Anne Thackeray

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.

An Examination of the Reliability of a Classification Algorithm for Subgrouping Patients With Low Back Pain

Study Design. Test-retest design to examine interrater reliability. Objective. Examine the interrater reliability of individual examination items and a classification decision-making algorithm using physical therapists with varying levels of experience. Summary of Background Data. Classifying patients based on clusters of examination findings has shown promise for improving outcomes. Examining the reliability of examination items and the classification decision-making algorithm may improve the reproducibility of classification methods. Methods. Patients with low back pain less than 90 days in duration participating in a randomized trial were examined on separate days by different examiners. Interrater reliability of individual examination items important for classification was examined in clinically stable patients using kappa coefficients and intraclass correlation coefficients. The findings from the first examination were used to classify each patient using the decision-making algorithm by clinicians with varying amounts of experience. The reliability of the classification algorithm was examined with kappa coefficients. Results. A total of 123 patients participated (mean age 37.7 [±10.7] years, 44% female), 60 (49%) remained stable between examinations. Reliability of range of motion, centralization/peripheralization judgments with flexion and extension, and the instability test were moderate to excellent. Reliability of centralization/peripheralization judgments with repeated or sustained extension or aberrant movement judgments were fair to poor. Overall agreement on classification decisions was 76% (kappa = 0.60, 95% confidence interval 0.56, 0.64), with no significant differences based on level of experience. Conclusion. Reliability of the classification algorithm was good. Further research is needed to identify sources of disagreements and improve reproducibility.

Early Physical Therapy vs Usual Care in Patients With Recent-Onset Low Back Pain: A Randomized Clinical Trial

IMPORTANCE Low back pain (LBP) is common in primary care. Guidelines recommend delaying referrals for physical therapy. OBJECTIVE To evaluate whether early physical therapy (manipulation and exercise) is more effective than usual care in improving disability for patients with LBP fitting a decision rule. DESIGN, SETTING, AND PARTICIPANTS Randomized clinical trial with 220 participants recruited between March 2011 and November 2013. Participants with no LBP treatment in the past 6 months, aged 18 through 60 years (mean age, 37.4 years [SD, 10.3]), an Oswestry Disability Index (ODI) score of 20 or higher, symptom duration less than 16 days, and no symptoms distal to the knee in the past 72 hours were enrolled following a primary care visit. INTERVENTIONS All participants received education. Early physical therapy (n = 108) consisted of 4 physical therapy sessions. Usual care (n = 112) involved no additional interventions during the first 4 weeks. MAIN OUTCOMES AND MEASURES Primary outcome was change in the ODI score (range: 0-100; higher scores indicate greater disability; minimum clinically important difference, 6 points) at 3 months. Secondary outcomes included changes in the ODI score at 4-week and 1-year follow-up, and change in pain intensity, Pain Catastrophizing Scale (PCS) score, fear-avoidance beliefs, quality of life, patient-reported success, and health care utilization at 4-week, 3-month, and 1-year follow-up. RESULTS One-year follow-up was completed by 207 participants (94.1%). Using analysis of covariance, early physical therapy showed improvement relative to usual care in disability after 3 months (mean ODI score: early physical therapy group, 41.3 [95% CI, 38.7 to 44.0] at baseline to 6.6 [95% CI, 4.7 to 8.5] at 3 months; usual care group, 40.9 [95% CI, 38.6 to 43.1] at baseline to 9.8 [95% CI, 7.9 to 11.7] at 3 months; between-group difference, -3.2 [95% CI, -5.9 to -0.47], P = .02). A significant difference was found between groups for the ODI score after 4 weeks (between-group difference, -3.5 [95% CI, -6.8 to -0.08], P = .045]), but not at 1-year follow-up (between-group difference, -2.0 [95% CI, -5.0 to 1.0], P = .19). There was no improvement in pain intensity at 4-week, 3-month, or 1-year follow-up (between-group difference, -0.42 [95% CI, -0.90 to 0.02] at 4-week follow-up; -0.38 [95% CI, -0.84 to 0.09] at 3-month follow-up; and -0.17 [95% CI, -0.62 to 0.27] at 1-year follow-up). The PCS scores improved at 4 weeks and 3 months but not at 1-year follow-up (between-group difference, -2.7 [95% CI, -4.6 to -0.85] at 4-week follow-up; -2.2 [95% CI, -3.9 to -0.49] at 3-month follow-up; and -0.92 [95% CI, -2.7 to 0.61] at 1-year follow-up). There were no differences in health care utilization at any point. CONCLUSIONS AND RELEVANCE Among adults with recent-onset LBP, early physical therapy resulted in statistically significant improvement in disability, but the improvement was modest and did not achieve the minimum clinically important difference compared with usual care. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01726803.

