Development of a clinical prediction rule to identify initial responders to mobilisation with movement and exercise for lateral epicondylalgia.

The aim of this post hoc analysis was to develop a preliminary clinical prediction rule (CPR) for identifying patients with lateral epicondylalgia (LE) likely to respond to mobilisation with movement and exercise (PT). Currently practitioners do not have an evidence-based means to identify such patients a priori. Potential predictive factors were recorded at baseline and reference measures at 3 weeks after treatment was initiated. Participants (n=64) received standardised PT. After 3 weeks, participants were categorised as having experienced 'improvement' or 'no improvement' with treatment. Factors with univariate relationship (p<0.15) to 'improvement' were entered into a step-wise logistic regression model. Receiver operator characteristic curves were used to calculate cut-off points for continuous variables. Analyses resulted in a CPR that included: age (<49 years, +LR=2.6) as well as pain free grip strength on the affected (>112N, +LR=2.3) and unaffected side (<336N, +LR=2.1). Probability of improvement rose from 79 to 100% if all three were positive. The CPR did not predict outcome for wait and see (n=57), indicating it was more accurate for PT. This post hoc analysis has created a Level IV CPR that with further validation will help practitioners identify responders. Future studies are required to validate the rule.