Development of an index of physical functional health status in rehabilitation

Predicting persisting disability in musculoskeletal pain patients with the STarT MSK screening tool: Results from a prospective cohort study

BACKGROUND

The STarT MSK screening tool aims to categorise musculoskeletal patients into three risk groups for treatment stratification. The tool has been translated and validated into Hebrew. However, its ability to predict persistent disability in patients has yet to be evaluated.

OBJECTIVE

The primary aim of this study was to assess the ability of the Hebrew version of the STarT MSK tool to predict persistent disability in patients experiencing musculoskeletal pain.

METHODS

A prospective observational cohort study was conducted, recruiting 135 patients with musculoskeletal pain in five common areas: back, neck, shoulder, knee, or multisite pain over the age of 21. At the first consultation, all patients completed demographic information, the Focus On Therapeutic Outcomes (FOTO) questionnaire (function, pain, and fear avoidance score), and the STarT MSK questionnaire. The patients completed the FOTO questionnaire again at the end of the physiotherapy treatments.

RESULTS

25 patients (18.5%) were classified into the low-risk group, 68 patients (50.3%) into the medium-risk group, and 42 (31.1%) into the high-risk group. The baseline STarT MSK tool score demonstrated an excellent ability to identify patients at high risk of developing persistent disability (AUC = 0.795, 95% CI 0.716-0.873).

CONCLUSIONS

The Hebrew version of the STarT MSK tool can differentiate between three chronic risk groups and has high predictive validity for chronicity. This may provide a tool to assist clinicians in identifying patients who require more intensive care, and thus, potentially prevent the transition to chronic disabling pain.

Patients' Perceptions and Outcome Measures after Undergoing the Enhanced Transtheoretical Model Intervention (ETMI) for Chronic Low Back Pain: A Mixed-Method Study

This study aimed to evaluate the outcome measures and perceptions of patients with chronic low back pain (CLBP) after being treated with the Enhanced Transtheoretical Model Intervention (ETMI). In this process evaluation mixed-methods study, 30 patients with CLBP electronically completed self-reported measures (function, pain, and fear-avoidance beliefs) before and after ETMI treatment. Subsequently, each patient participated in one-on-one, semi-structured interviews, which were audio-recorded, transcribed, coded, and analyzed thematically. Quantitative analysis showed significant improvements in function (p < 0.001), pain (p < 0.001), and fear-avoidance beliefs (p < 0.001) after receiving ETMI treatment, with a large effect size (Cohen’s d = 1.234). Moreover, the average number of physiotherapy sessions was 2.6 ± 0.6 for the ETMI intervention, while the annual average number in Maccabi is estimated at 4.1 ± 1.5. Three main themes emerged from the thematic analysis: (1) communication between the patient and the practitioner; (2) psychosocial treatment elements, and (3) ETMI as a long-term solution for CLBP. The findings of the current study highlight patients’ perceived need for an open and sincere dialogue and for receiving reassurance and encouragement about their LBP. Notably, they had no problem with the fact that they did not receive passive treatment. Accordingly, together with the significant improvement in post-treatment outcome measures, patients perceived the ETMI method as a practical tool for self-managing their back problems in the long term.

Importance of Early Improvement in the Treatment of Low Back Pain With Physical Therapy

STUDY DESIGN

.: A retrospective observational study.

OBJECTIVE

Assess the time course of functional outcome improvements during a physical therapy (PT) episode of care for patients with low back pain. In addition, assess the impact of patient variables, such as symptom duration, on the time course of functional outcome improvements.

SUMMARY OF BACKGROUND DATA

Early improvement in patient-reported symptoms and functional limitations may play an important role in the eventual success of an intervention. Early improvements in pain are associated with greater improvement in disability and depression in patients with low back pain.

METHODS

A total 11,945 patients were included. Intake functional status (FS), FS change at discharge, predicted FS change at discharge, FS change at first progress report (FS1), duration of symptoms before treatment, and duration of PT episode of care were assessed. Pearson correlation analysis was used to assess correlation between collected variables and FS change.

RESULTS

The mean FS change was 16.995 units, mean FS1 was 12.024 units, total duration was 63.591 days, and duration at FS1 was 28.969 days, indicating 70.72% of FS change occurred in the first 45.45% of the episode of care. Similar results occurred in all symptom duration categories, ranging from "0 to 7 days' to "greater than 6 months' duration. Correlation analysis demonstrated that FS1 had the greatest correlation to FS. A strong correlation (r > 0.7) was demonstrated in all symptom duration categories ranging from 0.741 to 0.805.

CONCLUSION

The results of this study yield further support for the importance of rapid functional improvements during a PT episode of care. In addition, patients demonstrated roughly two-thirds of their improvement in the first 40% of visits regardless of their symptom duration. This study may help clinicians identify a need to modify a plan of care if insufficient early improvement is observed.

LEVEL OF EVIDENCE

3.

Astym® therapy improves FOTO® outcomes for patients with musculoskeletal disorders: an observational study

Background

Current healthcare providers function in an environment where there is increased emphasis on value-based models of reimbursement; therefore, the delivery of better patient outcomes is critical. Consequently, it is necessary to identify successful treatments that improve outcomes and can be applied across a broad range of clinic settings, treatment styles and therapist expertise.

Methods

Data from 2,450 patients who received Astym therapy as component of their outpatient rehabilitation (treatment group) was matched to data from 2,450 randomly chosen patients with similar orthopedic impairments who did not receive Astym therapy during their rehabilitation (control group). Data was collected across 116 clinics in 17 U.S. states. All patients completed a standardized functional status survey at admission and at discharge. The effectiveness (discharge functional status score), efficiency (number of treatment visits, treatment duration) and utilization (unit of functional improvement per visit) was compared across two groups. Ethics approval was not required for this study as this is an observational study, with both sets of participants receiving actual (not placebo) treatment.

Results

Compared to the control sample, patients who received Astym therapy as part of their rehabilitation had higher discharge functional status (FS) scores (68.5 vs. 64.5, F_1,4897 =53.1, P<0.001) and had more functional improvement per visit noted with a higher utilization index (2.0 vs. 1.9, ANCOVA F_1,4897 =5.5, P=0.019), and after risk adjustment, had the same number of visits. There was no difference in duration of treatment episode across groups (Astym, 47.8±31.1 days; control, 47.5±30.0 days) (ANCOVA F_1,4897 =1.7, P=0.199).

