Cross-cultural adaptation and validation of the Pittsburgh Sleep Quality Index (PSQI) in the Igbo language

Sleep disturbances are associated with decreased quality of life, increased use of healthcare resources, and poor mood. The Pittsburgh Sleep Quality Index (PSQI) is a standardised questionnaire that was created to help measure sleep quality and to alert medical professionals to the need for additional evaluation of patients exhibiting sleep-related complaints in seven domains based on the previous month. The non-availability of the Igbo version can affect its effective use among Igbo speakers in Southeast Nigeria. To translate and cross-culturally adapt the PSQI scale to the Igbo Culture and Environment among Igbo language speakers in Southeast Nigeria using established guidelines. The PSQI was translated, combined, back-translated, and reviewed by an expert panel, leading to the development of the final Igbo version (I-PSQI). A sample size of 100 was calculated using G-power, and the PSQI and I-PSQI were distributed to 100 apparently healthy adults (40% males and 60% females) recruited conveniently in Otolo Nnewi, Nigeria. The data were analysed using frequency counts, percentages, means, standard deviations, Spearman rank order tests, Cronbach’s alpha, and principal component analysis (PCA). The level of significance was set at 0.05. There was no statistically significant difference observed between the PSQI and I-PSQI scores (p < 0.001). The correlations between the corresponding domains and total scores on both versions of the PSQI were excellent (ρ = 0.86–1.0). The Cronbach’s alpha value of the I-PSQI was 0.7, indicating acceptable internal consistency between the items on the I-PSQI. The I-PSQI proved to be a valid and reliable instrument, making it suitable for assessing sleep quality among Igbo language speakers.