title: Sociodemographic factors associated with physical activity in Mexican adults.
abstract: OBJECTIVE
  To estimate the physical activity level among Mexican adults and to establish the sociodemographic variables that may be linked to active lifestyles.
  
  
  METHODS
  Data from a cross-sectional survey were analysed. Physical activity was assessed using the short version of the International Physical Activity Questionnaire. The independent variables were sex, age, socio-economic status and size of town. Ordinal regression models were fitted to assess the association of physical activity levels with sociodemographic factors.
  
  
  METHODS
  Fieldwork was conducted from November 2002 through April 2003; the non-response rate was 3.1%.
  
  
  METHODS
  Data from a national representative sample (n 38,746) of Mexican adults aged >18 years old were analysed.
  
  
  RESULTS
  Almost 60% of the population was classified into the high physical activity level. Women were less active than men in rural areas; in urban areas, the opposite trend was observed. In women, higher socio-economic status was associated with less physical activity, while among men there were no differences. People from rural and urban areas had a higher probability of engaging in physical activity than those from cities. In urban localities and cities, respondents of low socio-economic status had a lower probability of engaging in physical activity.
  
  
  CONCLUSIONS
  Using a validated instrument to measure physical activity, we found that the prevalence of active lifestyle among Mexican adults was high. The socio-economic and gender inequalities are different according to size of town (i.e. an effect modifier), which must be considered in the design of policies and programmes to promote physical activity.
authors.affiliation: Health Care Department, Metropolitan Autonomous University campus Xochimilco, Calz. Del Hueso 1100, Col. Villa Quietud, Del. Coyoacán, Distrito Federal, CP 04960, México. lortiz@correo.xoc.uam.mx
authors.forename: Luis
authors.initials: L
authors.lastname: Ortiz-Hernández
authors.forename: Norma
authors.initials: N
authors.lastname: Ramos-Ibáñez
mesh_terms: D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology* / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico; D008875:Middle Aged; D012424:Rural Population / Q000706:statistics & numerical data*; D017678:Sex Distribution; D012923:Social Class; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014505:Urban Population / Q000706:statistics & numerical data*; D055815:Young Adult