NZ Journal of Physiotherapy – July 2006, Vol. 34 (2) 50

Research Report

Measurement of the functional improvement in patients receiving physiotherapy for musculoskeletal conditions

Celia Monk, DipPhys, DipMDTPhysiotherapist, Northwest Physiotherapy Centre, Christchurch, New Zealand

AbsTRACTPurpose: In order to objectively assess whether a clinically significant improvement in a patient’s function has occurred, it is important that physiotherapists monitor change in their patients’ functional disability.Methods: This study assessed the difference between the functional disability score (FDS) during the initial assessment with the FDS recorded on discharge, for each patient presenting with low back pain or a lower extremity condition. Two validated FDSs were used: The Roland-Morris Disability Index and the Lower Extremity Functional Scale. Sixty-eight (68) consecutive participants with low back pain or lower extremity conditions completed a functional disability questionnaire on their initial assessment and again on discharge from the clinic following a course of physiotherapy treatment. Results: The patients’ functional disability was reduced by an average of 70%. The mean number of treatments given was 5.1.Conclusion: A statistically significant improvement was seen in the patients’ functional ability following a course of physiotherapy treatment for low back pain or lower extremity conditions. This process provides an objective measurement of functional improvement in individual patients, as well as average improvement across patients with varying presenting conditions. It is hoped this report will encourage other physiotherapists to perform similar studies within their own clinical settings. Monk C (2006): Measurement of the functional improvement in patients receiving physiotherapy for musculoskeletal conditions 34(2): 50-55.Key Words: Low back pain, Questionnaires, Function, Outcome, Lower Extremity Functional scale, Roland-Morris Disability Index

IntRoductIonImproving functional ability is one of the main

goals of providing physiotherapy treatment to patients with musculoskeletal conditions and injuries. “Successful physical therapy intervention is usually not reflected in simply better movement but in improvements in functioning” (Kane, 1994). In the clinical setting, the usual method of deciding a patient has improved enough to be discharged from treatment relies on verbal reporting by the patient, coupled with an improvement in objective findings found by the physiotherapist during the reassessment process. As patient reporting is subjective in its nature, functional outcome questionnaires have been developed to gain a more objective measurement of the patient’s interpretation of their improvement, or lack thereof, although these still rely on self-reporting by the patient.

The use of validated Functional Outcome Measurement Tools to measure improvements in a patient’s functional ability is not widespread within physiotherapy clinics in New Zealand, or in several other countries around the world including England (May, 2003), Ireland (Caulfield & Reilly), Australia (Beattie & Maher, 1997), or Canada (Kirkness & Korner-Bitensky, 2002). A literature search revealed no studies have been published in New Zealand looking at the use of the functional outcome measurement tools within the physiotherapy clinical setting.

In this study we use a validated functional outcome measurement tool to assess whether there is a functional improvement in patients from the time of their first assessment to the time they are discharged. In this day of evidence-based medicine, it is vital that as a profession physiotherapists are able to objectively justify and measure the effect of the treatment provided (Caulfield & Reilly).

It is suggested that the main reasons for physiotherapists not utilising functional outcome tools are pressures of time, lack of access to measurement instruments and a lack of knowledge of which instruments to use, the scoring methods, and how to interpret the results (Caulfield & Reilly). There are specific questionnaires that have been developed to apply to various parts of the musculoskeletal system. To be effective, they must have had their validity, reliability and sensitivity to change established by previous research. One functional outcome tool for the lumbar spine that has been well established in the literature is the Roland-Morris Disability Index,(Deyo et al., 1998; Roland & Morris, 1983; P. Stratford & Binkley, 1997).

Another well established functional outcome tool is the Lower Extremity Functional Scale (LEFS) (Binkley et al., 1999). Its validity, reliability, sensitivity to change, and specificity have been reported (Binkley et al, 1999) and it is commonly utilised in the literature (Riddle et al., 2004; P. W. Stratford et al., 2003; White et al., 2004).

