The Spine Journal - (2014) -

Clinical Study

Outcomes are not different for patient-matched versus nonmatchedtreatment in subjects with chronic recurrent low back pain:

a randomized clinical trial

Sharon M. Henry, PT, PhD, ATCa,*, Linda R. Van Dillen, PT, PhDb,Rebecca H. Ouellette-Morton, MS, MPTa, Juvena R. Hitt, BSa, Karen V. Lomond, PhDa,

Michael J. DeSarno, MSc, Janice Y. Bunn, PhDc

aDepartment of Rehabilitation and Movement Science, College of Nursing and Health Science, University of Vermont, 305 Rowell Bldg, 106 Carrigan Drive,

Burlington, VT 05405-0068, USAbProgram in Physical Therapy and Department of Orthopaedic Surgery, Washington University School of Medicine, Campus Box 8502, 4444 Forest Park

Avenue, St. Louis, MO 63108, USAcDepartment of Biostatistics, College of Medicine, University of Vermont, 305 Rowell Bldg, 106 Carrigan Drive, Burlington, VT 05405-0068, USA

Received 13 March 2013; revised 20 January 2014; accepted 16 March 2014

Abstract BACKGROUND CONTEXT: Classification

FDA device/drug

Author disclosures

LVD: Grant: NIH (B

(salary E, Paid directl

rectly to institution).

close. JYB: Grant: N

salary for several NIH

port (Investigator

NIH-sponsored projec

The disclosure key

TheSpineJournalOnlin

This study was

1529-9430/$ - see fro

http://dx.doi.org/10.10

schemas for low back pain (LBP), such as theTreatment-Based Classification and the Movement System Impairment, use common clinical fea-tures to subgroup patients with LBP and are purported to improve treatment outcomes.PURPOSE: To assess if providing matched treatments based on patient-specific clinical featuresled to superior treatment outcomes compared with an unmatched treatment for subjects withchronic recurrent LBP.STUDY DESIGN: This study is a randomized controlled trial.PATIENT SAMPLE: Subjects (n5124) with LBP ($12 months) with or without recurrencesunderwent a standardized clinical examination to group them into one of two strata: ineligible oreligible for stabilization exercises based on the Treatment-Based Classification schema. Subjectsunderwent additional clinical tests to assign them to one of the five possible Movement SystemImpairment categories.OUTCOME MEASURES: Questionnaires were collected electronically at Week 0 (before treat-ment), Week 7 (after the 6-week 1-hour treatment sessions), and 12 months. Using the Oswestrydisability index (0–100) and the Numeric Pain Rating Scale (0–10), the primary analysis was per-formed using the intention-to-treat principle. Secondary outcomes included fear-avoidance beliefsand psychosocial work-related and general health status.METHODS: After subjects were categorized based on their particular clinical features using boththe Treatment-Based Classification and Movement System Impairment schemas, they were random-ized into one of two treatments using a 3:1 ratio for matched or unmatched treatments. The treat-ments were trunk stabilization exercise or Movement System Impairment–directed exercises.RESULTS: Of the patients allocated to treatment for this study, 76 received a matched treatmentand 25 received an unmatched treatment. After treatment, both groups showed a statistically

status: Not applicable.

: SMH: Grant: NIH (E, Paid directly to institution).

, Paid directly to institution). RHO-M: Grant: NIH

y to institution). JRH: Grant: NIH (salary E, Paid di-

KVL: Grant: NIH (salary D). MJD: Nothing to dis-

IH (D, Paid directly to institution) (Investigator

-sponsored projects [about E/year]); Research sup-

salary): NIH (Investigator salary for several

ts [about E/year]).

can be found on the Table of Contents and at www.

e.com.

supported by NIH/NCMRR/2R01HD040909-07

(principal investigator: SMH) and funded by National Institutes of Health

(NIH/NCMRR/R01HD040909; $1,485,000). There are no study-specific

conflicts of interest to report.

Clinical Trials Registration: NCT01362049.

Preliminary results of this study were presented at the American Phys-

ical Therapy Association Combined Section Meeting, New Orleans, LA,

USA, February 10, 2012.

* Corresponding author. Department of Rehabilitation and Movement

Science, College of Nursing and Health Science, University of Vermont,

305 Rowell Bldg, 106 Carrigan Drive, Burlington, VT 05405-0068,

USA. Tel.: (802) 656-8146; fax: (802) 656-6586.

E-mail address: sharon.henry@uvm.edu (S.M. Henry)

nt matter � 2014 Elsevier Inc. All rights reserved.

16/j.spinee.2014.03.024

2 S.M. Henry et al. / The Spine Journal - (2014) -

significant improvement in the primary outcome measures and almost all the secondary measures;however, the matched treatment group did not demonstrate superior outcomes at Week 7 or 12months, except on one of the secondary measures (Graded Chronic Pain Scale [Disability Scale])(p5.01).CONCLUSIONS: Providing a matched treatment based on either the Treatment-Based Classifica-tion or the Movement System Impairment classification schema did not improve treatment out-comes compared with an unmatched treatment for patients with chronic LBP, except on onesecondary disability measure. � 2014 Elsevier Inc. All rights reserved.