Conclusions

Patients with musculoskeletal disorders who received Astym therapy as part of the treatment process experienced increased treatment effectiveness as compared to those who did not receive Astym therapy. The addition of Astym therapy improved physical therapy outcomes for patients across a broad range of treatment styles, clinical settings and therapist expertise.

Hospital nurses' attitudes, negative perceptions, and negative acts regarding workplace bullying

BACKGROUND

Workplace bullying is a prevalent problem in today's work places that has adverse effects on both bullying victims and organizations. To investigate the predictors of workplace bullying is an important task to prevent bullying victims of nurses in hospitals.

OBJECTIVE

This study aims to explore the relationships among nurses' attitudes, negative perceptions, and negative acts regarding workplace bullying under the framework of the theory of planned behavior (TPB).

METHODS

A total of 811 nurses from three hospitals in Taiwan were surveyed. Nurses' responses to the 201 items of 10 scales were calibrated using Rasch analysis and then subjected to path analysis with partial least-squares structural equation modeling (PLS-SEM).

RESULTS

The instrumental attitude was significant predictors of nurses' negative perceptions to be bullied in the workplace. Instead, the other TPB components of subjective norm and perceived behavioral control were not effective predictors of nurses' negative acts regarding workplace bullying.

CONCLUSIONS

The findings provided hospital nurse management with important implications for prevention of bullying, particularly to them who are tasked with providing safer and more productive workplaces to hospital nurses. Awareness of workplace bullying was recommended to other kinds of workplaces for further studies in future.

Risk Adjustment for Lumbar Dysfunction: Comparison of Linear Mixed Models With and Without Inclusion of Between-Clinic Variation as a Random Effect

BACKGROUND

Valid comparison of patient outcomes of physical therapy care requires risk adjustment for patient characteristics using statistical models. Because patients are clustered within clinics, results of risk adjustment models are likely to be biased by random, unobserved between-clinic differences. Such bias could lead to inaccurate prediction and interpretation of outcomes.

PURPOSE

The purpose of this study was to determine if including between-clinic variation as a random effect would improve the performance of a risk adjustment model for patient outcomes following physical therapy for low back dysfunction.

DESIGN

This was a secondary analysis of data from a longitudinal cohort of 147,623 patients with lumbar dysfunction receiving physical therapy in 1,470 clinics in 48 states of the United States.

METHODS

Three linear mixed models predicting patients' functional status (FS) at discharge, controlling for FS at intake, age, sex, number of comorbidities, surgical history, and health care payer, were developed. Models were: (1) a fixed-effect model, (2) a random-intercept model that allowed clinics to have different intercepts, and (3) a random-slope model that allowed different intercepts and slopes for each clinic. Goodness of fit, residual error, and coefficient estimates were compared across the models.

RESULTS

The random-effect model fit the data better and explained an additional 11% to 12% of the between-patient differences compared with the fixed-effect model. Effects of payer, acuity, and number of comorbidities were confounded by random clinic effects.

LIMITATIONS

Models may not have included some variables associated with FS at discharge. The clinics studied may not be representative of all US physical therapy clinics.

CONCLUSIONS

Risk adjustment models for functional outcome of patients with lumbar dysfunction that control for between-clinic variation performed better than a model that does not.

The Development and Psychometric Properties of the Patient Self-Report Neck Functional Status Questionnaire (NFSQ)

STUDY DESIGN

Retrospective analysis of cross-sectional data.

OBJECTIVE

To describe the development of a new self-report Neck Functional Status Questionnaire (NFSQ) and to assess its psychometric properties and practical application. The NFSQ was designed to assess functional status in patients with cervical (spine) disorders who seek outpatient therapy.

BACKGROUND

Many patients seek outpatient therapy due to cervical disorders. Currently, no patient-reported outcome measures exist that capture the ability to perform functional activity in a manner that reflects the experience of this patient population.

METHODS

Four hundred thirty-nine patients who were being treated for cervical disorders responded to a set of survey questions to assess activity-related functional outcomes associated with cervical disorders. Using item response theory, we assessed candidate items for unidimensionality and local independence, item fit, person separation, precision, targeting, and differential item functioning. We also compared discriminant validity of functional status measures estimated by the item response theory model (NFSQ fixed) and measures generated using a simulated computerized adaptive test (NFSQ computerized adaptive test).

RESULTS

Based on expert opinion and subsequent processing and analyses, a final set of 28 items was used to develop the NFSQ. Unidimensionality and local independence were supported. The mean ± SD sample ability level of 57.6 ± 14.3 (scale range, 0-100) matched well with the mean item difficulty of the NFSQ of 51.3 ± 7.4. Differential item functioning was negligible for levels of age group, sex, and symptom acuity. The NFSQ computerized adaptive test measures were as precise as the NFSQ fixed measures.

CONCLUSION

Study results supported the preliminary validity of the 28-item NFSQ for use in assessing patients with different levels of functional status related to their cervical disorders in outpatient rehabilitation settings.

Validation of the student athletes' motivation towards sports and academics questionnaire to Korean student-athletes

The current study had three aims: (1) to validate a Korean version of the Student Athletes’ Motivation toward Sports and Academics Questionnaire (SAMSAQ-Kr), (2) to examine South Korean university student-athletes’ motivation towards athletic and academic achievement, and (3) to identify the relationship between athletic identity and their athletic and academic achievement. A total of 126 South Korean university student-athletes (41.4% males and 58.6% females; mean age 20.5, SD = 2.74) completed the SAMSAQ-Kr. To investigate the validity evidence of the SAMSAQ-Kr a confirmatory factor analysis (CFA) and Rasch model were employed. To examine the relationship between Athletic Identity Measurement Scale (AIMS) and SAMSAQ for Spearman correlation coefficients were calculated. Findings indicated that the SAMSAQ-Kr showed a different model from other versions and revealed positive correlations between AIMS scores and athletic motivations. The current study highlighted that importance of considering socio-cultural context in developing questionnaire and contributed to help understand South Korean university student-athletes’ motivation towards athletic and academic achievement.

