thus contributing to unravel
ABOUT THE AUTHOR Sandhi M. Barreto is with the Social and Preventive Medicine Department, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil. Correspondence should be sent to Prof. Sandhi M Barreto, Av Alfredo Balena 190, Belo Horizonte, Brazil, CEP 30130100 (e-mail: [email protected]). Reprints can be ordered at http://www.ajph.org by clicking the “Reprints” link. This editorial was accepted June 16, 2016. doi: 10.2105/AJPH.2016.303330
AJPH
September 2016, Vol 106, No. 9
BACKGROUND AND BEGINNINGS The ALSWH arose from the 1989 Australian National Women’s Health Policy, which recommended research into the health of Australian women.1 The remit was to establish a longitudinal study that took a social view of health, and that would inform health policy. The study, funded by the Australian Government was established in 1995 following a competitive tender process. The overall aim is to examine social, psychological, physical, and environmental factors that determine good health, and those that cause ill-health, in women across the life course, with particular emphasis on
September 2016, Vol 106, No. 9
AJPH
their use of health services. The study is led by investigators from the Universities of Newcastle and Queensland, but is a national resource that, so far, has been used by almost 800 researchers. In planning the study, we examined several other well-established cohort studies to develop recruitment, data collection, and retention strategies, and to inform the development of our surveys. The NHS established in 1976 in the United States was a primary source of information and inspiration.2 The NHS, with more than 122 000 women initially recruited, was a beacon. But we knew we would not have resources to sustain a study with so many participants. So, to span a wide age range, we chose to recruit as many women as we could afford in three five-year age cohorts. The youngest cohort was born in 1973 to 1978 and so was aged 18 to 23 years when ALSWH started in 1996 (18 years being the youngest age at which participants could consent to the study without needing parental consent); the midaged cohort, born in 1946 to 1951, was aged 45 to 50 years; and the oldest cohort was born in 1921 to 1926 and aged 70 to 75 years. Between 12 000 and 14 000 women were initially recruited in each cohort. The age
groups were chosen so that most women began their participation in the ALSWH before the occurrence of major events such as first pregnancy, menopause, retirement, or death of partner. By comparison, the original NHS participants were born between 1921 and 1946, spanning the ages of the two older ALSWH cohorts, but including all ages in between. While the NHS was originally designed as a prospective study to gain information on the effects of the oral contraceptive pill, it has been broadened to investigate risk factors for cancer and cardiovascular disease, as well as a range of other public health issues. By contrast, a major initial focus for the ALSWH was the appropriateness of health services to meet women’s needs, but that too has expanded. As with the NHS, ALSWH aims to provide data that aids in understanding the origins of health and disease, and to inform effective social strategies and health
care delivery. Both studies include repeated measures of exposures and outcomes over time, allowing the associations between changes in risk factors and changes in health to be assessed. Both studies also link survey data to health records, providing detailed information on health service use and outcomes.3,4
RECRUITMENT AND RETENTION NHS researchers were remarkably successful in recruiting participants using a series of mailings. For ALSWH, we used a similar three-stage mailing protocol based on the methods described by Dillman.5 The initial NHS cohort was recruited from married nurses registered with the American Nurses Association in the 11 most populous States. By contrast, ALSWH aimed to recruit nationally representative samples of women from all walks of life. To achieve this, for the sampling frame we used the database of the Australian universal health insurance scheme, now called Medicare Australia, which includes all residents of Australia. To obtain reliable estimates for women living outside the major urban centers, we deliberately oversampled women in rural and remote areas. For ALSWH we also employed some of the retention strategies employed by the
ABOUT THE AUTHORS Annette J. Dobson is with the School of Public Health, The University of Queensland, Brisbane, Australia. Julie E. Byles is with the Centre for Generational Health and Ageing, The University of Newcastle, Newcastle, Austrialia. Wendy J. Brown is with the School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane. Correspondence should be sent to Annette J. Dobson, Professor of Biostatistics, School of Public Health, The University of Queensland, Herston, Queensland 4006 Australia (e-mail: [email protected]. au). Reprints can be ordered at http://www.ajph.org by clicking the “Reprints” link. This editorial was accepted June 22, 2016. doi: 10.2105/AJPH.2016.303352
Dobson et al.
Editorial
1533
AJPH PERSPECTIVES
NHS, such as asking women to provide the name and address of a relative (usually their mother) or a close friend, who would always know where the woman was if we lost touch with her. This approach has proven particularly helpful with the youngest cohort who have been more mobile than the women in their mothers’ and grandmothers’ generations.