Exercise Only, Exercise With Mechanical Traction, or Exercise With Over-Door Traction for Patients With Cervical Radiculopathy, With or Without Consideration of Status on a Previously Described Subgrouping Rule: A Randomized Clinical Trial

STUDY DESIGN Randomized clinical trial. OBJECTIVES To examine the effectiveness of cervical traction in addition to exercise for specific subgroups of patients with neck pain. BACKGROUND Cervical traction is frequently used, but its effectiveness has not been adequately examined. Existing studies have failed to target patients most likely to respond. Traction is typically recommended for patients with cervical radiculopathy. A prediction rule has been described to identify a narrower subgroup of patients likely to respond to cervical traction. METHODS Patients with neck pain and signs of radiculopathy were randomized to 4 weeks of treatment with exercise, exercise with mechanical traction, or exercise with over-door traction. Baseline assessment included subgrouping-rule status. The primary outcome measure (Neck Disability Index, scored 0-100) and secondary outcome measure (neck and arm pain intensity) were assessed at 4 weeks, 6 months, and 12 months after enrollment. The primary analyses examined 2-way treatment-by-time interactions. Secondary analyses examined validity of the subgrouping rule by adding 3-way interactions. RESULTS Eighty-six patients (53.5% female; mean age, 46.9 years) were enrolled in the study. Intention-to-treat analysis found lower Neck Disability Index scores at 6 months in the mechanical traction group compared to the exercise group (mean difference between groups, 13.3; 95% confidence interval: 5.6, 21.0) and over-door traction group (mean difference between groups, 8.1; 95% confidence interval: 0.8, 15.3), and at 12 months in the mechanical traction group compared to the exercise group (mean difference between groups, 9.8; 95% confidence interval: 0.2, 19.4). Secondary outcomes favored mechanical traction at several time points. The validity of the subgrouping rule was supported on the Neck Disability Index at the 6-month time point only. CONCLUSION Adding mechanical traction to exercise for patients with cervical radiculopathy resulted in lower disability and pain, particularly at long-term follow-ups. The study protocol was registered at http://clinicaltrials.gov (NCT00979108).

A Pilot Study Examining the Effectiveness of Physical Therapy as an Adjunct to Selective Nerve Root Block in the Treatment of Lumbar Radicular Pain From Disk Herniation: A Randomized Controlled Trial

Background Therapeutic selective nerve root blocks (SNRBs) are a common intervention for patients with sciatica. Patients often are referred to physical therapy after SNRBs, although the effectiveness of this intervention sequence has not been investigated. Objective This study was a preliminary investigation of the effectiveness of SNRBs, with or without subsequent physical therapy, in people with low back pain and sciatica. Design This investigation was a pilot randomized controlled clinical trial. Setting The settings were spine specialty and physical therapy clinics. Participants Forty-four participants (64% men; mean age=38.5 years, SD=11.6 years) with low back pain, with clinical and imaging findings consistent with lumbar disk herniation, and scheduled to receive SNRBs participated in the study. They were randomly assigned to receive either 4 weeks of physical therapy (SNRB+PT group) or no physical therapy (SNRB alone [SNRB group]) after the injections. Intervention All participants received at least 1 SNRB; 28 participants (64%) received multiple injections. Participants in the SNRB+PT group attended an average of 6.0 physical therapy sessions over an average of 23.9 days. Measurements Outcomes were assessed at baseline, 8 weeks, and 6 months with the Low Back Pain Disability Questionnaire, a numeric pain rating scale, and the Global Rating of Change. Results Significant reductions in pain and disability occurred over time in both groups, with no differences between groups at either follow-up for any outcome. Nine participants (5 in the SNRB group and 4 in the SNRB+PT group) underwent surgery during the follow-up period. Limitations The limitations of this study were a relatively short-term follow-up period and a small sample size. Conclusions A physical therapy intervention after SNRBs did not result in additional reductions in pain and disability or perceived improvements in participants with low back pain and sciatica.

