Table 2. Comparison of duration, frequency, and intensity of hot flashes in participants.
| Variable | Group | Before intervention (mean ± SD) | After intervention (adjusted mean ± SD)a | Cohen's db (95% CI) | F | P valuec |
|---|---|---|---|---|---|---|
| Duration of hot flashes | Evening primrose oil | 4.8 ± 0.4 | 4.1 ± 2.7 | 0.003 (–0.30, 0.31) | 0.01 | 0.93 |
| Placebo | 4.6 ± 0.7 | 4.1 ± 2.8 | ||||
| Frequency of hot flashes/day | Evening primrose oil | 8.0 ± 6.0 | 2.8 ± 4.6 | 0.06 (–0.24, 0.37) | 1.16 | 0.28 |
| Placebo | 6.9 ± 2.4 | 2.5 ± 4.9 | ||||
| Intensity of hot flashes | Evening primrose oil | 2.7 ± 0.6 | 1.9 ± 1.7 | 0.13 (–0.17, 0.44) | 4.54 | 0.03 |
| Placebo | 2.7 ± 0.6 | 2.1 ± 1.7 |
The duration score was less than 30 seconds (1), 30–60 seconds (2), 1–3 minute(s) (3), 3–5 minutes (4), and more than 5 minutes (5).
The intensity score was classified into mild (1), moderate (2), and severe (3) grades.
SD: standard deviation, CI: confidence interval.
aAdjusted for before intervention score; bCohen's d effect size: 0.2–0.4 considered small, 0.5–0.7 considered moderate, ≥ 0.8 considered large; cANOVA/ANCOVA.