Keywords: Randomized controlled trial; Chronic low back pain; Classification; Physical therapy; Subgroups; Exercise

Introduction

Low back pain (LBP) remains a public health issue be-cause it is a heterogeneous musculoskeletal condition thataffects up to 80% of all people at some point in their life[1]. In 85% of persons with LBP, no pathoanatomic causecan be identified [2,3], which makes prescribing treatmentsfor patients difficult. Classification of patients with LBP in-to homogenous subgroups with relevant clinical featureshas been identified as a research priority by several groups[4–6] and may be used to direct treatment and improvetreatment outcomes.

Two promising classification systems for LBP are theTreatment-Based Classification [7] and the Movement Sys-tem Impairment [8] approaches. The Treatment-BasedClassification system uses clusters of clinical features froma patient’s medical history and physical examination, tocategorize and direct the patient into one of 4 types of treat-ments [9]: trunk stabilization exercises, specific exercises,spinal manipulation, or traction. Hicks et al. [10] and Fritzet al. [9] have identified four clinical features associatedwith patient improvement after stabilization treatment:age less than 40 years, a positive score on the prone insta-bility test [10,11], more than 91� of hip flexion during apassive straight-leg test [10,11], and aberrant trunk move-ments with lumbar-spine flexion [10]. At least any threeof the four clinical features, taken together, now comprisea clinical prediction rule used to identify patients likelyto improve with stabilization exercises [12]. Additionally,Fritz et al. [13] have identified another clinical feature ofpatients with LBP who improve with stabilization treat-ment: lumbar-spine hypermobility. Rater agreement whenclassifying patients based on shared clinical features usingthe Treatment-Based Classification system ranges from akappa statistic of 0.52 to 0.62 with a percent agreementranging from 67% to 81% [12,14].

The Movement System Impairment system classifiestypes of LBP based on impaired trunk movements and pos-tures associated with the patient’s LBP observed during astandardized examination [8]. The Movement System Im-pairment system draws on the Kinesiopathologic model,which assumes that altered precision in spinal movementmay result in specific changes in the neuromusculoskeletalsystem, such as changes in the activation patterns of trunkmuscles. The Kinesiopathologic model also assumes that,

unless persons with LBP modify these repeated direction-specific trunk movements and postures, they are at riskfor persistent or recurrent LBP [8].

In the Movement System Impairment examination, thephysical therapist conducts standardized tests [8,15] and as-sesses for changes in the patient’s LBP symptoms. If any testincreases the patient’s symptoms, the physical therapist modi-fies the test and has the patient perform thismodified test to de-termine if the patient’s movement patterns, trunk posture, and/or symptoms are altered. If the patient reports that themodifiedtest decreases or eliminates the LBP, this response confirmsthat the direction-specific movement or posture contributesto the patient’s LBP [16]. Results from the initial andmodifiedtests are used to classify the patient into one of five movementsystem impairment (MSI) subgroups (named for the observedlumbarmovement or alignment impairments): rotation, exten-sion, flexion, rotationwith extension, and rotationwithflexion.The fiveMSI subgroups serve to help the physical therapist de-sign a matched treatment to the patient’s specific signs andsymptoms. The reliability of physical therapists classifyingpatients based on theMovement System Impairment approachhas been examined [17–19], and the kappa statistic rangedfrom 0.61 to 0.81 with a percent agreement ranging from75% to 87% that reflects moderate-to-excellent agreement inclassification of patients.

The Treatment-Based Classification–directed trunk sta-bilization approach focuses on three components of spinalstability: motor control of the deep trunk muscles (transver-sus abdominis, internal oblique, and multifidus) [10,20,21];strengthening of the flexor, extensor, and oblique trunkmuscles [10]; and incorporating trunk muscle control intoactivities of daily living. The Movement System Impair-ment–directed approach focuses on direction-specific func-tional activity modifications to change lumbopelvicmovement patterns to patterns that are pain free, exercisesto modify lumbopelvic movements and postures in specificdirections that are pain free, and patient education on howspecific lumbopelvic movement patterns and postures re-peated daily might accelerate lumbar-tissue stress and edu-cation about the importance of modifying the movementpatterns throughout the day. The treatments directed bythe Treatment-Based Classification and Movement SystemImpairment classification approaches share similar goals ofimproving the patient’s ability to control his trunk and to

3S.M. Henry et al. / The Spine Journal - (2014) -

stabilize his spine during activities of daily living, duringisolated and combined trunk movements, and during trunkmovement that is induced by limb movement.

The purpose of this study was to compare the pain andfunctional outcomes for patients with chronic LBP whowere either matched or unmatched to a treatment that fo-cused on improving their trunk control and ability to stabi-lize their spine. We hypothesized that patients who werematched to treatment based on particular clinical featureswould improve their function and decrease their symptomsmore over short- (7 weeks) and long-term (12 months)follow-up periods compared with patients who were notmatched to treatment.

