Health-related quality of life (Nottingham Health Profile) in knee osteoarthritis: correlation with clinical variables and self-reported disability

The aims of this study were to assess the health-related quality of life (HRQoL) in patients with knee osteoarthritis (OA) using the Nottingham Health Profile (NHP) and to determine its relationships with conventional clinical measures and self-reported disability. One hundred and forty patients with knee OA (104 female, 36 male, mean age 59.39 ± 7.62 years, mean disease duration 58.56 ± 56.78 months) and 40 sex and age-matched controls were included in the study. HRQoL, disability and pain were assessed using NHP, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Visual Analog Scale (VAS), respectively. Results showed that the six subgroups of the NHP revealed higher scores in the knee OA patients compared with controls (p < 0.001). All subgroups of the NHP significantly correlated to VAS-rest, VAS-activity, 15-m walk test and WOMAC scores (p < 0.05, p < 0.01, p < 0.005, p < 0.001, respectively). The knee flexion or restricted extension range of motion was significantly correlated with the pain, energy and physical mobility subgroups of the NHP (p < 0.05, p < 0.005). Although there were statistically significant correlations between the NHP pain, emotional reaction, and physical mobility subgroup scores and body mass index (BMI) (p < 0.01, p < 0.05, p < 0.05, respectively), there were no correlations between all the NHP scores and duration of disease (p > 0.05). We conclude that patients with knee osteoarthritis undergo a significant impact on multiple dimensions of HRQoL, compared with healthy controls. The NHP is related to the clinical status and functional ability of patients with knee OA, and it can be used as a sensitive health status measure for clinical evaluation.