Standardized Treatment of Pulmonary Exacerbations (STOP) study: Observations at the initiation of intravenous antibiotics for cystic fibrosis pulmonary exacerbations

Abstract

Background: The Standardized Treatment of Pulmonary Exacerbations (STOP) program has the intent of defining best practices in the treatment of pulmonary exacerbations (PEx) in patients with cystic fibrosis (CF). The objective of this analysis was to describe the clinical presentations of patients admitted for intravenous (IV) antibiotics and enrolled in a prospective observational PEx study as well as to understand physician treatment goals at the start of the intervention.

Methods: We enrolled adolescents and adults admitted to the hospital for a PEx treated with IV antibiotics. We recorded patient and PEx characteristics at the time of enrollment. We surveyed treating physicians on treatment goals as well as their willingness to enroll patients in various study designs. Additional demographic and clinical data were obtained from the CF Foundation Patient Registry.

Results: Of 220 patients enrolled, 56% were female, 19% were adolescents, and 71% were infected with P. aeruginosa. The mean (SD) FEV₁ at enrollment was 51.1 (21.6)% predicted. Most patients (85%) experienced symptoms for ≥7days before admission, 43% had received IV antibiotics within the previous 6months, and 48% received oral and/or inhaled antibiotics prior to IV antibiotic initiation. Forty percent had ≥10% FEV₁ decrease from their best value recorded in the previous 6months, but for 20% of patients, their enrollment FEV₁ was their best FEV₁ recorded within the previous 6months. Physicians reported that their primary treatment objectives were lung function recovery (53%) and improvement of symptoms (47%) of PEx. Most physicians stated they would enroll patients in studies involving 10-day (72%) or 14-day (87%), but not 7-day (29%), treatment regimens.

Conclusions: Based on the results of this study, prospective studies are feasible and physician willingness for interventional studies of PEx exists. Results of this observational study will help design future PEx trials.

Keywords: FEV(1); Pseudomonas aeruginosa; Symptoms.

Figure 1

Study design for STOP.

Figure 2

Mean absolute (A) and relative (B) change from 12-month and 6-month best FEV₁ % predicted at the time of enrollment. Sample sizes are shown adjacent to point estimates. Vertical bars represent 95% confidence intervals.

Figure 3

Absolute difference between specified target FEV₁ (% predicted) and admission FEV₁ (% predicted), and absolute difference between specified target FEV₁ (% predicted) and best FEV₁ (% predicted) 6 months prior. Numbers adjacent indicate the number of patients included.