Benchmarking Outpatient Rehabilitation Clinics Using Functional Status Outcomes

OBJECTIVE

To utilize functional status (FS) outcomes to benchmark outpatient therapy clinics.

DATA SOURCES

Outpatient therapy data from clinics using Focus on Therapeutic Outcomes (FOTO) assessments.

STUDY DESIGN

Retrospective analysis of 538 clinics, involving 2,040 therapists and 90,392 patients admitted July 2006-June 2008. FS at discharge was modeled using hierarchical regression methods with patients nested within therapists within clinics. Separate models were estimated for all patients, for those with lumbar, and for those with shoulder impairments. All models risk-adjusted for intake FS, age, gender, onset, surgery count, functional comorbidity index, fear-avoidance level, and payer type. Inverse probability weighting adjusted for censoring.

DATA COLLECTION METHODS

Functional status was captured using computer adaptive testing at intake and at discharge.

PRINCIPAL FINDINGS

Clinic and therapist effects explained 11.6 percent of variation in FS. Clinics ranked in the lowest quartile had significantly different outcomes than those in the highest quartile (p < .01). Clinics ranked similarly in lumbar and shoulder impairments (correlation = 0.54), but some clinics ranked in the highest quintile for one condition and in the lowest for the other.

CONCLUSIONS

Benchmarking models based on validated FS measures clearly separated high-quality from low-quality clinics, and they could be used to inform value-based-payment policies.

Restless legs syndrome status as a predictor for lower physical function

OBJECTIVE

To examine the potential long-term impact of restless legs syndrome (RLS) and other common sleep complaints on subsequent physical function (PF), we conducted a longitudinal analysis of 12,556 men in the Health Professionals Follow-up Study.

METHODS

We used a set of questions recommended by the International RLS Study Group to assess RLS in 2002. We asked questions regarding other sleep complaints--insomnia, sleep fragmentation, and excessive daytime sleepiness--in 2004. We used the Physical Function (PF-10) survey of the Short Form-36 Health Survey to characterize PF in 1996 and 2008. We examined the 2008 PF-10 scores across categories of baseline RLS (2002), adjusted for age, 1996 PF-10 score, and other potential confounders.

RESULTS

The participants with RLS at baseline had significantly lower PF-10 score 6 years later than those without RLS (mean difference = -2.32, p = 0.01), after adjusting for potential confounders. The magnitude of difference in PF-10 score for RLS symptoms ≥ 15 times/month vs no RLS was more than that of a 5-year increase of age or moderate amount of smoking. Having daily daytime sleepiness and sleep duration ≥ 9 hours/day were associated with lower mean PF value than not having these symptoms (p < 0.05 for both).

CONCLUSIONS

RLS and other sleep complaints are associated with lower PF. Our findings need to be replicated by more longitudinal studies including women and populations of other social and cultural backgrounds. It is important to understand whether RLS is an independent risk factor or a marker for other unknown risk factors for disability.

Association between centralization and directional preference and functional and pain outcomes in patients with neck pain

STUDY DESIGN

Retrospective cohort.

OBJECTIVES

In subjects with neck pain, the present study aimed (1) to describe the prevalence of centralization (CEN), noncentralization (non-CEN), directional preference (DP), and no directional preference (no DP); (2) to determine if age, sex, fear-avoidance beliefs about physical activity, number of comorbid conditions, or symptom duration varies among subjects who demonstrate CEN versus non-CEN and DP versus no DP; and (3) to determine if CEN and/or DP are associated with changes in function and pain.

BACKGROUND

CEN and DP are prevalent among patients with low back pain and should be considered when determining treatment strategies and predicting outcomes; however, these findings are not well investigated in patients with neck pain.

METHODS

Three hundred four subjects contributed data. CEN and DP prevalence were calculated, as was the association between CEN and DP, and age, sex, number of comorbid conditions, fear-avoidance beliefs, and symptom duration. Multivariate models assessed whether CEN and DP predicted change in function and pain.

RESULTS

CEN and DP prevalence were 0.4 and 0.7, respectively. Younger subjects and those with fewer comorbid conditions were more likely to centralize; however, subjects who demonstrated DP were more likely to have acute symptoms. Subjects who centralized experienced, on average, a 3.6-point (95% confidence interval: -0.3, 7.4) improvement in function scores, whereas subjects with a DP averaged a 5.4-point (95% confidence interval: 0.8, 10.0) improvement. Neither CEN nor DP was associated with pain outcomes.

CONCLUSION

DP and, to a lesser extent, CEN represent evaluation categories that are associated with improvements in functional outcomes.

The self-report fecal incontinence and constipation questionnaire in patients with pelvic-floor dysfunction seeking outpatient rehabilitation

BACKGROUND

Fecal incontinence and constipation affect men and women of all ages.

OBJECTIVE

The purpose of this study was to psychometrically analyze the Fecal Incontinence and Constipation Questionnaire (FICQ) in patients seeking outpatient rehabilitation services due to pelvic-floor dysfunction (PFD).

DESIGN

This was a retrospective analysis of cross-sectional data from 644 patients (mean age=52 years, SD=16, range=18-91) being treated for PFD in 64 outpatient rehabilitation clinics in 20 states (United States).

METHODS

We assessed the 20-item FICQ for unidimensionality and local independence, differential item functioning (DIF), item fit, item hierarchical structure, and test precision using an item response theory model.

RESULTS

Factor analyses supported the 2-factor subscales as originally defined; items related to severity of leakage or constipation. Removal of 2 leakage items improved unidimensionality and local independence of the leakage scale. Among the remaining items, 2 items were suggestive of adjustment for DIF by age group and by number of PFD comorbid conditions. Item difficulties were suitable for patients with PFD with no ceiling or floor effect. Mean item difficulty parameters for leakage and constipation subscales ranged from 38.8 to 62.3 and 28.1 to 63.3 (0-100 scale), respectively. Endorsed leakage items representing highest difficulty levels were related to delay defecation and confidence to control bowel leakage. Endorsed constipation items representing highest difficulty levels were related to the need to strain during a bowel movement and the frequency of bowel movements.

LIMITATIONS

A limitation of this study was the lack of medical diagnostic criteria to classify patients.

