Large differences in PA scores
between the two administrations would indicate that at least one of the two measurements is not accurate. However, similar to the finding of a Mexican study,38 scores on the Hausa IPAQ-LF were consistently lower during the second administration of the questionnaire compared to the first administration. calcitriol?hormone Since familiarity with the IPAQ questions may improve over multiple exposures to the questionnaire, it is possible that participants in our study might have over-reported their PA levels during the first administration of the Hausa IPAQ-LF. These kind of findings may have implications for the utility of IPAQ for surveillance. Generally, due to issues of social desirability phenomenon and over-reporting of PA that has been associated with the IPAQ,39 40 it may be necessary to start considering the need for multiple measurements when using the IPAQ for evaluating PA, especially in developing African countries. However, patterns of PA as measured by the modified IPAQ-LF during both administrations were consistently similar, and both administrations were able to discriminate PA in the expected direction
between subgroups of our sample. For example, at both measurement time points, and consistent with hypothesis, men reported more time in active transportation, occupational PA and leisure PA than women, while women reported more time in domestic PA and sedentary activity than men. In the absence of objective criterion standards for evaluating an absolute estimate of PA, the consistency of items on IPAQ with variables known to be related to PA, such as BMI, blood pressure, heart rate, indicators of lipid and glucose metabolism, and fitness index have been
used as important construct validity measures.7 10 21 24 In the present study, the correlations of the PA domains and intensities with biological and anthropometric variables were mostly significant in the expected direction, but they were low, suggesting a modest evidence of construct validity for the modified IPAQ-LF in Nigeria. However, observed correlations were comparable with the values in other studies that Batimastat have evaluated the IPAQ-LF.5 7 8 24 30 33 39 Since better validity coefficients have been reported for other PA measures above those of the IPAQ,39 41 with the present African finding, it is possible that the IPAQ-LF only has modest evidence of construct validity. However, our findings on the relationships between PA and biological and anthropometric variables should be interpreted in the light of an important caution. Since hypertensive and obese people may get oriented to exercise,3 cross-sectional associations of PA and blood pressure or BMI could also occur in the opposite direction and may not represent much information as indicators of construct validity of PA measures.