OBJECTIVES: This study aimed to determine the convergent, divergent and known-group validity of the IKHOAM among patients with knee osteoarthritis (OA).

METHODS: Patients with knee OA participated in this cross-sectional study. Convergent, divergent and known-group validity of the IKHOAM was determined using the Osteoarthritis Knee and Hip Quality of Life Questionnaire (OAKHQoL), Quadruple Visual Analogue Scale (QVAS), and socio-demographic characteristics (age and sex). Data was summarised using descriptive statistics. Inferential statistics of Pearson’s correlation and factor analysis to determine the sampling adequacy, test of sphericity and multi-collinearity of IKHOAM and OAKHoL was carried out.

RESULTS: One hundred and three patients with a mean age of 58.07 years completed the study. There were significant correlations between each of IKHOAM’s activity limitation assistance (r=-0.458 - -0.892), activity limitations difficulty (r = -0.311 - 0.328), activity limitations domains (-0.311 - -0.364) and participation restrictions domain (r=-.364 - -0.367) with each domain of QVAS (p<0.05). There was significant correlation between IKHOAM’s activity limitations difficulty (r=0.398, p=.001), activity limitations domain (r=0.473, p=.001), participation restrictions domain (r=0.420, p=.001), and physical performance domains (r=-0.361, p=.009) with OAKHQoL’s physical activity dimension. There was significant correlation between IKHOAM’s activity limitation assistance (r=-0.202, p=.041), activity limitations difficulty (r=0.441, p=.001), activity limitations domain (r=0.278, p=.005), participation restrictions domain (r=0.238, p=.015), and physical performance domains (r=0.644, p=.001) with OAKHQoL’s mental health dimension. There was significant relationship between IKHOAM’s activity limitation assistance (r=-0.618, p=.001), activity limitations difficulty (r=0.681, p=.001), and activity limitations domain (r=0.223, p=.023) with OAKHQoL’s pain dimension.

CONCLUSIONS: The IKHOAM is a valid and psychometrically sound instrument to measure health-related quality of life in patients with OA. Thus, IKHOAM seems to be useable in other context where the OAKHoL can be utilised as it captures specific attributes of quality of life measured by other tools.