IPAQ interview version: convergent validity with accelerometers and comparison of physical activity and sedentary time levels with the self-administered version

This study aimed to assess convergent validity of International Physical Activity Questionnaire (IPAQ) interview (long form, last seven days), and to examine differences in reported physical activity and sedentary time between the self-administered and interview versions of the long IPAQ (last seven days); and whether these differences depend on gender, age, educational level and weight status. In total, 542 Belgian adults (45.3% male, 43.8±12.1 years) completed the IPAQ self-administered version. Data of these adults were compared with data of 542 adults (45.2% male, 43.5±12.3 years) who completed the IPAQ interview version and wore an accelerometer for seven consecutive days. Samples were matched on gender, age, education, neighborhood characteristics and time of data collection. Convergent validity of the IPAQ interview version was moderate for total physical activity (Spearman ρ=0.37, P