Impact of Restricted Phosphorus, Calcium-adjusted Diet on Musculoskeletal and Mental Health in Hypophosphatasia

Context

Impairments in musculoskeletal and mental health are common in adults with Hypophosphatasia (HPP). Restricted phosphorus intake has been suggested to positively affect symptoms in HPP, but there is a lack of interventional evidence.

Objective

This work aimed to evaluate the effect of a phosphorus-restricted, calcium-adjusted diet on musculoskeletal and mental health in HPP.

Methods

A prospective, noncontrolled, single-center interventional study (NuSTEPS II) was conducted among outpatients at the Osteology Department, University of Wuerzburg, Germany. A total of 26 adults with an established HPP diagnosis received a standardized diet with a defined daily intake of phosphorus (1160-1240 mg/d) and calcium (870-930 mg/d) over 8 weeks. Main outcome measures were functional testing and patient-reported outcome measures.

Results

At 8 weeks, significant improvements were observed in usual gait speed (P = .028) and the chair-rise test (P = .019), while no significant changes were seen in the 6-minute walk test (P = .468) and the timed up-and-go test (P = .230). Pain was not significantly reduced according to the visual analog scale (VAS) (P = .061), pain subscale of the 36-Item Short-Form Health Survey (SF-36) (P = .346), and Pain Disability Index (P = .686). Further, there was a significant improvement in the SF-36 vitality subscale (P = .022) while all other subscales as well as the Lower Extremity Functional Scale (P = .670) and the Fatigue Assessment Scale (P = .392) did not change significantly. Adjustments of mineral intake were not associated with relevant alterations regarding the intake of energy and energy-supplying nutrients or body composition.

Conclusion

Adjusting phosphorus and calcium intake may positively affect individual symptoms in adults with HPP, but overall clinical effectiveness regarding major issues like pain and endurance appears limited.

Kinematic adaptations to restricting spine motion during symmetrical lifting

When lifting an object from the ground a person has many possible whole-body movement solutions to accomplish the task. It is unclear why lifters use most of their available lumbar spine flexion range-of-motion despite many ergonomic guidelines advising against doing so. Experimentally restricting spine motion and observing compensatory movement strategies is one approach to address this knowledge gap. A kinematic analysis was performed on 16 participants who completed symmetrical lifting tasks with and without wearing a spine motion-restricting device. Sagittal trunk, lumbar spine, and lower extremity kinematics, along with stance width and foot orientation in the transverse plane were evaluated between restricted and unrestricted lifting conditions. Restricting spine motion required greater ankle dorsiflexion (p < 0.001), knee flexion (p < 0.001), and hip flexion (p < 0.001) motion in comparison to unrestricted lifting. Motion was reallocated such that hip flexion showed the largest increase in restricted lifting, followed by ankle dorsiflexion, then knee flexion compared to unrestricted lifting. Trunk inclination decreased (i.e., more upright) in restricted compared to unrestricted lifting (p < 0.001). Neither stance width (p = 0.163) nor foot orientation (p = 0.228) were affected by restricting spine motion. These adaptive movements observed indicate lower extremity joint motion must be available and controlled to minimize lumbar spine flexion during lifting.

Cost-Effectiveness of Group-Based Outpatient Physical Therapy After Total Knee Replacement: Results From the Economic Evaluation Alongside the ARENA Multicenter Randomized Controlled Trial

OBJECTIVE

To assess the cost-utility and cost-effectiveness of a group-based outpatient physical therapy intervention delivered 6 weeks after primary total knee replacement (TKR) compared with usual care, alongside the Activity-Orientated Rehabilitation Following Knee Arthroplasty (ARENA) multicenter, randomized, controlled trial.

METHODS

The economic analyses were performed from the perspective of the health and social care payer. We collected resource use for health and social care and productivity losses and patient outcomes for 12 months after surgery to derive costs and quality-adjusted life years (QALYs). Results were expressed in incremental cost-effectiveness ratios (ICERs), and incremental net monetary benefit statistics (INMBs) for a society willingness-to-pay (WTP) threshold of £20,000 per QALY gained, with sensitivity analyses to model specification and perspective.

RESULTS

The cost of the ARENA physical therapy classes was mean ± SD £179 ± 39 per patient. Treatment in the year following surgery cost was, on average, £1,739 (95% confidence interval [95% CI] -£742, £4,221) per patient in the intervention group (n = 89), which was an additional £346 (95% CI £38, £653) per patient compared with usual care (n = 91) (£1,393 [95% CI -£780, £3,568]). QALY benefits were 0.0506 higher (95% CI 0.009, 0.09) in the intervention group, corresponding to an additional 19 days in "perfect health." The ICER for the intervention group was £6,842 per QALY gained, and the INMB was £665 (95% CI £139, £1,191), with a 92% probability of being cost-effective, and no less than 73% in all sensitivity analysis scenarios.

CONCLUSION

The addition of group-based outpatient physical therapy classes to usual care improves quality of life and is a cost-effective treatment option following TKR for a society WTP threshold of £20,000 per QALY gained.

