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.

J Orthop Sports Phys Ther 2009;39(10):753-764. doi:10.2519/jospt.2009.3122

KEY WORDS: assessment of patient-reported outcomes, computerized adaptive testing, Lower Extremity Functional Scale, outpatient rehabilitation

STUDY DESIGN: Single-group, repeated-measures study. OBJECTIVE: To estimate the test-retest reliability, construct validity, and responsiveness of the Lower Extremity Functional Scale (LEFS) on inpatients attending an orthopaedic rehabilitation ward. BACKGROUND: The LEFS has acceptable validity on outpatients in assessing functional mobility, but it has not been tested for use on an inpatient orthopaedic ward. METHODS AND MEASURES: Inpatients in an orthopaedic ward (n = 142) completed the 20-item, self-report LEFS on admission, 7 to 10 days after admission, and on discharge. To test reliability, 24 patients had the LEFS repeated 1 day after the admission test, and the intraclass correlation (ICC) and the standard error of measurement (SEM) were calculated. Change scores of the LEFS were evaluated against patients’ and therapists’ rating of improvement, and change scores of comparison measures that included pain, functional performance, and the composite index created from scores of these comparison measures. The standardized response mean (SRM) of the LEFS was also computed. RESULTS: The ICC of the LEFS was 0.88, and the SEM was 4 LEFS points (LEFS score range, 0-80). The change in LEFS correlated with changes of comparison measures in the same direction of improvement. Patients rated as improved by both themselves and their therapists had significantly larger change in LEFS scores than subjects rated as no change. The SRM of the LEFS from admission to discharge was 1.76 on patients rated as improved. CONCLUSION: The LEFS is reliable and valid toassess group and individual change, and has large responsiveness. The LEFS and the comparison measures likely assess different constructs.

J Orthop Sports Phys Ther 2009;39(6):468-477, Epub 2 February 2009. doi:10.2519/jospt.2009.2971

KEY WORDS: inpatients, LEFS, orthopaedic, outcome measure

This study tested knee extensor and flexor strength using a reciprocal testing protocol on the Kin-Com isokinetic dynamometer. The purposes were: 1) to identify the variability associated with subjects, repetitions, occasions, and their various interactions; 2) to express the overall measurement error in clinically relevant terms; and 3) advance a strategy for maximizing reliability while simultaneously ensuring that all major sources of measurement error are represented. Fourteen healthy women were tested on two separate occasions (test sessions). On each occasion, measurements of knee extensor and flexor peak torque, average torque, and peak torque angle were gathered for each subject. The results indicated a high overall reliability (range 0.936-0.952) for all measures except peak torque angle (0.630-0.799). Reliability coefficients were consistently lower between occasions than among repetitions, indicating that this type of testing should occur on more than one occasion so as to include all sources of measurement error. This study has expressed measurement error in clinically relevant terms using a 95% confidence range. The findings indicate that a high reliability for isokinetic leg strength measurements can be achieved using a reciprocal testing protocol on the Kin-Com device.

J Orthop Sports Phys Ther 1988;10(6):218-223.

J Orthop Sports Phys Ther 1990;11(8):362-366.

STUDY DESIGN: Single-group repeated-measures study. OBJECTIVE: To examine the test-retest reliability of the timed up and go (TUG) test and its validity for measuring change and predicting length of stay (LOS) on an inpatient orthopaedic rehabilitation ward. BACKGROUND: The TUG test is used to measure functional mobility of persons with musculoskeletal conditions but it has not been thoroughly tested for use in an inpatient orthopaedic rehabilitation ward. METHODS AND MEASURES: The TUG test was administered to 142 patients on admission to an orthopaedic rehabilitation ward 7 to 10 days after admission and on discharge. To test reliability, 24 subjects had these tests repeated 1 day after admission, and the intraclass correlation (ICC) and standard error of measurement (SEM) were calculated. Change scores of the TUG test were evaluated against change scores in pain and function, and the rating of improvement of the patient and therapist. The standardized response mean (SRM) was also calculated. A regression analysis was performed to determine whether the admission TUG test score could predict LOS. RESULTS: The ICC of the TUG test was 0.80 and the SEM was 10.2 seconds. The change in TUG test scores correlated with the changes in pain (r = 0.21, P<.01) and function (r = -0.23, P<.01), and resulted in an SRM of 0.89 for subjects rated as improved. The admission TUG test scores accounted for only 3.4% of the variance in inpatient LOS. CONCLUSION: The TUG test is reliable and valid to assess group change of inpatients on an orthopaedic rehabilitation ward but is not a good predictor of LOS. LEVEL OF EVIDENCE: Prognosis, level 1b.

