title: Diabetes incidence and projections from prevalence surveys in Samoa over 1978-2013.
abstract: OBJECTIVE
  This study estimates type 2 diabetes (T2DM) incidence in Samoans aged 25-64 years from sequential, irregularly spaced, cross-sectional population prevalence surveys.
  
  
  METHODS
  T2DM prevalence from eight population surveys conducted over 1978-2013 (n = 12,516) was adjusted for census region, sex, and 5-year age group to the nearest previous census. Annual T2DM incidence was calculated from adjusted prevalences (by sex), using birth cohorts constructed from age-period matrices. Projections of T2DM incidence to 2020 were estimated, based on various scenarios of population weight change using Poisson regression.
  
  
  RESULTS
  Over 1978-2013, T2DM incidence was estimated to increase from 1.12 to 8.44 per 1000 person-years in men and from 2.55 to 8.04 per 1000 in women. Based on regression modeling, if mean population weight was stabilized from 2013, absolute incidence reductions of 0.9 per 1000 person-years (7% lower) are predicted in 2020, compared to the current period trend in weight gain.
  
  
  CONCLUSIONS
  T2DM incidence can be calculated from irregularly conducted population risk factor surveys which may be useful in developing countries with limited resources.
authors.affiliation: School of Public Health and Community Medicine, University of New South Wales, Sydney, Australia.
authors.forename: Sophia
authors.initials: S
authors.lastname: Lin
authors.affiliation: Ministry of Health, Apia, Samoa.
authors.forename: Take
authors.initials: T
authors.lastname: Naseri
authors.affiliation: School of Public Health and Community Medicine, University of New South Wales, Sydney, Australia.
authors.forename: Christine
authors.initials: C
authors.lastname: Linhart
authors.affiliation: School of Public Health and Community Medicine, University of New South Wales, Sydney, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Morrell
authors.affiliation: School of Public Health and Community Medicine, University of New South Wales, Sydney, Australia. r.taylor@unsw.edu.au.
authors.forename: Richard
authors.initials: R
authors.lastname: Taylor
authors.affiliation: International Health Institute, Brown University, Providence, Rhode Island, USA.
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Mcgarvey
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Australia.
authors.forename: Dianna J
authors.initials: DJ
authors.lastname: Magliano
authors.affiliation: Baker IDI Heart and Diabetes Institute, Melbourne, Australia.
authors.forename: Paul
authors.initials: P
authors.lastname: Zimmet
mesh_terms: D000328:Adult; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D018947:Samoa / Q000453:epidemiology; D011795:Surveys and Questionnaires
keywords: Developing Country; Incidence; Pacific Islands; Prevalence; Samoa; Type 2 diabetes