The Relationship Between Pain and Quality of Life Among Adults With Knee Osteoarthritis: The Mediating Effects of Lower Extremity Functional Status and Depression

Pain, lower extremity functional status, and depression have been associated with quality of life among patients with knee osteoarthritis (KOA). However, little is known about the manner in which these factors influence quality of life. The present study examined the mediating effects of lower extremity functional status and depression on the relationship between pain and quality of life among adults with KOA. A descriptive cross-sectional study was conducted among 135 adults with KOA who visited an orthopaedic outpatient clinic in Korea. The participants responded to the Numeric Rating Scale, Lower Extremity Functional Scale, Beck Depression Inventory, and the Korean version of the World Health Organization Quality of Life-BREF. Mediation analysis was conducted using the PROCESS macro for SPSS. The serial mediating effects of lower extremity functional status and depression on the relationship between pain and quality of life were significant. These findings suggest that the assessment and management of lower extremity functional status and depression are important means by which the quality of life of adults with painful KOA can be improved.

Translation into modern standard Arabic, cross-cultural adaptation and psychometric properties' evaluation of the Lower Extremity Functional Scale (LEFS) in Arabic-speaking athletes with Anterior Cruciate Ligament (ACL) injury

BACKGROUND

The Lower Extremity Functional Scale evaluates the functional status of patients that have lower extremity conditions of musculoskeletal origin. Regional Arabic dialects often create barriers to clear communication and comparative research. We aimed to cross-culturally adapt the Lower Extremity Functional Scale in modern standard Arabic that is widely used and understood in the Middle East and North Africa region, and assess its psychometric properties.

METHODS

Cross-cultural adaptation followed a combination of recommended guidelines. For psychometric evaluation 150 patients with anterior cruciate ligament injury and 65 asymptomatic individuals were recruited. All measurement properties as indicated by the Consensus-based Standards for the selection of health status Measurement Instruments recommendations were evaluated, including content-relevance analysis, structural validity, longitudinal reproducibility, anchor- and distribution-based methods of responsiveness, as well as the longitudinal pattern of change of Lower Extremity Functional Scale in anterior cruciate ligament injured patients' functional status.

RESULTS

The questionnaire presented excellent internal consistency (α = 0.96), reliability (0.80-0.98), and good convergent validity (ρ = 0.85). For reproducibility testing: minimal detectable change was 9.26 points; for responsiveness assessment: minimal clinically important difference was 9 points and presented moderate effect sizes (Glass'Δ = 0.71, Cohen's d = 0.81). Its unidimensionality was not confirmed and an exploratory factor analysis indicated a 2-factor solution explaining 78.1% of the variance.

CONCLUSION

The Arabic Lower Extremity Functional Scale presented acceptable psychometric properties comparable to the original version. The Arabic version of Lower Extremity Functional Scale can be used in research and clinical practice to assess the functional status of Arabic-patients suffering an anterior cruciate ligament injury.

Normative data for the lower extremity functional scale (LEFS)

Background and purpose - The lower extremity functional scale (LEFS) is a well-known and validated instrument for measurement of lower extremity function. The LEFS was developed in a group of patients with various musculoskeletal disorders, and no reference data for the healthy population are available. Here we provide normative data for the LEFS. Methods - Healthy visitors and staff at 4 hospitals were requested to participate. A minimum of 250 volunteers had to be included at each hospital. Participants were excluded if they had undergone lower extremity surgery within 1 year of filling out the questionnaire, or were scheduled for lower extremity surgery. Normative values for the LEFS for the population as a whole were calculated. Furthermore, the influence of sex, age, type of employment, socioeconomic status, and history of lower extremity surgery on the LEFS were investigated. Results - 1,014 individuals fulfilled the inclusion criteria and were included in the study. The median score for the LEFS for the whole population was 77 (out of a maximum of 80). Men and women had similar median scores (78 and 76, respectively), and younger individuals had better scores. Participants who were unfit for work had worse scores. There were no statistically significant correlations between socioeconomic status and type of employment on the one hand and LEFS score on the other. A history of lower extremity surgery was associated with a lower LEFS score. Interpretation - High scores were observed for the LEFS throughout the whole population, although they did decrease with age. Men had a slightly higher score than women. There was no statistically significant correlation between socioeconomic status and LEFS score, but people who were unfit for work had a significantly worse LEFS score.

Managing mobility outcomes in vulnerable seniors ( MMOVeS): a randomized controlled pilot study

OBJECTIVE

To estimate feasibility and potential for efficacy of an individualized, exercise-focused, self-management program (i.e. Managing Mobility Outcomes In Vulnerable Seniors ( MMOVeS)), in comparison to exercise information in improving mobility after six months among seniors recently discharged from hospital.

DESIGN

Randomized pilot study.

SETTING

Two McGill University-teaching hospitals.

SUBJECTS

Community dwelling seniors, aged 70 years and older, recently discharged from either participating hospitals.

INTERVENTIONS

The physiotherapy-facilitated intervention consisted of (1) evaluation of mobility capacity, (2) setting short- and long-term goals, (3) delineation of an exercise treatment plan, (4) an educational booklet to enhance mobility self-management skills, and (5) six monthly telephone calls. Control group received a booklet with information on exercises targeting mobility limitations in seniors.

