AN ECONOMIC MODEL TO COMPARE THE DIFFERENT EMPIRIC AND FIRST/SECOND LINE TREATMENT REGIMENS FOR SUSPECTED METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS NOSOCOMIAL PNEUMONIA IN CHINA
Appropriate and timely empiric treatment is critical for methicillin-resistant Staphylococcus aureus (MRSA)-related infections. Inadequate empiric treatment is associated with increased mortality and longer hospital stay. This study compared economic impact of empiric linezolid (Emp-LIN) vs. vancomycin (Emp-VAN) vs. no empiric MRSA coverage (NE-MRSA) before culture-confirmed treatment, for suspected MRSA nosocomial pneumonia (NP) from a Chinese payer perspective.
Method(s): A 4-week decision model was developed capturing empiric, 1st and 2nd line therapy. Published literature and expert opinion provided clinical and resource use data, including efficacy, incremental mortality for NE-MRSA, adverse events, and length of hospital/ICU stay. Cost and health utilities data were obtained from published literature. Base-case analysis used 3-day empiric, 10-day 1st/2nd-line treatment duration, 27% MRSA rate, and 1st-line linezolid for NE-MRSA after culture confirmation. MRSA negative patients exited the model after empiric treatment, and were assigned a fixed cost for remaining treatment. Univariate and probabilistic sensitivity analyses were conducted. Costs were reported in 2015 Chinese Yuan.
Result(s):
Emp-LIN was associated with marginally lower total costs (¥73,880 vs. ¥73,969), and greater QALY gain and overall treatment success compared to Emp-VAN, resulting in Emp-LIN ‘dominating’ Emp-VAN. Compared to NE-MRSA, Emp-LIN was more costly by ¥3,629, but had greater QALY gain (+0.75) and incremental treatment success (+5.3%), resulting in an incremental cost effectiveness ratio (ICER) of ¥4,825 per QALY gain, and ¥68,821 per additional successfully treated patient. Days in ICU stay, clinical efficacy, and MRSA rate impacted most on ICER. Probability of Emp-LIN being cost-effective was 73% (vs. Emp-VAN) and 99% (vs. NE-MRSA) assuming a willingness-to-pay (WTP) of ¥50,000 per additional successfully treated patients and QALY gain, respectively.
Conclusion(s): Early treatment with Emp-LIN is a cost-effective alternative to Emp-VAN and NE-MRSA at reasonable WTP threshold, and should be considered a preferred treatment choice, especially at hospitals with high MRSA rate.