Research
Fear of hypoglycaemia: defining a minimum clinically important difference in patients with type 2 diabetes
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* Corresponding author: Tom Stargardt Stargardt@bwl.lmu.de
1 Health Services Management, Munich School of Management, Munich University, Germany
2 Institute of Health Economics and Health Care Management, Helmholtz Zentrum Munich, Germany
3 Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, VA, USA
4 Outcomes Research, MSD Sharp & Dohme GMBH, Haar, Germany
5 Outcomes Research, Merck & Co, Inc, Whitehouse Station, NJ, USA
Health and Quality of Life Outcomes 2009, 7:91 doi:10.1186/1477-7525-7-91
Published: 22 October 2009Abstract
Background
To explore the concept of the Minimum Clinically Important Difference (MID) of the Worry Scale of the Hypoglycaemia Fear Survey (HFS-II) and to quantify the clinical importance of different types of patient-reported hypoglycaemia.
Methods
An observational study was conducted in Germany with 392 patients with type 2 diabetes mellitus treated with combinations of oral anti-hyperglycaemic agents. Patients completed the HFS-II, the Treatment Satisfaction Questionnaire for Medication (TSQM), and reported on severity of hypoglycaemia. Distribution- and anchor-based methods were used to determine MID. In turn, MID was used to determine if hypoglycaemia with or without need for assistance was clinically meaningful compared to having had no hypoglycaemia.
Results
112 patients (28.6%) reported hypoglycaemic episodes, with 15 patients (3.8%) reporting episodes that required assistance from others. Distribution- and anchor-based methods resulted in MID between 2.0 and 5.8 and 3.6 and 3.9 for the HFS-II, respectively. Patients who reported hypoglycaemia with (21.6) and without (12.1) need for assistance scored higher on the HFS-II (range 0 to 72) than patients who did not report hypoglycaemia (6.0).
Conclusion
We provide MID for HFS-II. Our findings indicate that the differences between having reported no hypoglycaemia, hypoglycaemia without need for assistance, and hypoglycaemia with need for assistance appear to be clinically important in patients with type 2 diabetes mellitus treated with oral anti-hyperglycaemic agents.