Measurement of Perceived Stress Among Pregnant Women: A Comparison of Two Different Instruments

Assess the amount of agreement between the classification of stress from the Perceived Stress Scale (PSS) and the Assessment of Stress portion of the Prenatal Psychosocial Profile (PPP) among pregnant women. A secondary data analysis on a cross-sectional study of 301 pregnant women from the New Orleans and Baton Rouge areas who were exposed to Hurricane Katrina was conducted. Women with complete data (219) were analyzed. Women scoring in the third tertile of each instrument were compared. The kappa statistic was used to assess agreement between instruments. Additional comparisons were made with three instruments that measure other important psychosocial constructs that could be related to stress: the Edinburgh Depression Scale (EDS) and the Assessments of Support (partner and other support) and Self-Esteem from the PPP. No significant difference was found between the two tests. The PSS and the PPP were both statistically significantly correlated to each other (ρ = 0.71, p < 0.01). Thirty-five women were classified discordantly resulting in a Kappa Coefficient of 0.61 (95% CI 0.50-0.72, p < 0.01). No significant differences were found between these two instruments in correlation with the EDS (PPP, r = 0.76; PSS, r = 0.72; p < 0.01 for each), partner support (PPP, r = -0.47; PSS r = -0.46; p < 0.01 for each), other support (PPP, r = -0.31; PSS r = -0.32; p < 0.01 for each) and self-esteem (PPP, r = -0.41; PSS, r = -0.52; p < 0.01 for each), respectively. Given the similarities between the PSS and PPP, researchers are encouraged to choose and administer one instrument to participants, or to use the instruments in combination as an external reliability check.