Performance Score (T2D)—A New Perspective in the Assessment of Six-Minute Walking Tests in Pulmonary Rehabilitation

Abstract

Because absolute changes in outcomes are difficult to interpret and the minimal clinically important difference (MCID) is not suitable to address this challenge, a novel method of classifying outcomes by relating changes to baseline values is warranted. We used the “performance score” (T2D), which reflects individual performance, enabling us to consider the functional status at the beginning of rehabilitation without dealing with the problems of mathematical coupling or regression effects, as encountered in ANCOVA. To illustrate the T2D, we retrospectively analyzed changes in the six-minute walking test (6MWT) in COPD patients undergoing outpatient pulmonary rehabilitation and compared the results with absolute differences related to a predetermined MCID. We evaluated a total of 575 COPD patients with a mean age of 61.4 ± 9.2 years. 6MWT improved significantly, with a mean change of 32.3 ± 71.2. A total of 105/311 participants who had reached the MCID were still classified as “below average” by the T2D. Conversely, 76/264 patients who had not reached the MCID were classified as “above average”. This new performance measure accounts for the patient’s current status and for changes over time, potentially representing a simple and user-friendly tool that can be used to quantify a patient’s performance and response to rehabilitation.

Mentalizing and epistemic trust as critical success factors in psychosomatic rehabilitation: results of a single center longitudinal observational study

“…Since we found a substantial variation in mentalizing at baseline, the performance score (T2D) was used in the SEM model. The T2D is a simple method to correct for baseline differences (46), which allows to use baseline corrected variables in SEM models and has been shown to facilitate interpretability in various fields of rehabilitation research (42,43,47,48). Moreover, we investigated additional factors that may be associated with the improvement of mentalizing in psychosomatic rehabilitation.…”

“…In model B, mean change in mentalizing as measured by the MZQ total score was added to the model as a mediator for this relationship, and changes in the epistemic trust subscales were added as predictors for mentalizing. Due to baseline differences, the calculation of change scores may lead to misleading effects (e.g., floor or ceiling effects) and thus may distort the interpretation of therapy effectiveness across groups with differences A simple solution might be the use of the "performance score (T2D), " based on the formula T2 + (T2-T1), which reflects the individual performance and considers the functional status at the beginning of rehabilitation (changes from T1 to T2; Δ) without problems of mathematical coupling or regression effects, as seen in ANCOVA (41)(42)(43). We therefore used the T2D mentalizing and epistemic trust scores in the models as moderator and predictor variables.…”

Improvements of complex post-traumatic stress disorder symptoms during a multimodal psychodynamic inpatient rehabilitation treatment – results of an observational single-centre pilot study

“…To account for baseline differences, the ‘performance score’ (T2D) of the mean PTSD / DSO change was created as dependent variable. The T2D is based on the formula ‘ T2 + (T2 – T1)’ , which reflects the individual performance and considers the functional status at beginning of rehabilitation (changes from T1 to T2 ; Δ) without problems of mathematical coupling or regression effects, as seen in ANCOVA (Wagner et al, 2022 ; Zdravkovic et al, 2022 ). Adjusting for baseline differences is crucial for contextualizing study outcomes.…”