title: Dry Eye Disease: Concordance Between the Diagnostic Tests in African Eyes.
abstract: OBJECTIVE
  To assess the concordance between the diagnostic tests for dry eye disease (DED) in a Nigerian hospital population.
  
  
  METHODS
  The study was a hospital-based cross-sectional survey of adults (≥18 years) presenting at the eye clinic of the University of Nigeria Teaching Hospital (UNTH), Enugu; September-December, 2011. Participants' socio-demographic data were collected. Each subject was assessed for DED using the "Ocular Surface Disease Index" (OSDI) questionnaire, tear-film breakup time (TBUT), and Schirmer test. The intertest concordance was assessed using kappa statistic, correlation, and regression coefficients.
  
  
  RESULTS
  The participants (n=402; men: 193) were aged 50.1±19.1 standard deviation years (range: 18-94 years). Dry eye disease was diagnosed in 203 by TBUT, 170 by Schirmer test, and 295 by OSDI; the concordance between the tests were OSDI versus TBUT (Kappa, κ=-0.194); OSDI versus Schirmer (κ=-0.276); and TBUT versus Schirmer (κ=0.082). Ocular Surface Disease Index was inversely correlated with Schirmer test (Spearman ρ=-0.231, P<0.001) and TBUT (ρ=-0.237, P<0.001). In the linear regression model, OSDI was poorly predicted by TBUT (β=-0.09; 95% confidence interval (CI): -0.26 to -0.03, P=0.14) and Schirmer test (β=-0.35, 95% CI: -0.53 to -0.18, P=0.18).
  
  
  CONCLUSIONS
  At UNTH, there is poor agreement, and almost equal correlation, between the subjective and objective tests for DED. Therefore, the selection of diagnostic test for DED should be informed by cost-effectiveness and diagnostic resource availability, not diagnostic efficiency or utility.
authors.affiliation: Department of Ophthalmology, University of Nigeria Teaching Hospital, Enugu, Nigeria.
authors.forename: Stella N
authors.initials: SN
authors.lastname: Onwubiko
authors.forename: Boniface I
authors.initials: BI
authors.lastname: Eze
authors.forename: Nnenma N
authors.initials: NN
authors.lastname: Udeh
authors.forename: Ernest N
authors.initials: EN
authors.lastname: Onwasigwe
authors.forename: Rich E
authors.initials: RE
authors.lastname: Umeh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044383:Black People; D003430:Cross-Sectional Studies; D003941:Diagnostic Techniques, Ophthalmological / Q000592:standards*; D015352:Dry Eye Syndromes / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods / Q000592:standards; D008875:Middle Aged; D009549:Nigeria; D012044:Regression Analysis; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires / Q000592:standards; D013666:Tears; D055815:Young Adult