Reliability of self-measured objective functional impairment using the timed up and go test in patients with diseases of the spine.

BACKGROUND: Accurate assessment of a patient's functional status is crucial for determining the need for treatment and evaluating outcomes. Objective functional impairment (OFI) measures, alongside patient-reported outcome measures (PROMs), have been proposed for spine diseases. The Timed-Up and Go (TUG) test, typically administered by healthcare professionals, is a well-studied OFI measure. This study investigates whether patient self-measurement of TUG is similarly reliable. METHODS: In a prospective, observational study, patients with spinal diseases underwent two TUG assessments: one measured by a healthcare professional and one self-measured by the patient. Interrater reliability was assessed using the intraclass correlation coefficient (ICC) with a two-way random-effects model, considered excellent between 0.75 - 1.00. Paired t-tests directly compared both measurements. The impact of variables such as age, sex, disease type, symptom severity (via PROMs), comorbidities, and frailty on reliability was also analysed. RESULTS: Seventy-four patients were included, with a mean age of 62.9 years (SD 17.8); 29 (39.2%) were female. The majority (64.9%) were treated for degenerative disc disease. The lumbo-sacral region was most affected (71.6%), and 47.3% had previous surgeries. Patient self-measurement reliability was excellent (ICC 0.8740, p < 0.001), and the difference between healthcare professional (19.3 ± 9.4 s) and patient measurements (18.4 ± 9.7 s) was insignificant (p = 0.116). Interrater reliability remained high in patients > 65 years (ICC 0.8584, p < 0.001), patients with ASA grades 3&4 (ICC 0.7066, p < 0.001), patients considered frail (ICC 0.8799, p < 0.001), and in patients not using any walking aid (ICC 0.8012, p < 0.001). High symptom severity still showed strong reliability (ICC 0.8279, p < 0.001 for Oswestry Disability Index > 40; ICC 0.8607, p = 0.011 for Neck Disability Index > 40). CONCLUSIONS: Patients with spine diseases can reliably self-measure OFI using the TUG test. The interrater reliability between self-measurements and those by healthcare professionals was excellent across all conditions. These findings could optimize patient assessments, especially in resource-limited settings.

Objective outcome measures may demonstrate continued change in functional recovery in patients with ceiling effects of subjective patient-reported outcome measures after surgery for lumbar degenerative disorders.

BACKGROUND CONTEXT: The 6-minute walking test (6WT) has been previously shown to be a reliable and valid outcome measure. It is unclear if the 6WT may further help to detect differences in well performing patients that reach a ceiling effect in PROMs after surgery. PURPOSE: To evaluate changes and timing of change in objective functional impairment (OFI) as measured with the smartphone-based 6WT in relation to patient-reported outcome measures (PROMs) after surgery for degenerative lumbar disorders (DLD). STUDY DESIGN: Prospective observational cohort study. PATIENT SAMPLE: Fifty consecutive patients undergoing surgery for DLD. OUTCOME MEASURES: Patients self-determined their OFI using the 6WT application (6WT-app) and completed a set of paper-based PROMs before, 6 weeks and 3 months after surgery. METHODS: Fifty patients undergoing surgery for DLD were assessed preoperatively (baseline), 6 weeks (6W) and 3 months (3M) postoperatively. Paired sample t-tests were used to establish significant changes in raw 6-minute walking distance (6WD) and standardized Z-scores, as well as PROMs. Pearson correlation coefficient was used to define the relationship between 6WT and PROMs. Floor and ceiling effects were assessed for each PROM (visual analogue scale [VAS], core outcome measure index [COMI], Zurich claudication questionnaire [ZCQ]). RESULTS: Mean 6WT results improved from 377 m (standard deviation - SD 137; Z-score: 1.8, SD 1.8) to 490 m (SD 126; -0.7, SD 1.5) and 518 m (SD 112; -0.4, SD 1.41; all p<.05) at 6W and 3M follow-up. No significant improvement was observed between 6W and 3M for the ZCQ, VAS back and leg pain. While correlation between 6WT and all PROMs were weak at baseline, correlation coefficient increased to moderate at 3M. A considerable ceiling effect (best possible score) was observed, most notably for the ZCQ physical performance, VAS back and leg pain in 24%, 20%, and 16% of patient at 6W and in 30%, 24%, and 28% at 3M. CONCLUSIONS: Objective functional tests can describe the continued change in the physical recovery of a patient and may help to detect differences in well performing groups as well as in cases where patients' PROM results cannot further improve because of a ceiling effect.

Expanding the indications for measurement of objective functional impairment in spine surgery: A pilot study of four patients with diseases affecting the spinal cord.