Methods

Subjects

Subjects in this study were part of a randomized clinicaltrial (NCT01362049), funded by the National Institutes ofHealth (R01HD040909), in which subjects with LBP(n51,022) were assessed for the study inclusion throughphone and e-mail contact. Subjects who were admitted tothe study were between 21 and 55 years old, had a historyof chronic LBP ($12 months) with or without recurrences,could stand and walk independently, had a modified Oswes-try disability index (ODI) score of 19% or more, and/or ascore less than 8 on at least one activity from the Patient-Specific Functional Scale [22], could understand English,and were currently employed or actively engaged in dailyactivities. Exclusion criteria included a structural spinal de-formity, spinal fracture, osteoporosis, systemic disease pro-cesses, disc herniation with corroborating clinical signs andsymptoms, previous spinal surgery, pregnancy or less than 6months postpartum or postweaning, magnified symptombehavior [23], and a body mass index of greater than 30.This study was approved by the institutional review boardat the University of Vermont. All subjects provided writteninformed consent, and the rights of each subject were pro-tected. There were no adverse events reported during thestudy and no changes to methods after the trial began. Oncerecruitment goals were met and the questionnaire data werecollected across the follow-up time points, the trial wasended. Fig. 1 gives an outline of subject flow and data col-lection procedures in this study.

Pretreatment assessments

Questionnaire completionAll subjects allocated to treatment for this study

(n5102) completed a medical history and demographicform and the ODI [24], Numeric Pain Rating Scale(NPRS) [25], Graded Chronic Pain Scale (GCPS) [26–28], Fear-Avoidance Behavior Questionnaire [29],Patient-Specific Functional Scale [22], and Short-Form36 [30,31].

Classification of subjectsTo maximize reliability, one physical therapist examiner

(RHO-M) performed the standardized clinical examinationon all subjects in a laboratory setting, and she determined ifthe subject was eligible or ineligible for stabilization exer-cises (as per the Treatment-Based Classification system)and also determined the subject’s Movement System Im-pairment classification. The standardized clinical examina-tion included the following tests that are part of theTreatment-Based Classification approach and are used toidentify which patients were likely to respond to stabiliza-tion exercises: the prone instability test [10,11], straight-legraise test [10,11], the lumbar-spine flexion test [10], ageless than 40 years, and the lumbar-spine hypermobility test[10,13,32]. Studies [12,33–35] have demonstrated thesetests to have fair-to-good interrater reliability. If a subjectwas positive on any three of the first four clinical tests listedand/or positive with the lumbar-spine hypermobility test, hewas assigned to the ‘‘eligible’’ stratum. If the subject didnot meet the eligible criteria of the Treatment-Based Clas-sification, he was assigned to the ‘‘ineligible’’ stratum. Thisstratification allowed us to have a nonmatched treatmentgroup for comparison with the matched treatment group.

In addition, all subjects underwent a standardized Move-ment System Impairment clinical examination that allowedthe physical therapist examiner to assign a person to one offive possible Movement System Impairment categories[17]. In a separate pilot study, two physical therapists(SMH and RHO-M) demonstrated an 80% agreement witha kappa statistic of 0.80 (confidence interval 0.53, 1.00) whenconducting the standardized Movement System Impairmentexamination and then independently using the clinical data toassign a Movement System Impairment category to each of20 subjects with LBP. At the completion of the standardizedclinical examination, all subjects had been classified usingboth the Treatment-Based Classification and the MovementSystem Impairment–based approaches (Fig. 1).

Subject randomization

After stratifying subjects into either the eligible or theineligible strata and then classifying them into one of fiveMovement System Impairment categories, they (n5102)were next randomized to receive one of two treatments:stabilization exercises or Movement System Impairment–based treatment (Fig. 1). The statistician used computer-generated randomization with centralized allocationconcealment to randomize subjects into one of twotreatments using a 3:1 ratio for matched to unmatched treat-ment. Because patients were classified using both theTreatment-Based Classification and the Movement SystemImpairment–based approaches, the randomization resultedin the majority of subjects (n576) receiving a matchedtreatment (ie, subjects who were ineligible receiving Move-ment System Impairment treatment, were eligible receivingMovement System Impairment treatment, or were eligible

Fig. 1. Study flow.

4 S.M. Henry et al. / The Spine Journal - (2014) -

receiving stabilization exercises). The other portion of sub-jects (n525) received an unmatched treatment (ie, subjectswho were ineligible receiving stabilization) (Fig. 1).

