Photo Credit: Oksana Horiun

Researchers found the CFRSD-CRISS score is an effective predictor of lung function recovery after a pulmonary exacerbation in cystic fibrosis.

Pulmonary exacerbation (PE) is a significant health risk for people with cystic fibrosis (CF) in that it can substantially worsen respiratory symptoms, decrease QOL, and increase morbidity and mortality. PEs are also a primary driver of lung function decline in patients with CF, putting them at risk for respiratory failure.

According to the authors of a recent study in Pulmonary Medicine, tools that can predict failure to recover lung function after PE onset can be valuable in developing appropriate treatment strategies.

CFRSD-CRISS

Clinicians use the Cystic Fibrosis Respiratory Symptom Diary (CFRSD)–Chronic Respiratory Infection Symptom Scale (CRISS) to gauge symptom burden in patients with CF after PE. However, this tool has not been studied to predict poor recovery risk after PE onset.

To explore this possibility, Eliana Gill, PhD, RN, and colleagues developed a secondary analysis of a longitudinal, observational study that investigated outcomes and systemic measurements of inflammation resulting from antibiotic therapy in patients with CF who have experienced a PE.

The researchers included patients if they had completed their percent predicted forced expiratory volume in one second (ppFEV₁) information as part of the primary inflammation study; the analysis included 56 patients. Of these, 52 were non-Hispanic White, 37 were female, and the mean age was 25.1 years (SD, 9.81). Forty-four of the participants were positive for P. aeruginosa. The median length of hospital stay was 16 nights, and the median time for IV antibiotics administered in the home was 12 nights. Thirty-eight participants did not use oxygen over the year, and 49 did not use oxygen at the start of their PE treatment regimen. No participants had a history of smoking.

Checkpoints in Treatment

The researchers identified four time points to gain perspective on the predictive value of CFRSD-CRISS:

1. the well-visit from the year prior to the patient’s enrollment in the study (Annual Visit);
2. the first 24 hours of initiation of IV treatment for a PEx episode (Visit 1);
3. the completion or near completion of IV antibiotic treatment, usually occurring at days 10-21 (Visit 2); and
4. two weeks after the hospitalization and completion of the IV treatment and termination of oral antibiotic treatment (Visit 3).

At the Annual Visit, the recorded mean ppFEV₁ was 58.4% (SD, 21.6); at Visit 1, it was 52.28% (SD, 20.24), and at Visit 2, it was 60.59% (SD, 23.65). Thirty-four participants recovered their baseline lung function after the PE.

When comparing data from the Annual Visit with that of Visit 2, the researchers found the average amount of recovered lung function was 1.52% (SD, 4.35; range, -6.28%-12.8%). Researchers noted, however, that 39.3% of participants did not fully recover their initial baseline lung function. Furthermore, 10.4% of patients could not recover their lung function within 10% of their recorded baseline by Visit 2.

Symptom Burden

The researchers applied the CRISS score to gauge symptom burden at the designated check-in times. At Visit 1, participants had a mean CRISS score of 44.75 (SD, 10.67); at Visit 2, the mean score was 23.69 (SD, 14.83). Researchers noted that with the administration of the IV antibiotic treatment, symptom burden significantly improved (P<0.001). CRISS scores also increased after systemic antibiotic treatment ended.

When controlling for age, sex, and P. aeruginosa infection, the CRISS score at Visit 1 significantly predicted the patient’s inability to recover ppFEV₁ by Visit 2.

“The model results predict that recovery of lung function decreased by 0.2%-predicted points for every increase in CRISS points, indicating that participants with a CRISS score greater than 48.3 were at 14% greater risk of not recovering to baseline lung function by Visit 2 than people with lower scores when all else is held constant,” Dr. Gill and colleagues wrote.

“A post-hoc sensitivity analysis… included baseline lung function as a control variable; the sensitivity analysis showed that higher CRISS scores continued to significantly predict (P<0.01) failure to return to baseline lung function by Visit 2.”