Missed Opportunities to Diagnose Tuberculosis Are Common Among Hospitalized Patients and Patients Seen in Emergency Departments

Abstract

Background. Delayed diagnosis of tuberculosis (TB) may lead to worse outcomes and additional TB exposures. Methods. To estimate the potential number of misdiagnosed TB cases, we linked all hospital and emergency department (ED) visits in California's Healthcare Cost and Utilization Project (HCUP) databases (2005-2011). We defined a potential misdiagnosis as a visit with a new, primary diagnosis of TB preceded by a recent respiratory-related hospitalization or ED visit. Next, we calculated the prevalence of potential missed TB diagnoses for different time windows. We also computed odds ratios (OR) comparing the likelihood of a previous respiratory diagnosis in patients with and without a TB diagnosis, controlling for patient and hospital characteristics. Finally, we determined the correlation between a hospital's TB volume and the prevalence of potential TB misdiagnoses. Results. Within 30 days before an initial TB diagnosis, 15.9% of patients (25.7% for 90 days) had a respiratory-related hospitalization or ED visit. Also, within 30 days, prior respiratory-related visits were more common in patients with TB than other patients (OR = 3.83; P < .01), controlling for patient and hospital characteristics. Respiratory diagnosis-related visits were increasingly common until approximately 90 days before the TB diagnosis. Finally, potential misdiagnoses were more common in hospitals with fewer TB cases (ρ = -0.845; P < .01). Conclusions. Missed opportunities to diagnose TB are common and correlate inversely with the number of TB cases diagnosed at a hospital. Thus, as TB becomes infrequent, delayed diagnoses may increase, initiating outbreaks in communities and hospitals.

Keywords: missed diagnosis; transmission; tuberculosis.

Figure 1.

Counts of patients with and without a respiratory diagnosis in a previous visit for different potential misdiagnosis windows. (A) Patients with tuberculosis (TB) are more likely to have a previous respiratory diagnosis than a nonrespiratory diagnosis for all time windows considered. (B) Patients without TB are far less likely to have a respiratory diagnosis than a nonrespiratory diagnosis for any window used.

Figure 2.

Adjusted odds ratios contrasting the odds of tuberculosis (TB) patients, with a previous visit in a given potential-misdiagnosis window, having a respiratory diagnosis relative to patients without TB. The TB patients are significantly more likely to have a respiratory diagnosis in a previous visit than patients without TB.