Diagnostic Stewardship in CAP with Syndromic Molecular Testing
Clinical question: Does syndromic polymerase chain reaction (PCR)-based testing of lower respiratory tract samples in patients hospitalized with community-acquired pneumonia (CAP) lead to faster pathogen-directed treatment?
Background: CAP is a leading cause of hospital admissions and mortality, yet most patients do not receive a microbiological diagnosis and targeted treatment. Culture-based methods can have low yields and are insufficient to influence early decisions on antimicrobial therapy. Rapid syndromic PCR-based panels can potentially facilitate pathogen-directed treatment, but limited evidence currently supports their routine use.
Study design: Parallel-arm, single-blinded, single-center, randomized, clinical superiority trial
Setting: Emergency department of a large tertiary care hospital in Bergen, Norway
Synopsis: Patients with suspected CAP were randomized into receiving syndromic PCR testing plus standard-of-care microbiological diagnostics or standard microbiological diagnostics alone. The study included 374 patients, with 187 randomized to each arm. Both arms showed similar patient characteristics. Patients were 40.9% female with a median age of 72 years. CAP was diagnosed in 208 patients, and 200 patients (97 in the intervention arm versus 103 in the standard arm) provided a lower respiratory tract sample. The two primary outcomes were provision of pathogen-directed treatment, and time to pathogen-directed treatment. At 48 hours, patients were more likely to receive pathogen-directed treatment in the intervention arm (35.3% versus 13.4%; OR, 3.53; 95% CI, 2.13 to 6.02; P <.001). Patients were also more likely to receive earlier pathogen-directed treatment in the intervention arm (mean difference, −9.4 hours; 95% CI, −12.7 to −6.0 hours; P <.001). Among those diagnosed with CAP, patients in the intervention arm were also more likely to receive pathogen-directed treatment at 48 hours (47.4% versus 15.5%, OR, 4.9; 95% CI, 2.57 to 9.77; P <.001) and received earlier pathogen-directed treatment (mean difference, −12.3 hours; 95% CI, −17.3 to −7.3 hours; P <.001). No differences were found in length of stay or clinical outcomes. The main limitation was that the trial was stopped early for efficacy.
Bottom line: Early PCR testing of lower respiratory tract samples for patients hospitalized with suspected CAP hastens more targeted microbial treatment.
Citation: Markussen DL, Serigstad S, et al. Diagnostic stewardship in community-acquired pneumonia with syndromic molecular testing: a randomized clinical trial. JAMA Netw Open. 2024;7(3):e240830. doi:10.1001/jamanetworkopen.2024.0830
Dr. Adrià Jiménez Bacardí is an academic hospitalist in the division of hospital medicine and a health sciences assistant professor of medicine at the University of California in San Diego.