A randomized clinical trial of the effectiveness of mechanical traction for sub-groups of patients with low back pain: study methods and rationale

BackgroundPatients with signs of nerve root irritation represent a sub-group of those with low back pain who are at increased risk of persistent symptoms and progression to costly and invasive management strategies including surgery. A period of non-surgical management is recommended for most patients, but there is little evidence to guide non-surgical decision-making. We conducted a preliminary study examining the effectiveness of a treatment protocol of mechanical traction with extension-oriented activities for patients with low back pain and signs of nerve root irritation. The results suggested this approach may be effective, particularly in a more specific sub-group of patients. The aim of this study will be to examine the effectiveness of treatment that includes traction for patients with low back pain and signs of nerve root irritation, and within the pre-defined sub-group.Methods/DesignThe study will recruit 120 patients with low back pain and signs of nerve root irritation. Patients will be randomized to receive an extension-oriented treatment approach, with or without the addition of mechanical traction. Randomization will be stratified based on the presence of the pre-defined sub-grouping criteria. All patients will receive 12 physical therapy treatment sessions over 6 weeks. Follow-up assessments will occur after 6 weeks, 6 months, and 1 year. The primary outcome will be disability measured with a modified Oswestry questionnaire. Secondary outcomes will include self-reports of low back and leg pain intensity, quality of life, global rating of improvement, additional healthcare utilization, and work absence. Statistical analysis will be based on intention to treat principles and will use linear mixed model analysis to compare treatment groups, and examine the interaction between treatment and sub-grouping status.DiscussionThis trial will provide a methodologically rigorous evaluation of the effectiveness of using traction for patients with low back pain and signs of nerve root irritation, and will examine the validity of a pre-defined sub-grouping hypothesis. The results will provide evidence to inform non-surgical decision-making for these patients.Trial RegistrationThis trial has been registered with http://ClinicalTrials.gov: NCT00942227

Identifying clinical measures that most accurately reflect the progression of disability in Parkinson disease

INTRODUCTION The temporal relationship between disease and disability progression in Parkinson disease (PD) is not well understood. Our objective was to describe the natural, multidimensional trajectory of disability in persons with PD over a two-year period. METHODS We conducted a multi-center, prospective cohort study involving four institutions. Data were collected at baseline and at 6-month intervals over 2 years using standardized clinical tests representing three World Health Organization defined disability domains: impairment, activity limitation, and participation restriction. Unadjusted mixed effects growth models characterized trajectories of disability in the three disability domains. The data set was analyzed using restricted maximum likelihood (REML) estimation. Standardized estimates of change were also computed using Cohens d for each measure. RESULTS Of the 266 enrolled participants, we analysed data from individuals who participated in at least 3 assessments (n = 207, 79%). Rates of disability progression over the 2-year period differed across domains. Moderate effects were detected for motor impairment (d = .28) and walking-related activity limitation (gait-related balance (d = .31); gait speed (d = .30)). Marginal effects were noted for upper extremity-related activity limitation (d = .11) and health-related quality of life participation restriction (d = .08). CONCLUSIONS The natural trajectory of walking-related activity limitation was the most potent indicator of evolving disability, suggesting that routine assessment of walking and periodic rehabilitation is likely to be warranted for many persons with PD. Natural trajectories of disability provide important comparison data for future intervention studies.

