Comparison of scales for evaluating premenstrual symptoms in women using oral contraceptives

Abstract

Study objective: To compare two scales used in research to evaluate daily premenstrual mood symptoms during use of a monophasic oral contraceptive.

Design: Subanalysis of data from a prospective study.

Setting: University-affiliated medical center. SUBJECTS; One hundred two reproductive-aged (18-48 yrs) women taking a monophasic oral contraceptive containing ethinyl estradiol and drospirenone in the standard 21-7 fashion (21 days of hormones followed by 7 days of placebo), and who had self-identified premenstrual symptoms of headache, mood changes, or pelvic pain.

Intervention: Subjects completed a single-item questionnaire, the Scott & White Daily Diary of Symptoms, and a multiple-item questionnaire, the Penn State Daily Symptom Report (DSR), to assess their premenstrual symptoms. The Scott & White diary used a visual analog scale of 0-10 to assess pelvic pain, headache, and mood (a composite of anxiety, depression, and irritability). The Penn State DSR contained 17 items: 10 behavioral and seven physical components, each rated on a scale of 0-4, with one item that specifically rated mood swings.

Measurements and main results: Scores from the two scales were compared by using Spearman correlation coefficients, the Kendall W for concordance, and linear regression of ranked sums for study cycles. The Scott & White mood score significantly correlated with the total of the 17 items on the Penn State DSR, as well as the 10 behavioral items, the seven physical items, and the single mood-swing item (p<0.0001); specific coefficients of concordance were 0.44, 0.23, 0.10, and 0.28, respectively, and R2 values were 0.39, 0.39, 0.30, and 0.34, respectively. The daily Scott & White mood score was positively correlated with all 17 elements of the Penn State DSR (0.25-0.57). The greatest correlation was seen with the mood-swing element. Both instruments demonstrated the same patterns during the 21-7 oral contraceptive cycle, with symptoms increasing immediately before and peaking during the 7-day hormone-free interval.

Conclusion: A single-item daily mood score using a rating scale of 0-10 was concordant with a relatively complex 17-element symptom index and demonstrated the same pattern of change during cycles of oral contraception. The simple scoring system offers an advantage, especially in clinical studies of long duration.