Nonreporting of body mass index: a research note on the interpretation of missing data.
OBJECTIVE
The aim of the study was to investigate the correlates of missing values on body mass index (BMI), with a view to distinguishing between potential hypotheses as to their origin.


METHODS
Participants were 1,452 secondary school students who completed questionnaire measures of BMI, perceived weight, body dissatisfaction, appearance investment, and eating disorder symptomatology.


RESULTS
More than one fourth of the sample had missing values on height or weight, the highest proportion of missing data occurring among older girls. Missing status on weight was associated with poorer body image and a greater investment in appearance for girls, but not for boys.


CONCLUSIONS
It was concluded that the pattern of results was most consistent with the hypothesis that missing values resulted from motivated nonresponding. More generally, the study provides an illustration of the usefulness of treating missing values as data in their own right.
Tiggemann
Marika
M
School of Psychology, Flinders University, Adelaide, South Australia. Marika.Tiggemann@flinders.edu.au
D000293:Adolescent; D001828:Body Image; D015992:Body Mass Index; D003625:Data Collection; D003627:Data Interpretation, Statistical; D001068:Feeding and Eating Disorders / Q000453:epidemiology* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D009042:Motivation; D015999:Multivariate Analysis; D000297:Psychology, Adolescent; D013021:South Australia / Q000453:epidemiology