The Reliability of the Long and Short IPAQ Forms in Czech Youth aged 15–24y

The International Physical Activity Questionnaire (IPAQ) is an effective instrument to determine the physical activity patterns in youth and identify the health-related outcomes of PA. The long and short IPAQ are equal forms assessing the time spent performing vigorous and moderate PA and walking during the last 7 days. The short IPAQ uses one question to assess PA in each category (vigorous, moderate and walking). The long IPAQ comprises of two questions asking about vigorous PA, six about moderate PA and three about walking. PURPOSE: To identify differences in the outcomes in MET-min/week from the long and short self-administrated version of the IPAQ to improve accuracy in explaining the findings. METHODS: The IPAQ was applied in a national sample of Czech youth aged 15-24y. The short IPAQ was completed by 890 females and 814 males in April, May September and October 2004. Long IPAQ was completed by 839 females and 751 males in April, May, September and October 2005. Data processing and clearing were done according to the Scoring Protocol for the IPAQ Long and Short Forms. To identify the differences in MET-min/week in each PA category between the short and long IPAQ forms 2×3 MANOVA was used. The statistical analysis was done separately for each sex. To determine the detailed differences between individual groups the post-hoc Scheffe test was used. RESULTS: Statistically significant differences were found in total PA expressed in MET-min/week between the long and short IPAQ forms both in females (F=12.55 p<0.0001) and males (F=5.27 p<0.006). Using the Scheffe post-hoc test we discovered the significant differences only in moderate PA in females (+427 MET-min/week p<0.0001) and males (+290 MET-min/week p<0.06). There were no significant differences between the long and short IPAQ forms in vigorous PA (female: 43 MET-min/week, male: 5 MET-min/week) and walking (female: 22 MET-min/week, male: 32 MET-min/week). The results suggest that the higher values of MET-min/week obtained from the long IPAQ form could be due to the higher number of questions asking about moderate PA. CONCLUSIONS: Both the long and short self-administrated IPAQ forms identify similar PA patterns. Assessing the volume of moderate PA shows differences therefore should be considered when explaining the findings.