•The TUG test and the 6WT are feasible to apply in ambulatory patients with spinal cord affection.•The objective measurement of functional impairment resembled the functional status of four patients in this pilot study.•The TUG test and the 6WT may detect and quantify functional decline and/or improvement resulting from spinal cord affection.•Modern smartphone app-based technology may help to accurately quantify impairment, which is key for decision-making and evaluating the efficacy of interventions.

Radiographic analysis of dynamic lumbar motion during the five-repetition sit-to-stand test in degenerative lumbar spondylolisthesis.

BACKGROUND: To investigate the mechanisms of low back pain triggered by the five-repetition sit-to-stand test (5R-STS test) in degenerative lumbar spondylolisthesis (DLS) from radiographic perspective, as well as to determine the most useful diagnostic modalities in the evaluation of segmental instability. METHODS: We retrospectively performed a study of 78 patients (23 men and 55 women) with symptomatic DLS at L4/5 in our institution between April 2020 and December 2021. Each patient was assessed by using the 5R-STS test and received a series of radiographs including the upright standing, normal sitting, standing flexion-extension radiographs, and supine sagittal MR images. Enrolled patients were divided into two groups based on the 5R-STS test score: severe group and mild group. Translational and angular motion was determined by comparing normal sitting radiograph (N) with upright standing radiograph (U) (Combined, NU), flexion/extension radiographs (FE) as well as normal sitting radiograph (N) with a supine sagittal MR image (sMR) (Combined, N-sMR). RESULTS: Overall, 78 patients were enrolled, and there were 31(39.7%) patients in group S and 47(60.3%) patients in group M, with an average age of 60.7 ± 8.4 years. The normal sitting radiograph demonstrated the maximum slip percentage (SP) and the highest kyphotic angle both in group S and group M. Compared with group M, group S revealed significantly higher SP in the normal sitting position (24.1 vs 19.6; p = 0.002). The lumbar slip angular in group S with a sitting position was significantly higher than that in group M (-5.2 vs -1.3; p < 0.001). All patients in group S had objective functional impairment (OFI) and 28 patients of them were diagnosed with lumbar instability by using the combination of normal sitting radiograph (N) and supine sagittal MR image (sMR) (Combined, N-sMR). CONCLUSION: DLS patients with positive sign of the 5R-STS test is a distinct subgroup associated with lumbar instability. The modality of the combination of normal sitting radiograph (N) and supine sagittal MR image (sMR) had a significant advantage in terms of the ability to identify segmental instability.

Distance to first symptoms measured by the 6-min walking test differentiates between treatment success and failure in patients with degenerative lumbar disorders.

PURPOSE: The smartphone-based 6-min walking test (6WT) is an established digital outcome measure in patients undergoing surgery for degenerative lumbar disorders (DLD). In addition to the 6WTs primary outcome measure, the 6-min walking distance (6WD), the patient's distance to first symptoms (DTFS) and time to first symptoms (TTFS) can be recorded. This is the first study to analyse the psychometric properties of the DTFS and TTFS. METHODS: Forty-nine consecutive patients (55 ± 15.8 years) completed the 6WT pre- and 6 weeks (W6) postoperative. DTFS and TTFS were assessed for reliability and content validity using disease-specific patient-reported outcome measures. The Zurich Claudication Questionnaire patient satisfaction subscale was used as external criterion for treatment success. Internal and external responsiveness for both measures at W6 was evaluated. RESULTS: There was a significant improvement in DTFS and TTFS from baseline to W6 (p < 0.001). Both measures demonstrated a good test-retest reliability (ß = 0.86, 95% CI 0.81-0.90 and ß = 0.83, 95% CI 0.76-0.87, both p < 0.001). The DTFS exceeded the 6WD capability to differentiate between satisfied (82%) and unsatisfied patients (18%) with an AUC of 0.75 (95% CI 0.53-0.98) vs. 0.70 (95% CI 0.52-0.90). The TTFS did not demonstrate meaningful discriminative abilities. CONCLUSION: Change in DTFS can differentiate between satisfied and unsatisfied patients after spine surgery. Digital outcome measures on the 6WT metric provide spine surgeons and researchers with a mean to assess their patient's functional disability and response to surgical treatment in DLD.

Machine learning-augmented objective functional testing in the degenerative spine: quantifying impairment using patient-specific five-repetition sit-to-stand assessment.

