Stability (test-retest) reliability, concurrent, convergent and divergent validity of the Igbo version of participation scale (I-Pscale) among people living with Hansen’s disease in South-east Nigeria
Objective: The Participation Scale is a researcher administered generic outcome instrument developed to measure participation restrictions. It addresses the ICF domains of community, social and civic life, mobility, major life domains, domestic life, learning and applying knowledge, self-care, and social interactions. It is designed as a generic, client-reported, and cross-culturally relevant measure of participation that is suitable for non-professional interviewers. The aim of this study was to determine the construct (convergent and divergent) validity, criterion (concurrent) validity, and stability (test-retest) reliability of the Igbo version of P-scale in order to enhance its use in the Igbo speaking population. Design: This cross sectional survey involved 60 participants (39 males and 21 females) affected by Hansen’s disease in South-Eastern region of Nigeria, with mean age of 49·8 ^ 12·8 years. Test-retest reliability was analysed with intraclass correlation coefﬁcient (ICC) and the Bland and Altman method. Construct validity and Criterion validity was investigated with the Spearman rank correlation coefﬁcient. Mann-Whitney U test was used to compare the difference between the sum score of the I-Pscale (Igbo version) and E-Pscale (English version). Result: Test-retest reliability was high (ICC ¼ 0·98–0·99; P¼0·001). There was a signiﬁcant correlation (r¼0·99; P¼0·001) between the scores obtained on English and Igbo versions of P-scale indicating good concurrent validity. There was no signiﬁcant difference between the sums of the Igbo and English versions of the P-scale score (U¼1799·00; P¼0·99), suggesting excellent concurrent validity. There was also a signiﬁcant correlation between the scores of the IP-scale and the Keele Assessment of Participation scores (r¼0·806; P¼0·001). A signiﬁcant correlation was also found between the IP-scale score and Falls Efﬁcacy Scale score (r¼ 0·290; P¼ 0·024) signifying a poor divergent validity. Alpha level was set at 0·05. Conclusion: The Igbo version of the P-scale is a valid and reliable outcome measure for those affected by Hansen’s disease in South-Eastern, Nigeria.