Development and Application of Clinical Prediction Rules to Improve Decision Making in Physical Therapist Practice

Update 䢇 Development and Application of Clinical Prediction Rules to Improve Decision Making in Physical Therapist Practice Clinical prediction rules have recently been developed that can improve decision making in physical therapist practice. Examples include prediction rules to improve the accuracy of diagnosing ankle fractures (ie, “the Ottawa Ankle Rules”)10 and knee fractures (ie, “the Ottawa Knee Rules”)11 in people with acute injuries and to determine when to order radiographs in patients with neck trauma.12 Other prediction rules have been developed to diagnose patients with cervical radiculopathy13 and carpal tunnel syndrome.14 A CPR also has been developed to establish the prognosis of patients with neck pain following a rear-end motor vehicle accident.15 [Childs JD, Cleland JA. Development and application of clinical prediction rules to improve decision making in physical therapist practice. Phys Ther. 2006;86:122–131.] Key Words: Clinical decision rule, Decision, Diagnosis, Diagnostic accuracy, Likelihood ratio, Prognosis, Sensitivity, Specificity. ўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўў John D Childs, Joshua A Cleland 122 Physical Therapy . Volume 86 . Number 1 . January 2006 ўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўўў C linical prediction rules (CPRs) are tools designed to improve decision making in clinical practice by assisting practitioners in making a particular diagnosis, establishing a prognosis, or matching patients to optimal interventions based on a parsimonious subset of predictor variables from the history and physical examination.1,2 Clinical prediction rules have been developed to improve decision making for many conditions in medical practice, including the diagnosis of proximal deep vein thrombosis (DVT),3 strep throat,4 coronary artery disease,5 and pulmonary embolism.6 Clinical prediction rules also have been developed to assist in establishing a prognosis such as determining when to discontinue resuscitative efforts after cardiac arrest in the hospital,7 determining the likelihood of death within 4 years for people with coronary artery disease,7 identifying children who are at risk for developing urinary tract infections,8 and identifying the characteristics of patients who are likely to develop postoperative nausea and vomiting after anesthesia.9 Clinical prediction rules have the potential to improve outcomes, In addition to their diagnostic utility, CPRs pertinent to physical therapist practice have recently been developed to assist with subgrouping patients into specific classifications that are useful in guiding management strategies. For example, CPRs have been developed to help practitioners match patients to optimal treatment approaches such as spinal manipulation17,18 and a lumbar stabilization exercise program.19 An advantage of CPRs is that they use the diagnostic properties of sensitivity, specificity, and positive and negative likelihood ratios (LR); thus, their interpretation can be readily applied to individual patients.1 Although helpful for guiding the early stages of treatment and assigning patients to a particular classification, they are not always useful for prescribing the exact treatment techniques to be used within the context of the patient’s assigned classification. Because CPRs are designed to improve decision making, it is important that they be developed and validated according to rigorous methodological standards. McGinn et al1 have suggested a 3-step process for developing and testing a CPR prior to widespread implementation of the rule in clinical practice. The purpose of this update is to describe the different steps involved in increase patient satisfaction, and decrease costs of care in physical therapist practice. developing and validating CPRs and illustrate how CPRs can be used to improve decision making in physical therapist practice. The First Step: Creating the Clinical Prediction Rule The initial step in the development of a CPR involves creation of the rule (Fig. 1). Researchers and practitioners may initially brainstorm to develop a list of all possible factors that they believe have some predictive value for identifying the condition of interest. Ultimately, a reasonable list of predictors are selected for consideration based on clinical experience and previous research, which demonstrates that the factor or set of factors has some diagnostic or prognostic accuracy. Although it may be ideal to include every possible factor from the clinical examination to ensure that no possible predictor variables are overlooked, the researcher must weigh the benefits of including a complete set of potential predictor variables against the increase in sample size required for each additional variable under consideration. Some authors20,21 have recommended that 10 to 15 subjects should be enrolled into the study to identify one predictor variable. The sample size also must be judged in the context of the risks and benefits of decision making based on the rule and the prevalence of a particular phenomenon. For example, there may be significant consequences associated with the failure to identify a clinically relevant cervical spine injury in a patient who has sustained neck trauma or with the failure to identify the presence of an ankle fracture. These studies, therefore, tend to enroll thousands of patients to achieve sufficiently narrow JD Childs, PT, PhD, MBA, OCS, FAAOMPT, is Assistant Professor and Director of Research, US Army-Baylor University Doctoral Program in Physical Therapy, Fort Sam Houston, San Antonio, Tex. Address all correspondence to Dr Childs at 508 Thurber Dr, Schertz, TX 78154 (USA) (). JA Cleland, DPT, OCS, is Assistant Professor, Department of Physical Therapy, Franklin Pierce College, Concord, NH, and Research Coordinator for Rehabilitation Services of Concord Hospital, Concord, NH. Dr Childs provided concept/idea/project design. Both authors provided writing. Dr Cleland provided consultation (including review of manuscript before submission). The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the US Air Force or Department of Defense. This Update was supported, in part, by a grant from the Foundation for Physical Therapy. Physical Therapy . Volume 86 . Number 1 . January 2006 Childs and Cleland . 123 With increasing attention focused on the rising costs of health care, CPRs provide practitioners with powerful diagnostic information from the history and physical examination that may serve as an accurate decisionmaking surrogate for more expensive diagnostic tests. For example, the Ottawa Ankle Rules identify only those patients in which the probability of having a fracture is sufficiently large to warrant radiographic imaging, thus (...truncated)