Comprehensive Knee Osteoarthritis Index (CKOAI): Scale Development, Validation and Reliability Testing
Condition: Osteo Arthritis Knee
MeSH terms: Osteoarthritis; Osteoarthritis, Knee
Study type: Interventional

Summary: 
      Background:

      Symptoms, balance, mobility, activities of daily life (ADL) and quality of life (QoL) are to
      be considered in rehabilitation of the individuals with knee osteoarthritis (IKOA). There are
      several scales to evaluate subjective perceptions and individual components in patients with
      osteoarthritis (OA). Till date, no scale is available to measure the combined balance,
      mobility, ADL and QoL in PKOA.

      Objectives:

      The objectives of the study are to develop a combined measure of symptoms, balance, mobility,
      ADL and QoL in PKOA, as comprehensive knee osteoarthritis index (CKOAI) and to validate the
      scale for its content, reliability and minimum detectable change (MDC)

      Methods:

      The study consists of a three stages. First stage is the scale (CKOI) item development and
      validation. This includes domain and item generating through systematic literature search to
      extract items related symptoms, balance, mobility, ADL and QoL in IKOA based on the
      International Classification of Functioning, Disability and Health (ICF) and through
      structured interviews. During scale validation, an expert panel will review the generated
      domains and items by Delphi Method, which will undergo revision and pilot testing. Based on
      the responsiveness of pilot testing will be revised finally. Second stage is to test re-test
      reliability. The third stage is to report the standard error of measurement (SEM) and minimal
      detectable change (MDC).

      Data analysis:

      All the domains and items in CKOAI will undergo reliability and criterion-related validity.
      Minimum 50 IKOA will be evaluated with the scale on two occasions within two weeks to
      establish test retest reliability. Cronbach's alpha for internal consistency and Intra class
      correlation coefficient for test retest reliability will be used to determine the degree of
      consistency of items in the scale. MDC will be calculated using the formulae, SEM = SD x √
      (1-reliability) and MDC95 = √2 x (1.9) x (SEM). Significant level will be set at p value less
      than 0.05 (p < 0.05) to minimize the type-I error.
    

Detailed description: 
      Introduction:

      One of the worldwide leading causes of disability and pain is osteoarthritis. 22% to 39% of
      1.252 billion population suffer from osteoarthritis (OA). Hip and knee OA are the most
      prevalent forms of OA with the overall prevalence of knee OA is 28.7%. This will increase by
      33.5% in 2030 due to alarming increase in aging population. Individuals with knee OA (IKOA)
      are seen with deficits in static and dynamic balance which comprises of impaired
      proprioception, muscle strength, disturbed postural control and decreased range of motion at
      knee joint. Furthermore, IKOA have pain and increase physical limitation and functional
      limitation. Eventually decreasing their quality of life (QoL).

      Static balance in IKOA are assessed using several outcome measures such as, timed single-leg
      stance, functional reach test and variation of postural sway in unipedal or bipedal stance.
      More than two decade, Berg Balance Scale and Tinetti Performance-Oriented Mobility Assessment
      (balance subscale) were used to asses dynamic balance. Recently, Community Balance and
      Mobility Scale (CB&M) have been validated for the purpose. Isokinetic dynamometer has been in
      use for the purpose of estimating muscle strength. Proprioception was measured by joint
      repositioning test. Several researchers explored QoL in IKOA,and combined with functional
      independence.

      Various measures of knee function adopted by International Knee Documentation Committee
      (IKDC) are subjective in nature. Patient reported problem based rating scale in IKOA with
      objective scoring is still lacking. There, the purpose of this research project is to develop
      a rating scale which does combine assessment of balance, mobility, ADL and QoL in IKOA.

      Statement of the Problem:

      The existing scales could not provide comprehensive assessment for balance, mobility, ADL and
      QoL in IKOA. Hence, there is a need to develop an objective scale to measure the above
      domains in IKOA

      Purpose of the study:

      The purpose of the study is to develop an objective combined assessment of symptoms, balance,
      mobility, ADL and QoL in IKOA (CKOAI) using systematic approach.

      Objectives of the study:

        1. To develop scale items and domains of CKOAI

        2. To validate the developed scale for content validity

        3. To estimate reliability of CKOAI

        4. To report SEM and MDC

      Procedure:

      The study will be of cross-sectional observational study of scale validation. The study
      protocol was approved by the Institutional Ethics Committee of Maharishi Markandeshwar
      (Deemed-to-be) University (MMU/IEC/1021) on 8.12.2017. The study will consists of three major
      phases, comprising of item and domain generation, validation, reliability testing and
      estimating MDC.

      Phase 1: Scale Development

      Sub-Phase 1:Domain and item development:

        1. Domain and item generating:

           using literature search and direct patient interviews.

           - Literature search: English language literature will be searched in databases.

           - Direct interview

        2. Grouping item in domain Sub-phase 2: Content Validation

             -  Using Delphi Method Sub-phase 3: First draft and scoring criteria Sub-phase 4:
                Pilot test Sub-phase 5: Revision Sub-phase 6: Final draft

      Phase 2: Reliability testing

        1. Check for internal consistency

        2. Intra-rater reliability

        3. Test-retest reliability

      Phase 3: Estimating SEM and MDC

      MDC will be calculated using the formulae, SEM = SD x √ (1-reliability) and MDC95 = √2 x
      (1.9) x (SEM). Significant level will be set at p≤ 0.05 to minimize the type-I error. For
      MCID, responsiveness of the scale will be determined on two occasions after regular
      conventional physiotherapy treatment of two week duration.
    

Intervention name(s): Test-retest reliability testing
Intervention type(s): Other
Intervention description(s): Set of patient reported outcome measures
Intervention model: Single Group Assignment
Intervention model description: All the domains and items in CKOAI will undergo reliability testing. Minimum 50 IKOA will be evaluated with the scale on two occasions within two weeks to establish test retest reliability. Cronbach's alpha for internal consistency and Intra class correlation coefficient for test retest reliability will be used to determine the degree of consistency of items in the scale. MDC will be calculated using the formulae, SEM = SD x √ (1-reliability) and MDC95 = √2 x (1.9) x (SEM). Significant level will be set at p value less than 0.05 (p < 0.05) to minimize the type-I error.
Masking: None (Open Label)
Primary purpose: Other
Keywords: domains; item development; osteoarthritis; scale formulation; test retest reliability