Social class inequalities in health among occupational cohorts from Finland, Britain and Japan: A follow up study Eero Lahelma n , Olli Pietiläinen, Ossi Rahkonen, Mika Kivimäki, Pekka Martikainen, Jane Ferrie, Michael Marmot, Martin Shipley, Michikazu Sekine, Takashi Tatsuse, Tea Lallukka Department of Public Health, PO Box 41, University of Helsinki, Helsinki 00014, Finland article info Article history: Received 30 May 2014 Received in revised form 17 November 2014 Accepted 3 December 2014 Keywords: Health inequalities Follow up Britain Finland Japan abstract We examined whether relative occupational social class inequalities in physical health functioning widen, narrow or remain stable among white collar employees from three affluent countries. Health functioning was assessed twice in occupational cohorts from Britain (1997–1999 and 2003–2004), Finland (2000–2002 and 2007) and Japan (1998–1999 and 2003). Widening inequalities were seen for British and Finnish men, whereas inequalities among British and Finnish women remained relatively stable. Japanese women showed reverse inequalities at follow up, but no health inequalities were seen among Japanese men. Health behaviours and social relations explained 4–37% of the magnitude in health inequalities, but not their widening. & 2014 Elsevier Ltd. All rights reserved. 1. Introduction Affluent societies are facing economic, social and demographic transitions that shape the development of population health and its distribution across the socioeconomic structure. Large post war baby-boomer generations are currently facing the end of their work career and subsequent transition to retirement (Oeppen and Vaupel, 2002; Christensen et al., 2009). These generations can be expected to live longer than any prior generation. Nevertheless under the long-term restructuring of welfare states equity in health and well-being is challenged. Despite positive overall trends, large socioeconomic inequalities in health persist world- wide (Mackenbach et al., 2008; Mackenbach, 2012). Comparative and national time trend studies suggest that health inequalities are not only universal across European and non-European populations but that they also have either remained stable or widened over time, with limited evidence of narrowing inequalities (Lahelma et al., 2002; Mackenbach et al., 2003; House et al., 2005; Kunst et al., 2005; Mirowsky and Ross, 2008; Hiyoshi et al., 2013a). The magnitude of health inequalities varies between countries, genders and periods suggesting that these inequalities depend on national contexts and individual characteristics, and are thus likely to be modifiable (Mackenbach, 2012). Previous comparative studies have been mainly cross-sectional or repeated cross-sections. Few prospective cohort studies follow- ing up health inequalities as people grow older in various national contexts are available, limiting our understanding of how health inequalities change over time among ageing men and women in different countries. We seek to address this limitation by following up health inequalities within cohorts from three affluent societies, i.e. Britain, Finland and Japan. These countries share both similarities and dissimilarities and provide opportunities for prospective and comparative studies (Allardt, 1990; Uzuhashi, 2003; Martikainen et al., 2004). Cross-sectional comparisons have shown inequalities in various health related outcomes among employed men and women from Britain and Finland in the 1990s and 2000s, whereas in Japan these inequalities have been unsystematic or even non-existent, in particular among women (Martikainen et al., 2004; Lahelma et al., 2010; Hiyoshi et al., 2013b). A Japanese study using repeated surveys from 1986 to 2007 found inequalities by income and social class in self-rated health among men and women (Hiyoshi et al., 2013a). These inequalities remained stable or narrowed over time but persisted. Population based follow ups from western Europe and the USA suggest widening health inequalities through adult- hood and towards later life (Elstad and Krokstad, 2003; Sacker et al., 2005; Mirowsky and Ross, 2008). There is also some evidence Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/healthplace Health & Place http://dx.doi.org/10.1016/j.healthplace.2014.12.004 1353-8292/& 2014 Elsevier Ltd. All rights reserved. n Corresponding author. Tel.: þ358 50 4151254; fax: þ358 9 191 27540. E-mail address: eero.lahelma@helsinki.fi (E. Lahelma). URL: http://www.hjelt.helsinki.fi (E. Lahelma). Health & Place 31 (2015) 173–179