title: The Bandim TBscore--reliability, further development, and evaluation of potential uses.
abstract: BACKGROUND
  The tuberculosis (TB) case detection rate has stagnated at 60% due to disorganized case finding and insensitivity of sputum smear microscopy. Of the identified TB cases, 4% die while being treated, monitored with tools that insufficiently predict failure/mortality.
  
  
  OBJECTIVE
  To explore the TBscore, a recently proposed clinical severity measure for pulmonary TB (PTB) patients, and to refine, validate, and investigate its place in case finding.
  
  
  METHODS
  The TBscore's inter-observer agreement was assessed and compared to the Karnofsky Performance Score (KPS) (paper I). The TBscore's variables underlying constructs were assessed, sorting out unrelated items, proposing a more easily assessable TBscoreII, which was validated internally and externally (paper II). Finally, TBscore and TBscoreII's place in PTB-screening was examined in paper III.
  
  
  RESULTS
  The inter-observer variability when grading PTB patients into severity classes was moderate for both TBscore (κW=0.52, 95% CI 0.46-0.56) and KPS (κW=0.49, 95% CI 0.33-0.65). KPS was influenced by HIV status, whereas TBscore was unaffected by it. In paper II, proposed TBscoreII was validated internally, in Guinea-Bissau, and externally, in Ethiopia. In both settings, a failure to bring down the score by ≥25% from baseline to 2 months of treatment predicted subsequent failure (p=0.007). Finally, in paper III, TBscore and TBscoreII were assessed in health-care-seeking adults and found to be higher in PTB-diagnosed patients, 4.9 (95% CI 4.6-5.2) and 3.9 (95% CI 3.8-4.0), respectively, versus patients not diagnosed with PTB, 3.0 (95% CI 2.7-3.2) and 2.4 (95% CI 2.3-2.5), respectively. Had we referred only patients with cough >2 weeks to sputum smear, we would have missed 32.1% of the smear confirmed cases in our cohort. A TBscoreII>=2 missed 8.6%.
  
  
  CONCLUSIONS
  TBscore and TBscoreII are useful monitoring tools for PTB patients on treatment, as they could fill the void which currently exists in risk grading of patients. They may also have a role in PTB screening; however, this requires our findings to be repeated elsewhere.
authors.affiliation: Bandim Health Project, INDEPTH Network, Bissau, Guinea-Bissau; Department of Infectious Diseases, Aarhus University Hospital, Aarhus, Denmark; frauke.rudolf@ki.au.dk.
authors.forename: Frauke
authors.initials: F
authors.lastname: Rudolf
mesh_terms: D000293:Adolescent; D000328:Adult; D003661:Decision Support Techniques; D005188:False Negative Reactions; D005260:Female; D006169:Guinea-Bissau / Q000453:epidemiology; D015658:HIV Infections / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D008297:Male; D008403:Mass Screening; D015588:Observer Variation; D011159:Population Surveillance; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000453:epidemiology; D055815:Young Adult
keywords: case finding; clinical score; diagnosis; health status indicator; low-resource setting; mortality prediction; reliability; triage