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The main objective of this study is to demonstrate the use of functional outcome measurement tools in a typical New Zealand private physiotherapy practice, and to determine if there is a statistically significant functional improvement in patients receiving physiotherapy at our practice, for either low back pain or a lower extremity condition.

Methodsetting

This study was performed in the Northwest Physiotherapy Centre in Christchurch, New Zealand. The Centre consists of two private Physiotherapy Clinics, and has two physiotherapists (including the author). Both Clinics are accredited by the New Zealand Physiotherapy Accreditation Scheme.

patient selectionAll consecutive patients who presented to the

Northwest Physiotherapy Centre between mid-March and mid-April 2005 for treatment of low back pain or a lower extremity condition who did not meet the exclusion criteria were invited to partake in the study. The exclusion criteria were: difficulty with the written English language, declined to give informed consent, a condition not involving the low back or lower extremity, and the presence of a condition that was not suitable for physiotherapy treatment.

Patients are referred to Northwest Physiotherapy by general practitioners, the public hospital, the private after hours medical centre, orthopaedic specialists, or by themselves (self-referral). The conditions seen are usually caused as a result of an accident, and therefore the Accident Rehabilitation and Compensation Corporation (ACC) covers the treatment costs, with no charge to the patient. Each condition has been assigned an ACC Read Code by the initial treatment provider and a recommended maximum number of required treatments is indicated by the Treatment Profile (ACC, 2000).

Interventions:Following consent being given, the patients

were asked to complete either the Roland-Morris Disability Index if they presented with low back pain, with or without referred pain, or the Lower Extremity Functional Scale if they presented with a lower extremity condition. The completed initial questionnaire was then scored according to the instructions for both the Roland-Morris and the Lower Extremity Functional Scale (LEFS). The Roland-Morris Disability Index was scored out of 24, with the higher number equating to a higher level of functional disability. The LEFS was scored out of 80, with the lower number equating to a higher level of functional disability.

The normal assessment and treatment procedures were then followed for each patient, according to the Northwest Physiotherapy Centre’s Policy and Procedure Manual.

The treatment philosophy of Northwest Physiotherapy is predominately based on the

principles of Mechanical Diagnosis and Therapy as described by McKenzie (McKenzie & May, 2000, 2003). This philosophy places a strong emphasis on a thorough initial assessment with the aim to determine the effective self-treatment strategies, including exercises, that the patient can apply to recover from the present episode of pain and disability. Electrotherapy is rarely used at Northwest Physiotherapy, and manual therapy techniques are utilised as required.

When the physiotherapist determined that the patient had improved and was ready for discharge the patient was asked to complete a repeat questionnaire. Again this was scored and the resultant data entered into the spreadsheet, along with the number of treatments given to achieve that functional outcome. Patients who had not attended the final treatment session were contacted by phone and either posted a repeat questionnaire or were asked to come into the clinic to complete one. When the last patient was discharged, the results were analysed using simple statistical methods.

MAIn outcoMe MeAsuResThe main outcome measures were the change in

the functional outcome scores, the average number of treatments given to achieve that result, and the average length of the present episode prior to receiving physiotherapy treatment.

The Roland-Morris Disability Index (Roland & Morris, 1983) is a 24-item questionnaire, where patients tick the appropriate statements for the pain and disability they are experiencing the day they are completing the questionnaire. The score is calculated by adding the statements ticked, giving a score out of 24. Typical analysis of the Roland-Morris Disability Index involves comparing the final score and the initial score for all patients. However, this process can introduce a bias if the patient population either has a very high or a very low initial score. For example, if the majority of patients presenting to the clinic have very low scores, there is little room for improvement and therefore the overall mean change in score of only one or two would reflect poorly on the treatment provided, called the floor effect. Conversely, if the average initial score is high, the resultant mean change could exaggerate the effectiveness of the treatment provided. It was therefore decided, for the purposes of this study, to introduce a method of analysing the proportion of change for each patient. To find the overall improvement, the following formula was utilised: Proportional Reduction = Initial score – Final Score

  First ScoreThis formula was used in order to find the

proportion of reduction in disability that had occurred in relation to the original amount of disability the patient was experiencing on their presentation to the clinic. For any given patient the best outcome we can expect is to reduce their disability to zero, which is considered to be 100% proportional reduction of disability regardless of the original level of disability.

