Restless legs syndrome and all-cause mortality in four prospective cohort studies.

OBJECTIVES

To evaluate the association between restless legs syndrome (RLS) and all-cause mortality.

DESIGN

Four prospective cohort studies.

SETTING

The Dortmund Health Study (DHS) and the Study of Health in Pomerania (SHIP) from Germany. The Women's Health Study (WHS) and the Physicians' Health Study (PHS) from the USA.

PARTICIPANTS

In DHS: a random sample (n=1 299) from the population of Dortmund; in SHIP: a sample (n=4 291) from residents living in West Pomerania were drawn by multistage random sampling design; in WHS: female healthcare professionals (n=31 370); in PHS: male physicians (n=22 926)

MAIN OUTCOME MEASURES

All-cause mortality.

RESULTS

The prevalence of RLS ranged between 7.4% and 11.9% at baseline. During follow-up (ranging between 6 and 11 years) RLS was not associated with increased risk of all-cause mortality in any of the four cohorts. The multivariable-adjusted HRs (95% CI) for all-cause mortality ranged from 0.21 (0.03 to 1.53) to 1.07 (0.93 to 1.23) across the four studies. The HRs for all-cause mortality did not differ according to gender.

CONCLUSIONS

In these four independently conducted large prospective cohort studies from Germany and the USA, RLS did not increase the risk of all-cause mortality. These findings do not support the hypothesis that RLS is a risk factor for mortality of any cause.