Assessment of physical activity in older Belgian adults: validity and reliability of an adapted interview version of the long International Physical Activity Questionnaire (IPAQ-L).
BACKGROUND
Adequate monitoring of older adults' physical activity (PA) is essential to develop effective health promotion programs. The present study examined criterion validity and test-retest reliability of the long International Physical Activity Questionnaire (IPAQ-L), adapted for Belgian, community-dwelling older adults (65 y and older).


METHODS
Participants (n = 434) completed the last seven days version of IPAQ-L, modified for the Belgian population of community-dwelling older adults. This elderly-adapted version of IPAQ-L combined vigorous and moderate activities, and questions on gait speed and recreational cycling were added. Furthermore, participants wore an ActiGraph GT3X(+) accelerometer for at least five days. Criterion validity was determined by comparing self-reported weekly minutes of moderate-to-vigorous physical activity (MVPA) and weekly minutes of total PA with accelerometer data, defined by two different cut points (Freedson vs. Copeland). To examine test-retest reliability, a subsample of 29 participants completed IPAQ-L for a second time within a ten day interval.


RESULTS
IPAQ-L showed moderate criterion validity for measuring weekly minutes of MVPA and total PA (Spearman's ρ range 0.33-0.40). However, plots on agreement between self-reported and accelerometer PA showed a systematic over-reporting of IPAQ-L for MVPA. In contrast, plots indicated that IPAQ-L under-estimated levels of total PA, however, this under-estimation of total PA was substantially lower than the observed over-reporting of MVPA. Test-retest reliability was moderate-to-good for work-related PA, domestic PA, MVPA and total PA (ICC range 0.52-0.81), but poorer for transportation and recreational PA (ICC 0.44 and 0.43, respectively).


CONCLUSIONS
Criterion validity results suggest that IPAQ-L is more valid to measure older adults' weekly minutes of total PA than weekly MVPA minutes. Moreover, results might imply that content validity of IPAQ-L can be improved if specific light-intensity PA items are incorporated into IPAQ-L. Test-retest reliability of IPAQ-L was moderate to good, except for weekly minutes of transportation and recreational PA, probably due to week-to-week variability of these behaviors.
Department of Movement and Sport Sciences, Ghent University, Watersportlaan 2, B-9000, Ghent, Belgium. veerle.vanholle@ugent.be.|Research Foundation Flanders, Egmontstraat 5, B-1000, Brussels, Belgium. veerle.vanholle@ugent.be.
Veerle
V
Van Holle
Department of Movement and Sport Sciences, Ghent University, Watersportlaan 2, B-9000, Ghent, Belgium. ilse.debourdeaudhuij@ugent.be.
Ilse
I
De Bourdeaudhuij
Department of Movement and Sport Sciences, Ghent University, Watersportlaan 2, B-9000, Ghent, Belgium. benedicte.deforche@vub.ac.be.|Department of Public Health, Ghent University, De Pintelaan 185 4 K3, B-9000, Gent, Belgium. benedicte.deforche@vub.ac.be.
Benedicte
B
Deforche
Department of Public Health, Ghent University, De Pintelaan 185 4 K3, B-9000, Gent, Belgium. jelle.van.cauwenberg@vub.ac.be.|Research Foundation Flanders, Egmontstraat 5, B-1000, Brussels, Belgium. jelle.van.cauwenberg@vub.ac.be.
Jelle
J
Van Cauwenberg
Department of Movement and Sport Sciences, Ghent University, Watersportlaan 2, B-9000, Ghent, Belgium. delfien.vandyck@ugent.be.|Research Foundation Flanders, Egmontstraat 5, B-1000, Brussels, Belgium. delfien.vandyck@ugent.be.
Delfien
D
Van Dyck
D056044:Actigraphy / Q000295:instrumentation; D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D015444:Exercise / Q000502:physiology*; D005260:Female; D015438:Health Behavior; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D015203:Reproducibility of Results; D057566:Self Report; D011795:Surveys and Questionnaires / Q000592:standards*