MAIN MEASURES

Mobility, pain, and health status were assessed at baseline and at six months using multiple indicators drawn from Disabilities of the Arm, Shoulder, and Hand (DASH) Score, Lower Extremity Functional Scale (LEFS) and Short-Form (SF)-36.

RESULTS

In all, 26 people were randomized to the intervention (mean age: 81 ± 8; 39% women), and 23 were randomized to the control (mean age: 79 ± 7; 33% women). The odds ratio for the mobility outcomes combined was 3.08 and the 95% confidence interval excluded 1 (1.65-5.77). The odds ratio for pain and health perception favored the MMOVeS group, but the 95% confidence interval included the null value.

CONCLUSIONS

This feasibility study highlights the potential for efficacy of an individualized, exercise-focused, self-management program in comparison to exercise information in improving mobility outcome for seniors. Furthermore, a home-program combining self-management skills and exercise taught with minimal supervision prove to be feasible. Finally, data from this study can be used to estimate sample size for a confirmatory trial.

A comparison study of KOOS-PS and KOOS function and sport scores

BACKGROUND

The KOOS-PS represents a shortened version of the Knee Injury and Osteoarthritis Outcome Score (KOOS) Function and Sport scales. Previous investigations have not evaluated the KOOS-PS against performance measures or self-report measures composed of items that assess a broad spectrum of ability levels.

OBJECTIVE

The purpose of this study was to compare the construct validity of the KOOS Function and Sport subscales with a shorter version of the measure (KOOS-PS).

METHODS

Using a cross-sectional, observational design, consecutive consenting patients diagnosed with knee osteoarthritis were recruited at an assessment center visit to determine need for conservative or surgical management. Participants completed the Lower Extremity Functional Scale (LEFS), KOOS, Timed "Up & Go" Test, and Six-Minute Walk Test. A single function-sport score (KOOS FunSportsum) and the KOOS-PS were abstracted from the KOOS. Pearson correlation coefficients were compared between the reference standards' scores (performance measures and LEFS) and KOOS scores. KOOS-PSraw scores were compared with KOOS-PSRasch scores.

RESULTS

Three hundred seventy-seven patients with a mean age of 64.4 years (SD=10.5) participated. The correlation between performance reference standard and KOOS-PSRasch scores was significantly lower than with KOOS FunSportsum scores (mean difference in r=.08 [95% confidence interval=.03, .11], z=4.45, P1<.001). A similar finding was observed with the LEFS comparison.

LIMITATIONS

The study sample did not consist of many patients with mild or severe functional status limitations.

CONCLUSIONS

For patients with knee osteoarthritis, the KOOS-PS appears too restricted in item content to provide a comprehensive estimate of lower extremity functional status level relative to the KOOS Function and Sport subscales. Pursuit of a computer-adapted test may be a productive direction for future inquiry.

Assessing the patient-specific functional scale's ability to detect early recovery following total knee arthroplasty

BACKGROUND

The Patient-Specific Functional Scale (PSFS) has received considerable attention over the last 2 decades; however, validation studies have not examined its performance in patients after total knee arthroplasty (TKA).

OBJECTIVE

The purpose of this study was to investigate the ability of the PSFS to detect change in patients post-TKA by comparing PSFS change scores with Lower Extremity Functional Scale (LEFS) and pooled impairment change scores.

METHODS

One hundred thirty-three patients participating in a post-TKA exercise class were assessed at their initial and discharge visits. Initial assessments occurred within 28 days of arthroplasty; follow-up assessments occurred within 80 days of surgery. At both assessments, participants completed the PSFS, LEFS, and the P4 pain measure, and their knee range of motion (ROM) and extensor strength were measured. The ability to detect change was expressed as the standardized response mean (SRM) and as a correlation between the PSFS change scores and 2 reference standards: (1) LEFS change scores and (2) pooled impairment change scores. The pooled impairment measure consisted of pain, ROM, and strength change scores.

RESULTS

The SRMs were PSFS 4.60 (95% confidence interval [CI]=4.00, 5.36) for the PSFS and 2.28 (95% CI=2.04, 2.60) for the LEFS. The correlation between the PSFS and pooled impairment change scores was 0.12 (95% CI=-0.04, 0.25), and the correlation between the PSFS and LEFS changes scores was 0.18 (0.02, 0.34).

LIMITATIONS

The order of measure administration was not standardized, and fixed activity set does not reflect clinical application in many instances.

CONCLUSIONS

The results suggest that the PSFS is adept at detecting improvement in patients post-TKA but that the PSFS, like other patient-specific measures, is likely to be of limited value in distinguishing different levels of change among patients.

Tracking patient outcomes after anterior cruciate ligament reconstruction

Purpose : To model how patients' knee range of motion (ROM), pain, and self-reported lower-extremity (LE) functional status change over the first 26 weeks following anterior cruciate ligament (ACL) reconstruction and to estimate the test-retest reliability of these measurements.

