title: Validity and reliability of the International Physical Activity Questionnaire among adults in Mexico.
abstract: OBJECTIVE
  To determine the test-retest reliability and validity of the Spanish version of the short-form International Physical Activity Questionnaire (IPAQ) among adults in Mexico.
  
  
  METHODS
  This was a cross-sectional study of a convenience sample of 267 adult factory workers in Mexico City. Participants were 19 - 68 years of age; 48% were female. Participants wore an accelerometer for 9 consecutive days and were administered the Spanish version of the short form IPAQ on two occasions (IPAQ1 and IPAQ2, separated by 9 days). The relation and differences between moderate-to-vigorous physical activity (MVPA) measures obtained from IPAQ1, IPAQ2, and the accelerometer were determined using correlations, linear regression, and paired t-tests.
  
  
  RESULTS
  IPAQ1 and IPAQ2 measures of MVPA were significantly correlated to each other (r = 0.55, P < 0.01). However, MVPA was 44 ± 408 minutes/week lower in IPAQ1 than in IPAQ2, although this difference did not reach statistical significance (P = 0.08). The (min/week) measures from IPAQ1 and IPAQ2 were only modestly correlated with the accelerometer measures (r = 0.26 and r = 0.31, P < 0.01), and by comparison to accelerometer measures, MVPA values were higher when based on IPAQ1 (174 ± 357 min/week, P < 0.01) than for IPAQ2 (135 ± 360 min/week, P < 0.01). The percentage of participants who were classified as physically inactive according to the World Health Organization guidelines was 18.0% in IPAQ1, 25.1% in IPAQ2, and 28.2% based on the accelerometer.
  
  
  CONCLUSIONS
  Similar to what has been observed in other populations, the short form IPAQ has a modest reliability and poor validity for assessing MVPA among Mexican adults.
authors.affiliation: School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada.
authors.forename: Catalina
authors.initials: C
authors.lastname: Medina
authors.forename: Simón
authors.initials: S
authors.lastname: Barquera
authors.forename: Ian
authors.initials: I
authors.lastname: Janssen
mesh_terms: D061725:Accelerometry; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006184:Habits; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D009043:Motor Activity; D050177:Overweight / Q000453:epidemiology; D015203:Reproducibility of Results; D012494:Sampling Studies; D011795:Surveys and Questionnaires; D014505:Urban Population; D055815:Young Adult