Seeking predictive factors for positive response to physical therapy for hip osteoarthritis

Knowing who responds best to treatment will reduce costs and expedite recovery
Osteoarthritis (OA), the most common form of arthritis, remains one of the few chronic diseases of aging for which there is little effective treatment. As the population over 60 will grow rapidly in coming years, and with obesity and physical inactivity increasing, the percentage of people with OA and its economic impact will also grow. To counter these looming trends, one suggested tactic is to find factors that will predict a positive response to interventions like manual therapy and exercise therapy administered by physical therapist (PTs) and focus on individuals most likely to benefit from therapy. Identifying prognostic variables for reduced pain and improved function following PT can lead to reduced costs, quicker recovery and more satisfaction for therapists and patients. Noting this, a study was created that sought out prognostic factors to identify patients with hip OA who were most likely to demonstrate reductions in pain and improvements in function after manual and exercise therapy.

Modest sample size divided into four groups
Potential participants were screened using inclusion criteria that selected only patients with confirmed hip OA and no other major physical impairments to the hip or related areas. Of 147 eligible candidates, 91 met the inclusion criteria and participated in the study. These patients were then divided into four intervention groups that received the following treatments: 1) manual therapy alone, 2) exercise therapy alone, 3) manual and exercise therapy, and 4) usual care (control group). All patients were assessed using a questionnaire and tests rating pain, function and disability, and data were collected at baseline and then one year after therapy.

Strong predictive factors associated with better recovery from treatment are found
Of the 68 participants in the three intervention groups, 22 were classified as having a successful response to treatment, while only three of the 23 participants in the control group responded successfully. Further analysis of the individuals who responded well to treatment led to identifying the following five variables as predictors of positive response to PT: unilateral hip pain, age of 58 or younger, pain of 6 or higher out of 10 on the numeric pain rating scale (NPRS), a time of 26 seconds or less on a 40-m self-paced walk test (SPWT) and a duration of symptoms of one year or less. The more of these factors possessed by the participants, the greater the likelihood was of success, with having three of the five predictor variables being considered more than sufficient for a positive turnout. The use of these predictor variables can have a major impact on hip OA treatment, and PTs should use them to determine which patients are most likely to improve in their condition, while patients should be encouraged to get treatment earlier since it’s shown to lead to better outcomes.

-Summarized by Greg Gargiulo

-As reported in the April ’11 edition of Physical Therapy