METHODS

Patients were assessed weekly over 26 weeks following ACL reconstruction. Outcomes were knee ROM, LE functional status measured by the Lower Extremity Functional Scale (LEFS), and pain measured by the 4-item pain intensity measure (P4). A nonlinear model was applied to describe change for each outcome. Intra-class correlation coefficients and standard errors of measurement were applied to estimate test-retest reliability and minimal detectable change.

RESULTS

A nonlinear model provided the following model fit values (R(2)): P4=0.71, extension ROM=0.51, flexion ROM=0.99, LEFS=0.97. For pain and ROM, the limit values were reached by approximately 12 weeks after reconstruction; LEFS values continued to increase up to 26 weeks. Test-retest reliability coefficients varied from 0.85 to 0.95.

CONCLUSIONS

The greatest improvement occurred in the first 8 weeks after surgery. Recovery was nearly complete by 12 weeks with respect to pain and ROM, although LE functional status continued to improve throughout the study period. Scores on all measures demonstrated reliability, which supports their use with individual patients.

The Dutch Lower Extremity Functional Scale was highly reliable, valid and responsive in individuals with hip/knee osteoarthritis: a validation study

Background

The WOMAC is the most widely used self-report measure to evaluate physical functioning in hip or knee osteoarthritis, however its ability to discriminate pain and physical functioning (i.e. discriminate validity) has repeatedly been questioned. Little to no data is available on the discriminant validity of alternative questionnaires that measure the same construct, for instance the Hip and Knee Osteoarthritis Outcome Score (HOOS and KOOS, respectively) and the Lower Extremity Function Scale (LEFS). Therefore, we translated the LEFS to Dutch and studied its psychometric properties (i.e. validity, reliability and responsiveness). In addition, we assessed the discriminate validity of the LEFS, HOOS and KOOS.

Methods

After translation with a forward/backward protocol, 401 individuals with hip or knee osteoarthritis completed the LEFS, HOOS/KOOS, SF-36, Hospital Anxiety and Depression Scale and Checklist Individual Strength questionnaires. To assess reliability and responsiveness, a sample of 106 and 108 patients completed a comparable set of questionnaires within 3 weeks and 3 months, respectively. Feasibility, validity, reliability and responsiveness were evaluated. Discriminant validity of the LEFS, HOOS and KOOS was examined by contrasting the scales’ correlations with the physical functioning subscale of the SF-36 with the scales’ correlations with the bodily pain subscale of the SF-36.

Results

The Dutch version of the LEFS was feasible, had good internal consistency (0.96), good reliability (ICC = 0.86), good construct and discriminant validity, and showed no floor or ceiling effects. The minimal detectable change (MDC₉₀) was ten points. Area under the receiver operating characteristic curve (AUC) analyses revealed good (AUC = 0.76) and fair (AUC = 0.63) responsiveness for the LEFS in improved and worsened patients, respectively. Discriminant validity for pain was apparent for the LEFS (p < 0.01), but not for the HOOS and KOOS (p = 0.21 and p = 0.20, respectively).

Conclusions

Considering the LEFS’ good psychometric qualities and ability to discriminate between pain and functioning, we recommend the LEFS as the outcome measure of choice to assess self-reported physical functioning in individuals with hip or knee osteoarthritis.

Longitudinal changes in the lower extremity functional scale after anterior cruciate ligament reconstructive surgery

OBJECTIVE

To describe the pattern of change in lower extremity physical function status as measured by the Lower Extremity Functional Scale (LEFS) during the first 16 weeks after anterior cruciate ligament (ACL) reconstructive surgery and illustrate how this information can be applied in clinical practice to assist with goal setting and the evaluation of patient outcomes. The secondary objective is to estimate the test-retest reliability of the LEFS in this population.

DESIGN

Prospective cohort, observational.

SETTING

Physiotherapy private practice.

PATIENTS

Forty-seven participants underwent ACL reconstructive surgery and were initially recruited. Two participants were excluded from the analysis, resulting in 45 participants (28 men, mean age 29.4 years; 17 women, mean age 29.0 years).

INTERVENTIONS

Participants underwent a rehabilitation protocol.

MAIN OUTCOME MEASURES

Participants completed the LEFS at each visit from their initial physiotherapy session to 16 weeks postsurgery. A nonlinear model of change was developed, which related LEFS scores to weeks postsurgery. Test-retest reliability was examined between the seventh and ninth weeks using intraclass correlation coefficients (ICC2,1) and standard error of measurement (SEM).

RESULTS

The nonlinear model demonstrated rapid improvements in LEFS scores within the first 7 to 8 weeks with a gradual tapering of this improvement. At 16 weeks, the predicted LEFS score was 63 out of a maximum score of 80. The LEFS demonstrated excellent test-retest reliability in this population (ICC2,1 = 0.90, SEM = 3.7).

CONCLUSIONS

This study provides a description of postsurgical change in functional status for patients after ACL reconstructive surgery that can assist clinicians in developing clinical goals.

