Joint hypermobility syndrome subclassification in paediatrics: a factor analytic approach
- 1Physiotherapy Department, The Children's Hospital at Westmead, Sydney, Australia
- 2Kids Rehab, The Children's Hospital at Westmead, Sydney, Australia
- 3Discipline of Biomedical Sciences, Sydney Medical School, The University of Sydney, Sydney, Australia
- 4Discipline of Physiotherapy, Faculty of Health Sciences, The University of Sydney, Sydney, Australia
- 5Discipline of Paediatrics and Child Health, Sydney Medical School, The University of Sydney, Sydney, Australia
- 6Endocrinology Department, The Children's Hospital at Westmead, Sydney, Australia
- Correspondence to Verity Pacey, Physiotherapy Department, The Children's Hospital at Westmead, Locked Bag 4001, Westmead, NSW 2145, Australia;
- Received 24 September 2013
- Revised 9 April 2014
- Accepted 28 April 2014
- Published Online First 26 May 2014
Objective To determine if exploratory factor analysis can identify subtypes comprising recognisable clinical patterns of the presenting signs and symptoms of children with joint hypermobility syndrome (JHS).
Patients Eighty-nine children with JHS aged 6–16 years.
Methods Twelve tests comprising anthropometric, musculoskeletal and functional assessments were conducted. Signs, symptoms and family history were recorded. Exploratory factor analysis was performed, factor scores generated, and correlations calculated to identify associations.
Results Sixty-six percent of the variance in the score set could be accounted for by five JHS subtypes (Eigenvalues >1). Factor 1, ‘joint affected’ JHS, had loadings on multiple joint pain, recurrent joint instability and postural orthostatic hypotension symptoms, and factor scores were associated with worse pain (r=0.48, p<0.01), fatigue (r=−0.54, p<0.01) and reduced health-related quality of life (HRQOL) (r=−0.5, p<0.01). Factor 2, ‘athletic’ JHS, loaded on muscle endurance, balance and motor skill proficiency, and scores were associated with less fatigue (r=0.3, p<0.01) and better HRQOL (r=0.44, p<0.01). Factor 3, ‘systemic’ JHS, loaded on skin involvement, incontinence symptoms, bowel involvement and recurrent joint instability, and was associated with reduced HRQOL (r=−0.24, p=0.03). Factor 4, ‘soft tissue affected’ JHS, loaded on recurrent soft tissue injuries and reduced muscle length, and was associated with greater fatigue (r=−0.43, p<0.01) and reduced HRQOL (r=−0.44, p<0.0001). Factor 5, ‘high BMI’ JHS, had high loadings on body mass index (BMI) for age, muscle endurance and no gastrointestinal involvement, and was associated with higher pain (r=0.33, p<0.01).
Conclusions The presenting signs and symptoms of children with JHS can be summarised in five clinically recognisable subtypes.