Health care costs in a randomized trial of antimicrobial duration among cystic fibrosis patients with pulmonary exacerbations

Pulmonary exacerbations are clinically debilitating and expensive to treat.Ideal duration of treatment with antimicrobial medication is unknown.Clinical outcomes (lung function) were similar between treatment duration groups.Thirty-day costs were lower in groups that were randomized to receive IV treatment for shorter durations. The purpose of these analyses was to determine whether overall costs were reduced in cystic fibrosis (CF) patients experiencing pulmonary exacerbation (PEx) who received shorter versus longer durations of treatment. Among people with CF experiencing PEx, we calculated 30-day inpatient, outpatient, emergency room, and medication costs and summed these to derive total costs in 2020 USD. Using the Kaplan-Meier sample average (KMSA) method, we calculated adjusted costs and differences in costs within two pairs of randomized groups: early robust responders (ERR) randomized to receive treatment for 10 days (ERR-10 days) or 14 days (ERR-14 days), and non-early robust responders (NERR) randomized to receive treatment for 14 days (NERR-14 days) or 21 days (NERR-21 days). Patients in the shorter treatment duration groups had shorter lengths of stay per hospitalization (mean ± standard deviation (SD) for ERR-10 days: 7.9 ± 3.0 days per hospitalization compared to 10.1 ± 4.2 days in ERR-14 days; for NERR-14 days: 8.7 ± 4.9 days per hospitalization compared to 9.6 ± 6.5 days in NERR-21 days). We found statistically significantly lower adjusted mean costs (95% confidence interval) among those who were randomized to receive shorter treatment durations (ERR-10 days: $60,800 ($59,150 - $62,430) vs $74,420 ($72,610 - $76,450) in ERR-14 days; NERR-14 days: $66,690 ($65,960-$67,400) versus $74,830 ($73,980-$75,650) in NERR-21 days). Tied with earlier evidence that shorter treatment duration was not associated with worse clinical outcomes, our analyses indicate that treating with shorter antimicrobial durations can reduce costs without diminishing clinical outcomes.