Measuring hot flashes : examination of an alternate criterion for ambulatory hot flash detection in post-menopausal women.

Hot flashes are a highly prevalent and severe symptom experienced in menopause and in cancer treatment. Objective measurement of hot flashes, essential for conducting research in this area, is achieved using skin conductance monitors. The current gold standard skin conductance level (SCL) criterion for detecting hot flashes is a ≥ 2 µmho rise in a 30-s period, however this standard criterion has shown limited sensitivity in ambulatory trials. A recent study of breast cancer survivors found an alternate criterion (≥ 1.2 µmho rise in a 30-s period) improved performance. The purpose of this dissertation is the comparison of the alternate and standard SCL criterion in population of healthy post-menopausal women, the determination of racial/ethnic group differences, and the determination of any relationship of SCL-derived hot flashes to hot flash related daily interference. This study is a retrospective analysis of data collected from a sample of 140 healthy post-menopausal women in a clinical trial of hypnosis for hot flashes. Skin conductance data sampled over one day using ambulatory SCL-monitors were analyzed using the standard and alternate criteria for hot flash detection. Indices of SCL-criterion performance, sensitivity, specificity, positive and negative predictive values, were subsequently calculated and compared. Comparison of these indices were made to examine racial/ethnic differences, however, limited sample sizes only allowed for the statistical examination of white versus non-whites. Correlations of the standard and alternate criteria-derived hot flashes with the Hot Flash Related Daily Interference Scale were performed. The results of this study showed that the alternate criterion has a distinct advantage in terms of sensitivity (77.4%, alternate vs. 56.9%, standard; p <.001), with only minor deficit to specificity (80.1% alternate vs. 86.1%, standard). Sensitivity of the alternate criterion differed significantly between Whites vs. Non-Whites (83.58%, vs. 73.81%, respectively; p <.05). No significant correlations were revealed. The alternate criterion is recommended for use in the ambulatory study of healthy, post-menopausal women. Additional research is needed to: 1) determine specific racial/ethnic group differences in SCL performance, 2) determine relative performance in perimenopause, and 3) ascertain if alternate physiologic measures (e.g. ECG; heart-rate variability) could improve performance.