Julie M. Fritz

Responsiveness of the numeric pain rating scale in patients with low back pain

Study Design. Cohort study of patients with low back pain (LBP) receiving physical therapy. Objective. To examine the responsiveness characteristics of the numerical pain rating scale (NPRS) in patients with LBP using a variety of methods. Summary of Background Data. Although several studies have assessed the reliability and validity of the NPRS, few studies have characterized its responsiveness in patients with LBP. Methods. Determination of change on the NPRS during 1 and 4 weeks was examined by calculating mean change, standardized effect size, Guyatt Responsiveness Index, area under a receiver operating characteristic curve, minimum clinically important difference, and minimum detectable change. Change in the NPRS from baseline to the 1 and 4-week follow-up was compared to the average of the patient and therapist’s perceived improvement using the 15-point Global Rating of Change scale. Results. The majority of patients had clinically meaningful improvement after both 1 and 4 weeks of rehabilitation. The standard error of measure was equal to 1.02, corresponding to a minimum detectable change of 2 points. The area under the curve at the 1 and 4-week follow-up was 0.72 (0.62, 0.81) and 0.92 (0.86, 0.97), respectively. The minimum clinically important difference at the 1 and 4-week follow-up corresponded to a change of 2.2 and 1.5 points, respectively. Conclusions. Clinicians can be confident that a 2-point change on the NPRS represents clinically meaningful change that exceeds the bounds of measurement error.

A clinical prediction rule for classifying patients with low back pain who demonstrate short-term improvement with spinal manipulation.

Study Design. A prospective, cohort study of patients with nonradicular low back pain referred to physical therapy. Objective. Develop a clinical prediction rule for identifying patients with low back pain who improve with spinal manipulation. Summary of Background Data. Development of clinical prediction rules for classifying patients with low back pain who are likely to respond to a particular intervention, such as manipulation, would improve clinical decision-making and research. Methods. Patients with nonradicular low back pain underwent a standardized examination and then underwent a standardized spinal manipulation treatment program. Success with treatment was determined using percent change in disability scores over three sessions and served as the reference standard for determining the accuracy of examination variables. Examination variables were first analyzed for univariate accuracy in predicting success and then combined into a multivariate clinical prediction rule. Results. Seventy-one patients participated. Thirty-two had success with the manipulation intervention. A clinical prediction rule with five variables (symptom duration, fear–avoidance beliefs, lumbar hypomobility, hip internal rotation range of motion, and no symptoms distal to the knee) was identified. The presence of four of five of these variables (positive likelihood ratio = 24.38) increased the probability of success with manipulation from 45% to 95%. Conclusion. It appears that patients with low back pain likely to respond to manipulation can be accurately identified before treatment.

Reliability and diagnostic accuracy of the clinical examination and patient self-report measures for cervical radiculopathy

Study Design. A blinded, prospective diagnostic test study was conducted. Objectives. To assess the reliability and accuracy of individual clinical examination items and self-report instruments for the diagnosis of cervical radiculopathy, and to identify and assess the accuracy of an optimum test-item cluster for the diagnosis of cervical radiculopathy. Summary of Background Data. Although cervical radiculopathy remains largely a clinical diagnosis, the reliability and diagnostic accuracy of clinical examination items, individually or in combination, for cervical radiculopathy is largely unknown. Methods. Patients with suspected cervical radiculopathy or carpal tunnel syndrome received standardized electrophysiologic examination of the symptomatic upper quarter followed by a standardized clinical examination by physical therapist examiners blinded to diagnosis. Diagnostic properties were assessed using a neural impairment reference criterion standard. Results. The study involved 82 patients. More than two thirds of 34 clinical examination items had reliability coefficients rated at least fair or better, and 13 items had likelihood ratio point estimates above 2 or below 0.50. A single diagnostic test item cluster of four variables was identified and produced a positive likelihood ratio point estimate of 30.3. The 95% confidence intervals for all likelihood ratio point estimates in this study were wide. Conclusions. Many items of the clinical examination were found to be reliable and to have acceptable diagnostic properties, but the test item cluster identified was more useful for indicating cervical radiculopathy than any single test item. Upper limb tension Test A was the most useful test for ruling out cervical radiculopathy. Further investigation is required both to validate the test item cluster and to improve point estimate precision.

