Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI, USA.
Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, MI, USA.
Int J Epidemiol. 2023 Oct 5;52(5):1612-1623. doi: 10.1093/ije/dyad085.
Shorter average lifespans for minoritized populations are hypothesized to stem from 'weathering' or accelerated health declines among minoritized individuals due to systemic marginalization. However, evidence is mixed on whether racial/ethnic differences exist in reproductive ageing, potentially due to selection biases in cohort studies that may systematically exclude 'weathered' participants. This study examines racial/ethnic disparities in the age of menopause after accounting for differential selection 'into' (left truncation) and 'out of' (right censoring) a cohort of midlife women.
Using data from the Study of Women's Health Across the Nation (SWAN) cross-sectional screener (N = 15 695) and accompanying ∼20-year longitudinal cohort (N = 3302) (1995-2016), we adjusted for potential selection bias using inverse probability weighting (left truncation) to account for socio-demographic/health differences between the screening and cohort study, and multiple imputation (right censoring) to estimate racial/ethnic differences in age at menopause (natural and surgical).
Unadjusted for selection, no Black/White differences in menopausal timing [hazard ratio (HR)=0.98 (0.86, 1.11)] were observed. After adjustment, Black women had an earlier natural [HR = 1.13 (1.00, 1.26)] and surgical [HR= 3.21 (2.80, 3.62)] menopause than White women with natural menopause-corresponding to a 1.2-year Black/White difference in menopause timing overall.
Failure to account for multiple forms of selection bias masked racial/ethnic disparities in the timing of menopause in SWAN. Results suggest that there may be racial differences in age at menopause and that selection particularly affected the estimated menopausal age for women who experienced earlier menopause. Cohorts should consider incorporating methods to account for all selection biases, including left truncation, as they impact our understanding of health in 'weathered' populations.
少数群体的平均预期寿命较短，据推测是由于少数群体成员因系统性边缘化而导致的“磨损”或健康加速衰退。然而，关于生殖衰老是否存在种族/民族差异的证据存在分歧，这可能是由于队列研究中的选择偏差，这些偏差可能会系统地排除“磨损”的参与者。本研究在考虑到对中年女性队列的选择“进入”（左截断）和“退出”（右删失）的差异后，检查了绝经年龄的种族/民族差异。
使用来自全国妇女健康研究（SWAN）横断面筛查（N=15695）和伴随的大约 20 年纵向队列（N=3302）（1995-2016）的数据，我们使用逆概率加权（左截断）来调整潜在的选择偏差，以说明筛查和队列研究之间的社会人口/健康差异，并用多重插补（右删失）来估计绝经年龄的种族/民族差异（自然和手术）。
未经选择调整，绝经时间上没有黑人/白人差异[风险比（HR）=0.98（0.86，1.11）]。调整后，黑人女性的自然绝经[HR=1.13（1.00，1.26）]和手术绝经[HR=3.21（2.80，3.62）]早于白人女性，黑人/白人之间的绝经时间差异总体上为 1.2 年。
未考虑多种形式的选择偏差，掩盖了 SWAN 中绝经时间的种族/民族差异。结果表明，绝经年龄可能存在种族差异，选择特别影响了经历更早绝经的女性的绝经年龄估计值。队列研究应考虑纳入考虑所有选择偏差的方法，包括左截断，因为这些偏差会影响我们对“磨损”人群健康的理解。
