Validity, cut-points, and minimally important differences for two hot flash-related daily interference scales

Abstract

Objectives To conduct psychometric analyses to (1) condense the Hot Flash Related Daily Interference Scale (HFRDIS) into a shorter form termed the Hot Flash Interference (HFI) scale, (2) evaluate cutpoints for both scales, and (3) establish minimally important differences (MIDs) for both scales. Methods We analyzed baseline and post-randomization 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 cutpoints and established MIDs by mapping HFRDIS and HFI to other measures. Results The 3-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, cutpoints 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. Conclusions 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 cutpoints and MIDs should prove useful in targeting those most in need of treatment, monitoring treatment response, and interpreting existing and future research findings.

A comparison of three outcome measures of the impact of vasomotor symptoms on women’s lives

“…The term 'impact of VMS' might capture the concept assessed by these measures. While the HFRS problem-rating is more strongly associated with the longer HFRDIS than the shorter HFI, in other respects the shorter HFI performs generally as well as the HRDIS, which supports findings of Carpenter et al 22 Interestingly HFRS Frequency was associated with measures of VMS impact (r=0.22-0.39), but not with work and social adjustment, mood nor medical help-seeking. These findings provide further evidence that considering frequency of VMS as the only outcome measure in clinical trials may fail to capture the important clinically relevant concept of impact of the symptoms on women's lives.…”

“…Internal consistency has been reported as high, Cronbach alpha= 0.92. 21 The Hot Flash Interference (HFI) 22 The internal reliability alpha coefficients were as follows: HFNS Problem Rating 0.84, HFRDIS 0.91 and HFI 0.76. Correlations between HFNS frequency, the three interference measures and the associations between HFNS measures and measures of functioning (WSAS scale, medical help seeking, PHQ9 and GAD7) are shown in Table 2.…”

“…19 Measures of impact include: the Hot Flush Rating Scale (HFRS) 20 , the Hot Flash Related Daily Interference Scale (HFRDIS) 21 and the Hot Flash Interference (HFI). 22 HFRS is a self-report measure of VMS frequency and problem-rating over the past week. The Hot Flush Rating Scale (HFRS) problem-rating is calculated as the mean of the scores on three Likert scales (scores range from 1-10) assessing the extent to which HFNS are problematic, distressing and causing interference in daily life.…”

“…The Hot Flush Rating Scale (HFRS) problem-rating is calculated as the mean of the scores on three Likert scales (scores range from 1-10) assessing the extent to which HFNS are problematic, distressing and causing interference in daily life. The Hot Flash Related Daily Interference Scale (HFRDIS) 21 , a 10-item questionnaire, assesses the impact of hot flushes on daily activities and quality of life in the past week, and the Hot Flash Interference (HFI) 22 measure is a 3 item shortened version of the HFRDIS (see table 1). The HFRS problem-rating scale tends to be used in UK and European trials, while the HFRDIS tends to be used in the USA, but they have been not been directly compared.…”

Variation in menopausal vasomotor symptoms outcomes in clinical trials: a systematic review

“…The Hot Flush Rating Scale (HFRS) measures how vasomotor symptoms interfere with daily routine and activities. The Hot Flush Related Daily Interference scales (HFRDIS) and the shortened Hot Flush Interference (HFI) scale have been used to measure interference due to vasomotor symptoms but were not the primary outcome of eligible RCTs, and so were not included in the systematic review. However, they will still be used for the subsequent Delphi process.…”