title: Time series analysis of demographic and temporal trends of tuberculosis in Singapore.
abstract: BACKGROUND
  Singapore is an intermediate tuberculosis (TB) incidence country, with a recent rise in TB incidence from 2008, after a fall in incidence since 1998. This study identified population characteristics that were associated with the recent increase in TB cases, and built a predictive model of TB risk in Singapore.
  
  
  METHODS
  Retrospective time series analysis was used to study TB notification data collected from 1995 to 2011 from the Singapore Tuberculosis Elimination Program (STEP) registry. A predictive model was developed based on the data collected from 1995 to 2010 and validated using the data collected in 2011.
  
  
  RESULTS
  There was a significant difference in demographic characteristics between resident and non-resident TB cases. TB risk was higher in non-residents than in residents throughout the period. We found no significant association between demographic and macro-economic factors and annual incidence of TB with or without adjusting for the population-at-risk. Despite growing non-resident population, there was a significant decrease in the non-resident TB risk (p < 0.0001). However, there was no evidence of trend in the resident TB risk over this time period, though differences between different demographic groups were apparent with ethnic minorities experiencing higher incidence rates.
  
  
  CONCLUSIONS
  The study found that despite an increasing size of non-resident population, TB risk among non-residents was decreasing at a rate of about 3% per year. There was an apparent seasonality in the TB reporting.
authors.forename: Win
authors.initials: W
authors.lastname: Wah
authors.forename: Sourav
authors.initials: S
authors.lastname: Das
authors.forename: Arul
authors.initials: A
authors.lastname: Earnest
authors.forename: Leo Kang Yang
authors.initials: LK
authors.lastname: Lim
authors.forename: Cynthia Bin Eng
authors.initials: CB
authors.lastname: Chee
authors.forename: Alex Richard
authors.initials: AR
authors.lastname: Cook
authors.forename: Yee Tang
authors.initials: YT
authors.lastname: Wang
authors.forename: Khin Mar Kyi
authors.initials: KM
authors.lastname: Win
authors.forename: Marcus Eng Hock
authors.initials: ME
authors.lastname: Ong
authors.affiliation: Centre for Infectious Disease Epidemiology & Research, Saw Swee Hock School of Public Health, National University of Singapore and NUHS, Singapore, Singapore. Liyang_hsu@yahoo.com.
authors.forename: Li Yang
authors.initials: LY
authors.lastname: Hsu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003710:Demography / Q000639:trends*; D054242:Emigrants and Immigrants / Q000706:statistics & numerical data*; D005544:Forecasting; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D008962:Models, Theoretical; D044382:Population Groups / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012846:Singapore / Q000453:epidemiology; D012959:Socioeconomic Factors; D013997:Time Factors; D014376:Tuberculosis / Q000453:epidemiology*; D055815:Young Adult