CONCLUSIONS

After removing 2 items and adjusting for DIF, the results supported sound psychometric properties of the FICQ items and its initial use for patients with PFD in outpatient rehabilitation services.

Developing a wellness program for people with multiple sclerosis: description and initial results

Because multiple sclerosis (MS) is a multidimensional chronic disease, effective management of the illness requires a multidimensional approach. We describe a wellness program that was designed to facilitate positive health choices throughout the course of MS and present initial data analyses. We hypothesized that over the course of the program, participants would demonstrate improvement in the domains assessed. The wellness program included educational sessions in physical, mental, social, intellectual, and spiritual domains specifically targeting improved self-efficacy, physical functioning, coping skills, symptom management, and nutrition. An outcomes data collection software program was adapted to facilitate real-time patient self-report and clinician entry data collection for many domains throughout the wellness program. Initial assessment of serial measures (intake to discharge) from 65 people with MS showed improvement in several domains, including functional status (P < .05), fatigue (P < .05), fear-avoidance beliefs regarding physical activities (P < .05), depression (P < .05), somatization (P < .05), and pain (P < .05). In addition, using a model of risk for interpersonal distress, patients whose risk of elevated depression and anxiety decreased over the course of the program reported greater gains in functional status (P < .05). The results suggest possible future treatment strategies and indicate strengths and weaknesses of the wellness program, which are being used to improve the program.

Referral source and outcomes of physical therapy care in patients with low back pain

STUDY DESIGN

Retrospective longitudinal cohort.

OBJECTIVES

To describe the clinical characteristics of patients with low back pain according to physician referral source, and to identify associations between referral source and discharge functional status, as well as number of physical therapy visits.

BACKGROUND

Little is known about associations between physician referral source and outcomes of physical therapy care for patients with low back pain. Exploring these associations can contribute to better understanding of physician-physical therapist relationships and may lead to improved referral patterns.

METHODS

Data from a proprietary clinical database were examined retrospectively. Physician referral source was classified as primary care, specialist, or occupational medicine. Outcomes were overall health status at discharge and number of physical therapy visits. Descriptive statistics and bivariate associations between referral source and each outcome were assessed by calculating differences and 95% confidence intervals (CIs) in means and proportions. To account for potential confounding, multilevel linear regression was used to adjust for baseline clinical covariates, effects related to clustering of patients treated by individual clinicians, and clinicians working within individual clinics.

RESULTS

Bivariate and multilevel analyses revealed significant associations between referral source and discharge overall health status, as well as number of visits. After multilevel adjustment for covariate and clustering effects, primary care and occupational medicine referrals were associated, on average, with point increases of 1.6 (95% CI: 0.7, 2.6) and 4.8 (95% CI: 2.7, 6.9) in discharge overall health status scores, respectively, compared to specialist referral. Similarly, primary care and occupational medicine referrals were associated, on average, with 0.44 (95% CI: 0.27, 0.61) and 0.83 (95% CI: 0.44, 1.22) fewer visits, respectively, compared to specialist referral.

CONCLUSION

After accounting for clinical covariates and clustering, patients with low back pain who were referred by occupational medicine and primary care physicians tended to have better functional outcomes and required fewer physical therapy visits per episode of care.

LEVEL OF EVIDENCE

Prognosis, level 2c.

Lumbar computerized adaptive test and Modified Oswestry Low Back Pain Disability Questionnaire: relative validity and important change

STUDY DESIGN

Retrospective analysis of longitudinal, observational cohort data.

OBJECTIVES

To compare discriminating ability and minimal clinically important improvement (MCII) calculated using functional status (FS) measures estimated from the lumbar computerized adaptive test (LCAT) and Modified Oswestry Low Back Pain Disability Questionnaire (ODQ).

BACKGROUND

The LCAT and ODQ are commonly used to estimate FS in patients seeking outpatient therapy but have not been compared directly.

METHODS

Data from 8198 adult patients who completed the LCAT and ODQ at intake were analyzed, 3379 (41%) of whom completed both surveys at discharge. Global ratings of change data were available for 980 patients. Discriminating ability of FS estimates from the LCAT and ODQ was estimated using relative validity, calculated by dividing F values from LCAT and ODQ analyses of covariance for important risk-adjustment variables. MCII was estimated using receiver-operating-characteristic analyses by quartiles of intake FS values, and areas under the curves were compared.

RESULTS

Relative validity ratios favored the LCAT for age (3.7; 95% confidence interval [CI]: 2.0, 8.9), acuity (1.3; 95% CI: 1.1, 1.6), comorbidities (1.8; 95% CI: 1.3, 2.6), and surgical history (1.8; 95% CI: 1.2, 2.9). MCII cut scores per quartile favored the LCAT. Receiver-operating-characteristic areas under the curves were not different.

CONCLUSION

FS measures estimated by both questionnaires had similar psychometric characteristics. The LCAT FS estimates tended to be more discriminating than ODQ FS estimates. MCII cut scores by quartile of intake FS favored the LCAT. Given the need to be efficient and precise in estimating measures of FS, particularly in older patients, results favor the LCAT in busy, automated outpatient therapy clinics, which are increasingly serving an aging population.

Construct Validity and Measurement Invariance of the Peabody Picture Vocabulary Test-III Form A in the Performance of Struggling Adult Readers: Rasch Modeling

PURPOSE: The aim of this study was to apply the Rasch model to an analysis of the psychometric properties of the PPVT-III Form A items with struggling adult readers. METHODS: The PPVT-IIIA was administered to 229 African-American adults whose isolated word reading skills were between third and fifth grades. Conformity of the adults' performance on the PPVT-III items was evaluated using the Winsteps software. RESULTS: Analysis of all PPVT-IIIA items combined did not fully support its use as a useful measure of receptive vocabulary for struggling adult readers who were African Americans. To achieve an adequate model fit, items 73 through item 156 were analyzed. The items analyzed showed adequate internal consistency reliability, unidimensionality, and freedom from differential item functioning for ability, gender, and age, with a minor modification. DISCUSSION: With an appropriate treatment of misfit items, the results supported the measurement properties, internal consistency reliability, unidimensionality of the PPVT-IIIA items, and measurement invariance of the test across subgroups of ability, age, and gender.

