Factor Structure of the Pittsburgh Sleep Quality Index among Women Undergoing Infertility Treatment: A Confirmatory Factor Analysis

People that undergo assisted infertility treatments experience more sleep problems. Alt-hough Pittsburgh Sleep Quality Index (PSQI) frequently has been used as a sleep quality assessment scale in different clinical and non-clinical settings, different sample characteristics may account for different structures. The current study aimed to evaluate the factor structure of PSQI among women seeking infertility treatment in Iran

Using a convenience sampling method, 157 infertile women or women whose husbands had infertility problems were included in a cross-sectional study in Royan Institute, a main referral infertility center in Teh-ran, Iran. The factor structure of PSQI was evaluated through exploratory factor analysis (EFA) and confirmatory factor analysis (CFA).

The Cronbach’s alpha coefficient for PSQI was 0.65. A two-factor model was extracted by EFA; 56% of the total variance was accounted for by this model. The results of CFA indicated that extracted model obtained acceptable fit statistics [comparative fit index (CFI) = 0.942, standardized root mean square residual (SRMR) = 0.042, root mean square error of approximation (RMSEA) = 0.128, χ2 = 19.8, degree of freedom (df) = 12, P = 0.071] compared to other original single-factor or 3-factor models.

Our results revealed the limited usefulness of single-factor structure of PSQI. A two-factor model of Per-sian version of PSQI should be used to assess sleep problems among women seeking assisted infertility treatments.