CLINICAL RELEVANCE

A rapid improvement in lower extremity physical function is demonstrated in the first 7 to 8 weeks after ACL reconstructive surgery with a tapering of this improvement after 8 weeks.

Baseline dependency of minimal clinically important improvement

BACKGROUND

Minimal clinically important improvement (MCII) is the smallest outcome measure change important to patients. Research suggests that MCII is dependent on patients' baseline functional status measures.

OBJECTIVE

The purposes of this study were: (1) to confirm whether MCII is dependent on patients' admission scores and (2) to test whether MCII is dependent on selected demographic characteristics.

STUDY DESIGN AND SETTING

This was a prospective, longitudinal, observational cohort study of 6,651 patients with orthopedic knee impairments treated in 332 outpatient rehabilitation clinics in 27 states in the United States.

OUTCOME MEASURES

Patient self-reports of functional status (FS) from the Lower Extremity Functional Scale were assessed using a computerized adaptive testing application (0-100 scale).

METHODS

An anchored-based longitudinal method, with a 15-point Likert-type scale (-7 to +7), was used to provide a global rating of change (GROC). The MCII threshold for the GROC was defined at a cut-score of +3 or greater and was determined using nonparametric receiver operating characteristic curve analysis for each of the following variables: sex, symptom acuity, age group, and quartile of baseline FS scores.

RESULTS

The results showed that MCII was dependent on patient baseline and demographic characteristics. Patients who were male, were younger, had more-acute symptoms, or had lower FS scores at admission required more FS change to report meaningful change.

LIMITATIONS

As this study was a secondary analysis, how the length of treatment mediated the relationship between the independent and dependent variables was unclear.

CONCLUSIONS

Although a single MCII index may provide a standard cut-score defining the smallest FS change that is meaningful to patients, researchers and clinicians should be aware that MCII is context specific and not a fixed attribute. Current results may help researchers, clinicians, and policy makers to interpret FS change related to the importance of the change to the patient.

Using outcome measure results to facilitate clinical decisions the first year after total hip arthroplasty

STUDY DESIGN

Variable-occasion, repeated-measures design.

OBJECTIVES

To model change in lower extremity functional status of patients 1 year after total hip arthroplasty (THA), using the Lower Extremity Functional Scale (LEFS) and the 6-minute walk test (6MWT), and, secondarily, to provide clinicians with useful data to guide practice.

BACKGROUND

Given the prevalence of THA and current resource pressures, standardized outcome measures play an important role in providing physical therapists with objective knowledge about postoperative recovery and prognosis.

METHODS

Seventy-five patients, with a mean age of 61 years and a diagnosis of hip osteoarthritis, consented to participate in the study. Assessments were conducted preoperatively and at multiple time points for up to 65 weeks postoperatively. Recovery was modeled using a nonlinear robust regression analysis for clustered data. The predictive ability of age, body mass index, and preoperative score was explored.

RESULTS

Gender-based recovery curves were generated to depict the rate and amount of change in LEFS scores and 6MWT distances over the first year. Preoperative baseline 6MWT distance was the only covariate predictive of postarthroplasty 6MWT distances for both males and females. None of the covariates examined were significantly associated with postarthroplasty LEFS scores.

CONCLUSION

Although there were variations in the recovery curves by measure, general patterns were noted. There was a rapid increase in both self-reported and physical performance measure scores for 12 to 15 weeks. Thereafter, we observed a slowing of recovery, with a plateau at 30 to 35 weeks for the 6MWT and later for the LEFS. These data can be used to make evidence-based decisions regarding prognosis and to guide the setting of measurable treatment goals.

LEVEL OF EVIDENCE

Prognosis, level 1b.

Translating shoulder computerized adaptive testing generated outcome measures into clinical practice

STUDY DESIGN

Prospective longitudinal cohort study.

INTRODUCTION

Increased use of computerized adaptive tests (CATs) to generate outcome measures during rehabilitation has stimulated questions concerning score interpretation.

PURPOSE OF THE STUDY

The purpose of the study was to describe meaningful interpretations of scores from patient self-report shoulder functional status (FS) outcome measures estimated using a shoulder CAT (score range=0-100).

METHODS

We applied four approaches to the clinical interpretation of outcomes data from 30,987 patients with shoulder impairments receiving outpatient rehabilitation in 518 clinics in 30 states (United States) between August 2007 and July 2009. First, we used standard error of estimates to construct 95% confidence intervals for each CAT estimated score. Second, we estimated the percentile rank (PR) of FS scores. Third, we used two threshold approaches to define individual patient-level change: statistically reliable change (i.e., minimal detectable change or MDC) and clinically important change. Fourth, we developed and applied a functional staging model, the Shoulder Function Classification System (SFCS).

RESULTS

Precision of a single score was estimated by FS score ±4. Based on score distribution, 25th, 50th, and 75th PRs corresponded to intake FS scores of 43, 52, and 59 and discharge FS scores of 59, 68, and 80, respectively. MDC calculations indicated that changes in FS scores of 11 or more units represented statistically reliable change. FS score increments of eight or more units were estimated to represent minimal clinically important improvement based on receiver operating characteristic. The five-level SFCS was judged to be clinically logical and provide insight for clinical interpretation of patient progress.

