Quantifying urbanization as a risk factor for noncommunicable disease.

The aim of this study was to investigate the poorly understood relationship between the process of urbanization and noncommunicable diseases (NCDs) in Sri Lanka using a multicomponent, quantitative measure of urbanicity. NCD prevalence data were taken from the Sri Lankan Diabetes and Cardiovascular Study, comprising a representative sample of people from seven of the nine provinces in Sri Lanka (n = 4,485/5,000; response rate = 89.7%). We constructed a measure of the urban environment for seven areas using a 7-item scale based on data from study clusters to develop an "urbanicity" scale. The items were population size, population density, and access to markets, transportation, communications/media, economic factors, environment/sanitation, health, education, and housing quality. Linear and logistic regression models were constructed to examine the relationship between urbanicity and chronic disease risk factors. Among men, urbanicity was positively associated with physical inactivity (odds ratio [OR] = 3.22; 2.27-4.57), high body mass index (OR = 2.45; 95% CI, 1.88-3.20) and diabetes mellitus (OR = 2.44; 95% CI, 1.66-3.57). Among women, too, urbanicity was positively associated with physical inactivity (OR = 2.29; 95% CI, 1.64-3.21), high body mass index (OR = 2.92; 95% CI, 2.41-3.55), and diabetes mellitus (OR = 2.10; 95% CI, 1.58 - 2.80). There is a clear relationship between urbanicity and common modifiable risk factors for chronic disease in a representative sample of Sri Lankan adults.