Objective  To compare the prevalence of insomnia among ecological migrants, local residents and original residents in Ningxia Hui Autonomous Region (Ningxia) and to explore the influence of ecological migration on sleep quality of the populations.

  Methods  We conducted a computer-assisted personal interview among 4 366 adult rural residents (1 726 ecological migrants, 1 458 local residents and 1 182 original residents) selected with probability-proportional-to-size sampling in 62 villages in Ningxia between 2011 and 2013. Insomnia was assessed using the Chinese Version World Health Organization Composite International Diagnostic Interview (WHO-CIDI) and the Tenth Revision of the International Classification of Disease (ICD-10) among the residents. Rao-Scott chi-square test was adopted to assess the difference in weighted insomnia prevalence among the three population groups. Unconditional logistic regression model was used to analyze risk factors for insomnia.

  Results  Weighted prevalence rate of insomnia in ecological migrants (14.22%) was significantly higher than that in original residents (10.00%) but did not differ significantly from that in local residents (12.25%). Among the three groups of the population, the differences in weighted prevalence rate for all the sleep problems (including taking much longer time to fall asleep, not early morning awakening and excessive daytime sleepiness) were statistically significant, except for waking up earlier than expected. After controlling the influences of gender, ethnicity, age, education and marriage status, the original residents still had a lower weighted prevalence rate of insomnia than the migrants (odds ratio OR = 0.74, 95% confidence interval 95% CI: 0.60 – 0.92); while the weighted prevalence rate of insomnia in the local residents was not significantly different from that in the ecological migrants (OR = 1.01, 95% CI: 0.83 – 1.22). Age was identified as a risk factor of insomnia and the risk of insomnia increased with the increment of age among the residents.

  Conclusion  The ecological migrants had a higher risk of insomnia than the original residents in Ningxia. The results suggest that ecological immigrant project may have an adverse impact on sleep among migrant population.