The fatigue descriptive scale (FDS): a useful tool to evaluate fatigue in multiple sclerosis

Although fatigue is common among multiple sclerosis (MS) patients, evaluati on of this symptom is difficult due to the subjectivity and variability of the complaint We proposed the Fatigue Descriptive Scale (FDS) as a tool to evaluate the severity and quality of fatigue in a group of patients sufferi ng from MS. As a way to demonstrate the usefulness of this scale we applied the FDS in a group of 155 patients (105 women and 50 men) with clinically- definite multiple sclerosis, as outlined according to Poser's criteria. Age was 36.2 +/- 11.1 years (range 12-62) and time of evolution was 8.3+/-9.4 years (range 1-44). The Fatigue Severity Scale (FSS) was also used. Descrip tive statistics techniques and techniques for nonparametric distribution (S pearman Rank, Kruskal-Wallis ANOVA) were used. One hundred and eighteen pat ients reported fatigue (73 spontaneously, 45 when questioned). All descript ions of fatigue were ranked according to FDS categories. Eighty-five patien ts defined the symptom as fatigue with exercise, 26 as asthenia and seven a s the worsening of other symptoms. Fatigue by itself produced limited or di srupted activity in 78 patients; work-related functions were limited in 48 patients; social relations were limited in 29 patients; and self-care was d ifficult for one patient Fifty-six patients suffered fatigue daily. FDS sco re was 4.9 +/- 3.9 (range 0-13). FSS was 3.1 +/- 1.7 (range 0.2-6.6). FDS a nd FSS of Krupp were highly correlated (R = 0.87, p < 0.001). Therefore, in comparison with other scales, the FDS shows remarkable usefulness in class ifying, periodicity and severity of fatigue in MS patients. The high correl ation with the FSS implies that it is a valid method to measure the severit y of fatigue as was demonstrated in our paper proposing the FDS. The import ance of this new scale is its ability to inform the clinicians in a very qu ick, easy, and at the some time complete way, how severe the fatigue really is and how it effects the patient.