First-generation Italians had a mortality advantage compared to native Swiss. This is in line with international findings-e.g., a Swedish study on migrants from southern Europe, ex-Yugoslavia and Turkey [1] and the only Swiss study on mortality among foreigners [27] which reported lower age-standardized mortality rates for foreigners compared to Swiss nationals (men −19%, women −14%). However, the latter study was cross-sectional and did not distinguish between migrants and their offspring. Nevertheless, the mortality advantage of Italian immigrants in Switzerland may be a real phenomenon rather than an artifact. This notion is also supported by a Belgian study based on register data [3].

We also found that second-generation Italian men were exposed to higher mortality risk. In this group, adoption of the regional language attenuated the excess mortality observed. Other authors have also documented higher mortality rates in the offspring of migrants. In England and Wales, second- and third-generation Irish people aged 15–44 years demonstrated excess mortality [28, 29]. Sons of Italian migrants in Sweden had a higher mortality risk than native Swedish nationals [12]. This is consistent with the acculturation hypothesis. As the duration of stay increases, immigrants increasingly adopt the local lifestyle and protective features of their culture of origin are only partially maintained by their offspring [12]. But for mortality, the acculturation hypothesis has been confirmed in some, but not all migrant populations [30–32].

In our study, the mortality advantage in first-generation Italians was greater for men than women but diminished in men and lost significance in women who had adopted the regional language.

In a study on second-generation Italians in Switzerland, two main types of orientation were differentiated: “casual Latins” emphasized their Italian origin and only rarely got involved in Switzerland’s political agenda and discourses [33]. A similar observation was made for Italians living in Peterborough, UK, characterized as economically integrated but socially encapsulated [34]. In contrast to the “casual Latins” the “sushi-eating secondos” adhered to a cosmopolitan kind of Italian culture and lifestyle and signalized interest in cultural diversity and Swiss values [33]. It may be assumed that adoption of the regional language corresponds with these constructed ideal types. If adoption of the regional language is interpreted as an indicator of acculturation, our results are also in line with the attenuation of health advantages over time as described above.

Notwithstanding the larger proportion of people with an Italian migration background in the French-speaking part of Switzerland, separate Cox regression models could not discern clear differences in mortality risk between Italians in German- vs. French-speaking Switzerland, irrespective of adoption of the regional language.

Controlling for period revealed a period effect which may be caused by undetected loss to follow-up in the second period. Apart from this, the hazard ratios were very similar when calculated for both periods separately. The relationships between migration background and mortality may therefore be assumed to be stable over time.

Strengths and limitations

The mortality advantage of first-generation Italians in the context of our study is meaningful as we avoid the numerator-denominator bias inherent to cross-sectional studies by using SNC data. Individuals were selected if they had taken part in both Swiss censuses (1990 and 2000) or are documented to have died or emigrated. This criterion is important because many migrants who re-emigrate do not report their move to the authorities. Indeed, in Sweden, it was estimated that 10% of the immigrants who leave the country do not fulfill this obligation in order to keep an option open for re-migration or access to better health care than in their country of origin [1, 35]. In France, the proportion of missing deaths among Moroccan men was estimated at 23% [10]. However, the SNC also includes deaths which had occurred abroad as covered by the foreigners’ registration system, but not the routine mortality statistics. In the first period, this applies to 381 deaths (4% of deaths of first-generation and 1% of Switzerland-born Italians), in the second period to 933 (10% and 4.5%, respectively).

A few methodical limitations should be mentioned. First, for the second period (after the 2000 census), information was missing for an unknown number of individuals having emigrated without notification and some deaths not linkable to the SNC. Restricting the analyses to the first period (1990–2000) may enhance reliability but at the expense of statistical power. Sensitivity analyses showed essentially the same patterns when limited to data from the first period. We, therefore, preferred to control the pooled analyses with a period dummy. Second, we had no information on the exact origin of migrants. Since there is a substantial south–north gradient in mortality within Italy [36, 37], analyses with this additional information may help explain differences in mortality between different migration groups. Third, the migration category ‘Swiss nationals born in Italy’ does not permit distinction between naturalized Italian immigrants and the offspring of Swiss nationals born in Italy. A fourth limitation is the lack of data on the duration of stay and on immigration class. The majority of Italians in Switzerland immigrated during the 1950s and 1960s. It is, therefore, possible that the observed differences between migration categories are confounded by cohort effects. However, immigration class should not bias our results.