Construct validity and factor structure of the Pittsburgh Sleep Quality Index among pregnant women in a Pacific-Northwest cohort

Abstract

Purpose Poor sleep quality during pregnancy is associated with adverse obstetric and neuropsychiatric outcomes. Despite its routine use as a sleep quality assessment scale among men and non-pregnant women, the psychometric properties of the Pittsburgh Sleep Quality Index (PSQI) have not been assessed among US pregnant women. We sought to evaluate the construct validity and factor structure of the PSQI among 1,488 pregnant women. Methods A structured interview was used to collect information about demographics and sleep characteristics in early pregnancy. The Patient Health Questionnaire-9 (PHQ-9) and the Depression, Anxiety, and Stress Scale-21 (DASS-21) were used to assess symptoms of depression, anxiety and stress. Consistency indices, exploratory and confirmatory factor analyses (EFA and CFA), correlations, and logistic regression procedures were used. Results The reliability coefficient, Cronbach’s alpha for the PSQI items was 0.74. Results of the EFA showed that a rotated factor solution for the PSQI contained two factors with eigenvalues >1.0 accounting for 52.8% of the variance. The PSQI was significantly positively correlated with the PHQ-9 (rs=0.48) and DASS-21 (rs=0.42) total scores. Poor sleepers (PSQI global score>5) had increased odds of experiencing depression (OR=6.47; 95%CI: 4.56–9.18), anxiety (OR=3.59; 95%CI: 2.45–5.26) and stress (OR=4.37; 95%CI: 2.88–6.65) demonstrating evidence of good construct validity. CFA results corroborated the two-factor structure finding from the EFA; and yielded reassuring measures indicating goodness of fit (comparative fit index=0.975) and accuracy (root mean square error of approximation=0.035). Conclusions The PSQI has good construct validity and reliability for assessing sleep quality among pregnant women.

Determinants of sleep quality among pregnant women in China: A cross-sectional survey

“…A relationship between prenatal depression and sleep quality in pregnant women has previously been demonstrated, showing that higher levels of prenatal depression predicted poorer sleep quality, as depression is one of the main psychological factors contributing to sleep complaints [7,14,34,35]. The association between poor sleep quality and depressed mood has also been shown in epidemiologic studies of sleep in the general population [36], and with postpartum women [37,38].…”

Preoperative sleep quality predicts postoperative pain after planned caesarean delivery

“…In obstetric cohorts, PSQI was both reliable and accurate (Qiu et al., ), and with good internal consistency (Cronbach's α = 0.73; Skouteris et al., ). In a study comparing sleep quality during second versus third trimester pregnancy, the internal consistency of the PSQI was supported with a Cronbach's α of 0.73 (Ko et al., ).…”

Evaluation of sleep quality in adolescent patients with osteosarcoma using Pittsburgh Sleep Quality Index

“…Since PSQI may be comprised of multiple dimensions, a good understanding of its factor structure in patients with OS can benefit further clinical application. The best factor structure of PSQI varies among previous studies (Koh, Lim, Chia, & Lim, ; Qiu et al, ; Raniti, Waloszek, Schwartz, Allen, & Trinder, ; de la Vega et al, ), probably due to divergent diagnosis of the subjects, inconsistent statistical methodology and different country of origin. Many studies supported a two‐factor solution, which can be more representative of the PSQI's scale structure than other models (Guo et al, ; Qiu et al, ).…”

“…The best factor structure of PSQI varies among previous studies (Koh, Lim, Chia, & Lim, ; Qiu et al, ; Raniti, Waloszek, Schwartz, Allen, & Trinder, ; de la Vega et al, ), probably due to divergent diagnosis of the subjects, inconsistent statistical methodology and different country of origin. Many studies supported a two‐factor solution, which can be more representative of the PSQI's scale structure than other models (Guo et al, ; Qiu et al, ). Guo et al () investigated the factor structure of the PSQI in a cohort of 631 undergraduate students and reported that a two‐factor model could best fit the data.…”