title: Application of nonhomogenous Markov models for analyzing longitudinal caries risk.
abstract: OBJECTIVE
  Markov modeling is a useful mathematical procedure for calculating probabilities of disease prognosis. Increasingly, Markov models are being applied in medical and health services research and also in social sciences research. The purpose of our study was to use the Markov process to determine time-dependent transition probabilities for caries-free children to convert to a caries-active state and to assess the impact of salivary mutans streptococci (MS) levels on caries status.
  
  
  METHODS
  Our analysis was based on data obtained from a 6-year longitudinal study of risk factors associated with caries onset in children.
  
  
  RESULTS
  Based on a two-state Markov model, the probability that a caries-free child would convert to a caries-active state during the study ranged between 0.0046 and 0.0471. The highest probability of converting from a caries-free state to a caries-active state was 0.0471 at age 8.5 years.
  
  
  CONCLUSIONS
  In addition to standard statistical methods of analyzing longitudinal caries data, Markov models show promise for use in the analysis of caries risk.
authors.affiliation: Eastman Department of Dentistry, University of Rochester, Rochester, NY 14620, USA. dorota_kopyckakedzierawski@urmc.rochester.edu
authors.forename: D T
authors.initials: DT
authors.lastname: Kopycka-Kedzierawski
authors.forename: R J
authors.initials: RJ
authors.lastname: Billings
mesh_terms: D000367:Age Factors; D002648:Child; D015331:Cohort Studies; D003731:Dental Caries / Q000382:microbiology; D003733:Dental Caries Susceptibility; D018450:Disease Progression; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008390:Markov Chains; D018570:Risk Assessment; D012307:Risk Factors; D012463:Saliva / Q000382:microbiology; D013295:Streptococcus mutans / Q000254:growth & development; D013997:Time Factors