CONCLUSIONS

Results may improve clinical interpretation of CAT-generated outcome measures and assist clinicians using patient-reported outcomes during clinical practice.

LEVEL OF EVIDENCE

Therapy level 2c.

Clinical interpretation of outcome measures generated from a lumbar computerized adaptive test

BACKGROUND

A computerized adaptive test (CAT) provides a way of efficiently estimating functional status in people with specific impairments.

OBJECTIVE

The purpose of this study was to describe meaningful interpretations of functional status (FS) estimated using a lumbar CAT developed using items from the Back Pain Functional Scale (BPFS) and selected physical functioning items. Design and Setting This was a prospective longitudinal cohort study of 17,439 patients with lumbar spine impairments in 377 outpatient rehabilitation clinics in 30 states. Outcome Measures Patient self-reports of functional status were assessed using a lumbar CAT (0-100 scale).

METHODS

Outcome data were interpreted using 4 methods. First, the standard error of the estimate was used to construct a 95% confidence interval for each CAT estimated score. Second, percentile ranks of FS scores were presented. Third, 2 threshold approaches were used to define individual patient-level change: minimal detectable change (MDC) and clinically important change. Fourth, a functional staging model, the Back Pain Function Classification System (BPFCS), was developed and applied.

RESULTS

On average, precision of a single score was estimated by FS score+/-4. Based on score distribution, 25th, 50th and 75th percentile ranks corresponded to intake FS scores of 44, 51, and 59, and discharge FS scores of 54, 62, and 74, respectively. An MDC(95) value of 8 or more represented statistically reliable change. Receiver operating characteristic analyses supported that changes in FS scores of 5 or more represented minimal clinically important improvement. The BPFCS appeared clinically logical and provided insight for clinical interpretation of patient progress.

LIMITATIONS

The BPFCS should be assessed for validity using prospective designs.

CONCLUSIONS

Results may improve clinical interpretation of CAT-generated outcome measures and assist clinicians using patient-reported outcomes during physical therapist practice.

Clinical interpretation of computerized adaptive test outcome measures in patients with foot/ankle impairments

STUDY DESIGN

Prospective cohort study of 10 287 patients with foot/ankle impairments receiving outpatient physical therapy.

OBJECTIVES

To describe meaningful interpretations of functional status (FS) outcomes measures, estimated using a body-part-specific computerized adaptive test (CAT).

BACKGROUND

Increased use of CATs to generate outcome measures in rehabilitation has stimulated questions concerning score interpretation. Identifying meaningful intra-individual change and reporting clinical interpretation of those generated outcomes are essential to advance the quality of rehabilitation practice.

METHODS

We performed 4 approaches to clinically interpret outcomes data. First, we used the standard error of the estimate to construct a 90% confidence interval for each CAT estimated score. Second, we presented the percentile rank of FS scores. Third, we used 2 threshold approaches to define individual-patient-level change: statistically reliable change and clinically important change. Last, we illustrated a functional staging method.

RESULTS

Precision of a single score was estimated by an FS score of +/-4. Based on score distribution, percentile ranks at 25th, 50th, and 75th percentiles corresponded to intake FS scores of 38, 47, and 57, and discharge FS scores of 52, 64, and 77, respectively. Minimal detectable change supported 7 or more FS change units out of 100 represented statistically reliable change, and ROC analyses supported 8 or more FS change units represented minimal clinically important improvement. Using a functional staging system, we established 5 hierarchical functional status levels.

CONCLUSION

CAT-generated outcome measures can be interpreted to improve clinical interpretation and to assist clinicians in using patient-reported outcomes during therapy practice.

Clinical interpretation of a lower-extremity functional scale-derived computerized adaptive test

BACKGROUND

The increasing use of computerized adaptive tests (CATs) to generate outcome measures during rehabilitation has prompted questions concerning score interpretation.

OBJECTIVE

The purpose of this study was to describe meaningful interpretations of functional status (FS) outcome measures estimated with a body part-specific CAT developed from the Lower-Extremity Functional Scale (LEFS).

DESIGN

This investigation was a prospective cohort study of 8,714 people who had hip impairments and were receiving physical therapy in 257 outpatient clinics in 31 states (United States) between January 2005 and June 2007.

METHODS

Four approaches were used to clinically interpret outcome data. First, the standard error of the estimate was used to construct the 90% confidence interval for each CAT-generated score estimate. Second, percentile ranks were applied to FS scores. Third, 2 threshold approaches were used to define individual subject-level change: statistically reliable change and clinically important change. The fourth approach was a functional staging method.

RESULTS

The precision of a single score was estimated from the FS score +/-4. On the basis of the score distribution, 25th, 50th, and 75th percentile ranks corresponded to intake FS scores of 40, 48, and 59 and discharge FS scores of 50, 61, and 75, respectively. The reliable change index supported the conclusion that changes in FS scores of 7 or more units represented statistically reliable change, and receiver operating characteristic analyses supported the conclusion that changes in FS scores of 6 or more units represented minimal clinically important improvement. Participants were classified into 5 hierarchical levels of FS using a functional staging method.

