Validation of Comprehensive International Classification of Functioning

INTRODUCTION

Osteoarthritis or Degenerative Arthritis is the most common non inflammatory degenerative joint disease. Osteoarthritis occurs more frequently in old age targeting both the gender and commonly including post menopausal women. It commonly affects weight bearing joints such as knee and hip, where knee joint is mostly affected in India due to cultural and other practices such as sitting on the ground, kneeling, cross-legged sitting, squatting etc. (Jayanth Joshi, Parakashkotwal). In Particular, rural population are more prone to such condition because of activities involving increased physical stress such as toileting in Indian restroom, cross legged sitting during eating and heavy manual labour works whereas urban population are less prone because of involvement of technology which replaces and lessens manual load. As aging occurs, cartilage begins to degenerate by flaking or forming tiny crevasses. In advanced osteoarthritis, there is a total loss of the cartilage cushion between the bones of the joints. Repetitive use of the worn joints over the years can mechanically irritate and inflame the cartilage, causing joint pain, stiffness and swelling. Osteoarthritis is classified into 2 major groups on the basis of cause as primary osteoarthritis and secondary osteoarthritis. Primary osteoarthritis is the most commonly diagnosed form of OA. It is considered largely due to “wear and tear” overtime. Age from 50-60 is the most potent risk factor and the longer a person uses their joints are more likely to suffer from this form of OA. Secondary osteoarthritis results from the conditions like significant trauma, congenital joint abnormalities, metabolic defects, diseases and disorders that alter normal function and structure of cartilage. Age groups of 45-50 are more likely to be affected. Risk factors like trauma, sedentary lifestyle, joint overuse, heredity leads to this type of osteoarthritis. However the intensity of osteoarthritis symptoms will vary from each individual, they typically become more severe, more frequent, and more debilitating over time.

In osteoarthritis, pain is the primary symptom which is gradual in onset and aggravates with activity and after prolonged sitting or standing, weight bearing activities. Later on, it becomes continuous even at rest. The joint becomes swollen due to synovitis and stiffness gradually sets in following severe pain. These makes the movement painful and restricted, where crepitus is felt on moving the joint passively. There may be some flexion deformity and advanced cases present with genu varum deformity ie. Bow legedness (Hunter Hsu et al,2018). Treatment for osteoarthritis can be done as non surgical and surgical management. Non surgical treatment options include physiotherapy interventions, life style modifications, weight loss, knee bracing and supportive devices, pharmacological support like NSAIDs and corticosteroids. surgical management include osteotomy, unicompartmental knee arthroplasty and total knee arthroplasty (Hunter Hsu et al,2018) Physiotherapy interventions include exercise therapy for strengthening surrounding structures, electrotherapy modalities for pain relief, thermotherapy, cryotherapy, supportive devices like braces, taping to improve the patients functional ability and quality of life (Riann M.Palmeiri et al 2010)

Important aspect in a treatment planning is not only diagnosis of the condition but also, assessing the level of disability and functioning capacity. Studies have shown that diagnosis alone does not predict service needs, length of hospitalization, level of care or functional outcomes. Although there are many questionnaires to assess functioning of an individual with osteoarthritis, it is seen that Western Ontario and McMaster universities osteoarthritis index (WOMAC) is commonly used in an clinical set up with good validity and reliability.

The Western Ontario and McMaster Universities osteoarthritis index is commonly used for assessing patients with osteoarthritis which includes five questions about pain, two about stiffness and seventeen about the level of disability in performing the ADL (Mohammad H Ebrahimzadeh et al.,2015).The scores for each subscale range from 0-20 for pain, 0-8 for stiffness, 0-68 for physical function. The sum of all sub scores gives a total WOMAC score. Higher score indicates severe the condition ie. increased pain, stiffness and functional limitation (WOMAC index,2013).

World Health Organization developed the International Classification of Functioning, disability and health which is a multipurpose classification that helps in organizing information on functioning and disability providing fine details of health and its related states (WHO geneva 2002). ICF provides a list of activities and participation which is similar to activities of daily life. It is useful to the person with all form of disability, not only for identifying their healthcare and rehabilitative needs but also in identifying and measuring the level of disability and the effect of physical, social environment that they experience in their daily life. The individuals functioning assessed through ICF is the outcome of interaction between body functions, body structures , activity and participation and environmental factors. Changes in one component may influence other components.

Even though International Classification of Diseases (ICD-10) is most widely used classification, there is a growing interest in the use of ICF particularly with regard to disability. Defining and measuring disability is difficult because it involves many aspect of life and interaction between people and his/her environment. Considering this WHO started a project on assessment and classification of Functioning, Disability and health by representatives from more than 100 countries, researchers and consumers in an international collaboration, to produce ICF as a universal framework (WHODAS 2.0). Although ICF contains extensive classification of individuals functioning, which helps in diagnosing a health condition by applying ICF before its been diagnosed clinically , the same appears to be a limitation as it is time consuming and tedious to be used in daily clinical practice(Sven Bolte et al., 2014). Both quantitative and qualitative data can be organized through ICF.

PROCEDURE

Sample collection: Data were collected using comprehensive international classification of functioning, disability and health (ICF) core set for OA and WOMAC from subjects diagnosed with knee osteoarthritis, above 50 years irrespective of gender from saveetha medical college and hospital and from surrounding communities. A total of 145 subjects diagnosed with knee osteoarthritis were included in the study after fulfilling the inclusion criteria of subject with age group 50 and above including both the gender and who were able to comprehend and read tamil, at the same time subjects who underwent surgeries for osteoarthritis were excluded. All subjects were explained about the study and informed consent were obtained.

Content validity: content validity of comprehensive ICF core set was evaluated by experts opinion. The questions were framed for every component in comprehensive ICF core set for OA. Whereas some components from the domain body structure were evaluated by observation of structures. In activity and participation domain, every component has to be assessed in two ways obtaining two qualifiers namely performance qualifier and capacity qualifier. Hence, two questions were framed for every component.

The self made questionnaire was submitted to three experts from physiotherapy department, physician and biostatistician and were kindly requested to validate the tool checking for relevance, clarity, simplicity and ambiguity. After getting their opinion corrections were made and validity was obtained.

Data collection: As the target comprise of rural population predominantly, the tool was translated to the regional language (Tamil) with the help of the expert. Data collection was done from subjects using translated self made questionnaire of comprehensive ICF core set for OA by interviewing method after assessing WOMAC with the same population. Demographics and basic health information were assessed according to the ICF format. Also certain components namely body structures were evaluated by observational method. The level of impairment for ICF categories in the Comprehensive ICF Core Set for OA was rated with the ICF qualifier (where 0 = no problem, 1 = mild problem, 2 = moderate problem, 3 = severe problem, and 4 = complete problem). For the environmental factors, the extent to which the category is a barrier or facilitator was quantified on a scale ranging from −4 to +4, with negative values indicating the extent to which it is a barrier and positive values indicating the extent to which the category is a facilitator. The qualifier 8 and qualifier 9 was applied when the available information was not sufficient to mark the severity and when the given component is not applicable to the subject.

4. Data analysis: The collected data from comprehensive ICF core set were analyzed by correlating the outcomes with that of WOMAC. Two correlations were done between ICF body function & body structure with WOMAC pain & stiffness and ICF participation with WOMAC activity. Pearson’s correlation method was used for statistical analysis.

RESULTS AND DISCUSSION: The collected data was tabulated and analyzed using descriptive & inferential statistics. To all parameters mean and standard deviation (SD) was used. Pearson’s correlation was used to analyze and correlate different variables.