Physical therapy treatment

After randomization, the subjectwas scheduled for his firsttreatment session as soon as possible in the clinic, usuallywithin 3 to 6 days of the pretreatment session. Both the stabi-lization exercises and Movement System Impairment–basedtreatment approaches share the common goal of improvingthe subject’s trunk control and the ability to stabilize the spineduring activities of daily living and during isolated and com-bined trunk and/or limb movements. Using exercises de-signed to improve recruitment and strength of trunk

muscles, the physical therapy clinicians progressed subjectsthrough the standardized treatment protocols, providing onetreatment per week for 6 weeks. All patients were given ahome exercise program and turned in their weekly exerciselog. Each physical therapy clinician passed a written test toshow an acceptable level of knowledge regarding exerciseprogression for the treatment that shewas providing and com-pleted the University of Vermont Human Subject Testing tu-torial on ethical treatment of human subjects.

Stabilization treatment protocolAll subjects in both the eligible and ineligible strata who

were randomized to stabilization exercises attended physi-cal therapy sessions at one of four physical therapy outpa-tient clinics and were treated by a PTwho provided only the

5S.M. Henry et al. / The Spine Journal - (2014) -

stabilization exercises as part of this study (Table 1). Thestabilization exercise protocol focused on three componentsof spinal stability: motor control of the deep trunk muscles[10,20,21]; strengthening of the flexor, extensor, and obli-que trunk muscles [10] by focusing on repeated submaxi-mal efforts to mimic the function of these muscles inspine stabilization [36,37], and patient education in theform of an education booklet [38] that describes how touse proper body mechanics to protect the spine duringactivities of daily living (for protocol details, seeSupplementary data). Subjects were instructed to performthese stabilization exercises daily and to keep an exerciselog. The four treating physical therapists received training(from SMH) in how to progress the stabilization exercisesand were blinded to the subjects’ strata assignment.

MSI treatment protocolAll subjects in both the eligible and ineligible strata who

were randomized to Movement System Impairment treat-ment attended physical therapy sessions at one of fourphysical therapy outpatient clinics and were treated by aPT who provided only the Movement System Impairmenttreatment as part of this study (Table 1). With the Move-ment System Impairment–based approach, the PT matchestreatment to correspond to the specific Movement SystemImpairment category. Based on the subject’s direction-specific LBP classification, the PT tailored the MovementSystem Impairment protocol to focus on education aboutpositions or postures to control his symptoms; ‘‘Exercisesfor Precision of Trunk Movement’’ where patients were

Table 1

Characteristics of the physical therapy clinicians

Entry-level physical therapy

education

BS58, MPT or MSPT53

Years in practice (mean6SD,

range)

13.366.2, 4–27 y

% FTE of time in physical therapy

practice (n)

0%–25% 3

26%–50% 1

51%–75% 1

76%–100% 6

Number of clinicians with previous

experience with the Treatment-Based

Classification system (n)

None 5

A little 6

Moderate 0

A lot 0

Number of clinicians with previous

experience with the Movement System

Impairment Classification system (n)

None 4

A little 5

Moderate 2

A lot 0

FTE, full-time equivalent; SD, standard deviation; BS, Bachelor of

Science; MPT, Master of Physical Therapy; MSPT, Master of Science in

Physical Therapy.

taught specific trunk movements and postures that werepain free; and functional activity modifications (based ontheir Patient-Specific Functional Scale) to change histrunk-movement and alignment patterns (for protocol de-tails for the rotation, rotation with extension, and rotationwith flexion categories, see Supplementary data). The par-ticular exercises that were prescribed depended on theMovement System Impairment classification to which asubject was assigned; however, all PTs used the same setof exercises for a particular Movement System Impairmentclassification. Subjects were instructed to perform theseMovement System Impairment exercises daily and to keepan exercise log. The four treating physical therapists re-ceived training (from SMH and LVD) as to how to progressthe Movement System Impairment exercises and wereblinded to the subjects’ strata assignment.

Posttreatment assessments

Within a week after treatment was completed, all sub-jects returned for the same assessments (questionnaires,standardized clinical examination). The same physicaltherapist examiner (RHO-M) conducted the clinicalexamination.

Masking of the study personnel

The statistician and recruitment coordinator were notmasked to strata and treatment assignment, whereas all oth-er study personnel were masked to both. Physical therapyclinicians who provided the treatment and the subjects weremasked to strata assignment but not to treatment. Aftertreatment but before posttreatment assessments, the physi-cal therapist examiner (RHO-M) and the principal investi-gator (SMH) guessed which treatment each subjectreceived to test if they had remained masked to treatmentassignment. The percentages for correct versus incorrectguesses were 57%/43% for the physical therapist examinerand 50%/50% for the principal investigator, indicating thatthe masking was successful.