Identifying subgroups of patients with acute/subacute nonspecific low back pain : Results of a randomized clinical trial

Study Design. Randomized clinical trial. Objective. Compare outcomes of patients with low back pain receiving treatments matched or unmatched to their subgrouping based on initial clinical presentation. Summary of Background Data. Patients with “nonspecific” low back pain are often viewed as a homogeneous group, equally likely to respond to any particular intervention. Others have proposed methods for subgrouping patients as a means for determining the treatment most likely to benefit patients with particular characteristics. Methods. Patients with low back pain of less than 90 days’ duration referred to physical therapy were examined before treatment and classified into one of three subgroups based on the type of treatment believed most likely to benefit the patient (manipulation, stabilization exercise, or specific exercise). Patients were randomly assigned to receive manipulation, stabilization exercises, or specific exercise treatment during a 4-week treatment period. Disability was assessed in the short-term (4 weeks) and long-term (1 year) using the Oswestry. Comparisons were made between patients receiving treatment matched to their subgroup, versus those receiving unmatched treatment. Results. A total of 123 patients participated (mean age, 37.7 ± 10.7 years; 45% female). Patients receiving matched treatments experienced greater short- and long-term reductions in disability than those receiving unmatched treatments. After 4 weeks, the difference favoring the matched treatment group was 6.6 Oswestry points (95% CI, 0.70–12.5), and at long-term follow-up the difference was 8.3 points (95% CI, 2.5–14.1). Compliers-only analysis of long-term outcomes yielded a similar result. Conclusions. Nonspecific low back pain should not be viewed as a homogenous condition. Outcomes can be improved when subgrouping is used to guide treatment decision-making.

Comparison of Classification-Based Physical Therapy With Therapy Based on Clinical Practice Guidelines for Patients with Acute Low Back Pain : A Randomized Clinical Trial

Study Design. A randomized clinical trial was conducted. Objective. To compare the effectiveness of classification-based physical therapy with that of therapy based on clinical practice guidelines for patients with acute, work-related low back pain. Summary of Background Data. Clinical practice guidelines recommend minimal intervention during the first few weeks after acute low back injury. However, studies supporting this recommendation have not attempted to identify which patients are likely to respond to particular interventions. Methods. For this study, 78 subjects with work-related low back pain of less than 3 weeks duration were randomized to receive therapy based on a classification system that attempts to match patients to specific interventions or therapy based on the Agency for Health Care Policy and Research guidelines. The subjects were followed for 1 year. Outcomes included the impairment index, Oswestry scale, SF-36 component scores, satisfaction, medical costs, and return to work status. Results. After adjustment for baseline factors, subjects receiving classification-based therapy showed greater change on the Oswestry (P = 0.023) and the SF-36 physical component (P = 0.029) after 4 weeks. Patient satisfaction was greater (P = 0.006) and return to full-duty work status more likely (P = 0.017) after 4 weeks in the classification-based group. After 1 year, there was a trend toward reduced Oswestry scores in the classification-based group (P = 0.063). Median total medical costs for 1 year after injury were

The effect of a fear-avoidance-based physical therapy intervention for patients with acute low back pain: results of a randomized clinical trial.

1003.68 for the guideline-based group and

The reliability and construct validity of the Neck Disability Index and patient specific functional scale in patients with cervical radiculopathy.

774.00 for the classification-based group (P = 0.13). Conclusions. For patients with acute, work-related low back pain, the use of a classification-based approach resulted in improved disability and return to work status after 4 weeks, as compared with therapy based on clinical practice guidelines. Further research is needed on the optimal timing and methods of intervention for patients with acute low back pain.

Development of a Clinical Prediction Rule for Guiding Treatment of a Subgroup of Patients With Neck Pain: Use of Thoracic Spine Manipulation, Exercise, and Patient Education

