Validity and Reliability of the International Physical Activity Questionnaire Among Mexican Adults

Abstract

Background: Because it is a strong determinant of chronic disease and mortality risk, physical activity is a health behaviour that is measured in most large health surveys. Questionnaires are the most commonly used method for measuring physical activity in health surveys. In the early 1990’s, an international physical activity questionnaire (IPAQ) was created to allow researchers from across the globe to employ the same questionnaire within their country. Several studies have been conducted on the IPAQ to determine whether the responses obtained are comparable when the questionnaire is administered on multiple occasions (reliability) and to determine the ability of the questionnaire to obtain the same physical activity result when compared to other direct measures, considered as “gold standard” (validity). However, none of these studies have been conducted in Mexico. Objective: Examine: 1) the reliability of the IPAQ among Mexican adults by comparing minutes per week (min/wk) spent in moderate-to-vigorous physical activity (MVPA) from the IPAQ administered two times, 2) the validity of the IPAQ surveys by comparing IPAQ min/wk of MVPA to those obtained by the accelerometer. Methods: 267 Mexican adults who worked in a factory in Mexico City participated. IPAQ was applied in a face-to-face interview during a first clinic visit. Participants received an accelerometer (motion sensor that measures and record physical activity) and wore it consecutively for the next 9 days. In a second visit, participants returned the accelerometer and completed a second IPAQ. The research team cleaned and analyzed the accelerometer data using standardized techniques. Results from the two IPAQ and the accelerometer were compared using the appropriate statistical tests. Results: IPAQ1 and IPAQ2 measures of MVPA were significantly correlated to each other (r=0.55, p<0.01). The MVPA (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). The percentage of the participants who were classified as inactive according to the World Health Organization physical activity guidelines was 18.0% in IPAQ1, 25.1% in IPAQ2, and 28.2% for the accelerometer. Conclusions: IPAQ was modestly correlated to each other and it was lowly correlated to values obtained by the accelerometer. Since IPAQ has been used to obtain physical activity prevalence worldwide, caution should be taken when this instrument is used. Future research should be focused on the importance of including direct measures to measure physical activity levels within epidemiological surveys.