title: Accuracy of medical subject heading indexing of dental survival analyses.
abstract: OBJECTIVE
  To assess the Medical Subject Headings (MeSH) indexing of articles that employed time-to-event analyses to report outcomes of dental treatment in patients.
  
  
  METHODS
  Articles published in 2008 in 50 dental journals with the highest impact factors were hand searched to identify articles reporting dental treatment outcomes over time in human subjects with time-to-event statistics (included, n = 95), without time-to-event statistics (active controls, n = 91), and all other articles (passive controls, n = 6,769). The search was systematic (kappa 0.92 for screening, 0.86 for eligibility). Outcome-, statistic- and time-related MeSH were identified, and differences in allocation between groups were analyzed with chi-square and Fischer exact statistics.
  
  
  RESULTS
  The most frequently allocated MeSH for included and active control articles were "dental restoration failure" (77% and 52%, respectively) and "treatment outcome" (54% and 48%, respectively). Outcome MeSH was similar between these groups (86% and 77%, respectively) and significantly greater than passive controls (10%, P < .001). Significantly more statistical MeSH were allocated to the included articles than to the active or passive controls (67%, 15%, and 1%, respectively, P < .001). Sixty-nine included articles specifically used Kaplan-Meier or life table analyses, but only 42% (n = 29) were indexed as such. Significantly more time-related MeSH were allocated to the included than the active controls (92% and 79%, respectively, P = .02), or to the passive controls (22%, P < .001).
  
  
  CONCLUSIONS
  MeSH allocation within MEDLINE to time-to-event dental articles was inaccurate and inconsistent. Statistical MeSH were omitted from 30% of the included articles and incorrectly allocated to 15% of active controls. Such errors adversely impact search accuracy.
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Layton
authors.forename: Michael
authors.initials: M
authors.lastname: Clarke
mesh_terms: D000043:Abstracting and Indexing / Q000592:standards* / Q000706:statistics & numerical data; D015706:Bibliometrics; D003729:Dental Care / Q000706:statistics & numerical data*; D019232:Dental Restoration Failure / Q000706:statistics & numerical data; D006801:Humans; D053208:Kaplan-Meier Estimate; D015993:Life Tables; D016239:MEDLINE / Q000706:statistics & numerical data; D046650:Medical Subject Headings; D016019:Survival Analysis; D016896:Treatment Outcome