Self-report versus ultrasound measurement of uterine fibroid status

J Womens Health (Larchmt). 2012 Mar;21(3):285-93. doi: 10.1089/jwh.2011.3008. Epub 2011 Nov 1.

Abstract

Background: Much of the epidemiologic research on risk factors for fibroids, the leading indication for hysterectomy, relies on self-reported outcome. Self-report is subject to misclassification because many women with fibroids are undiagnosed. The purpose of this analysis was to quantify the extent of misclassification and identify associated factors.

Methods: Self-reported fibroid status was compared to ultrasound screening from 2046 women in Right From The Start (RFTS) and 869 women in the Uterine Fibroid Study (UFS). Log-binomial regression was used to estimate sensitivity (Se) and specificity (Sp) and examine differences by ethnicity, age, education, body mass index, parity, and miscarriage history.

Results: Overall sensitivity was ≤0.50. Sensitivity was higher in blacks than whites (RFTS: 0.34 vs. 0.23; UFS: 0.58 vs. 0.32) and increased with age. Parous women had higher sensitivity than nulliparae, especially in RFTS whites (Se ratio=2.90; 95% confidence interval [CI]: 1.51, 5.60). Specificity was 0.98 in RFTS and 0.86 in UFS. Modest ethnic differences were seen in UFS (Sp ratio, black vs. white=0.90; 95% CI: 0.81, 0.99). Parity was inversely associated with specificity, especially among UFS black women (Sp ratio=0.84; 95% CI: 0.73, 0.97). Among women who reported a previous diagnosis, a shorter time interval between diagnosis and ultrasound was associated with increased agreement between the two measures.

Conclusions: Misclassification of fibroid status can differ by factors of etiologic interest. These findings are useful for assessing (and correcting) bias in studies using self-reported clinical diagnosis as the outcome measure.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Abortion, Spontaneous / ethnology
  • Adult
  • African Americans
  • African Continental Ancestry Group / psychology
  • Body Mass Index
  • European Continental Ancestry Group / psychology
  • Female
  • Humans
  • Leiomyoma / diagnostic imaging*
  • Leiomyoma / surgery
  • Middle Aged
  • North Carolina / epidemiology
  • Parity
  • Pregnancy
  • Regression Analysis
  • Self Report
  • Sensitivity and Specificity
  • Surveys and Questionnaires
  • Ultrasonography, Interventional
  • Women's Health / ethnology