Material
The three Scandinavian studies included women 15-34, 12-30 and 15-25 years old, and the study periods 2000-2013, 2010-2011, and 2010-2017, respectively (Table 1). Study populations were 1.1, 0.8 and 0.7 million, sufficiently large to assess risk estimates for specific age groups and specific product groups.