Noorduyn J1, van de Graaf VA2, Mokkink LB3, Willigenburg NW2, Poolman RW2
1OLVG, Physical Therapy, Amsterdam, Netherlands, 2OLVG, Orthopaedic Surgery, Amsterdam, Netherlands, 3Vrije Universiteit Amsterdam, Clinical Epidemiology and Biostatistics, Amsterdam, Netherlands
Background: Responsiveness and the minimal important change (MIC) are important measurement properties to evaluate treatment effects and to interpret clinical trial results. The International Knee Documentation Committee Subjective Knee Form (IKDC) is a reliable and valid instrument to measure patient reported knee specific symptoms, functioning and sports activities in a population with meniscal tears. However, evidence on responsiveness is of limited methodological quality and the MIC has not yet been established in patients with symptomatic meniscal tears.
Purpose: This study aims to evaluate the responsiveness and determine the MIC of the IKDC in patients with meniscal tears.
Methods: This study was part of the ESCAPE trial, a non-inferiority multi-center randomized controlled trial comparing APM with PT. Patients between the age of 45 and 70 years who were treated for a meniscal tear by APM or PT completed the IKDC and three other questionnaires (Rand-36, EuroQol 5 dimensions 5 Level Survey and visual analogue scales for pain), at baseline and at six months follow-up. Responsiveness was evaluated by testing predefined hypotheses related to the relation the change in IKDC with regard to the change in the other self-reported outcomes. An external anchor question was used to distinguish between patients that reported improvement versus no change in daily functioning. The MIC was determined by the optimal cut-off point in the receiver operating characteristic curve, which quantifies the IKDC score that best discriminated between patients with and without improvement in daily function.
Results: Data from all 298 patients who completed baseline and six months follow up questionnaires were analyzed. Responsiveness of the IKDC was confirmed in seven out of ten predefined hypotheses related to the change in IKDC score with regard to other patient reported outcome measures. One hypothesis differed in expected direction, while two hypotheses failed to meet the expected magnitude (by 0.02 and 0.01 points, respectively). An MIC of 10.9 points was calculated for the IKDC in middle aged and older patients with a meniscal tear.
Conclusion(s): This study showed that the IKDC is responsive to change in middle aged and older patients with a meniscal tear, with an MIC of 10.9 points. This strengthens the value of the IKDC to quantify treatment effects in this population.
Implications: Since primary treatment in this population is currently shifting from surgically to conservative treatment, we advise all physical therapists to use the IKDC for the evaluation of the treatment effect.
Keywords: Meniscus, IKDC, clinimetrics
Funding acknowledgements: The Netherlands Organization for Health Research and Development (ZonMw)
Zilverenkruis Health Insurance
OLVG research foundation
Purpose: This study aims to evaluate the responsiveness and determine the MIC of the IKDC in patients with meniscal tears.
Methods: This study was part of the ESCAPE trial, a non-inferiority multi-center randomized controlled trial comparing APM with PT. Patients between the age of 45 and 70 years who were treated for a meniscal tear by APM or PT completed the IKDC and three other questionnaires (Rand-36, EuroQol 5 dimensions 5 Level Survey and visual analogue scales for pain), at baseline and at six months follow-up. Responsiveness was evaluated by testing predefined hypotheses related to the relation the change in IKDC with regard to the change in the other self-reported outcomes. An external anchor question was used to distinguish between patients that reported improvement versus no change in daily functioning. The MIC was determined by the optimal cut-off point in the receiver operating characteristic curve, which quantifies the IKDC score that best discriminated between patients with and without improvement in daily function.
Results: Data from all 298 patients who completed baseline and six months follow up questionnaires were analyzed. Responsiveness of the IKDC was confirmed in seven out of ten predefined hypotheses related to the change in IKDC score with regard to other patient reported outcome measures. One hypothesis differed in expected direction, while two hypotheses failed to meet the expected magnitude (by 0.02 and 0.01 points, respectively). An MIC of 10.9 points was calculated for the IKDC in middle aged and older patients with a meniscal tear.
Conclusion(s): This study showed that the IKDC is responsive to change in middle aged and older patients with a meniscal tear, with an MIC of 10.9 points. This strengthens the value of the IKDC to quantify treatment effects in this population.
Implications: Since primary treatment in this population is currently shifting from surgically to conservative treatment, we advise all physical therapists to use the IKDC for the evaluation of the treatment effect.
Keywords: Meniscus, IKDC, clinimetrics
Funding acknowledgements: The Netherlands Organization for Health Research and Development (ZonMw)
Zilverenkruis Health Insurance
OLVG research foundation
Topic: Orthopaedics; Musculoskeletal: lower limb; Outcome measurement
Ethics approval required: Yes
Institution: MEC-U
Ethics committee: MEC-U
Ethics number: NL 4418810013
All authors, affiliations and abstracts have been published as submitted.