Change in psychosocial distress associated with pain and functional status outcomes in patients with lumbar impairments referred to physical therapy services

STUDY DESIGN

Prospective, longitudinal, observational cohort design.

OBJECTIVE

The primary aim was to examine the association between changes in psychosocial distress (PD), and functional status (FS) and pain intensity at discharge from physical therapy.

BACKGROUND

Patients with lumbar impairments seeking physical therapy commonly demonstrate elevated PD. However, it is not clear if PD changes that occur during physical therapy management are associated with improved clinical outcomes.

METHODS

Data from adults (n = 692) with lumbar impairment were analyzed. Patients were screened using the Symptom Checklist Back Pain Prediction Model questionnaire (SCL BPPM) to identify patients at intake and discharge into 3 levels of risk for persistent disability (high, intermediate, or low). SCL BPPM classifications allowed for 5 patterns of change in PD during therapy (decreased, stable low, stable intermediate, stable high, or increased). Associations between PD change patterns and discharge FS and pain intensity were assessed using multivariable linear regression models, controlling for selected risk-adjustment variables.

RESULTS

Proportions of patients classified by patterns of PD change for decreased, stable low, stable intermediate, stable high, and increased were 0.34, 0.52, 0.05, 0.06, and 0.03, respectively. Compared to the decreased PD group, (1) increased, stable high, and stable intermediate PD patterns were associated with worse discharge FS scores (-7.9 [95% CI: -13.5, -2.21], -10.9 [95% CI: -15.25, -6.49], and -8.9 [95% CI: -13.65, -4.21] units, respectively), and (2) stable high and stable intermediate PD patterns were associated with higher pain intensity (2.59 [95% CI: 1.81, 3.56] and 2.14 [95% CI: 1.25, 3.04] units, respectively).

CONCLUSIONS

Lower FS and higher pain intensity outcomes were associated in similar but not identical patterns with patients whose SCL BPPM classification of PD increased, or remained at high or intermediate levels during physical therapy. Serial assessments of change in PD during rehabilitation are recommended as a possible treatment-monitoring tool.

Effect of fear-avoidance beliefs of physical activities on a model that predicts risk-adjusted functional status outcomes in patients treated for a lumbar spine dysfunction

STUDY DESIGN

Retrospective analysis of a prospective, longitudinal cohort study of 30 858 patients being treated for a lumbar spine dysfunction in outpatient physical therapy.

OBJECTIVES

To determine effect of adding a single-item screening variable classifying patients with elevated versus not-elevated scores of fear-avoidance beliefs of physical activities at intake, on a model predicting risk-adjusted functional status (FS) outcomes.

BACKGROUND

Outcomes must be risk-adjusted before making meaningful interpretations. Elevated fear-avoidance beliefs scores have been predictive of poor outcomes. But the importance of elevated fear-avoidance scores in a multivariable model predicting FS outcomes needs further study.

METHODS

Using retrospective analyses, predictive ability (R2) of multivariable linear regression models of discharge FS with and without classification by elevated versus not-elevated fear-avoidance scores were compared, while controlling for intake FS, age, symptom acuity, surgical history, gender, number of comorbidities, and payer. Percent variance controlled and beta coefficients (95% confidence intervals) of each variable in both models were compared. A split-half design was used for model cross-validation. Predictive ratios (predicted FS, divided by actual discharge FS) were assessed.

RESULTS

Adding fear-avoidance beliefs classification to the discharge FS model improved (P<.001) model predictive ability but only slightly (R2 without, and with, fear-avoidance classification, 0.2997 and 0.3010, respectively). Variables impacted models similarly (95% confidence intervals not different). Fear-avoidance classification added 0.2% data variance control to the existing model. Cross-validation was supported. Predictive ratios were 1.09 and 1.10, without and with fear-avoidance, respectively.

CONCLUSION

Although screening for elevated fear-avoidance beliefs of physical activities significantly improves the FS outcomes predictive model, the amount of additional meaningful interpretation of FS outcomes was minimal. Exploration of other clinically relevant variables designed to improve outcomes prediction is warranted.

LEVEL OF EVIDENCE

Prognosis, level 2c.

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.

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

STUDY DESIGN

Outcomes instrument validation study.

OBJECTIVE

We evaluated administrative efficiency and psychometric adequacy of a computerized adaptive test (CAT) for patients with lumbar spine impairments seeking rehabilitation in outpatient therapy clinics.

SUMMARY OF BACKGROUND DATA

CATs promise efficient outcomes data collection in clinical applications with little loss of measurement precision compared to paper and pencil surveys. The lumbar CAT has been developed and simulated and is currently used routinely in therapy clinics. The CAT has not been assessed for administrative efficiency, and the outcomes measures estimated using the CAT have not been assessed using prospective data collection for validity, sensitivity to change, or responsiveness.

METHODS

Data from 17,439 patients with lumbar spine impairments receiving outpatient rehabilitation in 377 clinics in 30 states (United States) were analyzed. We evaluated efficiency of routine CAT administration and assessed construct validity, sensitivity to change, and responsiveness of CAT measures of lumbar functional status (FS).

RESULTS

On average, patients took less than 2 minutes (standard deviation <1 minute) to answer 7 CAT items (standard deviation, 3), which produced 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 before receiving rehabilitation reported worse discharge FS. A total of 66% of patients obtained statistically significant change (95% confidence interval minimal detectable change) at discharge. Change of 5 FS units (scale, 0-100) represented minimal clinically important improvement, which 70% of patients obtained. Minimal detectable change and minimal clinically important improvement were associated with intake FS.

CONCLUSION

We concluded the lumbar CAT administration was efficient, and CAT FS measures were precise, valid, sensitive, and responsive, supporting lumbar CAT use in clinical and research applications.

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.

Weighted index explained more variance in physical function than an additively scored functional comorbidity scale

OBJECTIVE

1) examine association between the Functional Comorbidity Index (FCI) and discharge functional status (FS); 2) examine impact of FCI on FS when added to comprehensive models; and 3) compare additive FCI with weighted FCI and list of condition variables (list).

STUDY DESIGN AND SETTING

Patients were drawn from Focus On Therapeutic Outcomes, Inc. (FOTO) database (1/1/06-12/31/07). FS collected using computer adaptive tests. Linear regression examined association between FCI and FS. Three methods of including functional comorbidities (FC) were compared.

