title: The quick motor function test: a new tool to rate clinical severity and motor function in Pompe patients.
abstract: Pompe disease is a lysosomal storage disorder characterized by progressive muscle weakness. With the emergence of new treatment options, psychometrically robust outcome measures are needed to monitor patients' clinical status. We constructed a motor function test that is easy and quick to use. The Quick Motor Function Test (QMFT) was constructed on the basis of the clinical expertise of several physicians involved in the care of Pompe patients; the Gross Motor Function Measure and the IPA/Erasmus MC Pompe survey. The test comprises 16 items. Validity and test reliability were determined in a cohort of 91 Pompe patients (5 to 76 years of age). In addition, responsiveness of the scale to changes in clinical condition over time was examined in a subgroup of 18 patients receiving treatment and 23 untreated patients. Interrater and intrarater reliabilities were good (intraclass correlation coefficients: 0.78 to 0.98 and 0.76 to 0.98). The test correlated strongly with proximal muscle strength assessed by hand held dynamometry and manual muscle testing (rs= 0.81, rs=0.89), and showed significant differences between patient groups with different disease severities. A clinical-empirical exploration to assess responsiveness showed promising results, albeit it should be repeated in a larger group of patients. In conclusion, the Quick Motor Function Test can reliably rate clinical severity and motor function in children and adults with Pompe disease.
authors.affiliation: Department of Pediatrics, Division of Metabolic Diseases and Genetics, Center for Lysosomal and Metabolic Diseases, Erasmus MC University Medical Center, Postbus 2060, 3000 CB, Rotterdam, the Netherlands.
authors.forename: Carine I
authors.initials: CI
authors.lastname: van Capelle
authors.forename: Nadine A M E
authors.initials: NA
authors.lastname: van der Beek
authors.forename: Juna M
authors.initials: JM
authors.lastname: de Vries
authors.forename: Pieter A
authors.initials: PA
authors.lastname: van Doorn
authors.forename: Hugo J
authors.initials: HJ
authors.lastname: Duivenvoorden
authors.forename: Robert T
authors.initials: RT
authors.lastname: Leshner
authors.forename: Marloes L C
authors.initials: ML
authors.lastname: Hagemans
authors.forename: Ans T
authors.initials: AT
authors.lastname: van der Ploeg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004185:Disability Evaluation; D005260:Female; D006009:Glycogen Storage Disease Type II / Q000175:diagnosis* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D017063:Outcome Assessment, Health Care; D011594:Psychometrics; D015203:Reproducibility of Results; D015996:Survival Rate; D055815:Young Adult