In patients with paroxysmal nocturnal hemoglobinuria (PNH), a 5-point change marks the clinically important change (CIC) in the functional assessment of chronic illness therapy-fatigue (FACIT-Fatigue) scale for gauging a meaningful treatment response.

These findings from the prospective, observational, noninterventional International PNH Registry have been published recently in the Journal of Patient-Reported Outcomes.

Among individuals with PNH, fatigue is the most frequently reported symptom, which is associated with declines in quality of life. FACIT-Fatigue, which was designed originally in response to the need for a more accurate method to evaluate fatigue linked to anemia in patients with cancer, was later used to assess fatigue in patients with other conditions, such as PNH. Use of the tool has been authenticated in individuals with PNH, with the FACIT-Fatigue scale utilized extensively in clinical trials.

In the FACIT-Fatigue scale used in PNH, there are 13 separate items, with each item scored from 0 to 4. A maximum score of 52 is possible, and higher scores are indicative of lower levels of fatigue. Each of the 13 questions on FACIT-Fatigue has the following 5 response options: 1) not at all, 2) a little bit, 3) somewhat, 4) quite a bit, and 5) very much.

Read more about experimental therapies for patients with PNH

In the current analysis, the investigators sought to estimate those values that would imply a CIC in the FACIT-Fatigue scale among patients with PNH. Patients 18 years of age or older enrolled in the International PNH Registry as of January 18, 2021, were included.

All study participants needed to have begun treatment with the recombinant humanized monoclonal antibody eculizumab within 21 days of enrollment in the registry and not to have received treatment with a noneculizumab anticomplement such as ravulizumab prior to enrollment. Study participants also needed to have baseline FACIT-Fatigue scores available.

In all study participants, FACIT-Fatigue scores were evaluated at baseline, as well as at 6, 12, 24, and 36 months of follow-up. Clinical outcome variables included the number of red blood cell transfusion units within the 12 months prior to initiating anticomplement treatment, along with the following multiple-item outcomes, both of which are subscales within the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30): EORTC Global Health Status/Quality of Life summary score and EORTC Fatigue Scale score.

The analysis population included 423 participants. At baseline, 93% of the patients had fatigue documented in their medical records. The researchers reported that a 5-point change on FACIT-Fatigue is meaningful in individuals with PNH.

“These results support the use of 5 points as the CIC for FACIT-Fatigue in patients with PNH, which is within the range of the CICs reported in other diseases (3-5 points),” they concluded.


Cella D, Johansson P, Ueda Y, et al. Clinically important change for the FACIT-Fatigue scale in paroxysmal nocturnal hemoglobinuria: a derivation from international PNH registry patient data. J Patient Rep Outcomes. Published online July 5, 2023. doi:10.1186/s41687-023-00609-4