Performance of pneumococcal urinary antigen test in patients with community-onset pneumonia: a propensity score-matching study

Abstract

Background/Aims: Although pneumococcal urinary antigen tests (PUATs) have universally been used for the diagnosis of pneumococcal pneumonia, data on the efficacy of these exams are limited. The objective of our study was to investigate the clinical impact of the PUAT in patients with community-onset pneumonia (CO-pneumonia). Methods: We conducted a retrospective cohort study of patients diagnosed with CO-pneumonia. Patients were classified according to their PUAT results and were matched using the propensity score-matching method. The primary outcome was 30-day mortality. Results: A total of 1,257 patients were identified and 163 (13.0%) demonstrated positive PUAT results. The sensitivity and specificity values of PUAT for overall pneumococcal pneumonia were 56.5% and 91.4%, respectively. In the full cohort, there were no significant differences in 30-day mortality between the two groups (6.1% in the positive PUAT group vs. 8.2% in the negative PUAT group, p = 0.357). However, in the propensity-matched cohort, the 30-day mortality rates were lower in the positive PUAT group (5.6% vs. 17.4%, p = 0.001). With respect to secondary outcomes, the proportion of patients with potentially drug-resistant pathogens, changes in antibiotics, and failure rates of initial antibiotic therapy were significantly lower in the positive PUAT group than in the negative PUAT group of the propensity-matched cohort. Conclusions: We found that the sensitivity of the index test was low and specificity was high in this clinical setting. And our findings suggest that positive PUAT results may be associated with favorable clinical outcomes in patients with CO-pneumonia.

Time Trend of the Sensitivity of the Pneumococcal Urinary Antigen Test for Diagnosing Pneumococcal Community-Acquired Pneumonia: An Analysis of 15-Year, Prospective Cohort Data

“…Recently, some studies have reported that the sensitivity of BinaxNOW was 50–60% [ 19 , 20 ], similar to the present result. In our view, the sensitivity of the UAT should be much higher for effective use in daily clinical practice, although the specificity is very high (90–99%) [ 9 , 10 , 41 ]. On the basis of the result of the present study, care is needed when interpreting the BinaxNOW result, even when the result is negative, especially in male patients or those without bacteraemia.…”

Bacterial etiology and pneumococcal urinary antigen in moderate exacerbation of chronic obstructive pulmonary disease

“…Because the collection of urinary samples is easier, UAT would be a very useful tool for deciding whether to prescribe antibiotics if their clinical values were proven. Lee et al showed that positive UAT results may be associated with favorable clinical outcomes after the use of antibiotics in patients with CAP ( 17 ). Nishimura et al compared the detection of S. pneumoniae by UAT and sputum culture, and they showed that UAT and sputum culture results did not match in many patients with stable COPD ( 18 ).…”