A literature review exploring whether meaningful change threshold estimates for patient-reported outcome (PRO)...

Meaningful change thresholds for patient-reported outcome (PRO) measures may differ according to patients' baseline disease severity. This review aimed to explore methods used in the peer-reviewed literature to assess the relationship between baseline severity and meaningful change thresholds and the nature of this relationship.

A structured literature review was conducted to identify relevant abstracts published between 2018-2022 reporting estimation of PRO meaningful change thresholds by baseline disease severity. Methods to estimate thresholds and direction of the relationship with baseline severity were extracted.

1029 abstracts were screened and 22 full-text articles were deemed eligible for inclusion in the review. All 22 articles reported meaningful change thresholds that were estimated by baseline severity. Nearly all studies (n = 21) used anchor-based methods and reported thresholds for improvement. Most studies (n = 19) used the baseline score of the PRO being examined to define baseline severity. Baseline severity dependency was often tested by repeating methods within baseline-stratified groups (n = 16). All studies reported at least one PRO score where meaningful change was dependent upon baseline severity. The direction of the relationship for improvement was predominately a larger meaningful change threshold for worse baseline severity (n = 21).

Methods used to assess baseline severity dependency for meaningful change thresholds vary, however most studies reviewed concluded that larger thresholds are warranted for worse baseline severity. Future work should explore how to distinguish true baseline severity dependency from statistical artifacts to ensure accurate interpretation of PROs in both clinical trials and clinical practice.