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The Lower Extremity Functional Scale (Binkley et al., 1999) is a 20-item questionnaire that requires the patients to score the level of difficulty they are experiencing with certain activities according to a scale from 0 for “extreme difficulty” to 4 for “no difficulty”. The resultant score is out of 80, with a high score reflecting a low level of functional disability. Some patients did not complete all aspects of the LEFS questionnaire because they felt the statements did not apply to them, or they could not answer them honestly. For example, some older patients were unable to state if the pain was causing difficulty running on uneven ground. For the purposes of statistical analysis, the percentage of answered questions was calculated and then pro-rated up to a total possible score of 80.

The LFS is scored in the opposite manner to the Roland-Morris Disability Index, which has a low score for a low level of functional disability, which could introduce the ceiling effect. However, the proportion of reduction in disability was calculated enabling the two different groups to be compared to each other and to give an overall percentage of reduction of disability for all patients in the study. To achieve this the LEFS score was transformed to the same scale as the RMD by calculating (100 – x) for both the initial and final scores, and calculating the reduction in disability from the transformed values.

data AnalysisThe Data Analysis Toolpak® in Microsoft Excel

® was used to perform the data analysis. The mean and standard deviation of the raw scores were reported. The Analysis of Variance (ANOVA) single factor t -test was applied to determine the p value for the data collected. Statistical significance was set at 0.05 in all analyses.

MAIn ResultsOver the four-week enrolment period for the

study, 79 patients attended the clinic for treatment of low back pain or a lower extremity condition. Four patients were excluded from the study due to a lack of understanding of the written English language (n = 2) or refusal to give consent for personal reasons (n = 2). Of the 75 patients initially included in the study, 6 were later excluded when it was identified that their conditions were unsuitable for physiotherapy (Table 1). Of the 69 patients included in the full study, 68 patients (99% follow-up rate) completed both the initial and the final questionnaires. One patient did not return for the final follow-up questionnaire, despite several phone calls from the clinical staff.

Characteristics of the participating patients are reported in Table 2. The average length of the present episode was 26.7 days (Table 2). 29 patients presented with Low Back Pain (with or without referred pain into the leg) and 39 presented with a condition of the Lower Extremity (Table 3). Overall, the average number of treatments given was 5.1

treatments. The low back pain patients received an average of 5.2 treatments, and the lower extremity patients received an average of 5.0 treatments. The ACC Treatment Profile for low back pain is 12 treatment sessions, and the average Treatment Profile for the lower extremity conditions seen in this study was 14.3 treatments. (Table 2)

At discharge from treatment, the average improvement for the low back patients was a decrease in the Roland-Morris score by 7.2 points. When the proportional reduction was calculated, the average improvement in the low back patients was 71% (p value <0.0001).

At discharge from treatment, the average improvement for the lower extremity patients was an increase in the LEFS score by 24 points. The proportional reduction calculation results in an average improvement in the lower extremity patients of 69% (p value <0.0001). (Table 4 and Figure 1).

dIscussIonThe primary aim of this study was to demonstrate

the use of functional outcome measurement tools in a typical New Zealand private physiotherapy practice. The results have shown that simple functional questionnaires can provide an objective measurement of the overall effectiveness of the treatment provided – regardless of the specific type of treatment given. The data analysis can be performed by using the internal tools within the Microsoft Excel® or similar computer program. In this day of evidence-based medicine and cost-effectiveness, it is vital that health professions can prove their effectiveness. This study has demonstrated a simple but effective way of achieving this, and I encourage physiotherapists to perform similar audits in their own clinical settings.

The secondary aim of this study was to demonstrate the amount of functional improvement experienced by patients following physiotherapy for either low back pain or a lower extremity condition, using previously validated functional questionnaires. At discharge patients showed a statistically significant improvement in the functional disability score, which reflected an average 70% reduction in the overall functional disability at the time of the initial assessment. This result was achieved within an average of 5.1 treatment sessions.

