To the Editor
We were interested to read the article authored by Nie et al1 published recently in the journal Menopause. The authors aimed to examine the validity and reliability of the Chinese version of the Menopause-Specific Quality-of-Life (MENQOL) questionnaire among postmenopausal women in China. They concluded that the Chinese version of the MENQOL has good psychometric properties and is appropriate to measure the health-related quality of life of Chinese postmenopausal women. Although the helpful study has been done and the results were interesting, some methodological and statistical questions must be raised.
Principal component analysis (PCA) was used in the present study to explore the factors in the studied questionnaire, and then its results were verified by confirmatory factor analysis (CFA) in the same dataset. This is problematic in validation studies.2 In fact, the results of CFA may be overfitted when PCA and CFA are applied in the same dataset, and the validity of the studied questionnaire can become questionable. To avoid this phenomenon, the developed factors through PCA should be validated by CFA in another dataset.3,4
We anticipate that the MENQOL questionnaire will be useful for subsequent studies which will be conducted in postmenopausal women in China, but retesting the validity of the questionnaire is suggested.