Published Papers

1. InterLACE: A new International Collaboration for a Life Course Approach to Women’s Reproductive Health and Chronic Disease Events

Mishra GD, Anderson D, Schoenaker DAJM, Adami HO, Avis NE, Brown D, . . . , Weiderpass E. InterLACE: A new International Collaboration for a Life Course Approach to Women's Reproductive Health and Chronic Disease Events. Maturitas. 2013;74(3):235-40.

Abstract: Evidence from population-based studies of women increasingly points to the inter-related nature of reproductive health, lifestyle, and chronic disease risk. This paper describes the recently established International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease. InterLACE aims to advance the evidence base for women's health policy beyond associations from disparate studies by means of systematic and culturally sensitive synthesis of longitudinal data. Currently InterLACE draws on individual level data for reproductive health and chronic disease among 200,000 women from over thirteen studies of women's health in seven countries. The rationale for this multi-study research programme is set out in terms of a life course perspective to reproductive health. The research programme will build a comprehensive picture of reproductive health through life in relation to chronic disease risk. Although combining multiple international studies poses methodological challenges, InterLACE represents an invaluable opportunity to strength evidence to guide the development of timely and tailored preventive health strategies.

2. The InterLACE study: Design, data harmonization and characteristics across 20 studies on women's health

Mishra GD, Chung HF, Pandeya N, Dobson AJ, Jones L, Avis NE, . . . , Anderson D. The InterLACE study: Design, data harmonization and characteristics across 20 studies on women's health. Maturitas. 2016;92:176-85.

OBJECTIVES: The International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease Events (InterLACE) project is a global research collaboration that aims to advance understanding of women's reproductive health in relation to chronic disease risk by pooling individual participant data from several cohort and cross-sectional studies. The aim of this paper is to describe the characteristics of contributing studies and to present the distribution of demographic and reproductive factors and chronic disease outcomes in InterLACE.
STUDY DESIGN: InterLACE is an individual-level pooled study of 20 observational studies (12 of which are longitudinal) from ten countries. Variables were harmonized across studies to create a new and systematic synthesis of life-course data.
MAIN OUTCOME MEASURES: Harmonized data were derived in three domains: 1) socio-demographic and lifestyle factors, 2) female reproductive characteristics, and 3) chronic disease outcomes (cardiovascular disease (CVD) and diabetes).
RESULTS: InterLACE pooled data from 229,054 mid-aged women. Overall, 76% of the women were Caucasian and 22% Japanese; other ethnicities (of 300 or more participants) included Hispanic/Latin American (0.2%), Chinese (0.2%), Middle Eastern (0.3%), African/black (0.5%), and Other (1.0%). The median age at baseline was 47 years (Inter-quartile range (IQR): 41-53), and that at the last follow-up was 56 years (IQR: 48-64). Regarding reproductive characteristics, half of the women (49.8%) had their first menstruation (menarche) at 12-13 years of age. The distribution of menopausal status and the prevalence of chronic disease varied considerably among studies. At baseline, most women (57%) were pre- or peri-menopausal, 20% reported a natural menopause (range 0.8-55.6%) and the remainder had surgery or were taking hormones. By the end of follow-up, the prevalence rates of CVD and diabetes were 7.2% (range 0.9-24.6%) and 5.1% (range 1.3-13.2%), respectively.
CONCLUSIONS: The scale and heterogeneity of InterLACE data provide an opportunity to strengthen evidence concerning the relationships between reproductive health through life and subsequent risks of chronic disease, including cross-cultural comparisons.

3. Early menarche, nulliparity and the risk for premature and early natural menopause

Mishra GD, Pandeya N, Dobson AJ, Chung HF, Anderson D, Kuh D, . . . , Weiderpass E. Early menarche, nulliparity and the risk for premature and early natural menopause. Human Reproduction. 2017; doi: 10.1093/humrep/dew350 [Epub ahead of print].

STUDY QUESTION: Are parity and the timing of menarche associated with premature and early natural menopause?
SUMMARY ANSWER: Early menarche (≤11 years) is a risk factor for both premature menopause (final menstrual period, FMP <40 years) and early menopause (FMP 40-44 years), a risk that is amplified for nulliparous women.
WHAT IS KNOWN ALREADY: Women with either premature or early menopause face an increased risk of chronic conditions in later life and of early death. Findings from some studies suggest that early menarche and nulliparity are associated with early menopause, however overall the evidence is mixed. Much of the evidence for a direct relationship is hampered by a lack of comparability across studies, failure to adjust for confounding factors and inadequate statistical power.
STUDY DESIGN, SIZE, DURATION: This pooled study comprises 51 450 postmenopausal women from nine observational studies in the UK, Scandinavia, Australia and Japan that contribute to the International collaboration for a Life course Approach to reproductive health and Chronic disease Events (InterLACE).
PARTICIPANTS/MATERIALS, SETTING, METHODS: Age at menarche (categorized as ≤11, 12, 13, 14 and 15 or more years) and parity (categorized as no children, one child and two or more children) were exposures of interest. Age at FMP was confirmed by at least 12 months of cessation of menses where this was not the result of an intervention (such as surgical menopause due to bilateral oophorectomy or hysterectomy) and categorized as premature menopause (FMP before age 40), early menopause (FMP 40-44 years), 45-49 years, 50-51 years, 52-53 years and 54 or more years. We used multivariate multinomial logistic regression models to estimate relative risk ratio (RRR) and 95% CI for associations between menarche, parity and age at FMP adjusting for within-study correlation.
MAIN RESULTS AND THE ROLE OF CHANCE: The median age at FMP was 50 years (interquartile range 48-53 years), with 2% of the women experiencing premature menopause and 7.6% early menopause. Women with early menarche (≤11 years, compared with 12-13 years) were at higher risk of premature menopause (RRR 1.80, 95% CI 1.53-2.12) and early menopause (1.31, 1.19-1.44). Nulliparity was associated with increased risk of premature menopause (2.26, 1.84-2.77) and early menopause (1.32, 1.09-1.59). Women having early menarche and nulliparity were at over 5-fold increased risk of premature menopause (5.64, 4.04-7.87) and 2-fold increased risk of early menopause (2.16, 1.48-3.15) compared with women who had menarche at ≥12 years and two or more children.
LIMITATIONS, REASONS FOR CAUTION: Most of the studies (except the birth cohorts) relied on retrospectively reported age at menarche, which may have led to some degree of recall bias.
WIDER IMPLICATIONS OF THE FINDINGS: Our findings support early monitoring of women with early menarche, especially those who have no children, for preventive health interventions aimed at mitigating the risk of adverse health outcomes associated with early menopause.
STUDY FUNDING/COMPETING INTERESTS: InterLACE project is funded by the Australian National Health and Medical Research Council project grant (APP1027196). G.D.M. is supported by Australian Research Council Future Fellowship (FT120100812). There are no competing interests.