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Criterion-oriented validity: correlation with other scales

In fact, the comparison with other scales of similar purpose is important.
Health related quality of life should be validated against quality of life measured with other generic QoL scales (e.g., SF36), but also against specific instruments to measure symptoms in aging women (e.g. Kupperman Index).
These data were published elsewhere [ 3 , 11 ].

Kupperman Index
Although the Kupperman index was not validated according to psychometric standards it is still in use in the medical practice to monitor menopausal symptoms.
Therefore a comparison with the fully standardized MRS seems to re reasonable.
If one divides the distribution of both scales into quartiles and compare the frequencies, both instruments were found to be closely associated: Kendall's tau-b coefficient 0.75 (95% CI 0.71-0.80) [ 6 ].

Similar was 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 he 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).
That means, the higher the score in the somatic dimension of the MRS, the lower the quality of life according to the somatic sum-score of the SF36 [ 3 , 11 ].
Similar was the results of the comparison of 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