The Hunter Syndrome-Functional Outcomes for Clinical Understanding Scale (HS-FOCUS) Questionnaire: evaluation of measurement properties
- 312 Downloads
This study was to conduct the psychometric validation of the patient and parent versions of the Hunter Syndrome-Functional Outcomes for Clinical Understanding Scale (HS-FOCUS).
Data collected in a 53-week placebo-controlled multinational trial were used to evaluate item performance and reliability, validity, and ability to detect change of the six HS-FOCUS function domains.
HS-FOCUS was completed by 49 patients above 12 years old and 84 parents. Floor effects and high average inter-item correlations suggested that some items were less informative or redundant. For both patients and parents, the internal consistency and test–retest reliability met the >0.70 criteria for all domains except for the breathing, sleeping, and schooling/work in patients. Construct validity showed moderate to high correlations with CHAQ, CHQ, and HUI3 in activity-related concepts. Significant differences in domain scores were found in most domains among severity in disability measured by CHAQ DIS. Significant differences in HS-FOCUS change scores were found in patients whose CHAQ DIS score also changed.
Psychometric validation of the HS-FOCUS demonstrates it is a reliable, valid, and responsive instrument that can be applied in clinical trials or disease registries. Findings on the individual item performance suggest some items could be removed without compromising its validity.
KeywordsHunter syndrome Mucopolysaccharidosis type II Lysosomal storage disease Patient-reported outcomes Hunter Syndrome-Functional Outcomes for Clinical Understanding Scale (HS-FOCUS)
Six-minute walk test
Analysis of covariance
Analysis of variance
Change in Health
Childhood Health Assessment Questionnaire
Childhood Health Questionnaire
Child Health Questionnaire-Child Form
Child Health Questionnaire-Parent Form
Disability Index Score
Forced expiratory volume
Functional Independence Measure
Forced vital capacity
General Health Perceptions
Health-related quality of life
Hunter Syndrome-Functional Outcomes for Clinical Understanding Scale
Health Utilities Index
Intraclass correlation coefficient
- MPS II
Mucopolysaccharidosis type II
Pediatric Outcomes Data Collection Instrument
Role/Social–Emotional and the Role/Social–Behavioral
World Health Organization International Classification of Impairment, Disability and Handicap
- 1.Alcalde-Martin, C., Muro-Tudelilla, J. M., Cancho-Candela, R., Gutierrez-Solana, L. G., Pintos-Morell, G., Marti-Herrero, M., et al. (2010). First experience of enzyme replacement therapy with idursulfase in Spanish patients with Hunter syndrome under 5 years of age: Case observations from the Hunter Outcome Survey (HOS). European Journal of Medical Genetics, 53(6), 371–377.PubMedCrossRefGoogle Scholar
- 6.Keilmann, A., Nakarat, T., Bruce, I. A., Molter, D., Malm, G., & on behalf of the HOS Investigators. Hearing loss in patients with mucopolysaccharidosis II: Data from HOS—the hunter outcome survey.Google Scholar
- 8.World Health Organization (WHO). (1999). WHO ear and hearing disorders survey protocol for a population-based survey of prevalence and causes of deafness and hearing impairment and other ear disorders. Retrieved April 14, 2011, from http://whqlibdoc.who.int/hq/1999/WHO_PBD_PDH_99.8(1).pdf.
- 10.Tran, K. T., Gold, K. F., Stephens, J. M., Kimura, A., & Muenzer, J. The development and validation of the hunter syndrome—functional outcomes for clinical understanding scale.Google Scholar
- 11.Abt. Associates. (2004). Clinical trials. Confirmatory validation study of the CHAQ. Video documentation of functional tasks, and development of a new supplement Questionnaire to assess functional status in hunter syndrome. Final Report.Google Scholar
- 13.Landgraf, J. M., Abetz, L. N., & Ware, J. E. (1999). The CHQ user’s manual. Boston: The Health Institute, New England Medical Center.Google Scholar
- 17.StataCorp. (2009). Stata statistical software: Release 11. College Station, TX: StataCorp LP.Google Scholar
- 19.Hays, R. D., & Revicki, D. A. (2005). Assessing reliability and validity of measurement in clinical trials. In P. Fayers & R. D. Hays (Eds.), Quality of life assessment in clinical trials: Methods and practice (2nd ed.). New York: Oxford University Press.Google Scholar
- 20.Nunnally, J. C., & Bernstein, I. H. (1994). Psychometric theory (3rd ed.). New York: McGraw-Hill.Google Scholar
- 24.Daltroy, L. H., Liang, M. H., Fossel, A. H., & Goldberg, M. J. (1998). The POSNA pediatric musculoskeletal functional health questionnaire: Report on reliability, validity, and sensitivity to change. Pediatric Outcomes Instrument Development Group. Pediatric Orthopaedic Society of North America. Journal of Pediatric Orthopedics, 18(5), 561–571.PubMedGoogle Scholar