LIMITATIONS

Because this study was a secondary analysis of prospectively collected data via a proprietary database management company, generalizability of results may be limited to participating clinics.

CONCLUSIONS

The results demonstrated how outcome measures generated from the hip LEFS CAT can be interpreted to improve clinical meaning. This finding might facilitate the use of patient-reported outcomes by clinicians during rehabilitation services.

The lower extremity functional scale has good clinimetric properties in people with ankle fracture

BACKGROUND

There is limited information on the clinimetric properties of questionnaires of activity limitation in people after ankle fracture.

OBJECTIVE

The purpose of this study was to investigate the clinimetric properties of the Lower Extremity Functional Scale, an activity limitation questionnaire, in people with ankle fracture.

DESIGN

This was a measurement study using data collected from 2 previous randomized controlled trials and 1 inception cohort study.

METHODS

Participants with ankle fracture (N=306) were recruited within 7 days of cast removal. Data were collected at baseline and at short- and medium-term follow-ups. Internal consistency and construct validity were assessed using Rasch analysis. Concurrent validity, responsiveness, and floor and ceiling effects were evaluated.

RESULTS

The Lower Extremity Functional Scale demonstrated high internal consistency (alpha > .90). The variance in activity limitation explained by the items was high (98.3%). Each item had a positive correlation with the overall scale, and most items supported the unidimensionality of the scale. These findings suggest that the scale has high internal consistency and construct validity. The scale also demonstrated high concurrent validity and responsiveness in the short term and no floor or ceiling effects. However, the scale would benefit from more-challenging items, as evident at the medium-term follow-up.

LIMITATIONS

This was a secondary analysis of existing data sets.

CONCLUSION

The Lower Extremity Functional Scale is a useful tool to monitor activity limitation in people with ankle fracture up to the short-term follow-up. More- difficult items may need to be added to improve the responsiveness of the scale for longer-term follow-up.

A computerized adaptive test for patients with hip impairments produced valid and responsive measures of function

OBJECTIVES

To describe the use of a computerized adaptive test (CAT) in routine clinical practice and evaluate content coverage and construct validity, sensitivity to change, and responsiveness of hip CAT functional status (FS) measures.

DESIGN

Longitudinal, prospective observational cohort study.

SETTING

Two hundred fifty-seven outpatient rehabilitation clinics in 31 states (United States).

PARTICIPANTS

Two samples were examined: intake and discharge rehabilitation FS data from patients (N=8714) treated for hip impairments between January 2005 and June 2007 and data from patients (N=444) used to develop the hip CAT were examined for comparison (2002-2004).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Hip functional status and global rating of change.

RESULTS

The CAT used on average 7 items to produce precise estimates of FS that adequately covered the content range with negligible floor and slight ceiling effects. Test information functions and SEs supported FS measure precision. FS measures discriminated patients in clinically logical ways. Sixty-one percent of patients obtained discharge FS measures greater than or equal to minimal detectable change (95% confidence intervals). Change of 6 FS units (scale: 0-100) represented minimal clinically important improvement, which 64% of patients obtained.

CONCLUSIONS

The hip CAT was efficient; produced valid, responsive measures of FS for patients receiving therapy for hip impairments; and functioned well in routine clinical application but would benefit from more difficult items.

Computerized adaptive test for patients with foot or ankle impairments produced valid and responsive measures of function

OBJECTIVE

We tested the item response theory (IRT) model assumptions of the original item bank, and evaluated the practical and psychometric adequacy, of a computerized adaptive test (CAT) for patients with foot or ankle impairments seeking rehabilitation in outpatient therapy clinics.

METHODS

Data from 10,287 patients with foot or ankle impairments receiving outpatient physical therapy were analyzed. We first examined the unidimensionality, fit, and invariance IRT assumptions of the CAT item bank. Then we evaluated the efficiency of the CAT administration and construct validity and sensitivity of change of the foot/ankle CAT measure of lower-extremity functional status (FS).

RESULTS

Results supported unidimensionality, model fit, and invariance of item parameters and patient ability estimates. On average, the CAT used seven items to produce precise estimates of FS that adequately covered the content range with negligible floor and ceiling effects. Patients who were older, had more chronic symptoms, had more surgeries, had more comorbidities, and did not exercise prior to receiving rehabilitation reported worse discharge FS. Seventy-one percent of patients obtained statistically significant change at follow-up. Change of 8 FS units (scale 0-100) represented minimal clinically important improvement.

CONCLUSIONS

We concluded that the foot/ankle item bank met IRT assumptions and that the CAT FS measure was precise, valid, and responsive, supporting its use in routine clinical application.

Computerized adaptive test for patients with knee impairments produced valid and responsive measures of function

OBJECTIVE

Assess practicality of using a computerized adaptive test (CAT) in routine clinical practice, perform a psychometric evaluation of content range coverage and test precision, and assess known group construct validity, sensitivity to change and responsiveness of knee CAT functional status (FS) measures.

