Is the MRS a valid tool for measuring outcome-based data?
The MRS was assessed as an outcome-measurement tool using data from 9,300 women taking hormone replacement therapy for menopausal symptoms13. The MRS was completed by women before and after 6 months of therapy. Results of the two questionnaires were then critically evaluated to assess whether the scale was able to measure the effect of hormone treatment therapy independent of the severity of complaints.
Overall, improvement of symptoms during treatment was equivalent to 36% of the baseline score, and similar also for all three subscales.
An improvement of complaints/QoL was seen in an increasing degree of severity of symptoms. An improvement of menopausal complaints during/after treatment was observed. The change relative to the baseline score was 36% on average. As can be seen in Figure 1, patients with little/no complaints before therapy improved by 11%, those with mild complaints at entry by 32%, with moderate by 44%, and with severe symptoms by 55% – compared with the baseline score. The scale is sensitive enough to detect even positive treatment effects in women with little complaints – although to a lesser degree.
After treatment MRS values approached normal population values
Results were also compared with MRS values from the ‘normal’ (asymptomatic) population. Not surprisingly, in the asymptomatic population, the percentage of women with no/little symptoms is higher and the percentage of women with severe complaints is relatively low. Women eligible for hormone replacement therapy show the opposite pattern – there is a relatively higher proportion of women with moderate or severe complaints and a lower proportion reporting no/mild menopausal symptoms. After 6 months of hormone treatment, the frequency distribution of severity scores returned towards a similar distribution as the general population. A visual comparison (as in table 1) should be used only to get a crude idea for the interpretation of results because patients usually differ from the general population, a difference hard to adjust for.
Analysis shows MRS effectively measures treatment effects in menopausal women
The MRS scale showed a convincing ability to measure treatment effects on quality of life across the full range of severity of menopausal complaints. The scale was further assessed to see if it predicts the subjective, clinical impression/opinion of the treating physician. At an individual level, the treating gynecologists and MRS scale assessment were comparable i.e. when a simple dichotomous treatment-effect (successful/not successful) was used, results from the gynecologist and MRS aligned (Table 2). The sensitivity (correct prediction of a positive assessment by the physician) was 70.8% and specificity (correct prediction of a negative assessment by the physician) 73.5%. However, both sensitivity & specificity might be over-estimated as it is hard to estimate to which degree “clinical judgment” and “MRS assessment were really independent.
The attached poster presented in 2005 at the Congress of the International Society of Pharamacoepidemiology (Nashville, USA) provides additional details.
Subsequent studies confirm applicability of MRS
A follow-up study of 3,282 women with pre- and post-treatment data was published 2006 17. In this study, the MRS was a self-administered questionnaire. Results were consistent with previously published work, however, the relative improvement after therapy was lower across all domains. Although one cannot exclude different treatment effects with the study method used, it is likely that the individual MRS interviews performed by the physician biased results towards over-estimation of the treatment effects.
Although the follow-up study confirmed evidence for the capacity of the MRS scale to measure treatment effects on quality of life across the full range of severity of complaints before treatment, the authors concluded that the MRS scale should be used as self-administered instrument in clinical studies to avoid overestimation of treatment effects.
13. Heinemann LAJ, DoMinh T, Strehlow F, Gerbsch S, Schnitker J, Schneider HPG. Validity of the Menopause Rating Scale as outcome measure. A clinical outcome study. Health and Quality of Life Outcomes 2004;2:45 (2 September 2004). www.hqlo.com/content/2/1/67
17. Dinger J, Zimmermann T, Heinemann LAJ, Stoehr D. Quality of life and hormone use: new validation results of MRS scale. Health and Quality of Life Outcomes, 2006;4:32. www.hqlo.com/content/4/1/32.