A literature search revealed no other studies have been published in New Zealand looking at specific functional improvement in patients receiving physiotherapy for low back pain or a lower extremity condition. A similar study was done in England (May, 2003) and found a 20 percentage point reduction in the functional outcome score over an average of 4 treatments. This was a retrospective audit in a community hospital in England with ten physiotherapists providing the treatment. The potential sample size was 1713 patients that had been discharged over the seven-month period reviewed by the study. Unfortunately there was a low rate of compliance by the physiotherapists

NZ Journal of Physiotherapy – July 2006, Vol. 34 (2)  53

gathering the data for both the initial and final scores, with only 53% of the patients having a complete set of data. To overcome the potential for a similar low compliance in this present study, the involved physiotherapists were included in the design process and were highly motivated to ensure the optimal amount of data was collected over the limited timeframe resulting in a 99% complete data set. This present study has similar findings to May’s study with a 30 percentage point reduction in the functional score over an average of 5 treatments.

One of the main strengths of the present study was the use of validated outcome measures: the Roland-Morris Disability Index (Roland & Morris, 1983) and the Lower Extremity Functional Scale (Binkley et al., 1999). Both these functional

measurement tools have been validated in the literature and proven to be specific, sensitive to change, and reliable. The study also had a very low drop out rate, which may reflect the effectiveness of the communication process used with the patients: the Study Information Sheet explained the reason and procedure for the study, and a follow-up phone call being made if they did not attend the clinic for a given appointment time. The short time frame over which this study was conducted (eight weeks: four weeks for enlisting patients into the study and another four weeks to finish their course of treatment) may have ensured a high compliance within the clinical setting. The physiotherapists involved had limited time for the gathering of information and to ensure the task

Table 1: Reasons for withdrawal from study and onward referral

Referred By Number of Treatments

Reason for Withdrawal Referred To Outcome

Patient 1 GP 1 Obvious infection present in knee on assessment

GP Full recovery

Patient 2 Self 2 Non-mechanical response to movements and positions

Pharmacy Recovering with anti-inflammatory treatment

Patient 3 GP 5 Initially improved then seriously re-injured calf, non-mechanical response

Orthopaedic Surgeon

MRI Scan and awaiting surgery

Patient 4 GP 8 Low back pain and leg pain which initially centralised but chemical signs persisted

GP then Rheumatologist

Improving with appropriate medication

Patient 5 Hospital 6 Initial ly improved but knee worsened on return to work, non-mechanical response to further treatment

Orthopaedic Surgeon

Awaiting knee arthroscopy

Patient 6 GP 7 Initially improved until re-injured knee, non-mechanical response to further treatment

Orthopaedic Surgeon

Awaiting knee arthroscopy

Patient 7 Self 2 Self-discharged once improved. Failed to return to clinic for follow-up questionnaire completion

Note: “ACC” Accident Rehabilitation and Compensation Corporation, “QTF” Quebec Task Force

Table 2: Demographic Results for study Participants

Mean Result (n=68)Age 47 years ±4.95 years SDMale 41 patientsFemale 27 patientsLength of Episode 26.7 days ±0.71 days SDACC Classification Acute (< 3 months) Chronic (> 3 months) 3 patientsQTF Classification Acute (< 7 days) 29 patients Subacute (< 7 weeks) 30 patients Chronic (> 7 weeks) 9 patientsPatients with Low Back Pain 29 (43%)Patients with Lower Extremity Condition 39 (57%)Number of treatments given: All Patients 5.1 ± 1.41 SD (ACC Profile = 13.2 treatments) Low Back Patients 5.2 ± 1.41 SD (ACC Profile = 12 treatments) Lower Extremity Patients 5.0 ± 1.41 SD (ACC Profile = 14.3 treatments)

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did not become burdensome. The potential for bias was reduced by ensuring the patient completed the initial questionnaire prior to their first assessment with no influence offered by the physiotherapist, or the assessment process.

