Just a quarter of a point change in score was enough to be clinically important, according to a secondary analysis of a clinical trial.
Using data from a randomized trial of Veterans with uncontrolled type 2 diabetes, a 0.25 or greater drop in DDS-17 score was determined to be a clinically meaningful improvement in diabetes distress, while an increase of 0.25 or more was considered a significant worsening, found researchers led by Jack Banks, PhD, a postdoctoral research fellow at UTHealth Houston.
Anything less than a 0.25 change was not considered to be clinically important, they wrote in .
"The DDS-17 is a key tool for evaluating distress levels in individuals living with type 2 diabetes," Banks told Ƶ. The 17-item scale aims to measure diabetes patients' perceptions in four domains: interpersonal distress, physician-related distress, regimen-related distress, and emotional distress.
"Prior studies that have employed the DDS-17 have utilized a cut-point of 2.0 as a dichotomous variable, with scores ≥2.0 signifying the presence of moderate diabetes distress in participants," Banks said. Thresholds below 2.0 represent little or no distress while scores of 3.0 or higher represent high distress.
"A limitation of this cut-point approach however is its inability to capture significant changes in DDS-17 scores that do not cross this 2.0 cut-point," said Banks.
He added that calculation of minimal clinically important difference (MCID) values determining the smallest meaningful change along the range of a continuous measure can help overcome this limitation.
"Distribution-based MCID values had not been established for the DDS-17," he said. "We wished to address this important research gap by calculating the MCIDs for the DDS-17 and each of its four subscales."
As for the four subscales, MCID was calculated to be 0.38 for both the emotional and interpersonal distress subscales and 0.39 for the physician- and regimen-related distress subscales.
"In calculating the MCIDs for the DDS-17 and each of its subscales, we now have a measure with the ability to capture meaningful improvements or worsening of diabetes distress that are independent of a cut-point," said Banks.
"We hope that clinicians and patients will use the MCID values we calculated to assess response to treatments or interventions surrounding diabetes distress," he added. "We also hope that researchers use these values to inform future research examining diabetes distress using the DDS-17 scale."
The new study drew on data from a multisite, randomized clinical trial comparing the Empowering Patients in Chronic Care (EPICC) intervention with an enhanced form of usual care. The EPICC intervention involved six bimonthly group sessions based on goal setting and motivational interviewing led by a variety of healthcare professionals followed by individual patient sessions. Alternatively, the other half of participants received routine care enhanced with education, nutritional counseling, medication management, weight-loss support, and primary care support.
The primary analysis of the study, , showed that the collaborative goal setting and motivational interviewing helped lower patients' HbA1c levels more than enhanced usual care, though the effect was not sustained after maintenance. Improvements in diabetes-associated distress with the EPICC program did hold up, however.
For the present secondary analysis, Banks' group included 248 individuals from the EPICC trial with complete DDS-17 and HbA1c data, with 123 participants in the EPICC group and 125 participants in the enhanced usual care group. Patients had an average age of 67 years and 95% were men. The study population was 49% white, 38% Black, and 11% Hispanic.
They reported that more diabetes patients who received EPICC compared with enhanced routine care fell into the MCID "improvement" category (51% vs 32%, P=0.003). Similarly, fewer EPICC participants ended up in the "worsened" category compared with routine care (16% vs 31%, P=0.008).
However, there was no significant association found between diabetes distress scale MCID improvement or worsening categories and HbA1c levels. "These findings suggest that significant change in HbA1c may require greater than MCID levels of improvement in diabetes distress," the researchers wrote.
Disclosures
The study was supported by grants from the VA Health Services Research and Development service and the Department of VA Health Services Research and Development. One co-author was supported by the National Institutes of Health and the National Institute of Diabetes and Digestive and Kidney Diseases.
Banks reported no disclosures. Other study authors reported personal fees from the Texas Medical Board Medical Record Review and grants from the Houston Center for Innovations in Quality, Effectiveness, and Safety.
Primary Source
JAMA Network Open
Banks J, et al "Ascertainment of minimal clinically important differences in the Diabetes Distress Scale–17" JAMA Netw Open 2023; DOI: 10.1001/jamanetworkopen.2023.42950.