Cost-effectiveness of blood culture and a multiplex real-time PCR in hematological patients with suspected sepsis: an observational propensity score-matched study

Abstract

We evaluated the costs and clinical outcomes of episodes of suspected sepsis in hematological patients. A propensity score-matched study was planned, comparing a retrospective cohort managed with standard assays and a prospective cohort managed with the addition of a molecular assay. Diagnostic procedures and therapy were considered as costs variables. The primary clinical endpoint was sepsis-related mortality, whereas the length of each suspected sepsis episode was investigated as a secondary endpoint. A total of 137 and 138 episodes in the prospective and the retrospective cohorts were studied, respectively; 101 pairs of highly matched episodes were analyzed, evidencing a trend of higher mortality in the retrospective cohort. No difference in length of suspected sepsis episode was observed. Significant savings were observed in the prospective cohort, especially due to reduced costs in antifungal therapy. The apparently more expensive molecular assay favored a more rational use of economic resources without influencing, and probably improving, the clinical outcome.

Keywords::

• cost-effectiveness study
• health technology assessment
• molecular diagnosis
• real-time PCR
• sepsis

Financial & competing interests disclosure

The study was funded by Roche Diagnostics, which also contributed to its design with B Pizzorno. B Pizzorno did not participate directly in data analysis and in the writing of the manuscript. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• An observational, propensity score-matched study was planned, comparing episodes of systemic inflammatory response syndrome with suspected sepsis (SIRS-SS) in a retrospective cohort managed with standard assays and a prospective cohort managed with the addition of LightCycler^® SeptiFast Test.

• A total of 131 in the prospective and 134 SIRS episodes in the retrospective cohort were considered for the propensity score matching.

• Patients in the retrospective cohort showed a trend of higher SIRS-SS-related mortality (13.48 vs 8.24%; p = 0.39) than the prospective cohort.

• The higher SIRS-SS-related mortality within the retrospective cohort was confirmed, reaching statistical significance, when more stringent pairing conditions were used (14.71 vs 3.13%; p = 0.04).

• No significant differences in the average length of SIRS-SS episodes were observed between the two cohorts.

• No significant differences were observed in costs for traditional diagnostic assays and instrumental procedures per each SIRS-SS episode between the two cohorts, although using the more expensive SeptiFast in the prospective cohort.

• A net saving (€457.86; p < 0.05) was observed per each SIRSS-SS episode in the prospective cohort when considering therapeutic charges, in particular due to significant saving in empirical antifungal therapy.

• The apparently more expensive combined use of traditional blood culture-based assays with a molecular assay in the management of SIRS-SS episodes resulted in a more rational use of economic resources without affecting, and probably improving, the clinical outcome.

Notes