Study determines the responsiveness of Global Rating Scale with knee outcome scores

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Created On: 21/07/2020

Study determines the responsiveness of Global Rating Scale with knee outcome scores

The prospective cohort study aimed to determine the responsiveness of 4 PROMs via effect size and the presence of a ceiling effect in the 5 years after ACLR (anterior cruciate ligament reconstruction).

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Key take away

The selection of PROMs (patient-reported outcome measures) is pivotal for procuring meaningful information to determine a plan of care, treat a patient, and make relevant clinical decisions. However, the process of selecting PROMs for clinical care is troublesome, with the requirement to balance these multiple factors. The variation makes it challenging to compare data across providers and studies. In patients with ACL (anterior cruciate ligament)-reconstructed knees followed for 5 years, the response of GRS (Global Rating Scale) was found to be similar to the IKDC-SKF (International Knee Documentation Committee–Subjective Knee Form), KOS-ADLS (Knee Outcome Survey–Activities of Daily Living Scale), KOOS (Knee injury and Osteoarthritis Outcome Score), and was responsive to patient change. The patient-specific nature of the question and ease of use means that for clinical practice, it may be appropriate to use the GRS as a frequent and consistent measure throughout rehabilitation.

Background

Method

After study enrollment, the subjects completed 10 preoperative rehabilitation sessions. Of the 300 enrolled subjects, 218 had ACLR, accomplished postoperative progressive criterion-based rehabilitation early after surgery. All the subjects were under supervision for 5 years. Data based on the GRS, KOS-ADLS, IKDC-SKF , and the KOOS before and after training and at 6, 12, 24, and 60 months after ACLR were collected.

Result

At all time points, the IKDC-SKF were found to have the largest effect sizes as depicted in Figure 1:

Figure 1: Effect sizes.

Medium effect size 0.5 (dashed line), large effect size 0.8 (dotted line)

ADL, Activities of Daily Living; GRS, Global Rating Scale; IKDC-SKF, International Knee Documentation Committee–Subjective Knee Form; KOS-ADLS, Knee Outcome Survey–Activities of Daily Living Scale; Post, posttraining time point; QOL, Quality of Life; Sport/Rec, Sport and Recreation Function.

At any time point, the KOOS-QOL did not demonstrate a ceiling effect. The IKDC-SKF depicted a ceiling effect at the 24-month time point only. All other measures had a ceiling effect at least at 1 time point (most at 12, 24, and 60 months). The KOOS-ADL had a ceiling effect at all time points and the KOOS-Pain had ceiling effects at all but pretraining. The GRS had a similar effect size and change in ceiling effect in comparison with the longer PROMs as depicted in Figure 2:

Figure 2: Ceiling effects

The dashed line is the 15% cutoff for ceiling effect.

ADL, Activities of Daily Living; GRS, Global Rating Scale; IKDC-SKF, International Knee Documentation Committee–Subjective Knee Form; KOS-ADLS, Knee Outcome Survey– Activities of Daily Living Scale; post, posttraining time point; pre, pretraining time point; QOL, Quality of Life; Sport/Rec, Sport and Recreation Function.

Furthermore, GRS responded similarly to the IKDC-SKF, KOS ADLS, and KOOS measures and was responsive to patient change, with evidence of construct validity and a small MDC. When the data were pooled across all time points, the GRS and IKDC-SKF were found to have a Pearson correlation coefficient of 0.72. Depending on methodology, the GRS had a MDC (minimal detectable change) of 2.9 or 4.8.