A qualitative study to examine meaningful change in physical function associated with weight-loss

Area of Science:

• Obesity research
• Patient-reported outcomes
• Health psychology

Background:

• Understanding patient perspectives on weight loss is crucial for effective treatment.
• Patient-reported outcome (PRO) measures assess treatment success from the patient's viewpoint.
• Meaningful weight loss is defined differently across individuals and clinical contexts.

Purpose of the Study:

• To explore patient perceptions of meaningful weight loss.
• To determine meaningful change thresholds on the SF-36v2 and IWQOL-Lite-CT PRO measures.
• To identify what constitutes treatment success for individuals with overweight or obesity.

Main Methods:

• Qualitative interviews (n=33) with US adults living with overweight or obesity.
• Concept elicitation to explore perceptions of minimally important/meaningful weight loss.
• Cognitive debriefing to assess meaningful change on the SF-36v2 and IWQOL-Lite-CT.

Main Results:

• A 5% total body weight loss was expected to provide some physical functioning benefit by most participants.
• All participants expected a 10% weight loss to yield meaningful and noticeable physical functioning improvements.
• A 1-point score change on each PRO measure was considered a noticeable improvement in physical functioning.

Conclusions:

• Moderate weight losses, particularly ≥10%, are perceived as noticeable and beneficial.
• The SF-36v2 and IWQOL-Lite-CT effectively capture meaningful improvements in physical functioning.
• Small changes on these PRO measures can signify substantial improvements in daily life for patients.