Minimal Clinically Important Improvement: A Novel Approach to Osteoarthritis Assessment

Patients with osteoarthritis (OA) who were treated with diclofenac sodium gel (DSG) 1% achieved minimal clinically important improvement (MCII) faster than those administered vehicle, according to research presented at the American Association of Nurse Practitioners 2019 annual meeting held June 18 to 23 in Indianapolis, Indiana.

Investigators conducted their research using data from a previous study to tabulate the number and percentage of patients aged ≥35 years with OS who achieved MCII, a measure of the smallest change that an individual patient views as an important improvement in symptoms of pain, function, and stiffness.

Data from a randomized, double-blind OA knee study that compared DSG with vehicle were used, and relative improvements at ≥20% and ≥30% from baseline were measured to compare MCII responses between the groups. Time to first MCII response was also recorded.

At week 1, 66% of patients in the DSG cohort and 55% in the vehicle cohort experienced MCII response for Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) pain; 56% of DSG-group and 42% of vehicle-group patients achieved MCII responses for WOMAC function; and 62% and 48%, respectively, achieved MCII response for WOMAC stiffness.

Except for pain, all other DSG responses remained significant through week 12. Significance was noted for WOMAC pain when 30% improvement was considered. DSG had lower time to first MCII response in all measures compared with vehicle.  

“The MCII is a new way of understanding clinically important improvement by taking the perspective of the patient into account,” the authors noted. “Using the MCII to express results in percentages is more clinically relevant and understandable for both the patient and the primary care physician.”

Disclosure: Most of the authors of this study are employed by GSK Healthcare.

Reference

Kenneally A, D’Arcy Y, Patel B, Garas SY. A novel approach to measuring clinical relevance: an analysis of minimal clinically important improvement (MCII) in knee osteoarthritis from a randomized clinical trial of diclofenac sodium gel (DSG) 1%. Presentation at: The American Association of Nurse Practitioners Annual Meeting; June 18-23, 2019; Indianapolis, IN. Poster 11.