SURVEY CONTENT Both the ALSWH and the NHS share a focus on women’s health, defined broadly. The initial surveys of ALSWH focused on medical conditions and symptoms, physical and emotional well-being, health behavior, use and satisfaction with health services; time use and social roles; weight and physical activity; self-image and satisfaction with life; violence against women; life stages and key events. Initially, we intended to ask similar questions to the NHS to allow comparisons between the two surveys; however, we also needed to use questions that would allow us to compare our data with other Australian surveys. ALSWH does have many similar questions to the NHS, for example in relation to body shape and size, and in
relation to sitting and standing at work. Of particular importance for ALSWH has been the methodology for the collection and analysis of dietary data pioneered by Willett.6
EVOLUTION AND IMPACTS Both studies have expanded by recruiting new cohorts. NHS II started in 1989 enrolling female nurses aged 25 to 42 years, NHS3 started in 2010 with both female and male nurses aged 19 to 45 years, and the Growing Up Today Study (GUTS) involves the children of the NHS II cohort. ALSWH has recruited a new cohort born in 1989 to 1995 and is currently collecting data for the Mothers and Their Children study, which involves mothers from the 1973 to 1978 cohort and their children. For both NHS3 and the ALSWH 1989 to 1995 cohort, the Internet was used for recruitment and data collection. While NHS started collecting blood samples in 1989 to 1990, ALSWH is only piloting the collection of biological samples in 2016. Data from both studies are made available openly to other researchers, and collaboration is actively encouraged.
Two of the NHS researchers have close links with the University of Queensland and have provided ongoing advice. Chris Bain worked with the NHS team in the late 1970s and early 1980s before returning to his alma mater. He was a source of advice about managing surveys and large data sets. Later, Graham Colditz, another University of Queensland medical graduate, went to Harvard and became a key member of the NHS team. On his regular visits to Brisbane he has given us valuable advice on analysis of weight gain in women, validation of self-reported diagnoses using hospital and other records, and a range of other issues.
1534
Editorial
Barreto
The Feminine Mystique, though not feminist in nature, NHS proposed an assertive and opportune research agenda aimed at reducing the burden of NCDs among women. For the past 40 years, the cohort of more than 100 000 North American nurses have
CONTRIBUTORS All authors contributed equally to this editorial.
ACKNOWLEDGMENTS The Australian Longitudinal Study on Women’s Health is funded by the Australian Government Department of Health.
REFERENCES 1. Lee C, Dobson AJ, Brown WJ, et al. Cohort profile: the Australian Longitudinal Study on Women’s Health. Int J Epidemiol. 2005;34:987–991. 2. Belanger CF, Hennekens CH, Rosner B, Speizer FE. The Nurses’ Health Study. Am J Nurs. 1978;78(6):1039–1040.
PUBLIC HEALTH INFRASTRUCTURE Just as the NHS contributed to the establishment of dietary and physical activity guidelines and regulations, findings from ALSWH provided much of the evidence for the Australian Government’s 2010 National Women’s Health Policy.7 Thus, both studies have had a profound effect on knowledge of women’s health, methodology for longitudinal studies, and relevant health policies.
Long-Term Cohort Studies in Brazil: On the Tracks of the Nurses’ Health Study and Beyond Epidemiological studies need sound and socially relevant questions, as well as timely health needs. When it comes to noncommunicable diseases (NCDs), the Nurses’ Health Study (NHS) has it all. Launched on the 13th anniversary of Betty Friedan’s book
Annette J. Dobson, PhD Julie E. Byles, PhD Wendy J. Brown, PhD
provided an extraordinary empirical base for testing hypotheses on
3. Colditz GA, Martin P, Stampfer MJ, et al. 1986). Validation of questionnaire information on risk factors and disease outcomes in a prospective cohort study of women. Am J Epidemiol. 1986;123(5):894–900. 4. Dobson AJ, Hockey R, Brown WJ, et al. Cohort profile update: Australian Longitudinal Study on Women’s Health. Int J Epidemiol. 2015;44(5):1547, 1547a–1547f. 5. Dillman DA. Mail and Telephone Surveys: The Total Design Method. New York, NY: Wiley; 1978. 6. Willett WC. Nutritional Epidemiology. 2nd ed. New York, NY: Oxford University Press; 1998. 7. Australian Government Department of Health and Ageing. National Women’s Health Policy 2010. Canberra, Australia: Commonwealth of Australia, 2010.
various risk factors for women’s health. Taking advantage of the rapid increase in obesity prevalence in the United States at that time, the study was able to estimate the impact of concurrent rapid shifts in diet and activity levels on weight gain, thus contributing to unravel
ABOUT THE AUTHOR Sandhi M. Barreto is with the Social and Preventive Medicine Department, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil. Correspondence should be sent to Prof. Sandhi M Barreto, Av Alfredo Balena 190, Belo Horizonte, Brazil, CEP 30130100 (e-mail: [email protected]). Reprints can be ordered at http://www.ajph.org by clicking the “Reprints” link. This editorial was accepted June 16, 2016. doi: 10.2105/AJPH.2016.303330
AJPH
September 2016, Vol 106, No. 9
