2015 ISAKOS Biennial Congress ePoster #1925

Use of the COSMIN Guidelines in the Development of a Disease-Specific Patellofemoral Instability Outcome Measure

Laurie A. Hiemstra, MD, PhD, FRCSC, Banff, AB CANADA
S. Mark A. Heard, MD, FRCS, Canmore, AB CANADA
Mark Lafave, PhD, Calgary, Alberta CANADA

Banff Sport Medicine, Banff, Alberta, CANADA

FDA Status Not Applicable

Summary: The COSMIN guidelines provided an essential framework for the iterative development of a patient-reported outcome measure for patients with patelofemoral instability.

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Abstract:

Use of the COSMIN Guidelines in the Development of a Disease-specific Patellofemoral Instability Outcome Measure

Background

The COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) initiative was undertaken to provide clinicians and researchers with tools to identify appropriate, high quality health measurement instruments. The development of high quality outcome measures is an iterative process that should be guided by the COSMIN initiative. Research of patellofemoral instability has historically used a variety of knee outcome measures for assessing this unique population. In order to accurately assess this challenging patient cohort, high quality disease-specific outcome measures are essential.

Purpose

The purpose of this study was to develop a disease-specific patient-reported quality of life outcome measure for patellofemoral instability.

Methods

The COSMIN checklist was used to guide the design of this health measurement instrument, as well as to assess the measurement properties of the tool in the three quality domains: validity, reliability, and responsiveness.

Results

The Banff Patella Instability Instrument (BPII) was published in 2013 as a disease-specific, patient-reported outcome measure for patellofemoral instability. The initial validity and reliability of the BPII was established based on completed questionnaires from 150 patients. Initial validity was demonstrated in the form of face and content validity (83.3% agreement). Initial criterion validity was assessed via a concurrent validation with the Kujala score (pearson r = 0.82). In addition, construct validity and responsiveness to change was demonstrated using a one-way analysis of variance in a patellofemoral instability population that proceeded to a stabilization procedure (p < 0.05). The reliability of the BPII was assessed in the areas of internal consistency (Cronbach’s alpha = 0.97) and test-retest reliability (ICC = 0.98). Concurrent validation of the BPII to the Kujala and Norwich Patellar Instability Scores demonstrated statistically significant correlations between the BPII and these patellofemoral assessment tools (p < 0.001). The BPII is the first patellofemoral instability outcome measure to be validated in both the pre- and post-surgical population, and the only instrument to measure overall quality of life in patellofemoral instability patients.

Conclusions

In keeping with the iterative nature of outcome measure development, ongoing validity, reliability and responsiveness testing will be necessary for the BPII to be considered a high quality tool. Testing these important factors identified by the COSMIN initiative is essential across a number of studies, and with new patients, to build greater scientific soundness.

Clinical Relevance:
The COSMIN guidelines provided an essential framework for the iterative development of a patient-reported outcome measure for patients with patellofemoral instability.