title: Diabetes incidence and projections from prevalence surveys in Fiji.
abstract: Type 2 diabetes mellitus (T2DM) incidence is traditionally derived from cohort studies that are not always feasible, representative, or available. The present study estimates T2DM incidence in Fijian adults from T2DM prevalence estimates assembled from surveys of 25-64 year old adults conducted over 30 years (n = 14,288).
  
  
  
  T2DM prevalence by five-year age group from five population-based risk factor surveys conducted over 1980-2011 were variously adjusted for urban-rural residency, ethnicity, and sex to previous censuses (1976, 1986, 1996, 2009) to improve representativeness. Prevalence estimates were then used to calculate T2DM incidence based on birth cohorts from the age-period (Lexis) matrix following the Styblo technique, first used to estimate annual risk of tuberculosis infection (incidence) from sequential Mantoux population surveys. Poisson regression of year, age, sex, and ethnicity strata (n = 160) was used to develop projections of T2DM prevalence and incidence to 2020 based on various scenarios of population weight measured by body mass index (BMI) change.
  
  
  
  T2DM prevalence and annual incidence increased in Fiji over 1980-2011. Prevalence was higher in Indians and men than i-Taukei and women. Incidence was higher in Indians and women. From regression analyses, absolute reductions of 2.6 to 5.1% in T2DM prevalence (13-26% lower), and 0.5-0.9 per 1000 person-years in incidence (8-14% lower), could be expected in 2020 in adults if mean population weight could be reduced by 1-4 kg, compared to the current period trend in weight gain.
  
  
  
  This is the first application of the Styblo technique to calculate T2DM incidence from population-based prevalence surveys over time. Reductions in population BMI are predicted to reduce T2DM incidence and prevalence in Fiji among adults aged 25-64 years.
authors.affiliation: School of Public Health and Community Medicine, Samuels Building, University of New South Wales, Randwick, NSW, 2052, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Morrell
authors.affiliation: School of Public Health and Community Medicine, Samuels Building, University of New South Wales, Randwick, NSW, 2052, Australia.
authors.forename: Sophia
authors.initials: S
authors.lastname: Lin
authors.affiliation: Ministry of Health and Medical Services, Dinem House, 88 Amy Street, Toorak, Suva, Fiji Islands.
authors.forename: Isimeli
authors.initials: I
authors.lastname: Tukana
authors.affiliation: School of Public Health and Community Medicine, Samuels Building, University of New South Wales, Randwick, NSW, 2052, Australia.
authors.forename: Christine
authors.initials: C
authors.lastname: Linhart
authors.affiliation: School of Public Health and Community Medicine, Samuels Building, University of New South Wales, Randwick, NSW, 2052, Australia. r.taylor@unsw.edu.au.
authors.forename: Richard
authors.initials: R
authors.lastname: Taylor
authors.affiliation: National Food and Nutrition Centre, 1 Clarke Street, Suva, Fiji Islands.
authors.forename: Penina
authors.initials: P
authors.lastname: Vatucawaqa
authors.affiliation: Baker IDI Heart & Diabetes Institute, 75 Commercial Road, Melbourne, VIC, 3004, Australia.
authors.forename: Dianna J
authors.initials: DJ
authors.lastname: Magliano
authors.affiliation: Baker IDI Heart & Diabetes Institute, 75 Commercial Road, Melbourne, VIC, 3004, Australia.
authors.forename: Paul
authors.initials: P
authors.lastname: Zimmet
mesh_terms: D000328:Adult; D044466:Asian People; D015992:Body Mass Index; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000209:etiology; D005006:Ethnicity; D005260:Female; D005367:Fiji / Q000453:epidemiology; D005544:Forecasting; D006306:Health Surveys; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009765:Obesity / Q000150:complications / Q000453:epidemiology*; D015995:Prevalence; D012307:Risk Factors; D012737:Sex Factors
keywords: Developing country; Fiji; Incidence; Obesity; Pacific islands; Prevalence; Trends; Type 2 diabetes mellitus