RESULTS

Relationship between FCI and FS varied by group (range, 0.02-0.9). Models with weighted index or list had similar R². Weighted FCI or list increased R² of crude models by <0.01 for cervical, shoulder, and lumbar; by 0.01 for wrist/hand, knee, and foot/ankle; by 0.02 for hip; by 0.03 for elbow; and by 0.08 for neurological. Addition of FCI to comprehensive models added <0.01 to R² (all groups). Weighted FCI increased R² by <0.01 for cervical, lumbar, and shoulder; by 0.01 for wrist/hand, hip, knee, and foot/ankle; by 0.02 for elbow; and by 0.04 for neurological; whereas list increased R² by <0.01 for cervical, shoulder, and lumbar; by 0.01 for knee and foot/ankle; by 0.02 for elbow, wrist/hand, and hip; and by 0.05 for neurological.

CONCLUSION

List of comorbidities or weighted FCI is preferable to using additive FCI.

Associations between treatment processes, patient characteristics, and outcomes in outpatient physical therapy practice

OBJECTIVE

To identify how treatment processes are related to functional outcomes for patients seeking treatment for musculoskeletal impairments while controlling for demographic and health characteristics at intake.

DESIGN

Prospective, observational cohort study. Treatment processes were not altered. Data were collected continuously from June 2005 to January 2008. Descriptive statistics were applied to compare patient characteristics, interventions, and outcomes between impairment categories. Ordinary least-squares multiple regressions were used to examine associations between patient characteristics at intake, treatment processes, and functional outcomes.

SETTING

Fifty-four community-based outpatient physical therapy clinics of Maccabi Healthcare Services, a public health plan in Israel.

PARTICIPANTS

A consecutive sample of 22,019 adult patients (mean age 51.2 y, standard deviation=15.7, range 18-96, 58% women) seeking treatment due to lumbar spine, knee, cervical spine, or shoulder impairments with functional measurements at intake and discharge.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Functional status at discharge.

RESULTS

Explanatory power ranged from 30% to 39%. Better outcomes were associated with patient compliance with self-exercise and therapy attendance, application of therapeutic exercise and manual therapy, and completion of 3 or more functional surveys during the episode of care. Worse outcomes were associated with women, electrotherapy for pain management, and therapeutic ultrasound for shoulder impairments. Mixed results were found for group exercise programs.

CONCLUSIONS

The study of associations between treatment processes, patient characteristics, and outcomes helps to describe practice and can be used to suggest ways to improve outcomes in outpatient physical 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.

Interactive, computer-based, self-reported, visual function questionnaire: the PalmPilot-VFQ

PURPOSE

To evaluate the testing performance, reliability, and validity of a self-administered visual function questionnaire designed for a Palm Pilot in comparison with the interviewer-administered-National Eye Institute Visual Function Questionnaire-25 (NEI-VFQ-25) (interviewer-NEI-VFQ-25) and self-administered-NEI-VFQ-25 (self-NEI-VFQ-25).

METHOD

The interviewer-NEI-VFQ-25 was administered to 135 sequential patients who visited a retina clinic, followed on separate days by the Palm Pilot-Visual Function Questionnaire (PalmPilot-VFQ) and self-NEI-VFQ-25. Rasch analysis of ordinal difficulty ratings for the PalmPilot-VFQ was used to estimate interval measures of perceived visual ability. Reliability was determined by calculating Cronbach's alpha and test-retest intraclass correlation coefficients (ICCs). Concurrent validity was determined by calculating correlations of the PalmPilot-VFQ score with that of a general vision question. For evaluating convergent validity, the PalmPilot-VFQ was compared with the interviewer-NEI-VFQ-25, habitual-correction visual acuity (HCVA), and with two visual analogue scale (VAS) questions. Performance time and testability were compared among the three questionnaires.

RESULTS

Rasch analysis eliminated two items in the PalmPilot-VFQ due to poor-fit statistics. The final items showed internal consistency (Cronbach's alpha=0.89) and test-retest reliability (ICC=0.79), as well as an excellent separation index (3.23 and 4.01) for item parameters with significant concurrent correlation (P<0.0001). On evaluating convergent validity, the PalmPilot-VFQ showed strong correlations with interviewer-NEI-VFQ-25, with the HCVA of the better-seeing eye, and with the VAS questions (P=0.0001). Ninety percent of the 135 patients (HCVA >20/200 in the better-seeing eye) could perform the PalmPilot-VFQ with their habitual correction or high-plus spectacles, but in significantly less time than either interviewer-NEI-VFQ-25 or self-NEI-VFQ-25 (P<0.0001).

CONCLUSION

The PalmPilot-VFQ seems to be a reliable, valid, interactive, computer-based, self-administered questionnaire that can be used routinely by physicians to evaluate functional vision disability in populations with a high prevalence of macular disease.

A first step in the development of an international self-report instrument for physical functioning in palliative cancer care: a systematic literature review and an expert opinion evaluation study

Decline in physical functioning (PF) in progressive cancer increases risk of psychological problems, dependence, and distress, and it considerably affects quality of life. Despite this, assessment of PF has received little attention. Standardized, internationally endorsed assessment tools are needed that assess activities of relevance to palliative cancer patients from very low to high levels of PF. This study was done in cooperation with the European Association for Palliative Care Research Network. It was initiated to develop a computer-based symptom-assessment tool and aimed to 1) identify relevant existing PF-assessment instruments, 2) extract relevant items and classify them into meaningful subdimensions, and 3) construct unidimensional scales of selected PF domains. A systematic literature review was performed to detect relevant PF items from existing instruments. The International Classification of Functioning and Health was used to decide relevant subdimensions of PF, and expert panels within palliative cancer care were consulted to make decisions on activities to be included. One hundred and thirty-five instruments containing 743 items were included from the literature review. Two relevant PF subdimensions were revealed: Mobility (386 items representing 65 different activities) and Self-Care (143 items representing 30 different activities). The final PF tool consisted of two unidimensional scales: 24 hierarchically ranked Mobility items ranging from turning in bed to running, and 16 non-hierarchically ranked Self-Care items. Further testing of the instrument in a palliative cancer population is needed to develop the final PF instrument.

