Alonso-Blanco C, Fernández-de-las-Peñas C, Cleland JA: Preliminary clinical prediction rule for identifying patients with ankylosing spondylitis who are likely to respond to an exercise program: A pilot study.
The aim of this study was to develop a preliminary clinical prediction rule to identify the potential predictors for identifying patients presenting with ankylosing spondylitis who are likely to respond to a specific exercise program.
Consecutive patients with ankylosing spondylitis underwent a standardized examination and then received eight physical therapy sessions during a 2-mo period, which included an exercise program based on the treatment of the shortened muscle chains, following the guideline described by the global posture re-education method. Patients were classified as having experienced a successful outcome at 1 mo after discharge based on a 20% reduction on Bath Ankylosing Spondylitis Functional Index and self-report perceived recovery. Potential predictor variables were entered into a stepwise logistic regression model to determine the most accurate set of variables for identifying treatment success.
Data from 35 patients were included, of which 16 (46%) experienced a successful outcome. A clinical prediction rule with three variables (physical role >37, bodily pain >27, and Bath Ankylosing Spondylitis Disease Activity Index >31) was identified. The most accurate predictor of success was if the patient exhibited two of the three variables, and the positive likelihood ratio was 11.2 (95% confidence interval, 1.7–76.0) and the posttest probability of success increased to 91%. The accuracy of prediction declined if either 1/3 (+likelihood ratio = 7.7; 95% confidence interval, 0.52–113.5) or 3/3 (+likelihood ratio = 2.6, 95% confidence interval, 1.6–4.0) variables were present.
The present preliminary clinical prediction rule provides the potential to identify patients with ankylosing spondylitis who are likely to experience short-term follow-up success with a specific exercise program. Future studies are necessary to validate the clinical prediction rule.
From the Department of Physical Therapy (CA-B, CF-d-l-P), Occupational Therapy, Physical Medicine and Rehabilitation of Universidad Rey Juan Carlos, Alcorcón, Madrid, Spain; Esthesiology Laboratory of Universidad Rey Juan Carlos (CF-d-l-P), Alcorcón, Madrid, Spain; Department of Physical Therapy (JAC), Franklin Pierce University; Physical Therapist (JAC), Rehabilitation Services, Concord Hospital, Concord, New Hampshire; and Faculty, Manual Therapy Fellowship Program (JAC), Regis University, Denver, Colorado.
All correspondence and requests for reprints should be addressed to César Fernández de las Peñas, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Avenida de Atenas s/n, 28922 Alcorcón, Madrid, Spain.