J Orthop Sports Phys Ther. 2008;38(7):410-417, published online 22 February 2008. doi:10.519/jospt.2008.2657

KEY WORDS:  joint replacement, length of stay, outcome measure, TUG test

J Orthop Sports Phys Ther. 2008;38(3):116-125, published online 9 November 2007. doi:10.2519/jospt.2008.2596

Study Design: Prospective observation study. Objectives: To compare the test-retest reliability and longitudinal validity (sensitivity to change) of 2 single-item numeric pain rating scales (NPRSs) with a 4-item pain intensity measure (P4). Background: Pain is a frequent outcome measure for patients seen in physical therapy; however, the error associated with efficient pain measures, such as the single-item NPRS, is greater than for self-report measures of functional status. Initial evaluation of the P4 suggests that it is more reliable and sensitive to change than the NPRS. Methods and Measures: Two single-item NPRSs and the P4 were administered on 3 occasions - initial visit (n = 220), within 72 hours of baseline (n = 213), and 12 days following baseline assessment (n = 183) - to patients with musculoskeletal problems receiving physical therapy. Reliability was assessed using a type 2,1 intraclass correlation coefficient. Longitudinal validity was assessed by correlating the measures' change scores with a retrospective rating of change that included patients' and clinicians' perspectives. Results: The test-retest reliability and longitudinal validity of the P4 were significantly greater (P₁<.05) than both single-item NPRSs. Minimal detectable change of the P4 at the 90% confidence level was estimated to be a change of 22% of the scale range (9 points) compared to 27.3% (3 points) and 31.8% (3.5 points) for the 2-day NPRS and 24-hour NPRS, respectively. Conclusions: The findings of this study suggest the P4 is more adept at assessing change in pain intensity than popular versions of single-item NPRSs.

J Orthop Sports Phys Ther. 2004;34(4):187-193. doi:10.2519/jospt.2004.1157

Key Words: measurement, outcome, reliability, responsiveness, validity

Information concerning a patient's functional status is often obtained by asking the patient about activities that cannot be assessed directly in the clinical setting. This information is usually acquired through a verbal exchange between the clinician and patient. The measurement properties of the verbal exchange are unknown. An alternate method of obtaining this information is when patients self-report their functional status. The measurement properties of self-report questionnaires are well known; however, these measures are used infrequently for the evaluation of functional status, progress, and outcome in the clinic. Two reasons are possible for the infrequent use of self-report questionnaires: (1) values obtained from self-report measures have not been used to guide the care of the patient, and (2) a perception exists that these measures take a great deal of time to administer and score. The purpose of this clinical commentary was to describe the application, scoring, and use of a functional status measure (the Roland-Morris Questionnaire) for persons with low back pain and to illustrate how this questionnaire can be efficiently incorporated into clinical practice to aid decision making concerning individual patients. Three patient scenarios are used to illustrate the issues raised in this paper.

J Orthop Sports Phys Ther. 1999;29(4):232-239.

Key Words: low back pain, disability, measurement

Study Design: Single group repeated measures with multiple raters. Objectives: To determine the interrater reliability of KT-1000 measurements of novice and experienced raters and to provide error estimates for these raters. Background: The KT-1000 arthrometer is often used clinically to quantify anterior tibial displacement. Few data have been documented, however, about the relative reliability of KT-1000 measurements obtained by novice compared with experienced users. Methods and Measures: Two novice and two experienced KT-1000 users performed measurements on 29 knees of 25 patients after anterior cruciate ligament (ACL) reconstruction or with a diagnosis of ACL deficiency. Measurements were performed at 131 N. Interrater and intertrial reliability coefficients (interclass correlation coefficient; ICC) and the standard error of measurement were calculated for expert and novice raters. Results: The interrater ICC for novices was 0.65 and the interrater error was ±3.52 mm (90% confidence interval [CI]). The interrater ICC for experts was 0.79 and the interrater error was ±2.94 mm (90% CI). Conclusions: These results suggest that experience in using the KT-1000 is related to the interrater error of measurements and that training is an important consideration when using the KT-1000 arthrometer.

J Orthop Sports Phys Ther. 1999;29(1):49-55.

Key Words: Standard error of measurement, reliability, testing

Self-report measures of disability are being used more frequently to assess patients' outcomes in clinical practice. This study examines the reliability, validity, and sensitivity to change of the Patient-Specific Functional Scale when applied to persons with neck dysfunction. The Patient-Specific Functional Scale and Neck Disability Index were applied at the initial visit, within 72 hours of the initial visit, and following 1-4 weeks of treatment in 31 patients with cervical dysfunction. At the time of the initial visit, the clinician made an estimate of patients' prognoses on a 5-point scale. This estimate served as an a priori construct for change: patients with better ratings would change more. The results demonstrate excellent reliability (R = .92), validity (r = .73-.83 compared with the Neck Disability Index, and r = .52-.64 compared with the prognosis rating), and sensitivity to change (r = .79-.83 compared with Neck Disability Index change scores, and r = .46-.53 compared with the prognosis rating). No difference was found between the Patient-Specific Functional Scale and Neck Disability Index in their ability to detect change over time. The results of this study are consistent with previous investigations, which have concluded that the Patient-Specific Functional Scale is an efficient and valid measure for assessing disability and change in disability in persons with low back pain and knee dysfunction.

