Validation of the uncertainty stress scale-high-risk pregnancy - Chinese brief version: Rasch analysis

High-risk pregnancy leads to uncertainty and stress in pregnant women due to the threatened of mother and fetus health. The Uncertainty Stress Scale High-Risk Pregnancy Version, a 54-item Chinese version (USS-HRPV-C), has been widely used to assess the uncertainty and stress that women experience during pregnancy. However, the length of the scale may result in a burden for respondents. Thus, a brief version of the USS-HRPV-C is needed for a concise and vigorous assessment. The aim of this study was to shorten the USS-HRPV-C and validate the brief version.

This study used a cross-sectional design. A convenience sample of 200 women with high-risk pregnancies completed the 54-item USS-HRPV- C. Confirmatory factor analysis (CFA) and Rasch model to examine the construct validity of the short version of the USS-HRPV-C. Rasch analysis was used with a stepwise approach to select items with better goodness-of-fit and no differential item functioning (DIF). Additionally, Cronbachs' α and Pearson correlations to evaluate the internal consistency of the original and brief versions. Test analysis modules (TAM) and Lavaan packages in R were used for data analyses.

The results of CFA supported a two-factor structure of the HRPV-C. Using the Rasch analysis, we reduced the USS-HRPV-C scale from 54 to 17 items. The selected 17 items were robust without displaying differential item functioning. Further, the 17-item short version exhibited satisfactory fit statistics that infit and outfit mean square ranged between 0.71 and 1.35, respectively. Internal consistency of Cronbach's α for the short version of the USS-HRPV-C scale ranged was 0.90 and 0.92 for the subscales of uncertainty and stress respectively. Both subscales of the brief version were significantly related to the original version of USS-HRPV-C.

This study developed a 17-item brief version of the USS-HRPV-C scale, which has demonstrated its satisfactory psychometric properties. Healthcare providers can use the validated brief version of the USS-HRPV-C to proficiently assess women's psychosocial stress and uncertainty during pregnancy.