Abstract and Introduction
Abstract
Objective. Studies of vasomotor symptoms (VMS) typically measure VMS via daily diaries completed at the end of the day. VMS can also be measured via diaries completed throughout the day or via physiological monitors-modalities with lower recall demands. We examined the degree of correspondence between three VMS measurement modalities: retrospective end-of-day/morning diaries, prospective reporting, and physiological monitoring. We determined whether discrepancies between measurement modalities varied by participant characteristics.
Methods. Twenty-five African-American women and 27 white women from the Pittsburgh site of the Study of Women's Health Across the Nation who were experiencing VMS, had intact uterus and ovaries, and were free of medications affecting VMS underwent 4 days of ambulatory VMS and Actiwatch monitoring. VMS were recalled in end-of-day and morning diaries, reported prospectively during the day, and measured physiologically via a hot flash monitor. Associations between anxiety, sleep, or race/ethnicity and VMS measurement modality difference scores were examined using generalized estimating equations.
Results. Women underestimated the number of daytime VMS at the end of the day as compared with VMS that were prospectively reported or physiologically measured throughout the day. This pattern was particularly pronounced among African-American women (b [SE] =−3.01 [0.93], P = 0.001) and women with higher anxiety (b [SE] =−3.13 [1.53], P = 0.04). For nighttime VMS, women overestimated the number of VMS in the morning upon waking as compared with prospective measures, particularly if they had poorer sleep (higher wakening after sleep onset: b [SE] = 0.03 [0.008], P=0.001).
Conclusions. Different measurement modalities yield different VMS estimates. Negative affect, sleep, and race/ ethnicity may affect the recall of VMS.
Introduction
Vasomotor symptoms (VMS), such as hot flashes and night sweats, affect approximately 70% of American women transitioning through menopause and are a leading concern for women during this time. For example, women cite VMS as the menopausal symptom most commonly discussed with their healthcare professionals, and women with VMS consult doctors more often than women without these symptoms. Therefore, VMS are an important health issue for midlife women.
The reluctance of many women to take postmenopausal hormone therapy since the publication of the Women's Health Initiative findings has led to a recent search for new nonhormonal treatments for VMS and associated clinical trials. In these trials, daily diaries are considered the gold standard measure of VMS. In many of these diaries, women are asked to recall at the end of the day their VMS experienced during the previous day and, upon waking, their VMS experienced during the night. Other methodologies ask women to recall their VMS during the prior 24 hours, summing those experienced during the day and during the night. In contrast to a prospective report in which women record a VMS event as they are experiencing it, these diaries are retrospective in that they ask women to recall their VMS during a given period. It is not known how well these retrospective reports correspond with prospective VMS reports or physiologically assessed VMS.
One key factor affecting VMS reporting is negative affect, which influences the memory for other physical symptoms. In fact, anxiety is the strongest and most consistent factor associated with the reporting of VMS. Although the relationship between anxiety and VMS may be multifactorial, higher baseline anxiety was significantly and independently associated with more VMS reporting in the Study of Women's Health Across the Nation (SWAN). Moreover, SWAN women with elevated negative affect reported being more bothered by their VMS even after controlling for the frequency at which VMS were reported to occur. One study found that reported VMS lacking physiological evidence were most common among women with elevated negative affect.
The primary aim of the current study is to compare VMS estimates from daily diaries to prospectively reported or physiologically recorded VMS during waking and sleeping hours across 4 days and nights. Next, we examine the role of negative affect in the degree of similarity or difference between these measurement modalities. Given anxiety's established association with VMS reporting, we hypothesize that, compared with women with low levels of anxiety, women with higher anxiety symptoms would (1) recall more daytime VMS at the end of the day than were prospectively reported or physiologically detected during the day and (2) recall more overnight VMS upon waking the next morning than were reported or physiologically detected during the prior night. In an exploratory fashion, we investigate whether discrepancies between VMS estimates via these measurement modalities vary by race/ ethnicity and sleep given the importance of these factors to VMS and their reporting.