Ability to perform daily physical activities in individuals with type 2 diabetes and moderate obesity: a preliminary validation of the Impact of Weight on Activities of Daily Living Questionnaire.

BACKGROUND

The aims of this study were (1) to demonstrate the reliability and validity of the Impact of Weight on Activities of Daily Living Questionnaire (IWADL), a measure of ability to perform daily physical activities, in individuals with type 2 diabetes who are moderately obese and (2) to characterize those individuals with low self-reported ability.

METHODS

Data from a web-based survey of individuals with type 2 diabetes and body mass index (BMI) of 30-40 k/mg(2) were used to calculate Cronbach's α and demonstrate both IWADL factorial and construct validity. These data were entered into a multivariable multinomial logistic regression model with survey variables (demographics, health status, weight- and diabetes-related) as the independent variables and three IWADL scoring groups (Low, Medium, and High) as the dependent variables.

RESULTS

Study participants were 349 individuals with type 2 diabetes (mean age = 59 years, 44% male, 91% white, mean BMI = 35 k/mg(2)). Factor analysis indicated a one-factor solution for a seven-item IWADL with Cronbach's α = 0.94. Significant (P < 0.05) relationships were identified between IWADL and variables previously shown to be related to level of physical activity. Ten variables remained independently (P < 0.05) related to IWADL scores, including age, gender, health status, current exercise, using exercise programs or hypnosis as a step to lose weight, and self-reported weight history.

CONCLUSIONS

The IWADL is a reliable and valid measure of the ability of individuals with type 2 diabetes and moderate obesity to perform daily physical activities. This ability may be an important patient-reported end point to include in clinical trials of antihyperglycemic medications that produce weight loss.