Data analyses

The primary analysis was an intention-to-treat analysis.To investigate our primary hypothesis, repeated-measureanalyses of variance were performed to examine the pri-mary outcome measures, the ODI and NPRS scores, forsubjects in the matched versus unmatched treatmentgroups, before and immediately after treatment at Week 7and at 12 months. A similar procedure was used for theother three questionnaires. Only subjects who were partici-pated in the Week 0 and Week 7 time points were includedin the analyses. In addition, a successful treatment outcomewas based on changes in the ODI score from pretreatmentto posttreatment such that reduction of 8 percentage pointsor more on the ODI was called a treatment success [39,40].Less than an 8 percentage point reduction was considered a

Table 2

Patient characteristics before treatment

Group Matched Unmatched

Number of subjects 76 25

Sex (number of males/

females)

35/41 15/10

Age (y) 40.15 (11.06) 45.88 (8.82)

Height (m) 1.72 (0.09) 1.74 (0.10)

Weight (kg) 70.52 (12.46) 73.44 (12.62)

Body mass index (kg/m2) 24.07 (3.23) 24.28 (2.63)

Note: All measures are reported as the mean and standard deviation ex-

cept where noted.

6 S.M. Henry et al. / The Spine Journal - (2014) -

treatment failure. Baseline patient characteristics andquestionnaire responses were compared using t tests orchi-square tests of independence, depending on the typeof variable being examined. All analyses were completedusing a statistical significance of p value less than .05 usingSAS 9.2 (SAS, Inc., Cary, NC, USA) procedures that couldaccommodate missing data without imputation.

Sample sizeChoosing a power of 80%, a significance level of 0.05,

and a subject distribution ratio of 3:1, our power analysesindicated that an overall sample size of 88 subjects wasneeded to detect a treatment difference over time in theODI score that was 7 percentage points greater for thematched treatment group compared with the unmatchedgroup. We assumed a standard deviation of 10% for theODI, which was based on data from our previous work.Thus, we needed 66 subjects in the matched treatmentgroup and 22 subjects in the unmatched group.

Results

In total, 1,022 volunteers were screened for inclusion inthe study and 898 were excluded because they did not meetthe inclusion criteria (prior surgery [n5230], body mass in-dex O30 [n571], age [n5114], pain below the knee[n556], minimal functional impairment [n533], LBP !1year [n527], excluded medical diagnosis [n581], litigation[n521], other [n5264], declined to participate [n51]).

Of the 102 subjects allocated to treatment for this studybetween March 2010 and September 2011, one subject wassubsequently excluded on Clinic Visit 1 because he had de-veloped pain below his knee that was not present during thepretreatment assessment session. Of the 101 subjects in-cluded in this study, 76 received a matched treatment (ie,subjects who were ineligible or eligible receiving Move-ment System Impairment treatment or were eligible receiv-ing stabilization exercises), whereas 25 received anunmatched treatment (ie, subjects who were ineligible re-ceiving stabilization exercises) (Fig. 1). There were no dif-ferences in baseline characteristics between the two groups(Table 2).

Out of six 1-hour planned treatment sessions, the sub-jects in the matched treatment group attended a mean(standard deviation) of 5.67 (1.03) sessions compared with5.53 (1.25) sessions for patients allocated to the unmatchedtreatment group. For both the pain (NPRS) and disability(ODI) scores, there was a visit main effect (for both ques-tionnaires, p!.0001) from pretreatment to posttreatmentbut no further improvement at 12 months (Table 3). Signifi-cant improvements across time were also noted for the oth-er questionnaires for both treatment groups combined (visitmain effects, p!.0001 to p!.01) with the exception of themental component summary score of the Short-Form 36questionnaire (visit main effect, p5.75). There was not a

superior treatment effect with either the matched or the un-matched treatment as evidenced by the complete lack of thegroup effects and by the lack of group by visit interactionsfor most of the questionnaires. The one exception was theGCPS (Disability Scale [DS]) that had a significant groupby visit interaction (p5.01); the matched group improvedsignificantly from pretreatment to immediately posttreat-ment and continued to improve at the 12-month time point(p!.0001), whereas the unmatched group did not improveover time (p5.14) (Table 3). Results from the per-protocol analysis were similar.

Approximately 45% of the matched and 48% of theunmatched group achieved treatment success, defined asan 8 or more percentage point reduction in the ODI score[39,40]. The mean ODI scores for the matched versus un-matched groups that achieved treatment success versus fail-ure are shown in Fig. 2.

Discussion

By identifying each subject’s particular clinical featuresdefined by the Treatment-Based Classification and Move-ment System Impairment classification schemas, we pro-vided either a classification-matched treatment based onclinical features or a classification unmatched treatmentfor 6 weeks and then compared the subjects’ pain and func-tional outcomes up to 12 months posttreatment. Using theprimary outcome measures, we found a reduction in bothpain (NPRS) and disability (ODI) scores after both thematched and unmatched treatments; however, superior out-comes were not achieved for subjects who received amatched treatment compared with subjects who receivedan unmatched treatment over this 1-year follow-up period.One of the secondary measures, the GCPS-DS, did reveal agreater reduction in disability for the matched treatmentgroup, compared with the unmatched group, immediatelyposttreatment and at the 12-month time point.

Using classification schemas to direct treatment

Although the theoretical basis for providing classification-directed treatment based on patients’ relevant clinical featuresis sound, the evidence that supports this assertion is mixed.