STUDY DESIGN AND SETTING

Secondary analysis of retrospective intake and discharge rehabilitation FS data collected in a prospective cohort study. Data represented a convenience sample of 21,896 patients with knee impairments receiving outpatient physical therapy in 291 clinics in 30 U.S. states (2005-2007).

RESULTS

The CAT used an average of seven items to produce precise estimates of FS that adequately covered the content range with negligible floor and ceiling effects. Test information functions and standard errors supported FS measure precision. FS measures discriminated patients by age, symptom acuity, surgical history, condition complexity, and prior exercise history in clinically logical ways. Seventy-two percent of patients obtained discharge FS measures > or = minimal detectable change (95% confidence interval). Change of 9 FS units (0-100 scale) represented minimal clinically important improvement, which 67% of patients obtained.

CONCLUSION

The knee CAT was efficient and produced precise, valid, and responsive measures of FS for patients receiving therapy for knee impairments and functioned well in routine clinical application.

Assessing recovery and establishing prognosis following total knee arthroplasty

BACKGROUND AND PURPOSE

Information about expected rate of change after arthroplasty is critical for making prognostic decisions related to rehabilitation. The goals of this study were: (1) to describe the pattern of change in lower-extremity functional status of patients over a 1-year period after total knee arthroplasty (TKA) and (2) to describe the effect of preoperative functional status on change over time.

SUBJECTS

Eighty-four patients (44 female, 40 male) with osteoarthritis, mean age of 66 years (SD=9), participated.

METHODS

Repeated measurements for the Lower Extremity Functional Scale (LEFS) and the Six-Minute Walk Test (6MWT) were taken over a 1-year period. Data were plotted to examine the pattern of change over time. Different models of recovery were explored using nonlinear mixed-effects modeling that accounted for preoperative status and gender.

RESULTS

Growth curves were generated that depict the rate and amount of change in LEFS scores and 6MWT distances up to 1 year following TKA. The curves account for preoperative status and gender differences across participants.

DISCUSSION AND CONCLUSION

The greatest improvement occurred in the first 12 weeks after TKA. Slower improvement continued to occur from 12 weeks to 26 weeks after TKA, and little improvement occurred beyond 26 weeks after TKA. The findings can be used by physical therapists to make prognostic judgments related to the expected rate of improvement following TKA and the total amount of improvement that may be expected.

Hop testing provides a reliable and valid outcome measure during rehabilitation after anterior cruciate ligament reconstruction

BACKGROUND AND PURPOSE

Although various hop tests have been proposed as performance-based outcome measures following anterior cruciate ligament (ACL) reconstruction, limited reports of their measurement properties exist. The purpose of this study was to investigate the reliability and longitudinal validity of data obtained from hop tests during rehabilitation after ACL reconstruction.

SUBJECTS

Forty-two patients, 15 to 45 years of age, who had undergone ACL reconstruction participated in the study.

METHODS AND MEASURES

The study design was prospective and observational with repeated measures. The subjects performed a series of 4 hop tests on 3 separate occasions within the 16th week following surgery and on a fourth occasion 6 weeks later. The tests were a single hop for distance, a 6-m timed hop, a triple hop for distance, and crossover hops for distance. Performance on the ACL-reconstructed limb was expressed as a percentage of the performance on the nonoperative limb, termed the "limb symmetry index." Subjects also completed the Lower Extremity Functional Scale and a global rating of change questionnaire.

RESULTS

Intraclass correlation coefficients for limb symmetry index values ranged from .82 to .93. Standard errors of measurement were 3.04% to 5.59%. Minimal detectable changes, at the 90% confidence level, were 7.05% to 12.96%. Changes in hop test scores on the operative limb were statistically greater than changes on the nonoperative limb. Pearson correlations (r) between change in hop performances and self-reported measures ranged from .26 to .58.

DISCUSSION AND CONCLUSION

The results show that the described series of hop tests provide a reliable and valid performance-based outcome measure for patients undergoing rehabilitation following ACL reconstruction. These findings support the use and facilitate the interpretation of hop tests for research and clinical practice.

A survey of self-reported outcome instruments for the foot and ankle

The information acquired from self-reported outcome instruments is useful only if there is evidence to support the interpretation of obtained scores. To properly interpret scores, there should be evidence for content validity, construct validity, reliability, and responsiveness. Evidence regarding score interpretation must also contain a description of the applicable test conditions, including information about the characteristics of subjects, timing of data collection, and construct of change. The objective of this review was to identify self-reported outcome instruments that have evidence to support their usefulness for assessingthe effect of treatment directed at individuals with foot and ankle-related pathologic conditions in an orthopaedic physical therapy setting. In addition, we provide specific information that will allow clinicians and researchers to select an appropriate instrument and properly interpret the obtained scores. Fourteen self-reported outcome instruments that met the objective of this review were identified. Five instruments, the Foot and Ankle Ability Measure, Foot Function index, Foot Health Status Questionnaire, Lower Extremity Function Scale, and Sports Ankle Rating System quality of life measure, satisfied all 4 categories of evidence (content validity, construct validity, reliability, and responsiveness) outlined herein.