title: Secular trends in menarcheal age in India-evidence from the Indian human development survey.
abstract: BACKGROUND
  Evidence from a number of countries in Europe and North America point towards the secular declining trend in menarcheal age with considerable spatial variations over the past two centuries. Similar trends were reported in several developing countries from Asia, Africa and Latin America. However, data corroborating any secular trend in the menarcheal age of the Indian population remained sparse and inadequately verified.
  
  
  METHODS
  We examined secular trends, regional heterogeneity and association of socioeconomic, anthropometric and contextual factors with menarcheal age among ever-married women (15-49 years) in India. Using the pseudo cohort data approach, we fit multiple linear regression models to estimate secular trends in menarcheal age of 91394 ever-married women using the Indian Human Development Survey.
  
  
  RESULTS
  The mean age at menarche among Indian women was 13.76 years (95 % CI: 13.75, 13.77) in 2005. It declined by three months from 13.83 years (95% CI: 13.81, 13.85) among women born prior to 1955-1964, to nearly 13.62 years (95% CI: 13.58, 13.67) among women born during late 1985-1989. However, these aggregate national figures mask extensive spatial heterogeneity as mean age at menarche varied from 15.0 years in Himachal Pradesh during 1955-1964 (95% CI: 14.89-15.11) to about 12.1 years in Assam (95% CI: 11.63-12.56) during 1985-1989.
  
  
  CONCLUSIONS
  The regression analysis established a reduction of nearly one month per decade, suggesting a secular decline in age at menarche among Indian women. Notably, the menarcheal age was significantly associated with the area of residence, geographic region, linguistic groups, educational attainment, wealth status, caste and religious affiliations among Indian women.
authors.affiliation: Department of Geography, Delhi School of Economics, University of Delhi, Delhi, India; International Institute for Population Sciences, Mumbai, Maharashtra, India.
authors.forename: Praveen Kumar
authors.initials: PK
authors.lastname: Pathak
authors.affiliation: International Institute for Population Sciences, Mumbai, Maharashtra, India.
authors.forename: Niharika
authors.initials: N
authors.lastname: Tripathi
authors.affiliation: Department of Society, Human Development and Health, Harvard School of Public Health, Boston, Massachusetts, United States of America.
authors.forename: S V
authors.initials: SV
authors.lastname: Subramanian
mesh_terms: D000293:Adolescent; D000328:Adult; D044466:Asian People; D015992:Body Mass Index; D015331:Cohort Studies; D003710:Demography; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D016014:Linear Models; D008572:Menarche / Q000208:ethnology / Q000502:physiology*; D008875:Middle Aged; D011157:Population Dynamics; D012959:Socioeconomic Factors