Table 3

Patient outcomes after matched versus unmatched treatment at week 7 and 12 months

Questionnaire Group (n)

Pretreatment (0 wk)

(mean/SE)

Posttreatment (7 wk)

(mean/SE)

Posttreatment (12 mo)

(mean/SE) Group (p) Visit (p) Interaction (p)

Overall statistics .20 !.0001 .46

ODI score (0%–100%) Matched (69) 20.58 (1.14) 12.55 (1.14) 9.36 (1.23)

Differences (CI) 8.03 (4.84, 11.22) 3.19 ( 0.12, 6.51)Unmatched (23) 18.70 (1.98) 9.22 (1.98) 10.20 (2.12)

Differences (CI) 9.48 (3.96, 15.00) 0.98 ( 6.70, 4.74)Overall statistics .56 !.0001 .12

NPRS score (0–10) Matched (68) 2.76 (0.22) 1.59 (0.18) 1.79 (0.25)

Differences (CI) 1.17 (0.76, 1.59) 0.20 ( 0.66, 0.25)Unmatched (24) 2.42 (0.36) 1.42 (0.29) 1.24 (0.41)

Differences (CI) 1.00 (0.31, 1.69) 0.18 ( 0.56, 0.91)Overall statistics .73 !.0001 .06

GCPS-CPI (0–100) Matched (69) 48.61 (1.63) 38.26 (1.84) 30.28 (2.26)

Differences (CI) 10.35 (7.88, 12.81) 7.98 (4.54, 11.42)Unmatched (23) 45.07 (2.82) 34.01 (3.21) 34.61 (3.92)

Differences (CI) 11.06 (6.74, 15.39) 0.60 ( 6.62, 5.42)Overall statistics .27 !.0001 .01

GCPS-DS (0–100) Matched (69) 33.71 (2.40) 26.91 (2.27) 14.26 (2.16) !.0001

Differences (CI) 6.80 (2.66, 10.93) 12.65 (8.35, 16.94)Unmatched (23) 25.07 (4.13) 18.56 (3.99) 18.53 (3.75) .14

Differences (CI) 6.51 ( 0.72, 13.75) 0.03 ( 7.53, 7.59)Overall statistics .63 .01 .82

FABQ-PA (0–24) Matched (69) 13.39 (0.51) 12.81 (0.58) 11.04 (0.70)

Differences (CI) 0.58 ( 0.51, 1.66) 1.77 (0.52, 3.03)Unmatched (24) 13.04 (0.86) 11.96 (0.99) 10.86 (1.18)

Differences (CI) 1.08 ( 0.75, 2.91) 1.10 ( 1.01, 3.20)Overall statistics .59 .01 .42

FABQ-W (0–42) Matched (69) 10.69 (0.93) 9.74 (0.93) 8.29 (0.89)

Differences (CI) 0.95 ( 0.36, 2.25) 1.45 ( 0.13, 3.03)Unmatched (24) 10.50 (1.57) 7.92 (1.58) 7.76 (1.49)

Differences (CI) 2.58 (0.38, 4.79) 0.16 ( 2.50, 2.81)Overall statistics .32 .01 .53

SF-36 (physical) (0–100) Matched (69) 46.67 (0.81) 50.51 (0.79) 50.56 (0.86)

Differences (CI) 3.83 ( 6.08, 1.59) 0.05 ( 2.36, 2.26)Unmatched (24) 48.89 (1.35) 50.21 (1.35) 51.42 (1.48)

Differences (CI) 1.32 ( 5.08, 2.44) 1.21 ( 5.15, 2.73)Overall statistics .69 .75 .87

SF-36 (mental) (0–100) Matched (69) 52.76 (1.02) 53.14 (1.00) 52.78 (1.08)

Differences (CI) 0.48 ( 3.73, 4.09) 0.14 ( 4.03, 3.75)Unmatched (24) 52.57 (1.70) 53.28 (1.70) 51.42 (1.86)

Differences (CI) 0.71 ( 5.44, 4.02) 1.36 ( 2.88, 5.61)

CI, confidence interval; FABQ-PA, Fear-Avoidance Behavior Questionnaire—physical activity subscale; FABQ-W, FABQ—work subscale; GCPS-CPI, Graded Chronic Pain Scale (Characteristic Pain

Index); GCPS-DS, GCPS (Disability Scale); NPRS, Numeric Pain Rating Scale; ODI, Oswestry disability index; SE, standard error; SF-36 (physical), physical component summary score of the Short-

Form 36; SF-36 (mental), mental component summary score of the SF-36.

