[Reproducibility and sensitivity of the Impact of Weight on Quality of Life questionnaire among obese Mexicans].
OBJECTIVE
Determine if the Spanish version of the IWQOL (Impact of Weight on Quality of Life) questionnaire is reproducible and sensitive to detect differences among WHO's classification of obesity.


METHODS
The IWQOL was translated into Spanish and adapted to the Mexican context while maintaining a wide comprehensive vocabulary applicable to Latin American countries. We measured reproducibility using a test-retest method (n=82, BMI 37.8+/-8.4), sensitivity to detect differences between types of obesity (n=105, BMI 35.1+/-9.5), and sensitivity to detect differences after treatment for weight loss within groups (n=40, BMI 39.2+/-7).


RESULTS
The IWQOL questionnaire was reliable and sensitive enough to detect differences among and within groups. All domains were highly reproducible (scores differed by less than 2 points) and had high internal validity (Cronbach alpha coefficient >0.92 for all scales). The IWQOL detected differences between groups stratfied by severity of obesity, the lowest score was for BMI >45. Subjects who underwent weight loss treatment and lost 6.4 kg (95% CI 4.6, 8.2) during a period of 2.70+/-1 month had an improvement in all scales except for the "Work" domain.


CONCLUSIONS
The IWQOL questionnaire is a reliable and sensitive tool that can be used for research purposes in Mexico and the Latin America region. Our study validates the use of IWQOL among Mexican subjects.
Bolado-García
Victoria Eugenia
VE
Clínica de Obesidad, Hospital Regional Gabriel Mancera, Instituto Mexicano del Seguro Social, México D.F., México.
López-Alvarenga
Juan Carlos
JC
González-Barranco
Jorge
J
Comuzzie
Anthony G
AG
D000328:Adult; D001835:Body Weight; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico; D008875:Middle Aged; D009765:Obesity; D011788:Quality of Life; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires