Evaluation of EQ-5D-5L and WOMAC Instruments in Assessing Health-Related Quality of Life Among Women Over 40 with Knee Osteoarthritis and Obesity

Technical Summary: Evaluation of EQ-5D-5L and WOMAC Instruments in Assessing Health-Related Quality of Life Among Women Over 40 with Knee Osteoarthritis and Obesity

Problem Statement
Knee osteoarthritis (KOA) represents a significant global musculoskeletal burden, affecting approximately 528 million individuals, with a disproportionate impact on women (60% of cases) and those over 55. In India, the condition is particularly prevalent in metropolitan areas, where sedentary lifestyles contribute to reduced Health-Related Quality of Life (HRQoL). While obesity is a known comorbidity, there is a paucity of research specifically examining the interplay between KOA, obesity, and HRQoL among women in the Indian context. This study addresses the need to characterize the relationship between HRQoL, Body Mass Index (BMI), and KOA severity in women over 40 in Chennai, aligning with Sustainable Development Goals (SDG) 3 (Good Health and Well-being) and 5 (Gender Equality).

Methodology
The study employed a cross-sectional design conducted between September 2025 and January 2026 at a tertiary care hospital in urban Chennai, India.

• Participants: The initial screening involved 121 patients, from which 62 women met the inclusion criteria: age >40 years, physician-diagnosed KOA, and a BMI >18.5 kg/m². Exclusion criteria included age <41, other types of osteoarthritis, psychiatric disorders, and bilateral total knee replacement.
• Instruments: Three tools were utilized:
  1. General Information Questionnaire (GIQ): Collected sociodemographic data (age, marital status, education, occupation, income) and clinical details (duration of disease, comorbidities, affected joints). BMI was categorized using Asia-specific cut-offs (Normal, Overweight, Obesity Class I, Obesity Class II).
  2. EQ-5D-5L: A generic HRQoL instrument comprising a descriptive system (five dimensions: Mobility, Self-care, Usual activities, Pain/Discomfort, Anxiety/Depression) and a Visual Analog Scale (EQ-VAS) for self-rated health (0–100). The Indian value set was applied.
  3. WOMAC Index: A disease-specific instrument with 24 items across three subscales (Pain, Stiffness, Physical Function). Scores range from 0 to 96, where higher scores indicate worse pain, stiffness, and functional limitations.
• Data Analysis: Descriptive statistics (means, standard deviations, frequencies, percentages) were used. Associations between BMI groups and socio-demographic/clinical factors were analyzed.

Key Results

• Demographics: The mean age of participants was 63.32 ± 10.02 years. The majority were aged 61–80 (59.7%), married (51.6%), unemployed (64.5%), and had unilateral knee involvement (59.7%). The average disease duration was 5–10 years.
• WOMAC Scores: The total mean WOMAC score was 65.4 ± 10.6 (noted as 67.1 in the discussion section), indicating significant functional impairment. The highest pain scores were observed for "Standing upright" (Mean 3.0), and the highest physical activity limitations were for "Ascending stairs" and "Performing heavy domestic work" (Mean 3.3).
• EQ-5D-5L Scores: The mean descriptive system score was 14.87 ± 3.53, and the EQ-VAS mean was 51.46 ± 9.19, indicating poor self-rated health. Most participants reported "Moderate problems" across all five dimensions, with "No problem" reported by only 0–1.6% of participants.
• Impact of Obesity: A strong correlation was observed between BMI and HRQoL.
  • Normal Weight: 51.2% suffering level (based on WOMAC).
  • Obesity Class II: 76.87% suffering level.
  • Participants in Obesity Class II demonstrated the highest mean WOMAC scores (73.80) and the highest EQ-5D-5L descriptive system scores (16.80), signifying the most severe condition and lowest quality of life.
• Correlations: Higher BMI levels were strongly correlated with higher pain scores (WOMAC) and lower HRQoL scores (EQ-5D-5L).

Key Contributions
The study validates the utility of both generic (EQ-5D-5L) and disease-specific (WOMAC) instruments in assessing the HRQoL of Indian women with KOA and obesity.

1. Instrument Validation: It demonstrates that while WOMAC provides granular detail on osteoarthritis-specific symptoms (pain, stiffness, function), EQ-5D-5L offers a broader assessment of overall health status, capturing the psychosocial impact (anxiety/depression) often missed by disease-specific scales.
2. Obesity-Severity Link: The research quantifies the negative impact of increasing obesity classes on HRQoL, showing a dose-response relationship where Obesity Class II patients experience significantly higher suffering and functional decline compared to normal-weight counterparts.
3. Demographic Insights: It highlights that factors such as age, education, occupation, and the number of household dependents significantly influence the HRQoL of these patients.

Significance and Claims
The authors claim that the study reveals a significant negative impact of multiple variables on the HRQoL of women with KOA. The findings underscore that providing social and clinical support is crucial for improving outcomes in this demographic. The paper modestly concludes that while the instruments are valuable, the study is limited by a small sample size (N=62) and limited data availability. Consequently, the authors recommend further research targeting this specific patient group to better understand the complex interplay between obesity, KOA, and quality of life in the Indian population. The study emphasizes that high physical activity levels and balanced diets are necessary interventions to improve BMI and, subsequently, the quality of life for these patients.