7S.M

.Henry

etal./TheSpineJournal-

(2014)-

8 S.M. Henry et al. / The Spine Journal - (2014) -

Some studies demonstrate support for the Treatment-BasedClassification subgrouping approach when considering theshort-term (eg, 4 weeks) but not long-term outcomes for pa-tients with acute work-related LBP of less than 3 weeks dura-tion [41]. Brennan et al. [6] reported that patients with acuteand subacute LBP (n5123) had a small but significant reduc-tion in disability at 4 weeks if they had received a matchedtreatment as per the Treatment-Based Classification schema.However, the long-term data at 1 year were incomplete limit-ing a definitive conclusion about treatment outcomes. In addi-tion, this study was designed not as a prospective randomizedclinical trial but as a study to validate the Treatment-BasedClassification subgrouping, which limits its direct comparisonwith our study. Furthermore, the treating therapist was permit-ted to determine the dosageof treatment in an attempt to reflectclinical practice. This approach may have limited the treat-ment effect for the matched group that may have been ob-served had strict protocols been used as in our present study.Other studies with the acute LBP population [42,43] reportedpositive results after a stabilization exercise approach, thussupporting the notion that clinical outcomes can be improvedwhen the initial treatment provided ismatched to the signs andsymptoms of patients with acute LPB.

In contrast, a more recent study by Apeldoorn et al. [44]reported no differences at 8, 26, and 52 weeks in treatmentgroups when using the Treatment-Based Classificationschema for patients with subacute (6–12 weeks) andchronic (O12 weeks) LBP. The initial baseline characteris-tics of our subjects were similar to those reported by Apel-doorn et al. [44] despite the increased chronicity in ourcohort (O1 year of LBP). Whereas their comparison treat-ment was usual physical therapy care as defined by the cur-rent Dutch LBP guidelines [40,45,46], our comparisontreatment was the stabilization exercise provided to sub-jects who did not meet the clinical prediction rule for stabi-lization exercises [9]. Thus, our comparison group (ie, theunmatched treatment group) should have provided the larg-est difference in treatment outcomes, but we did not ob-serve this result in our study cohort. Similar to Apeldoornet al. [44], we used the decision-making algorithm pre-sented by Fritz et al. [9] and did not need to use the portionof the algorithm that describes ‘‘Factors Favoring’’ or‘‘Factors Against’’ for the three categories listed there (ie,‘‘manipulation,’’ ‘‘stabilization,’’ and ‘‘specific exercise’’).Given that we excluded patients with pain below the kneewho would likely be managed with traction, we did notneed to include the ‘‘traction’’ category that is the fourthcategory in the Treatment-Based Classification schema. Incontrast with Apeldoorn et al. [44], we used standardizedexercises with progression guidelines for the treating thera-pists to use.

In addition, the treating therapists in our study gave gen-eral instruction to the subjects in the stabilization exercisegroup on how to modify a generic list of activities of dailyliving (from an instructional book), whereas those receivingmatched Movement System Impairment–directed exercises

got very specific instruction in how to modify their lumbo-pelvic coordination (based on their assigned MovementSystem Impairment category) during their specific daily ac-tivities. In another study using similar motor control princi-ples as we did, Costa et al. [20] (n5154 patients withchronic LBP) demonstrated small but significant short-term improvements in favor of the motor control groupfor both patient activity tolerance and global impressionof recovery. However, the exercise interventions failed toreduce pain greater than nontherapeutic modalities overthe same period. Another study [47] did use a chronicLBP population that was subgrouped based on the presenceof radiologically confirmed symptomatic spondylolysis orspondylolisthesis. The authors reported superior treatmentoutcomes for patients who received the stabilization exer-cises (n512) compared with those who received a controltreatment (n515) directed by their medical practitioner thatconsisted of regular weekly general exercise (eg, swim-ming, walking, gym work). These results suggest that thestabilization exercise approach may be indicated for specif-ic subgroups of the chronic LBP population.

The study by Hicks et al. [10], from which the clinicalprediction rule for stabilization exercise was derived, iden-tified subjects who were successful with stabilization exer-cise retrospectively, whereas for our study, these subjectswere defined a priori. Furthermore, we used the three offour clinical features identified by Hicks et al. [10] to pre-dict treatment success with stabilization exercise andlumbar-spine hypermobility that Fritz et al. [34] identifiedas another clinical feature of patients with LBP who im-prove with stabilization treatment. Hicks et al. [10] didnot identify lumbar-spine hypermobility as a predictor ofimproved outcomes after stabilization treatment, likely be-cause of biased recruitment resulting in limited numbers ofsubjects with lumbar-spine hypermobility. Thus, our cohortwas likely more homogeneous based on the Treatment-Based Classification schema for stabilization exercisescompared with other studies; yet, we still did not observea superior treatment outcome compared with the un-matched treatment group.

Evidence in support of the Movement System Impair-ment classification directed treatment is similarly mixed.Using case-based reports [48–50], patient outcomes afterMovement System Impairment–directed treatment demon-strate superior improvement (1 year) compared with otherclassification systems [51] and treatment approaches[52,53]. Results from a larger randomized clinical trial thatcompares Movement System Impairment–directed treat-ment and general strengthening and flexibility exercise pro-tocol are not available at this time (NCT00802724).

Are classification schemas ready for clinical use?