External validation of a simple clinical tool used to predict falls in people with Parkinson disease

BACKGROUND Assessment of fall risk in an individual with Parkinson disease (PD) is a critical yet often time consuming component of patient care. Recently a simple clinical prediction tool based only on fall history in the previous year, freezing of gait in the past month, and gait velocity <1.1 m/s was developed and accurately predicted future falls in a sample of individuals with PD. METHODS We sought to externally validate the utility of the tool by administering it to a different cohort of 171 individuals with PD. Falls were monitored prospectively for 6 months following predictor assessment. RESULTS The tool accurately discriminated future fallers from non-fallers (area under the curve [AUC] = 0.83; 95% CI 0.76-0.89), comparable to the developmental study. CONCLUSION The results validated the utility of the tool for allowing clinicians to quickly and accurately identify an individuals risk of an impending fall.

Two-Year Trajectory of Fall Risk in People With Parkinson Disease: A Latent Class Analysis.

OBJECTIVE To examine fall risk trajectories occurring naturally in a sample of individuals with early to middle stage Parkinson disease (PD). DESIGN Latent class analysis, specifically growth mixture modeling (GMM), of longitudinal fall risk trajectories. SETTING Assessments were conducted at 1 of 4 universities. PARTICIPANTS Community-dwelling participants with PD of a longitudinal cohort study who attended at least 2 of 5 assessments over a 2-year follow-up period (N=230). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Fall risk trajectory (low, medium, or high risk) and stability of fall risk trajectory (stable or fluctuating). Fall risk was determined at 6 monthly intervals using a simple clinical tool based on fall history, freezing of gait, and gait speed. RESULTS The GMM optimally grouped participants into 3 fall risk trajectories that closely mirrored baseline fall risk status (P=.001). The high fall risk trajectory was most common (42.6%) and included participants with longer and more severe disease and with higher postural instability and gait disability (PIGD) scores than the low and medium fall risk trajectories (P<.001). Fluctuating fall risk (posterior probability <0.8 of belonging to any trajectory) was found in only 22.6% of the sample, most commonly among individuals who were transitioning to PIGD predominance. CONCLUSIONS Regardless of their baseline characteristics, most participants had clear and stable fall risk trajectories over 2 years. Further investigation is required to determine whether interventions to improve gait and balance may improve fall risk trajectories in people with PD.

Use of Physical Therapy for Low Back Pain by Medicaid Enrollees

Background Medicaid insures an increasing proportion of adults in the United States. Physical therapy use for low back pain (LBP) in this population has not been described. Objective The study objectives were: (1) to examine physical therapy use by Medicaid enrollees with new LBP consultations and (2) to evaluate associations with future health care use and LBP-related costs. Design The study was designed as a retrospective evaluation of claims data. Methods A total of 2,289 patients with new LBP consultations were identified during 2012 (mean age=39.3 years [SD=11.9]; 68.2% women). The settings in which the patients entered care and comorbid conditions were identified. Data obtained at 1 year after entry were examined, and physical therapy use was categorized with regard to entry setting, early use (within 14 days of entry), or delayed use (>14 days after entry). The 1-year follow-up period was evaluated for use outcomes (imaging, injection, surgery, and emergency department visit) and LBP-related costs. Variables associated with physical therapy use and cost outcomes were evaluated with multivariate models. Results Physical therapy was used by 457 patients (20.0%); 75 (3.3%) entered care in physical therapy, 89 (3.9%) received early physical therapy, and 298 (13.0%) received delayed physical therapy. Physical therapy was more common with chronic pain or obesity comorbidities and less likely with substance use disorders. Entering care in the emergency department decreased the likelihood of physical therapy. Entering care in physical medicine increased the likelihood. Relative to primary care entry, physical therapy entry was associated with lower 1-year costs. Limitations A single state was studied. No patient-reported outcomes were included. Conclusions Physical therapy was used often by Medicaid enrollees with LBP. High rates of comorbidities were evident and associated with physical therapy use. Although few patients entered care in physical therapy, this pattern may be useful for managing costs.