TY - JOUR

T1 - Fatigue in patients with spinal muscular atrophy type II and congenital myopathies

T2 - evaluation of the fatigue severity scale

AU - Werlauff, Ulla

AU - Højberg, A

AU - Firla-Holme, R

AU - Steffensen, B F

AU - Vissing, J

PY - 2014/6

Y1 - 2014/6

N2 - PURPOSE: The aim of this study was to evaluate whether the fatigue severity scale (FSS) is an appropriate instrument to assess fatigue in patients with spinal muscular atrophy type II (SMA II) and congenital myopathies (CM).METHODS: FSS and visual analog scale (VAS) were administered to 33 SMA II- and 72 CM patients. The psychometric properties of the FSS were evaluated by means of classical test theories for each of the disease groups. If abnormal fatigue was present in the disease group, the construct of fatigue was evaluated by means of focus group interviews.RESULTS: Fatigue was rare in SMA II patients, but very frequent in patients with CM. The cut-off score designating abnormal fatigue (FSS score ≥ 4) was exceeded by 10% of the SMA II patients in contrast to 76% of the CM patients, of whom 52% suffered from severe fatigue (FSS score ≥ 5). Focus group interviews demonstrated that fatigue had an adverse effect on motor function, level of energy, social relations, and identity, four themes that could be captured by the FSS. The FSS and VAS were strongly correlated in SMA II patients, but only moderately in CM patients. The psychometric properties indicated that the original FSS with nine items measures more than one construct of fatigue, eliminating the first two items improved scale properties.CONCLUSION: This study demonstrates that fatigue is characteristic in patients with CM, but not in patients with SMA II, in whom fatigue does not seem to impact daily life. While fatigue in CM and SMA II can be captured by FSS, omitting the first two items of the scale will improve its properties and content validity, along with comprehension of the scale itself.

AB - PURPOSE: The aim of this study was to evaluate whether the fatigue severity scale (FSS) is an appropriate instrument to assess fatigue in patients with spinal muscular atrophy type II (SMA II) and congenital myopathies (CM).METHODS: FSS and visual analog scale (VAS) were administered to 33 SMA II- and 72 CM patients. The psychometric properties of the FSS were evaluated by means of classical test theories for each of the disease groups. If abnormal fatigue was present in the disease group, the construct of fatigue was evaluated by means of focus group interviews.RESULTS: Fatigue was rare in SMA II patients, but very frequent in patients with CM. The cut-off score designating abnormal fatigue (FSS score ≥ 4) was exceeded by 10% of the SMA II patients in contrast to 76% of the CM patients, of whom 52% suffered from severe fatigue (FSS score ≥ 5). Focus group interviews demonstrated that fatigue had an adverse effect on motor function, level of energy, social relations, and identity, four themes that could be captured by the FSS. The FSS and VAS were strongly correlated in SMA II patients, but only moderately in CM patients. The psychometric properties indicated that the original FSS with nine items measures more than one construct of fatigue, eliminating the first two items improved scale properties.CONCLUSION: This study demonstrates that fatigue is characteristic in patients with CM, but not in patients with SMA II, in whom fatigue does not seem to impact daily life. While fatigue in CM and SMA II can be captured by FSS, omitting the first two items of the scale will improve its properties and content validity, along with comprehension of the scale itself.

KW - Activities of Daily Living

KW - Adult

KW - Denmark

KW - Fatigue

KW - Female

KW - Focus Groups

KW - Humans

KW - Interpersonal Relations

KW - Interviews as Topic

KW - Male

KW - Neuromuscular Diseases

KW - Psychometrics

KW - Qualitative Research

KW - Reproducibility of Results

KW - Severity of Illness Index

KW - Sickness Impact Profile

KW - Spinal Muscular Atrophies of Childhood

KW - Visual Analog Scale

U2 - 10.1007/s11136-013-0565-8

DO - 10.1007/s11136-013-0565-8

M3 - Journal article

C2 - 24214178

VL - 23

SP - 1479

EP - 1488

JO - Quality of Life Research

JF - Quality of Life Research

SN - 0962-9343

IS - 5

ER -