J Orthop Sports Phys Ther. 1998;27(5):331-338.

Key Words: functional status, clinical outcome, measurement

Some studies have shown a relationship between trunk muscle strength and low back pain. Measures of trunk muscle strength and endurance, which are feasible in the clinical setting, are needed. The purpose of this study was to determine interrater reliability of 6 tests of abdominal and trunk extensor muscle strength and endurance. The tests included abdominal and extensor dynamic endurance, hand-held dynamometry of isometric flexion and extension, and abdominal and extensor static endurance. Thirty-nine healthy workers were recruited as subjects. Each was tested by 3 raters on 3 days within 1 week. Intraclass correlation coefficients (ICC) and the standard error of measurement (SEM) were calculated: abdominal dynamic endurance ICC = .89, SEM = 8 repetitions; extensor dynamic endurance ICC = .78, SEM = 9 repetitions; abdominal isometric force ICC = .25, SEM = 60 N; extensor isometric force ICC = .24, SEM = 68 N; abdominal static endurance ICC = .51, SEM = 35 seconds; extensor static endurance ICC = .59, SEM = 20 seconds. The dynamic endurance tests had acceptable interrater reliability. For the others, reliability was poor and the SEMs were large.

J Orthop Sports Phys Ther. 1997;26(4):200-208.

Key Words: muscle strength, assessment, low back

Clinicians frequently use the results of clinical diagnostic tests to make decisions concerning patients. The intent of this paper is to review the technical aspects and measurement properties of the McMurray test and, more globally, to illustrate the impact that indiscriminate test application has on test interpretation. The literature shows that diagnostic accuracy studies, which evaluate the test described by McMurray, yield remarkably similar estimates of sensitivity (about 26%) and specificity (about 94%). These test characteristics are applied to 3 case scenarios to illustrate the impact that history-specific prevalence (ie, the likelihood a patient has the condition based on the history) has on the predictive values. The results show a high false positive rate when applied to patients who, based on the history, have a low pre-physical examination likelihood for the condition of interest and a higher false negative rate when applied to patients who have a high history-specific prevalence. Readers are warned that the exhaustive examination approach effectively lowers the prevalence and results in a high false positive rate. The impact that the exhaustive approach has on increasing the false positive rate is universal to all diagnostic investigations and is not unique to the McMurray test.

J Orthop Sports Phys Ther. 1995;22(3):116-120.

Key Words: diagnosis, knee, McMurray test

The assessment of muscle strength is a task performed frequently by physical therapists. The purposes of this study were to determine whether intrasession test-retest reliability differs between make and break tests and strength tests that do not require an assessor (eg, isometric Kin-Com test) and hand-held dynamometer (HHD) assessments. The elbow flexor strength of 32 healthy, female volunteers was measured under 4 test conditions: Kin-Com make and break, and HHD make and break. Two measurements were performed for each test condition by the same rater. The results showed: 1) measurements obtained using the HHD deviated from a normal distribution, 2) comparable reliability coefficients for the make and break tests were obtained from the Kin-Com device, 3) there was a higher reliability coefficient for the make test compared with the break test for the HHD tests, and 4) the measured forces for the break tests were higher than the make tests. The results support the premise that hand-held dynamometry is a viable alternative to more costly modes of isometric strength measurements, provided the assessor's strength is greater than that of the specific muscle group being measured.

J Orthop Sports Phys Ther. 1994;19(1):28-32.

Key Words: muscle strength, measurement, methods

Studies are needed to enhance our understanding of functional outcomes. The purpose of this paper is to describe a community clinic program for injured workers with low back pain and to report outcomes of the first 50 consecutive patients to enter the program who were evaluated using a standardized assessment procedure. Data for this report were collected from a retrospective chart review as part of an evaluation of the program. The patients referred to the clinic entered a 4-week treatment program. They were assessed at entry and discharge using the Toronto-Hamilton Lumbar Database. The database assessment is a standardized evaluation for documenting subjective and objective clinical data, and the protocol includes a diagnostic classification system and pain and function ratings. The results of this investigation include a statistically significant (p<.05) decrease in pain and increase in function as measured by the Jan van Breemen pain and disability scales and the Sickness Impact Profile. Seventy-four percent of the treatment group had returned to work by 6 weeks postdischarge from the program. This study suggests that a significant improvement in functional capabilities, a decrease in pain and disability indices, and higher return-to-work rates can be achieved through a 4-week, community-based multiprofessional rehabilitation program.

J Orthop Sports Phys Ther. 1994;20(1):11-16.

Key Words: low back pain, community clinic, standardized assessment