Psychometric evaluation of the Diabetes Symptom Checklist-Revised (DSC-R)--a measure of symptom distress

Value Health. Nov-Dec 2009;12(8):1168-75. doi: 10.1111/j.1524-4733.2009.00571.x. Epub 2009 Jun 24.

Abstract

Objective: To assess the psychometric validity, reliability, responsiveness, and minimal important differences of the Diabetes Symptoms Checklist-Revised (DSC-R), a widely used patient-reported outcome measure of diabetes symptom distress.

Research design and methods: Psychometric validity of the DSC-R was assessed using blinded data from a large-scale trial of approximately 4000 type 2 diabetes patients. Confirmatory factorial analysis (CFA) and multitrait analysis were used to examine the construct validity of the structure of DSC-R. DSC-R internal consistency, discriminative validity, and responsiveness were also assessed. Distribution and anchor-based methods were used to estimate minimal important differences for DSC-R domains.

Results: Mean age of the sample was 56 years, 42% were female, 88% were Caucasian. Patients had a mean body mass index (BMI) of 32.2 and mean glucose-fasting level of 151.7 md/dl. CFA and multitrait analysis indicated that the scoring of the DSC-R has acceptable construct validity. Item-scale correlations ranged from 0.44 to 0.78. Cronbach's alpha coefficients ranged from 0.69 to 0.87. At baseline, DSC-R scores were higher among patients with higher BMI scores (P < 0.0001), supporting the discriminative validity of the DSC-R. Minimal important difference estimates ranged from 0.39 to 0.60 points when using distribution methods and from 0.00 to 0.33 when estimated using anchor-based methods.

Conclusions: The DSC-R demonstrated excellent psychometric properties when tested in a large-scale diabetes clinical trial. Responsiveness and test-retest reliability of the DSC-R warrant further evaluation.

Publication types

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

MeSH terms

  • Adaptation, Psychological
  • Analysis of Variance
  • Blood Glucose
  • Body Mass Index
  • Cross-Sectional Studies
  • Diabetes Mellitus, Type 2 / drug therapy
  • Diabetes Mellitus, Type 2 / psychology*
  • Female
  • Global Health
  • Glyburide / therapeutic use
  • Glycated Hemoglobin A / analysis
  • Health Status Indicators
  • Humans
  • Hypoglycemic Agents / therapeutic use*
  • Male
  • Metformin / therapeutic use
  • Middle Aged
  • Outcome Assessment, Health Care / methods*
  • Psychometrics
  • Quality of Life*
  • Reproducibility of Results
  • Rosiglitazone
  • Severity of Illness Index
  • Sickness Impact Profile
  • Stress, Psychological*
  • Surveys and Questionnaires / standards*
  • Thiazolidinediones / therapeutic use

Substances

  • Blood Glucose
  • Glycated Hemoglobin A
  • Hypoglycemic Agents
  • Thiazolidinediones
  • hemoglobin A1c protein, human
  • Rosiglitazone
  • Metformin
  • Glyburide