Menopause: The Journal of The North American Menopause Society Vol. 21, No. 8, pp. 792/793 DOI: 10.1097/gme.0000000000000288 * 2014 by The North American Menopause Society
EDITORIAL Assessing menopause-specific quality of life in studies of the menopausal transition and early postmenopause n this issue of Menopause, Bushmakin et al1 advance the measurement of menopause-specific quality of life by confirming the factor structure of the Menopause-Specific Quality of Life Questionnaire (MENQOL), an instrument used in clinical trials assessing pharmaceuticals, supplements, and behavior change. Menopause-specific quality of life is defined as the quality of life estimated by women experiencing the menopausal transition or early postmenopause in relation to the symptoms they perceive.2 Typically, studies assessing menopause-specific quality of life incorporate measures that elicit ratings, such as bother or interference with multiple dimensions of daily life, as they are affected by specific symptoms that women report during this period. The MENQOL3 and the Women’s Health Questionnaire4 are two measures used frequently in research about symptoms and in clinical trials of agents to alleviate symptoms. Despite their widespread use, MENQOL items were not examined using exploratory factor analysis until Van Dole et al5 recently evaluated the factor structure of MENQOL items. Although four of the original factors were supported (vasomotor, psychosocial, sexual, and physical), the investigators identified a set of items that did not load with their hypothesized theoretical domain or appeared to belong to multiple domains.5 These items were feeling tired/worn out; accomplishing less than I used to; changes in the appearance, texture, or tone of my skin; difficulty sleeping; and poor memory. In an effort to confirm the measurement model for the domains of the MENQOL, Bushmakin et al1 used confirmatory factor analysis to assess the relationship among MENQOL items and their domains. They specified a measurement model linking each item to a sexual, psychosocial, or vasomotor symptom domain. Because several items in the MENQOL did not load on a hypothesized domain in the analyses of Van Dole et al,5 Bushmakin et al1 allowed 16 of the symptoms on the MENQOL to be uncorrelated and assessed them as a single summative scale of physical symptoms. Among these items were five symptoms that did not load on a hypothesized factor, as Van Dole et al5 found. Four items (feeling tired or worn out; accomplishing less than I used to; changes in the appearance, texture, or tone of my skin; and difficulty sleeping) belonged to the physical function domain as it was initially specified by Hilditch et al,3 the developer of the original MENQOL. An additional 12 items were included in the original physical function subscale, and Bushmakin et al1 linked these to the physical domain in their analyses. This thoughtful approach to including all of the original items of the MENQOL in further analyses was warranted by
the statistical properties of the items observed by confirmatory factor analysis. In addition to the statistical properties of the item scores, it is also useful to consider the scope of the item pool for such a scale and the extent to which it represents the symptoms that women experience. A variety of observational and clinical trial studies indicate that many sets of symptoms vary across the menopausal transition stages, are related to endocrine changes associated with the menopausal transition (eg, estrogen), and are experienced by a large proportion of women. Among these are symptoms such as sleep disruption, pain, and difficulty concentrating. In addition to specifying the more general Bphysical domain[ of symptoms, it will be useful for investigators to be able to identify these sets of symptoms with greater precision than is currently possible with a single item indicator and/or as they are embedded in a large physical domain. Given the recent growth in the understanding of symptoms associated with the menopausal transition, enlarging the symptom pool of the MENQOL and expanding the number of domains to achieve greater precision of measurement are timely. In addition, given the recent identification of differential responses of various groups of symptoms to treatments such as those in MsFLASH (Menopause Strategies: Finding Lasting Answers for Symptoms and Health) trials, it would seem important to explicitly assess sleep symptoms and pain symptoms included in the aggregated physical functioning scale. Careful use of the MENQOL, as well as validated measures such as the Hot Flash Daily Interference Scale, Insomnia Severity Index, Pittsburgh Sleep Quality Inventory, Pain (average pain intensity [P], interference with enjoyment of life [E], and interference with general activity [G]), General Anxiety Scale, and others, confirms the importance of measuring symptoms (such as sleep disruption) separately from others.6 A more robust item pool, such as that found in the nine domains of the Women’s Health Questionnaire developed by Hunter4 (eg, depressed mood, somatic symptoms, memory/concentration, vasomotor symptoms, anxiety/fear, sexual behavior, sleep problems, and menstrual symptoms), would support the clinical utility of measures such as the MENQOL. Greater specificity of subscales identified from an enlarged item pool would provide clinicians with a more specific profile of symptom clusters with which to select optimal symptom management strategies. Evidence that a variety of symptoms are related to interference with everyday life supports the need for greater precision in identifying a profile of symptoms using an instrument such as the MENQOL.7 In addition, evidence
Menopause, Vol. 21, No. 8, 2014
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supporting women’s experiences of symptom clusters during this part of the life span warrants efforts to enhance measurement capable of revealing such a profile. For example, one profile of a cluster could include high-severity hot flashes along with moderate levels of sleep disruption, depressed mood, anxiety, pain, and difficulty concentrating, as found by Cray et al.8 Such a profile could support healthcare providers as they focus on the optimal therapeutic regimen for a woman who experiences multiple co-occurring symptoms. Using a matrix of symptom groups (the MENQOL or related scales could be used to generate reports of the profile for providers with an inventory of these), providers could quickly review therapeutic options, narrowing the focus to those agents most likely to yield positive outcomes. Such an approach was suggested decades ago by Halbreich et al9 for the groups of symptoms associated with premenstrual syndrome and could easily be created to guide care for women with clusters of symptoms related to menopause. The possible benefits of using profiles based on a scale such as the MENQOL support enlarging the item pool to incorporate symptoms identified in studies (such as the Study of Women’s Health Across the Nation, Penn Ovarian Aging Study, Seattle Midlife Women’s Health Study, and Melbourne Midlife Women’s Health Project) to be associated with the menopausal transition.10