Some have suggested that the majority of research todate in defining subgroups of patients with LBP is still inthe hypothesis generation stage and that no classification

Fig. 2. The mean pretreatment and posttreatment Oswestry disability index (ODI) scores (%) of subjects grouped as ‘‘treatment success’’ (matched n534,

unmatched n512) versus ‘‘treatment failure’’ (matched n535, unmatched n511). For the missing posttreatment data, there were seven matched and two

unmatched subjects.

9S.M. Henry et al. / The Spine Journal - (2014) -

system has demonstrated sufficient evidence to recommendits use in the clinic [54,55].

Providing matched interventions to those with acutefirst-time LBP theoretically has long-term implications,including the reduction of chronic LBP. Although therehas been progress in creating and supporting thedecision-making algorithm for those with acute LBP[10,41,56], some have suggested that subgrouping maybe less important among patients with more chronic symp-toms [57]. However, given that 15% to 45% of the popu-lation currently has LBP with lifetime recurrences in up to80% of the people [58] and the high recurrence rate [59],there is also a need for treatment algorithms for patientswith more mild disability or more chronic symptoms giventhese patients will likely benefit from alternative decision-making schemes. Given that 85% to 95% of patients withLBP are diagnosed by their general practitioner as havingnonspecific LBP [60], clearly, there is a mandate to im-prove treatment algorithms, but, perhaps, current treat-ment is ineffective because it is misdirected. Furtherresearch is needed as indicated by our study results andmay need to include psychosocial measures [46,61,62],cortical [55] and neuromuscular measures [63,64], andcognitive factors [65].

Determining treatment success

Another way to examine the outcomes of matched ver-sus unmatched treatments is to define treatment outcomesas successful, failed, or improved [10]. Patients with LBPjudged to be appropriately matched to their treatment pro-gram reported improvements in ODI scores ranging from57% to 83%, whereas patients receiving unmatched treat-ments experienced improvements from 20% to 38% overa 1- to 4-week treatment period [56,66,67]. For our study,

given our cohort was more chronic than in these previousstudies and our subjects had a lower mean ODI at baseline,we were concerned about using these same guidelines.Thus, a successful treatment outcome was based onchanges in the ODI score from pretreatment to posttreat-ment such that a reduction of 8 percentage points or moreon the ODI was called a treatment success [39,40]. Lessthan an 8 percentage point reduction was a treatment fail-ure. The threshold for determining treatment success is lessconservative than thresholds used for determining treatmentsuccess with a more acute LBP population [10], but we be-lieve that it is justified based on reports that determine sig-nificant changes in the ODI for the chronic LBP population[39,40]. The initial ODI scores of those subjects in the‘‘treatment failure’’ category were lower on average thanthose in the ‘‘treatment success’’ category that may havecontributed to a smaller reduction in the posttreatmentODI score because of a floor effect.

Study limitations

The results of this study must be considered in light ofseveral limitations. The sample size was relatively small,providing adequate power for only comparing the matchedto unmatched treatments (and not the stabilization vs.Movement System Impairment exercises). Although thephysical therapy clinicians were trained to provide bothtreatment approaches (in case of vacation or unexpected ab-sence from the clinic), they only provided one treatment themajority of the time. So although clinicians could not beblinded to treatment, this bias was reduced because eachtherapist delivered only one treatment. Although the num-ber of treatments given to each group was equal, the poten-tial influence of the therapists cannot be discounted. Theexclusion criteria used in this study should be taken into

10 S.M. Henry et al. / The Spine Journal - (2014) -

account when considering the clinical implications of theresults. In particular, it is important to note that patientswith signs of nerve root compression or prior surgery tothe low back were excluded.

Conclusions

In summary, superior outcomes were not achieved forsubjects with chronic LBP who received a matched treat-ment compared with subjects who received an unmatchedtreatment over a 1-year period.

Acknowledgments

The authors would like to acknowledge the consultationservices of Dr Julie Fritz on the Treatment-Based Classifica-tion schema and the related standardized clinical examinationitems. The authors would also like to acknowledge the Ver-mont physical therapists who participated in this study: JustineDee,MS, PT,MatthewOdachowski,MPT, and JeffreyAlbert-son, MPT, of Dee Physical Therapy, South Burlington; JanetCarscadden, PT, and Andrea Trombley, MPT, of EvolutionPhysical Therapy and Yoga, Burlington; Rose Bernier, PT,Traci Glanz, PT, Lucia Ryan, PT, Diane Stevens, PT, and So-nya Worth, PT, PGDipHSc, of Fletcher Allen Health Care,Burlington; Candice Brueck, MPT, of Timberlane PhysicalTherapy, South Burlington; and Karen Westervelt, PT,PGDipHSc, and Jane Eliasson, PT, of Copley Hospital, Mor-risville,Vermont.Data assistancewas provided byMsJenniferChennette, Ms Claire Freson, and Ms Kelsey McLaren.

Appendix

Supplementary data

Supplementary data related to this article can be found athttp://dx.doi.org/10.1016/j.spinee.2014.03.024.

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