Correlation among AMS sub-scales
Ideally, the correlations between subscales would approach 0 demonstrating independence as designed in the statistical modeling. Our analysis found a lower correlation among sub-scales (0.4-0.7) than those with the total score (0.7-0.9), suggesting that the subscales are not completely indepdenent.
Criterion-oriented validity: correlation with other scales
The AMS has been successfully validated against generic QoL scales (e.g., SF36) and specific instruments to measure symptoms in aging women3, 11. A summary of these validation studies can be viewed below:
Although the Kupperman index has not been validated according to psychometric standards, it continues to be used in medical practice to assess menopausal symptoms. The Kupperman index and AMS were found to be closely associated with a Kendall’s tau-b coefficient 0.75 (95% CI 0.71-0.80) 6. Similarly, the Pearson correlation coefficient with r= 0.91(95% CI 0.89-0.93; Pearson correlation coefficient r= 0.48 (95% CI 0.58-0.37)).
The two scales can be regarded as measuring the same phenomena. However, some methodological problems of the Kupperman Index were identified in this comparison (see 11 for details).
Generic QoL Scale SF 36
Two sub-scales of the multi-domain quality of life scale SF36 was compared with the MRS: the somatic sum score (with somatic domain of MRS) and the psychologic sub-scales of both instruments. Both somatic domains were sufficiently good and significant associated: Kendall’s tau-b = 0.43 (95% CI 0.52-0.35). A higher score in the somatic dimension of the MRS retranslated to lower quality of life according to the somatic sum-score of the SF36 3, 11. Similar results were seen when comparing the psychological scores of both instruments: Kendall’s tau-b = 0.49 (95% CI 0.56-0.41); Pearson correlation coefficient r= 0.73 (95% CI 0.81-0.65).
3. Schneider HPG, Behre HM. Contemporary evaluation of climacteric complaints: Its impact on quality of life. In: Hormone replacement therapy and quality of life. The Parthenon Publishing Group. (Edited by: Schneider HPG) Boca Raton, London, New York, Washington. 2002: 45-61.
6. Heinemann LAJ, Potthoff P, Schneider HPG. International versions of the Menopause Rating Scale (MRS). Health and Quality of Life Outcomes 2003;1:28 (30 July 2003).
11. Schneider HPG, Heinemann LAJ, Rosemeier HP, Potthoff P, Behre HM. The Menopause Rating Scale (MRS): Comparison with Kupperman Index and Quality of Life Scale SF-36. Climacteric 2000;3:50-58