Concordance between self-reported and sternal skin conductance measures of hot flushes in symptomatic perimenopausal and postmenopausal women: a systematic review

Objective: Sternal skin conductance is considered the gold standard in hot flush and night sweat measurement, but results sometimes differ from women's own self-reports. To date, there has been no systematic review of concordance between sternal skin conductance and self-report measures. An exploratory meta-analysis was conducted to quantify concordance between these measures and to explore the reasons for discordance between them. Methods: A search of Medline, EMBASE, Web of Science, and PsychInfo from inception to December 2009 was conducted. Studies that measured self-reported hot flushes and/or night sweats and sternal skin conductance concurrently in symptomatic perimenopausal and postmenopausal women were retained for data extraction. Studies were included if data on concordance between the two measures were available. Results: Concordance rates overall were 29%, but variability between studies was too broad to identify a single typical concordance rate. However, concordance rates for ambulatory monitoring were more homogeneous and also had a 29% concordance rate. Nonambulatory studies tended to result in more concordant hot flushes (54%) than ambulatory studies did, and night sweats tended to be under-reported more often than over-reported (46% and 22%, respectively). Conclusions: Concordance rates were typically lower than early reports of sternal skin conductance measures but were highly variable between studies. Possible measurement error and study conditions might partly explain the discordance and variation in study findings, but further exploration of the effects of symptom perception is warranted. Use of both measures concurrently is likely to achieve more reliable and valid measurement of hot flushes and night sweats than either measure alone.