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.

Predictors of physical therapy clinic performance in the treatment of patients with low back pain syndromes

BACKGROUND AND PURPOSE

Little is known about organizational and service delivery factors related to quality of care in physical therapy. This study sought to identify characteristics related to differences in practice outcomes and service utilization.

SUBJECTS

The sample comprised 114 outpatient clinics and 1,058 therapists who treated 16,281 patients with low back pain syndromes during the period 2000-2001. Clinics participated with the Focus on Therapeutic Outcomes, Inc (FOTO) database.

METHODS

Hierarchical linear models were used to risk adjust treatment outcomes and number of visits per treatment episode. Aggregated residual scores from these models were used to classify each clinic into 1 of 3 categories in each of 3 types of performance groups: (1) effectiveness, (2) utilization, and (3) overall performance (ie, composite measure of effectiveness and utilization). Relationships between clinic classification and the following independent variables were examined by multinomial logistic regression: years of therapist experience, number of physical therapists, ratio of physical therapists to physical therapist assistants, proportion of patients with low back pain syndromes, number of new patients per physical therapist per month, utilization of physical therapist assistants, and setting.

RESULTS

Clinics that were lower utilizers of physical therapist assistants were 6.6 times more likely to be classified into the high effectiveness group compared with the low effectiveness group, 6.7 times more likely to be classified in the low utilization group compared with the high utilization group, and 12.4 times more likely to be classified in the best performance group compared with the worst performance group. Serving a higher proportion of patients with low back pain syndromes was associated with an increased likelihood of being classified in the lowest or middle group. Years of physical therapist experience was inversely associated with being classified in the middle utilization group compared with the highest utilization group.

DISCUSSION AND CONCLUSION

These findings suggest that, in the treatment of patients with low back pain syndromes, clinics that are low utilizers of physical therapist assistants are more likely to provide superior care (ie, better patient outcomes and lower service use).

Benchmarking physical therapy clinic performance: statistical methods to enhance internal validity when using observational data

Many clinics and payers are beginning programs to collect and interpret outcomes related to quality of care and provider performance (ie, benchmarking).

OUTCOMES

assessment is commonly done using observational research designs, which makes it important for those involved in these endeavors to appreciate the underlying challenges and limitations of these designs. This perspective article discusses the advantages and limitations of using observational research to evaluate quality of care and provider performance in order to inform clinicians, researchers, administrators, and policy makers who want to use data to guide practice and policy or critically appraise observational studies and benchmarking efforts. Threats to internal validity, including potential confounding, patient selection bias, and missing data, are discussed along with statistical methods commonly used to address these limitations. An example is given from a recent study comparing physical therapy clinic performance in terms of patient outcomes and service utilization with and without the use of these methods. The authors demonstrate that crude differences in clinic outcomes and service utilization tend to be inflated compared with the differences that are statistically adjusted for selected threats to internal validity. The authors conclude that quality of care measurement and ranking procedures that do not use similar methods may produce findings that may be misleading.

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.

Implementing an integrated electronic outcomes and electronic health record process to create a foundation for clinical practice improvement

BACKGROUND AND PURPOSE

Improving clinical outcomes requires continuous measurement and interpretation in conjunction with treatment process and patient characteristics. The purposes of this study were: (1) to describe implementation and integration of electronic functional status outcomes into an electronic health record (EHR) for the promotion of clinical practice improvement processes and (2) to examine the effect of ongoing outcomes data collection in a large physical therapy service in relation to patient and clinic burden.

SUBJECTS

Data were examined from 21,523 adult patients (mean age=50.6 years, SD=16.3, range=18-99; 58.9% women, 41.1% men) referred for physical therapist management of neuromusculoskeletal disorders.

METHODS

Process and patient characteristic data were entered into the EHR.

OUTCOMES

data collected using computerized adaptive testing technology in 11 outpatient clinics were integrated into the EHR. The effect of data collection was assessed by measuring the participation rate, completion rate, and data entry time. Qualitative assessment of the implementation process was conducted.

RESULTS

After 1 year, the average participation rate per clinic was 79.8% (range=52.7%-100%), the average completion rate per clinic was 45.1% (range=19.3%-64.7%), and the average data entry time per patient (minutes:seconds) was 03:37 (SD=02:19). Maximum estimate of average administrative time per patient was 9.6% of overall episode time. Barriers to and facilitators of the implementation process were identified.

DISCUSSION AND CONCLUSION

The results indicate that routine collection of outcome data is realistic in a large public physical therapy service and can be successfully integrated with EHR data to produce a valuable clinical practice improvement platform for service evaluation and outcomes research. Participation and completion rate goals of 90% and 65%, respectively, appear to be feasible.

Repeatability of a Rasch model of the AQ20 over five assessments

Rasch analysis is now used widely to assess the measurement properties of health status questionnaires. This study tested the stability of the AQ20 - a dichotomous-response measure of health status in asthma, using parameters estimated by a Rasch model. One hundred forty-four asthma patients completed the AQ20 on five occasions over 3 months. At visit 1, two items showed significant misfit and were deleted. At each visit, the overall mean item-person and item-trait interaction statistics from the remaining 18 items (AQ18) were very similar. The repeatability of the item calibrations was excellent (intraclass correlation coefficient 0.95), despite the patients' health having changed (repeated-measures ANOVA: FEV(1) and AQ18 score p<0.0001). Tests of differential item functioning (DIF) over time showed that one item increased in severity. This item refers to ability to garden, and changes in response patterns could be related to seasonal changes over the study period. We conclude that this study has highlighted the usefulness of multiple repeat assessments which allow items to be tested for DIF over time. This is important as inclusion of 'time-dependent' items in a questionnaire may reduce the reliability of the instrument.

Simulated computerized adaptive test for patients with lumbar spine impairments was efficient and produced valid measures of function

OBJECTIVE

To equate physical functioning (PF) items with Back Pain Functional Scale (BPFS) items, develop a computerized adaptive test (CAT) designed to assess lumbar spine functional status (LFS) in people with lumbar spine impairments, and compare discriminant validity of LFS measures (theta(IRT)) generated using all items analyzed with a rating scale Item Response Theory model (RSM) and measures generated using the simulated CAT (theta(CAT)).

