A. Elsolh et al., VALIDITY OF A DECISION TREE FOR PREDICTING ACTIVE PULMONARY TUBERCULOSIS, American journal of respiratory and critical care medicine, 155(5), 1997, pp. 1711-1716
Citations number
19
Categorie Soggetti
Emergency Medicine & Critical Care","Respiratory System
The recent outbreaks of multidrug-resistant strains of M. tuberculosis
in health care facilities has increased concern over its transmission
in health care facilities. Isolation has been recommended for all pat
ients suspected to have tuberculosis even though the feasibility and t
he cost of this recommendation can be substantial. We have developed a
classification tree using clinical and radiographic data from 277 iso
lation episodes in patients admitted between August 1992 and March 199
4 who required isolation for suspicion of tuberculosis. The classifica
tion tree was developed with a sensitivity and negative predictive val
ue of 100% by binary recursive partitioning to predict those patients
who are unlikely to require isolation. The predictor variables were up
per zone disease on chest radiograph, a history of fever, weight loss,
and CD4 count. The tree was validated in a separate cohort of 286 iso
lation episodes between April f994 and December 1995. In this validati
on cohort, no erroneous prediction was made of not isolating a patient
with active pulmonary tuberculosis. The classification tree had a sen
sitivity of 100% (95% confidence interval [CI]: 92.5 to 100%), a speci
ficity of 48.1% (95% CI: 43.8 to 52.4%), and a negative predictive val
ue of 100% (95% CI: 98.5 to 100%). We estimate that the use of the tre
e could have reduced the number of patients requiring isolation by mor
e than 40% without increasing the risk of cross infection.