hotflashes. Thesefindings suggest that the relations between sleep and hotflashes
may largely be driven by subjective experience and reporting. However, more
studies using both self-report and physiologic measures of both sleep and hot
flashes are urgently needed to better understand the relations between these two
important experiences.
Racial/Ethnic and Cultural Differences
The study of the association of racial/ethnic and cultural differences in the prevalence,
experience, and measure of hotflashes is vibrant and ongoing. International preva-
lence varies widely; a 2007 systematic review of hotflash prevalence by geographic
region revealed rates of hotflashes varying from 14 to 80% among international
studies (16–46%, in North American studies, 73% pan-European, 21–48% Chinese,
25 – 80% Southeast Asian, 0–68% Latin American, 14–42% South Asian, 20–33%
Middle Eastern, and 23–57% African) (Freeman and Sherif 2007 ). Studies within the
USA also show substantial ethnic diversity. Results from the SWAN study, the
largest and most ethnically diverse longitudinal study of the menopausal transition in
the USA, showed that African American women were the most likely to report hot
flashes, Asian American women the least likely to report hotflashes, and Hispanic
and Caucasian women of moderate likelihood (Thurston and Joffe 2011 ).
Additionally, there may be significant variation across ethnic groups of Hispanic
women living in the USA, with the highest rates reported among Central American
women and the lowest in Cuban women (Green et al. 2010 ). Ratings of hotflash
bother above and beyond the frequency of hotflashes also vary by race/ethnicity
within the USA, with the most bothersome hotflashes among African American
women and the least bothersome among Asian women (Gold et al. 2006 ; Thurston
et al.2008a). The postulated reasons for intra- and inter-country differences in
symptom reporting are varied and may include differences in genetics, dietary factors,
body habitus, socioeconomic status, reproductive histories, climate, perception and
reporting of symptoms, and cultural norms surrounding menopausal symptoms.
In addition to the ethnic differences in symptom prevalence, ethnicity may play a
role in the phenomenology and assessment of hotflashes. Research indicates ethnic
and cultural differences in sweating patterns, the locus of the sensation of heat, and
the meaning of and attitudes toward hotflashes (Sievert et al. 2002 , 2004 , 2008 ;
Sievert 2014 ; Sievert and Espinosa-Hernandez 2003 ; Brown et al. 2009 ). The
reasons for these differences are not well understood, but ethnic and cultural dif-
ferences in the assessment of hotflashes may be contributive. Self-reported hot
flashes on questionnaires and diaries may be subject to cultural and ethnic variation.
Variation in the salience of physical and emotional phenomenon as well as the
cultural mores surrounding the expression of these symptoms may lead to signifi-
cant differences in reporting (Sievert 2014 ). Moreover, the language used to indi-
cate hotflashes may impact hotflash reporting. In a study of healthy Japanese
women aged 45–55 years, hot flash prevalence ranged from 3.0%, when
11 Hot Flashes: Phenomenology and Measurement 243