Testing for inter-group contamination in a controlled longitudinal study of added physical education.
OBJECTIVE
This case report examines whether there was any cross-contamination between students enrolled in classes that received additional physical education, and their siblings who were enrolled in preceding and succeeding class-cohorts.


METHODS
A controlled longitudinal study extending over 6 years of primary school.


METHODS
An urban and a rural primary school in Québec.


METHODS
546 primary students, comprising approximately equal numbers of boys and girls from the urban and the rural school.


METHODS
Entire class-cohorts were given and hour of additional physical education ach day throughout their primary schooling, with immediately preceding and succeeding class-cohorts serving as controls.


METHODS
The measured data included standing height, body mass, maximal oxygen intake (direct treadmill test) and PWC170.


RESULTS
We found no evidence of cross-contamination between siblings in experimental and control class-cohorts.


CONCLUSIONS
Although a theoretical possibility, cross-contamination between students in preceding and succeeding class-cohorts does not seem an important source of error in primary school students, presumably because such children prefer to play with friends from their immediate age cohort.
Labarre
R
R
Faculty of Health Sciences, Université de Québec à Trois Rivières, Canada.
Jéquier
J C
JC
Shephard
R J
RJ
Lavallée
H
H
Rajic
M
M
D015982:Bias; D001824:Body Constitution; D001827:Body Height; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010101:Oxygen Consumption; D010806:Physical Education and Training; D011792:Quebec; D012107:Research Design; D012423:Rural Health; D012801:Sibling Relations; D014504:Urban Health; D014938:Work Capacity Evaluation