One of the main limitations of the study is the small sample size (68 patients); however the small sample size did not reduce the statistical power

of the findings. As there was no control group in the study, there was no method of ensuring that the functional improvement seen was due to the treatment received and not natural history, non-specific treatment effects, regression to the mean, or other factors. As the study was a single-group design, there is an inability to identify the specific cause of the functional improvement measured especially the influence of placebo effects. Another weakness within this study was the potential for bias with the physiotherapist asking the patient to complete the final questionnaire. The physiotherapists were careful not to verbally influence the patient’s response, but their presence may have had a non-verbal influence. Another potential weakness of the study is that the data analysis was not performed by intention to treat, as the data from the withdrawn patients was not utilised in the calculations.

A design weakness in the Roland-Morris Disability Index is that several patients marked statements in the final questionnaire that were not perceived to be a

Table 3: Read Codes and conditions seen

Read Code reference: (ACC, 2000)

Read Code ACC Definition Number of Patients (n=68) Number of Treatments (mean)

S572 Lumbar Spine 29 5.2

S53 Sprain Hip/thigh 2 2.5

S54 Sprain Knee 6 3.8

S54x1 Strain Gastrocnemius 4 6.0

S550 Sprain Ankle 11 4.8

S5504 Strain TA 5 5.0

S460 Medial Meniscus tear 1 4.0

SE41 Contusion knee/lower leg 1 5.0

S463 Dislocation patella 1 9.0

S33 Fracture Tibia and Fibula 2 9.5

S535 Strain hamstring 1 5.0

S551 Foot Sprain 2 3.5

S541 Sprain Med Ligt Knee 3 5.7

Figure 1: Mean Change in Functional Disability Percentages

Table 4: Mean Change in Functional Questionnaire scores

Initial Score(Mean)

Final Score(Mean)

Mean Change in Raw Score

P Value Reduction in DisabilityInitial – final

initial

Low Back Pain(From total of 24)

10.142%

2.912%

7.2 p<0.0001 71%

Lower Extremity Condition(From total of 80)

46.1

58%

69.8

87%

23.7 p<0.0001 69%

Lower ExtremityReversed Score

42% 13%

Note: The Lower Extremity Score was transformed to (100 – x) to enable comparison to be made between the two groups, as a low R-M Score reflects a low disability level, whereas a low LEFS score reflects a high disability level.

NZ Journal of Physiotherapy – July 2006, Vol. 34 (2)  55

problem when they completed the initial questionnaire It would appear that, at the initial assessment, they were not aware of the true implications of their pain on some aspects of function. It was important that the physiotherapist did not point this out to the patient and thereby influence the independent answer given by the patient.

clinical ImplicationsIt could be argued that if the patients in this study

were given more treatment sessions then the average functional improvement would be greater. However, the treatment philosophy of the clinical setting for this study is that functional goals are set during the initial assessment, which are determined by the functional difficulties the patient describes that they are experiencing as a result of their present episode of pain. Once these goals have been achieved, and the patient is satisfied with the outcome, they are discharged from the clinic. In some cases there is still a low level of pain and disability present, but the self-management procedures taught to the patient are designed to fully abolish these residual symptoms. The patients are always instructed to contact the clinic if any residual signs and symptoms persist for more than two to three weeks. This results in the patients being satisfied with the treatment provided as their goals have been achieved over a short period of time without prolonged treatment offered. We measure satisfaction by internal clinical audits at regular intervals.

Although this study was not designed to assess the effectiveness of specific forms of physiotherapy treatments, it is interesting to note that the six patients who were withdrawn from the study (Table 1) were identified as being unsuitable for further treatment within an average of two to three treatment sessions. Two of the six patients initially improved and prior to their discharge sustained a re-injury, which did not respond to the treatment given within two further sessions. This is a strength of the Mechanical Diagnosis and Therapy Method as described in several studies (Werneke & Hart, 2003, 2004; Werneke et al., 1999). Early intervention and onward referral was therefore possible to be offered to those patients in this study who required it, reducing unnecessary use of physiotherapy resources.

This study has demonstrated the simple but effective use of functional outcome measurement tools in a typical New Zealand private physiotherapy practice. Further study is required, across a wider range of body sites, pathologies, acuity and chronicity, to determine the effectiveness of physiotherapy to produce functional improvement in patients treated across various New Zealand physiotherapy practice settings.

