Quality of life in individuals with knee osteoarthritis versus asymptomatic individuals.

Background: Osteoarthritis (OA) is characterised by joint degeneration and represents the leading cause of disability in old age. OA entails a personal burden, with suffering and reduced quality of life (QoL).

Objective: To compare the QoL of individuals with OA to that of asymptomatic individuals in order to determine the actual impact of OA on the affected population.

Method: Cross-sectional study with a sample of 140 patients diagnosed with OA. Another 51 sex- and age-matched asymptomatic individuals with no clinical signs of knee OA or lower limb osteoarticular symptoms for at least the preceding six months were recruited. Knee OA was stratified radiologically according to the Ahlbäck classification (1968). QoL was measured using the SF-36 questionnaire (Medical Outcomes Study 36-Item Short-Form Health Survey). The participants were assigned to "osteoarthritis" (OG) or "asymptomatic" (AG) groups.

Results: The OG presented greater body mass and BMI than the AG. Perceived QoL was worse for the OG than the AG across SF-36 domains. In the comparison of the grades of OA degeneration, the group with Ahlbäck grades 4 and 5 (severe) perceived their QoL as poorer than those with grades 1, 2, and 3 (moderate). The grade of OA, older age, and BMI were shown to be strong independent predictors of poor perceived quality of life.

Conclusion: Individuals with knee OA showed worse perceived QoL compared with asymptomatic individuals. The domains with the lowest scores were physical functioning and functional limitation. Quality of life was influenced by BMI, age, sex, and grade of osteoarthritis.