OBJECTIVE: What is considered "abnormal" in clinical testing is typically defined by simple thresholds derived from normative data. For instance, when testing using the five-repetition sit-to-stand (5R-STS) test, the upper limit of normal (ULN) from a population of spine-healthy volunteers (10.5 seconds) is used to identify objective functional impairment (OFI), but this fails to consider different properties of individuals (e.g., taller and shorter, older and younger). Therefore, the authors developed a personalized testing strategy to quantify patient-specific OFI using machine learning. METHODS: Patients with disc herniation, spinal stenosis, spondylolisthesis, or discogenic chronic low-back pain and a population of spine-healthy volunteers, from two prospective studies, were included. A machine learning model was trained on normative data to predict personalized "expected" test times and their confidence intervals and ULNs (99th percentiles) based on simple demographics. OFI was defined as a test time greater than the personalized ULN. OFI was categorized into types 1 to 3 based on a clustering algorithm. A web app was developed to deploy the model clinically. RESULTS: Overall, 288 patients and 129 spine-healthy individuals were included. The model predicted "expected" test times with a mean absolute error of 1.18 (95% CI 1.13-1.21) seconds and R2 of 0.37 (95% CI 0.34-0.41). Based on the implemented personalized testing strategy, 191 patients (66.3%) exhibited OFI. Type 1, 2, and 3 impairments were seen in 64 (33.5%), 91 (47.6%), and 36 (18.8%) patients, respectively. Increasing detected levels of OFI were associated with statistically significant increases in subjective functional impairment, extreme anxiety and depression symptoms, being bedridden, extreme pain or discomfort, inability to carry out activities of daily living, and a limited ability to work. CONCLUSIONS: In the era of "precision medicine," simple population-based thresholds may eventually not be adequate to monitor quality and safety in neurosurgery. Individualized assessment integrating machine learning techniques provides more detailed and objective clinical assessment. The personalized testing strategy demonstrated concurrent validity with quality-of-life measures, and the freely accessible web app (https://neurosurgery.shinyapps.io/5RSTS/) enabled clinical application.

Responsiveness of the self-measured 6-minute walking test and the Timed Up and Go test in patients with degenerative lumbar disorders.

OBJECTIVE: The 6-minute walking test (6WT) and the Timed Up and Go (TUG) test are two of the most commonly applied standardized measures of objective functional impairment that help support clinical decision-making for patients undergoing surgery for degenerative lumbar disorders. This study correlates smartphone-app-based 6WT and TUG results to evaluate their responsiveness. METHODS: In a prospective study, 49 consecutive patients were assessed preoperatively and 6 weeks postoperatively using the 6WT, the TUG test, and commonly used patient-reported outcome measures. Raw values and standardized z-scores of both objective tests were correlated. An external criterion for treatment success was created based on the Zurich Claudication Questionnaire patient satisfaction subscale. Internal and external responsiveness for both functional tests was evaluated. RESULTS: The mean preoperative 6WT results improved from 401 m (SD 129 m), z-score -1.65 (SD 1.6) to 495 m (SD 129 m), z-score -0.71 (SD 1.6, p < 0.001). The mean preoperative TUG test results improved from 10.44 seconds (SD 4.37, z-score: -3.22) to 8.47 seconds (SD 3.38, z-score: -1.93, p < 0.001). The 6WT showed a strong negative correlation with TUG test results (r = -66, 95% CI 0.76-0.53, p < 0.001). The 6WT showed higher internal responsiveness (standardized responsive mean = 0.86) compared to the TUG test (standardized responsive mean = 0.67). Evaluation of external responsiveness revealed that the 6WT was capable of differentiating between patients who were satisfied and those who were unsatisfied with their treatment results (area under the curve = 0.70), whereas this was not evident for the TUG test ( area under the curve = 0.53). CONCLUSIONS: Both tests adequately quantified functional impairment in surgical candidates with degenerative lumbar disorders. The 6WT demonstrated better internal and external responsiveness compared with the TUG test. Clinical trial registration no.: NCT03977961 (clinicaltrials.gov). ABBREVIATIONS: AUC = area under the curve; COMI = Core Outcome Measures Index; DLDs = degenerative lumbar disorders; LDH = lumbar disc herniation; LSS = lumbar spinal stenosis; PROM = patient-reported outcome measure; ROC = receiver operating characteristic; SRM = standardized responsive mean; TUG = Timed Up and Go; VAS = visual analog scale; 6WD = 6-minute walking distance; 6WT = 6-minute walking test; ZCQ = Zurich Claudication Questionnaire.

External Validation of the Timed Up and Go Test as Measure of Objective Functional Impairment in Patients With Lumbar Degenerative Disc Disease.

