Comparison of patient- and clinician-reported outcome measures in lower back rehabilitation: introducing a new integrated performance measure (t2D)

Abstract

Purpose: Patient- and clinician-reported outcome measures (PROMs, CROMs) are used in rehabilitation to evaluate and track the patient's health status and recovery. However, controversy still exists regarding their relevance and validity when assessing a change in health status.

Methods: We retrospectively analyzed the changes in a CROM (Fingertip-To-Floor Test - FTF) and PROMs (ODI, HAQ-DI, NPRS, EQ5D) and the associations between these outcomes in 395 patients with lower back pain (57.2 ± 11.8 years, 49.1% female). We introduced a new way to measure and classify outcome performance using a distribution-based approach (t2D). Outcome measures were assessed at baseline and after 21 days of inpatient rehabilitation.

Results: Overall, the rehabilitation (Cohens d = 0.94) resulted in a large effect size outcome. Medium effect sizes were observed for FTF (d = 0.70) and PROMs (d > 0.50). Best performance rating was observed for pain (NPRS). We found that 13.9% of patients exhibited a deterioration in the PROMs, but only 2.3%, in the FTF. The correlation between the PROMs and FTF were low to moderate, with the highest identified for HAQ-DI (rho = 0.30-0.36); no significant correlations could be shown for changes. High consistency levels were observed among the performance scores (t2D) in 68.9% of the patients.

Conclusions: Different and complementary assessment modalities of PROMs and CROMs can be used as valuable tools in the clinical setting. Results from both types of measurements and individual performance assessments in patients provide a valid basis for the meaningful interpretation of the patients' health outcomes.

Trial registration: This clinical study was entered retrospectively on August 14, 2020 into the German Clinical Trials Register (DRKS, registration number: DRKS00022854).

Keywords: Clinician-reported outcome measures; Inpatient; Lower back pain; Orthopedic rehabilitation; Patient-reported outcome measures; Performance score.

Fig. 1

Baseline values (t1) and changes of CROM-FTF (t2 – t1). Changes of a Fingertip-To-Floor (FTF) test in relation to baseline values (t1) and the categorized performance score (t2 + Δ; tertiles highlighted in from and color). Tertiles were chosen because the expected and observed improvements in outcome measures (see Table 2) in inpatient rehabilitation are clearly visible in around 2/3 of patients [16]. Among the LBP patients, 73 had optimal values (0) for t1 and t2

Fig. 2

ab FTF improvements vs. performance score and changes of FTF. Classification for improvements is based on the value distributions (z-differences; SMD; a top). Difference values with no significant changes normally range randomly from 0.00 ± 0.20 (1/5 SD) [36]. Tertiles for FTF performance score were chosen, because the expected and observed improvements are around 2/3 (b bottom) [16]

Fig. 3

Consistency within CROM vs. PROMs performance scores. In most cases (68.9%), the performance scores between CROM-FTF and PROMs point in the same direction. Specifically, 27.3% of results in mean PROM performance scores showed moderate agreement in terms of performance with CROM-FTF. In 3.8% of the cases, the results between CROM-FTF vs PROMs were contrary to each other (discrepant)