Test-retest, responsiveness, and minimal important change of the ability to perform physical activities of daily living questionnaire in individuals with type 2 diabetes and obesity

Diabetes Technol Ther. 2012 Dec;14(12):1118-25. doi: 10.1089/dia.2012.0123. Epub 2012 Sep 27.


Background: The Ability to Perform Physical Activities of Daily Living Questionnaire (APPADL) measures the self-reported ability of individuals with type 2 diabetes mellitus (T2DM) and obesity to perform daily physical activities. The primary objective of this study was to estimate APPADL test-retest reliability, responsiveness, and minimal important change (MIC).

Subjects and methods: Study participants were individuals with T2DM and body mass index ≥30 kg/m(2) enrolled in clinical weight loss programs in the United States. Data were obtained for clinical measures, APPADL, and other patient-reported instruments. APPADL test-retest reliability was estimated with intraclass correlation coefficient. To estimate responsiveness in a subgroup of participants, baseline and 6-month data were analyzed using paired t test and calculation of responsiveness indices (e.g., effect size [ES]). To estimate MIC, both distribution-based and anchor-based methods were used.

Results: Test-retest data for 106 study participants (mean age, 52 years; 69% female; 31% white; mean body mass index, 38 kg/m(2)) yielded an intraclass correlation coefficient of 0.91. In the subgroup (n = 40) used to estimate responsiveness, weight was significantly less at end point than at baseline (mean, 222.0 vs. 231.9 pounds; P < 0.001, ES = 0.24), and APPADL scores were significantly better than at baseline (mean, 77.0 vs. 70.8; P = 0.01, ES = 0.32). Results of distribution- and anchor-based methods to establish MIC suggest values of 6-14 points (0-100 scale).

Conclusions: The APPADL has demonstrated reliability and validity. In addition, it has demonstrated responsiveness to weight loss in individuals with T2DM and obesity, thereby making it a potentially valuable tool in the evaluation of weight loss interventions (e.g., antihyperglycemic medications that produce weight loss) targeted toward patients with T2DM.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Activities of Daily Living
  • Adult
  • Aged
  • Body Mass Index
  • Diabetes Mellitus, Type 2 / complications
  • Diabetes Mellitus, Type 2 / epidemiology
  • Diabetes Mellitus, Type 2 / physiopathology*
  • Exercise*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Mobility Limitation
  • Obesity / epidemiology
  • Obesity / physiopathology*
  • Obesity / prevention & control
  • Patient Compliance
  • Prospective Studies
  • Reproducibility of Results
  • Surveys and Questionnaires
  • United States / epidemiology
  • Weight Loss*
  • Weight Reduction Programs*