Evaluation of the Indian Migration Study Physical Activity Questionnaire (IMS-PAQ): a cross-sectional study.
BACKGROUND
Socio-cultural differences for country-specific activities are rarely addressed in physical activity questionnaires. We examined the reliability and validity of the Indian Migration Study Physical Activity Questionnaire (IMS-PAQ) in urban and rural groups in India.


METHODS
A sub-sample of IMS participants (n = 479) was used to examine short term (≤ 1 month [n = 158]) and long term (> 1 month [n = 321]) IMS-PAQ reliability for levels of total, sedentary, light and moderate/vigorous activity (MVPA) intensity using intraclass correlation (ICC) and kappa coefficients (k). Criterion validity (n = 157) was examined by comparing the IMS-PAQ to a uniaxial accelerometer (ACC) worn ≥ 4 days, via Spearman's rank correlations (ρ) and k, using Bland-Altman plots to check for systematic bias. Construct validity (n = 7,000) was established using linear regression, comparing IMS-PAQ against theoretical constructs associated with physical activity (PA): BMI [kg/m2], percent body fat and pulse rate.


RESULTS
IMS-PAQ reliability ranged from ICC 0.42-0.88 and k = 0.37-0.61 (≤ 1 month) and ICC 0.26 to 0.62; kappa 0.17 to 0.45 (> 1 month). Criterion validity was ρ = 0.18-0.48; k = 0.08-0.34. Light activity was underestimated and MVPA consistently and substantially overestimated for the IMS-PAQ vs. the accelerometer. Criterion validity was moderate for total activity and MVPA. Reliability and validity were comparable for urban and rural participants but lower in women than men. Increasing time spent in total activity or MVPA, and decreasing time in sedentary activity were associated with decreasing BMI, percent body fat and pulse rate, thereby demonstrating construct validity.


CONCLUSIONS
IMS-PAQ reliability and validity is similar to comparable self-reported instruments. It is an appropriate tool for ranking PA of individuals in India. Some refinements may be required for sedentary populations and women in India.
Department of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK. ruth.sullivan@lshtm.ac.uk
Ruth
R
Sullivan
Sanjay
S
Kinra
Ulf
U
Ekelund
A V
AV
Bharathi
Mario
M
Vaz
Anura
A
Kurpad
Tim
T
Collier
K Srinath
KS
Reddy
Dorairaj
D
Prabhakaran
Shah
S
Ebrahim
Hannah
H
Kuper
D056044:Actigraphy; D000273:Adipose Tissue; D000328:Adult; D001823:Body Composition; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D004641:Emigration and Immigration; D015444:Exercise; D005260:Female; D015438:Health Behavior; D006306:Health Surveys / Q000592:standards*; D006339:Heart Rate; D006801:Humans; D007194:India; D016014:Linear Models; D008297:Male; D015203:Reproducibility of Results; D057185:Sedentary Behavior; D012737:Sex Factors; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires / Q000592:standards*