Key Points:1. With the use of validated functional disability

questionnaires, Physiotherapy services can perform outcomes research with minimal disruption to their normal clinical practice.

2. Functional disability of the patients enrolled in this study reduced by a mean of 70%, over an average of 5.1 treatment sessions.

AcknowledgeMents:I would like to thank Gerald Cummins, Principal Physiotherapist,

Northwest Physiotherapy Centre, for assisting with the patient data collection and his support through the whole study process. Also thank you to Ian Viney, Engineering Manager, Trimble Navigation, Christchurch, for his assistance in the data analysis.

RefeRencesACC (2000): Physiotherapy treatment profiles. Wellington, New

Zealand.ACC (2004): New Zealand acute low back pain guide. Wellington:

Accident Compensation Corporation.Atlas S, Deyo R, Patrick D, Convery K, Keller R and Singer

D (1996): The Quebec task force classification for spinal disorders and the severity, treatment, and outcomes of sciatica and lumbar spinal stenosis. Spine 21: 2885-2892.

Beattie P and Maher C (1997): The role of functional status questionnaires for low back pain. Australian Physiotherapy 43(1): 29-36.

Binkley J, Stratford P, Lott SA and Riddle D (1999): The lower extremity functional scale (LEFS): Scale development, measurement properties, and clinical application. Physical Therapy 79(4): 371-383.

Caulfield B and Reilly C: Outcome measurement in physiotherapy - why and how. Physiotherapy Ireland 24(1): 8-11.

Deyo R, Battie M, Beurskens A, Bombardier C, Croft P, Koes B, et al (1998): Outcome measures for low back pain research. Spine 23(18): 2003-2013.

Kane R (1994): Looking for physical therapy outcomes. Physical Therapy 74(5): 425-429.

Kirkness C, and Korner-Bitensky N (2002): Prevalence of outcome measure use by physiotherapists in the management of low back pain. Physiotherapy Canada Fall: 249-257.

May S (2003): An outcome audit for musculoskeletal patients in primary care. Physiotherapy Theory and Practice 19:189-198.

McKenzie R and May S (2000): The human extremities mechanical diagnosis and therapy: Spinal Publications New Zealand.

McKenzie R and May S (2003): The lumbar spine mechanical diagnosis and therapy (2nd ed. Vol. 1): Spinal Publications New Zealand Ltd.

Riddle DL, Pulisic M and Sparrow K (2004): Impact of demographic and impairment-related variables on disability associated with plantar fasciitis. Foot & Ankle International 25(5): 311-317.

Roland M and Morris R (1983): A study of the natural history of low back pain. Part 2: Development of guidelines for trials of treatment in primary care. Spine 8(2): 145-150.

Stratford P and Binkley J (1997): Measurement properties of the rm-18. A modified version of the Roland Morris disability scale. Spine 22(20): 2416-2421.

Stratford PW, Kennedy D, Pagura SM and Gollish JD (2003): The relationship between self-report and performance-related measures: Questioning the content validity of timed tests. Arthritis & Rheumatism 49(4): 535-540.

Werneke M and Hart D (2003): Discriminant validity and relative precision for classifying patients with non-specific neck and back pain by anatomic pain patterns. Spine 28(2): 161-166.

Werneke M and Hart D (2004): Categorising patients with occupational low back pain by use of the Quebec task force classification system versus pain pattern classification procedures: Discriminant and predictive validity. Physical Therapy 84(3): 243-254.

Werneke M, Hart D and Cook D (1999): A descriptive study of the centralisation phenomenon. Spine 24(7): 676-683.

White LJ, Straube D and Keehn MT (2004): Using compensations to assess physical performance for ambulatory outpatients. Archives of Physical Medicine & Rehabilitation 85(9): 1519-1524.

AddRess foR coRRespondenceNorthwest Physiotherapy Centre, PO Box 29 182, Fendalton,

Christchurch. Email: celiamonk@clear.net.nz