To conduct psychometric analyses to condense the Hot Flash-Related Daily Interference Scale (HFRDIS) into a shorter form termed the Hot Flash Interference (HFI) scale; evaluate cut-points for both scales; and establish minimally important differences (MIDs) for both scales.
We analyzed baseline and postrandomization patient-reported data pooled across three randomized trials aimed at reducing vasomotor symptoms (VMS) in 899 midlife women. Trials were conducted across five MsFLASH clinical sites between July 2009 and October 2012. We eliminated HFRDIS items based on experts’ content validity ratings and confirmatory factor analysis, and evaluated cut-points and established MIDs by mapping HFRDIS and HFI to other measures.
The three-item HFI (interference with sleep, mood, and concentration) demonstrated strong internal consistency (alphas of 0.830 and 0.856), showed good fit to the unidimensional “hot flash interference factor,” and strong convergent validity with HFRDIS scores, diary VMS, and menopausal quality of life. For both scales, cut-points of mild (0-3.9), moderate (4-6.9), and severe (7-10) interference were associated with increasing diary VMS ratings, sleep, and anxiety. The average MID was 1.66 for the HFRDIS and 2.34 for the HFI.
The HFI is a brief assessment of VMS interference and will be useful in busy clinics to standardize VMS assessment or in research studies where response burden may be an issue. The scale cut-points and MIDs should prove useful in targeting those most in need of treatment, monitoring treatment response, and interpreting existing and future research findings.
1School of Nursing, Indiana University, Indianapolis, IN
2Department of Biostatistics, Fairbanks School of Public Health, School of Medicine, Indiana University, Indianapolis, IN
3Department of Psychology, School of Science, Indiana University-Purdue University Indianapolis, IN
4University of Washington School of Nursing, Seattle, WA
5Group Health Research Institute, Seattle, WA
6Brigham and Women's Hospital, Dana Farber Cancer Institute, Harvard Medical School, Boston, MA
7Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, and Harvard School of Public Health, Boston, MA
8Departments of Obstetrics/Gynecology and Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, PA
9MsFLASH Data Coordinating Center, Fred Hutchinson Cancer Research Center, Seattle, WA.
Address correspondence to: Janet S. Carpenter, PhD, RN, FAAN, IU School of Nursing, 600 Barnhill Drive NU338, Indianapolis, IN 46260. E-mail: email@example.com
Received 18 November, 2016
Revised 18 January, 2017
Accepted 18 January, 2017
Funding/support: The MsFLASH studies were supported by a cooperative agreement issued by the National Institute of Aging (NIA), in collaboration with the Eunice Kennedy Shriver National Institute of Child Health and Development (NICHD), the National Center for Complementary and Alternative Medicine (NCCAM), and the Office of Research and Women's Health (ORWH), and NIA grants U01AG032659, U01AG032669, U01AG032682, U01AG032699, and U01AG032700. In Indiana, the project was supported by the Indiana Clinical and Translational Sciences Institute, funded in part by grant UL1 RR025761 from the National Institutes of Health, National Center for Research Resources, Clinical, and Translational Sciences Award.
Financial disclosure/conflicts of interest: One author (C.X.C.) was supported by the National Institute of Nursing Research of the National Institutes of Health under Award Number T32NR007066. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.