Purpose: To assess the healthcare resource utilization (HCRU) and costs from a Chinese payer's perspective (Nanjing city) for MRSA-NP in hospitalized adults treated with linezolid or vancomycin, including the economic impact of renal failure.
Method: A post-hoc analysis was conducted using data from a phase IV, randomized, double-blind, global multicenter study (Wunderink, CID: 2012, NCT00084266) in culture-proven MRSA-NP patients [microbiologic confirmed intent-to-treat (MITT) cohort]. Renal failure was defined by ≥1 of the following: 1) investigator-reported renal failure adverse events; 2) acute kidney injury defined renal failure using RIFLE criteria; 3) initiated dialysis after study drug started. HCRU from treatment initiation through end of study visit (EOS) included study drug use, mechanical ventilator (MV) days, intensive care unit (ICU) days, length of stay (LOS), and dialysis days. Chinese costs were calculated by applying Nanjing-specific unit costs (2012 ¥) to the HCRU collected from the global trial. Between-group differences were tested using chi-square test for renal failure rates and t test for HCRU/costs, and the non-parametric Wilcoxon rank-sum test for comparisons with sample size < 30.
Result: MITT patients (224 linezolid/224 vancomycin) were followed for 23.3±10.1 days (linezolid 23.0±10.0, vancomycin 23.6±10.2), with 39% hospitalized at EOS for both linezolid and vancomycin. Linezolid vs. vancomycin had similar total costs: ¥77,089±¥51,211 vs. ¥77,695±¥52,450, p=0.90. Linezolid patients had a significantly lower incidence of renal failure vs. vancomycin (4% [n=9] vs. 15% [n=34], p<0.001). Patients with renal failure (vs. no renal failure) had significantly more MV days (12.0±9.9 vs. 7.8±9.0, p=0.004) and ICU days (13.5±9.9 vs. 10.0±8.5, p=0.013), similar LOS (18.8±9.8 vs. 18.2±9.6, p=0.74) and incurred higher total costs ¥100,449±¥65,080 vs. ¥74,944±¥49,632, p=0.002, Table 1). linezolid-treated (vs. vancomycin-treated) patients who developed renal failure trended towards lower HCRU (MV days: 7.6±3.6 vs.13.2±10.7, p=0.21; ICU days: 9.9±6.6 vs. 14.4±10.5, p=0.30; LOS: 16.1±11.0 vs. 19.5±9.5, p=0.26) and, when correcting for mortality differences using a per-person day approach tended to incur lower per person-day total cost (¥4,805±¥1,930 vs. ¥5,347±¥2,395, p=0.32). Table 1 reports the unadjusted mean costs for various cohorts.
Conclusion: Linezolid was associated with a significantly lower incidence of renal failure than vancomycin. HCRU and costs from a Chinese (Nanjing) payer perspective were similar between linezolid and vancomycin. Patients who developed renal failure incurred more HCRU and greater costs versus those who did not.