Background There has been rapid urbanisation in China over the past few decades. Urbanisation may influence development of non-communicable disease through adoption of detrimental health behaviours. With a large population in China, and many other low and middle income countries following a similar trajectory, investigation of how health behaviour changes with rural to urban migration will increase understanding of future disease burden and opportunities for intervention/prevention. Our objective was to examine the difference in non-communicable disease risk factor prevalence in urban, rural and rural-to-urban migrant participants in the Chinese portion of the WHO Study of global AGEing and adult health (SAGE).

Methods Study participants were adults aged 18+ within SAGE-China, surveyed 2007–2010 (Wave 1), and designed as a nationally representative sample. Participants were coded as urban, rural or migrant based on responses to questions on current and past home locations. Outcome measures included health behaviours (tobacco smoking, alcohol consumption, physical activity and fruit and vegetable consumption) and physiological risk factors (obesity, raised waist circumference, hypertension and doctor diagnosed diabetes). Odds ratios (OR) and 95% confidence intervals (CI) were calculated using logistic regression. Other variables included in the analysis were age, sex and income quintile.

Results 13,628 participants were included in this study (5878 urban; 1215 migrants; 7207 rural). Adjusting for age and gender, migrant participants were more likely to have smoked during their lifetime than urban participants, OR 1.29 (95% CI 1.08–1.53), although the prevalence of current smokers was not significantly different. Migrant participants were also more likely to drink alcohol regularly. Rural participants had a very different risk factor profile to urban participants; they were more likely to smoke and to drink alcohol regularly, less likely to consume five portions of fruit and vegetables per day, OR 0.73 (95% CI 0.65–0.82) and more likely to have hypertension, OR 1.22 (95% CI 1.14–1.31). However, rural participants were less likely to be overweight, or have a high waist circumference. Rural participants are also less likely to have diabetes, OR 0.29 (95% CI 0.24–0.34), however this may be due to lower rates of diagnosis or a lower true prevalence.

Conclusion In China, urbanisation appears to increase the risk of obesity and possibly of diabetes. However, it is also associated with increased fruit and vegetable consumption and lower prevalence of smoking and drinking and hypertension. In our study, rural to urban migrants had a similar risk factor profile to urban participants