METHODS

We performed a secondary analysis of retrospective intake rehabilitation data.

RESULTS

Unidimensionality and local independence of 25 BPFS and PF items were supported. Differential item functioning was negligible for levels of symptom acuity, gender, age, and surgical history. The RSM fit the data well. A lumbar spine specific CAT was developed that was 72% more efficient than using all 25 items to estimate LFS measures. theta(IRT) and theta(CAT) measures did not discriminate patients by symptom acuity, age, or gender, but discriminated patients by surgical history in similar clinically logical ways. theta(CAT) measures were as precise as theta(IRT) measures.

CONCLUSION

A body part specific simulated CAT developed from an LFS item bank was efficient and produced precise measures of LFS without eroding discriminant validity.

Simulated computerized adaptive test for patients with shoulder impairments was efficient and produced valid measures of function

BACKGROUND AND OBJECTIVE

To test unidimensionality and local independence of a set of shoulder functional status (SFS) items, develop a computerized adaptive test (CAT) of the items using a rating scale item response theory model (RSM), and compare discriminant validity of measures generated using all items (theta(IRT)) and measures generated using the simulated CAT (theta(CAT)).

STUDY DESIGN AND SETTING

We performed a secondary analysis of data collected prospectively during rehabilitation of 400 patients with shoulder impairments who completed 60 SFS items.

RESULTS

Factor analytic techniques supported that the 42 SFS items formed a unidimensional scale and were locally independent. Except for five items, which were deleted, the RSM fit the data well. The remaining 37 SFS items were used to generate the CAT. On average, 6 items were needed to estimate precise measures of function using the SFS CAT, compared with all 37 SFS items. The theta(IRT) and theta(CAT) measures were highly correlated (r = .96) and resulted in similar classifications of patients.

CONCLUSION

The simulated SFS CAT was efficient and produced precise, clinically relevant measures of functional status with good discriminating ability.

Simulated computerized adaptive tests for measuring functional status were efficient with good discriminant validity in patients with hip, knee, or foot/ankle impairments

BACKGROUND AND OBJECTIVE

To develop computerized adaptive tests (CATs) designed to assess lower extremity functional status (FS) in people with lower extremity impairments using items from the Lower Extremity Functional Scale and compare discriminant validity of FS measures generated using all items analyzed with a rating scale Item Response Theory model (theta(IRT)) and measures generated using the simulated CATs (theta(CAT)).

METHODS

Secondary analysis of retrospective intake rehabilitation data.

RESULTS

Unidimensionality of items was strong, and local independence of items was adequate. Differential item functioning (DIF) affected item calibration related to body part, that is, hip, knee, or foot/ankle, but DIF did not affect item calibration for symptom acuity, gender, age, or surgical history. Therefore, patients were separated into three body part specific groups. The rating scale model fit all three data sets well. Three body part specific CATs were developed: each was 70% more efficient than using all LEFS items to estimate FS measures. theta(IRT) and theta(CAT) measures discriminated patients by symptom acuity, age, and surgical history in similar ways. theta(CAT) measures were as precise as theta(IRT) measures.

CONCLUSION

Body part-specific simulated CATs were efficient and produced precise measures of FS with good discriminant validity.

Short-form activity measure for post-acute care

OBJECTIVE

To develop a comprehensive set of short forms using item response theory (IRT) and item pooling procedures for the purpose of monitoring postacute care functional recovery.

DESIGN

Prospective study.

SETTING

Six postacute health care networks in the greater Boston area, including inpatient acute rehabilitation, transitional care units, home care, and outpatient services.

PARTICIPANTS

A convenience sample of 485 adult volunteers who were currently receiving skilled rehabilitation services.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

We developed a set of 6 short forms across 3 activity domains from new items and items from existing postacute care instruments.

RESULTS

Inpatient- and community-based short forms were developed for each of 3 activity domains: physical & movement, applied cognition, and personal care & instrumental. Items were selected for inclusion on the short forms to maximize content coverage and information value of items across the range of content and to minimize ceiling and floor effects. We were able to match the distribution of sample scores with very good item precision for 1 of the constructs (physical & movement); the other 2 domains (personal care & instrumental, applied cognition) were more challenging because of the variability in patient recovery and ceiling effects.

CONCLUSIONS

ITR methods and item pooling procedures were valuable in developing paired sets of short-form instruments for inpatient and community rehabilitation that provided estimates of functioning along a common metric for use across postacute care settings.

A low back-specific version of the SF-36 Physical Functioning scale

STUDY DESIGN

A prospective repeated measures design was used to produce a back-specific version of the Short Form-36 Physical Functioning scale (SF-36 PF) by Rasch analysis of a pool of items from the SF-36 PF, Oswestry Disability Questionnaire, and the Quebec Back Pain Disability Scale.

OBJECTIVES

To identify items for a back-specific version of the SF-36 PF scale and to compare the psychometric properties of the new version with the original 10-item scale.

SUMMARY OF BACKGROUND DATA

Adequate assessment of patient function requires the administration of a generic and a condition-specific questionnaire. A back-specific version of the SF-36 PF would facilitate comprehensive patient assessment in the clinical setting.

METHODS

Consecutive patients with low back pain presenting for physiotherapy treatment were recruited at three public hospitals, three community health services, and four private practices. Patients completed questionnaires on two occasions 6 weeks apart.

RESULTS

A scale of 18 items showed a better fit to the Rasch model than the original SF-36 PF scale. Items in the original scale that had a poor fit (INFIT/OUTFIT statistics outside the range 0.7-1.3) showed an acceptable fit in the new scale. The augmented scale had comparable reliability and improved responsiveness to the original 10-item SF-36 PF scale. The minimum detectable change (90% confidence) and the minimum clinically important difference were 12 points. Floor and ceiling effects were practically eliminated. The psychometric properties of the new scale were comparable to those of the Oswestry Disability Questionnaire.

CONCLUSIONS

The Low-Back SF-36 PF18 comprises the 10-item SF-36 PF scale and four items each from the Oswestry and Quebec back pain questionnaires. The possible total score ranges from 0 to 100, with a higher score indicating better function. The new scale appears to offer advantages over the use of the original scale for the assessment of functioning in patients with low back pain.