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

Abstract

Purpose This study explored perceptions of meaningful weight-loss and the level of change on two patient-reported outcome (PRO) measures, the 36-item Short Form Health Survey® [SF-36v2®] and Impact of Weight on Quality of Life Lite-Clinical Trials© [IWQOL-Lite-CT©], that individuals living with overweight or obesity consider to be meaningful and indicative of treatment success. Methods Thirty-three qualitative interviews were conducted in the US with adults living with overweight or obesity. Concept elicitation explored perceptions of minimally important/meaningful weight-loss using open-ended questions. Cognitive debriefing was used to understand thresholds for meaningful change on both measures. Results Most participants (n = 23/33) expected a 5% total body weight-loss to yield some benefit in physical functioning, while all participants expected a 10% weight-loss to provide a meaningful and noticeable improvement in their physical functioning. Participants indicated that an item-level 1-point score change on each measure would represent a noticeable improvement in physical functioning and indicate treatment success. Conclusions Participants expected moderate weight-losses to be noticeable, with ≥ 10% weight-loss yielding the most consistent results. The findings suggested that both measures provide strong opportunity to demonstrate treatment benefit in relation to physical functioning as a small change on the response scale would represent a noticeable improvement in participants’ daily lives.

Introduction to the special section: “Methodologies and considerations for meaningful change”

“…The team combined the use of a longitudinal graded response model with a transition item to measure latent change. The method produced tighter estimates of meaningful change when compared to traditional methods, with the methods overlapping most when the proportion of responders was [23] N/A Individual Change over time N/A Griffiths et al [24] Meaningful change Group, Individual Change over time Minimal Ho et al [33] Distribution-based Individual, Group Change over time N/A Jones et al [21] Meaningful change Individual Change over time Not specified Lee et al [32] Both Individual Change over time Minimal Li [18] Distribution-based Individual Change over time N/A Peipert et al [30] Distribution-based Individual Change over time N/A Poon et al [29] Meaningful change Individual Change over time (hypothetical) Minimal Qin et al [27] Meaningful change Individual Change over time Not specified Smit et al [16] Both Individual Change over time Meaningful a Wyrwich & Norman [22] Meaningful change General General General Wyrwich et al [19] Meaningful change Individual Change over time (hypothetical) Meaningful b about 50% of participants. Extensions of this approach show promise for a range of applications [25,26].…”

“…The authors documented that due to extensive discussions online by patients about hair loss issues, they were able to make appropriate ratings of their hair loss that were largely consistent with values provided by clinical experts. The first part ends with a qualitative study to define meaningful change in physical function after weight loss [29]. The team conducted a qualitative study to evaluate how much weight loss would be meaningful hypothetically for overweight and obese individuals, if they were to lose weight.…”

Introduction to the special section "Methodologies and Considerations for Meaningful Change"

“…The authors documented that due to extensive discussions online by patients about hair loss issues, they were able to make appropriate ratings of their hair loss that were largely consistent with values provided by clinical experts. The first part ends with a qualitative study to define meaningful change in physical function after weight-loss (30). The team conducted a qualitative study to evaluate how much weight loss would be meaningful hypothetically for overweight and obese individuals, if they were to lose weight.…”