Study Design. A randomized clinical trial with 4-week and 6-month follow-up periods. Objective. To compare the effect of a fear-avoidance–based physical therapy intervention with standard care physical therapy for patients with acute low back pain. Summary of Background Data. The disability reduction strategy of secondary prevention involves providing specific treatment for patients that are likely to have chronic disability from low back pain. Previous studies have indicated that elevated fear-avoidance beliefs are a precursor to chronic disability from low back pain. However, the effectiveness of physical therapy intervention based on a fear-avoidance model is unknown. Methods. Sixty-six consecutive patients referred to physical therapy with low back pain of less than 8 weeks’ duration were randomly assigned to receive fear-avoidance–based physical therapy (n = 34) or standard care physical therapy (n = 32). The intervention period lasted 4 weeks for this study. Disability, pain intensity, and fear-avoidance beliefs measures were recorded before and after treatment. A 6-month follow-up of the same measures was obtained by mail. Results. An intention-to-treat principle (last value forward) was used for data analyses that tested the primary and secondary hypotheses. The prediction of disability at 4 weeks and 6 months after treatment was significantly improved by considering the interaction between the type of treatment and the initial level of fear-avoidance beliefs. Both groups had significant within group improvements for disability and pain intensity. The fear-avoidance treatment group had a significant improvement in fear-avoidance beliefs, and fear-avoidance beliefs about physical activity were significantly lower than the standard care group at 4 weeks and 6 months after treatment. Conclusion. Patients with elevated fear-avoidance beliefs appeared to have less disability from fear-avoidance–based physical therapy when compared to those receiving standard care physical therapy. Patients with lower fear-avoidance beliefs appeared to have more disability from fear-avoidance–based physical therapy, when compared to those receiving standard care physical therapy. In addition, physical therapy supplemented with fear-avoidance–based principles contributed to a positive shift in fear-avoidance beliefs.

Interrater reliability of clinical examination measures for identification of lumbar segmental instability.

Study Design. Cohort study of patients with cervical radiculopathy undergoing physical therapy. Objectives. Examine the test-retest reliability, construct validity, and minimum levels of detectable and clinically important change for the Neck Disability Index (NDI) and Patient Specific Functional Scale (PSFS) in cohort of patients with cervical radiculopathy. Summary of Background Data. To date, no studies have investigated the psychometric properties of the NDI or PSFS in a cohort of patients with cervical radiculopathy. Methods. Thirty-eight patients with cervical radiculopathy undergoing physical therapy completed the NDI and PSFS, and Numerical Pain Rating Scale (NPRS) at the baseline examination and at a follow-up. In addition, at follow-up, patients completed a 15-point global rating of change (GROC), which was used to dichotomize patients as improved or stable. Changes in the NDI and PSFS were then used to assess test-retest reliability, construct validity, and minimal levels of detectable and clinically important change. Results. Test-retest reliability was moderate for the NDI (intraclass correlation coefficient [ICC] = 0.68; 95% confidence interval [CI], 0.30–0.90) and high for the PSFS (ICC = 0.82; 95% CI, 0.54–0.93). The PSFS was more responsive to change than the NDI. The minimal detectable change for the NDI was 10.2 and for the PSFS 2.1. The minimally clinically important change for the NDI was 7.0 and PSFS 2.0. Conclusions. Our results suggest that the PSFS exhibits superior reliability, construct validity, and responsiveness in this cohort of patients with cervical radiculopathy compared with the NDI. Further research is needed to examine the ability of these measures to accurately reflect changes in individuals, as well as large samples of patients.

Reliability of Rehabilitative Ultrasound Imaging of the Transversus Abdominis and Lumbar Multifidus Muscles

Background and Purpose To date, no studies have investigated the predictive validity of variables from the initial examination to identify patients with neck pain who are likely to benefit from thoracic spine thrust manipulation. The purpose of this study was to develop a clinical prediction rule (CPR) to identify patients with neck pain who are likely to experience early success from thoracic spine thrust manipulation. Subjects This was a prospective, cohort study of patients with mechanical neck pain who were referred for physical therapy. Methods Subjects underwent a standardized examination and then a series of thoracic spine thrust manipulation techniques. They were classified as having experienced a successful outcome at the second and third sessions based on their perceived recovery. Potential predictor variables were entered into a stepwise logistic regression model to determine the most accurate set of variables for prediction of treatment success. Results Data for 78 subjects were included in the data analysis, of which 42 had a successful outcome. A CPR with 6 variables was identified. If 3 of the 6 variables (positive likelihood ratio=5.5) were present, the chance of experiencing a successful outcome improved from 54% to 86%. Discussion and Conclusion The CPR provides the ability to a priori identify patients with neck pain who are likely to experience early success with thoracic spine thrust manipulation. However, future studies are necessary to validate the rule.