Validation of the nausea and vomiting of pregnancy specific health related quality of life questionnaire

BACKGROUND: The only existing NVP-specific quality of life (QOL) questionnaire is the "Health-Related Quality of Life for Nausea and Vomiting during Pregnancy" (NVPQOL). However, the reliability and validity of the NVPQOL have never been established. In order to justify its usage, the internal consistency and criterion validity of the NVPQOL questionnaire must be ascertained. METHODS: A prospective observational study including pregnant women attending CHU Sainte-Justine or René-Laennec clinics for their prenatal care was conducted from 2004 to 2006. Women were eligible if they were > or = 18 years of age and < or = 16 weeks of gestation at the time of their first prenatal visit. During this initial visit, women who reported NVP were also asked to complete the NVPQOL and the SF-12. Cronbach's alpha coefficients were calculated as the measures of the internal consistency of the NVPQOL. With respect to the criterion validity, linear regression models were built to measure the association between the NVPQOL and the SF-12 scores. RESULTS: Of the 367 women included in the study, 288 (78.5%) reported NVP in the first trimester of pregnancy. Among these women, the Cronbach's alpha coefficients were high for the complete NVPQOL questionnaire (alpha = 0.98), and for the four distinct domains physical symptoms and aggravating factors (alpha = 0.90); fatigue (alpha = 0.94); emotions (alpha = 0.86); limitations (alpha = 0.97). NVP-specific QOL as measured by the NVPQOL was significantly associated with physical and mental QOL as measured by the SF-12. CONCLUSION: Our data suggest that the NVPQOL is a reliable and valid index to measure NVP-specific QOL in the first trimester of pregnancy.