BACKGROUND: The Timed Up and Go (TUG) test is the most commonly applied objective measure of functional impairment in patients with lumbar degenerative disc disease (DDD). OBJECTIVE: To demonstrate external content validity of the TUG test. METHODS: Consecutive adult patients, scheduled for elective lumbar spine surgery, were screened for enrollment into a prospective observational study. Disease severity was estimated by patient-reported outcome measures (PROMs; Visual Analog Scales [VAS], Core Outcome Measures Index [COMI] back, Zurich Claudication Questionnaire [ZCQ]) and the TUG test. Pearson correlation coefficients (PCCs) were used to describe the relationship between logarithmic TUG test raw values and PROMs. RESULTS: A total of 70 patients (mean age 55.9 ± 15.4 yr; 38.6% female; 27.1% previous spine surgery; 28.6% lower extremity motor deficits) with lumbar disc herniation (50%), lumbar spinal stenosis (34.3%), or instability requiring spinal fusion (15.7%) were included. The mean TUG test time was 10.8 ± 4.4 s; age- and sex-adjusted objective functional impairment (OFI) T-score was 134.2 ± 36.9. A total of 12 (17.1%) patients had mild, 14 (20%) moderate, and 9 (12.9%) severe OFI, while 35 (50%) had TUG test results within the normal population range (no OFI). PCCs between TUG test time and VAS back pain were r = 0.37 (P = .002), VAS leg pain r = 0.37 (P = .002), COMI back r = 0.50 (P < .001), ZCQ symptom severity r = 0.41 (P < .001), and ZCQ physical function r = 0.36 (P = .002). CONCLUSION: This external validation demonstrated similar OFI rates and PCCs between logarithmic TUG test results and PROMs compared to the original article from 2016. These findings support the TUG test being a quick, easy-to-use objective test, which provides the physician with a robust estimate of pain and functional impairment.

Patients undergoing surgery for lumbar degenerative spinal disorders favor smartphone-based objective self-assessment over paper-based patient-reported outcome measures.

BACKGROUND CONTEXT: Smartphone-based applications enable new prospects to monitor symptoms and assess functional outcome in patients with lumbar degenerative spinal disorders. However, little is known regarding patient acceptance and preference towards new modes of digital objective outcome assessment. PURPOSE: To assess patient preference of an objective smartphone-based outcome measure compared to conventional paper-based subjective methods of outcome assessment. STUDY DESIGN: Prospective observational cohort study. PATIENT SAMPLE: Fourty-nine consecutive patients undergoing surgery for lumbar degenerative spinal disorder. OUTCOME MEASURES: Patients completed a preference survey to assess different methods of outcome assessment. A 5-level Likert scale ranged from strong disagreement (2 points) over neutral (6 points) to strong agreement (10 points) was used. METHODS: Patients self-determined their objective functional impairment using the 6-minute Walking Test application (6WT-app) and completed a set of paper-based patient-reported outcome measures (PROMs) before and 6 weeks after surgery. Patients were then asked to rate the methods of outcome assessment in terms of suitability, convenience, and responsiveness to their symptoms. RESULTS: The majority of patients considered the 6WT-app a suitable instrument (median 8.0, interquartile range [IQR] 4.0). Patients found the 6WT more convenient (median 10.0, IQR 2.0) than the Zurich Claudication Questionnaire (ZCQ; median 8.0, IQR 4.0, p=.019) and Core Outcome Measure Index (COMI; median 8.0, IQR 4.0, p=.007). There was good agreement that the 6WT-app detects change in physical performance (8.0, IQR 4.0). 78 % of patients considered the 6WT superior in detecting differences in symptoms (vs. 22% for PROMs). Seventy-six percent of patients would select the 6WT over the other, 18% the ZCQ and 6% the COMI. Eighty-two percent of patients indicated their preference to use a smartphone app for the assessment and monitoring of their spine-related symptoms in the future. CONCLUSIONS: Patients included in this study favored the smartphone-based evaluation of objective functional impairment over paper-based PROMs. Involving patients more actively by means of digital technology may increase patient compliance and satisfaction as well as diagnostic accuracy.

Evaluation of the 6-minute walking test as a smartphone app-based self-measurement of objective functional impairment in patients with lumbar degenerative disc disease.

OBJECTIVE: Digital transformation enables new possibilities to assess objective functional impairment (OFI) in patients with lumbar degenerative disc disease (DDD). This study examines the psychometric properties of an app-based 6-minute walking test (6WT) and determines OFI in patients with lumbar DDD. METHODS: The maximum 6-minute walking distance (6WD) was determined in patients with lumbar DDD. The results were expressed as raw 6WDs (in meters), as well as in standardized z-scores referenced to age- and sex-specific values of spine-healthy volunteers. The 6WT results were assessed for reliability and content validity using established disease-specific patient-reported outcome measures. RESULTS: Seventy consecutive patients and 330 volunteers were enrolled. The mean 6WD was 370 m (SD 137 m) in patients with lumbar DDD. Significant correlations between 6WD and the Core Outcome Measures Index for the back (r = -0.31), Zurich Claudication Questionnaire (ZCQ) symptom severity (r = -0.32), ZCQ physical function (r = -0.33), visual analog scale (VAS) for back pain (r = -0.42), and VAS for leg pain (r = -0.32) were observed (all p < 0.05). The 6WT revealed good test-retest reliability (intraclass correlation coefficient 0.82), and the standard error of measurement was 58.3 m. A 4-tier severity stratification classified patients with z-scores > -1 (no OFI), -1 to -1.9 (mild OFI), -2 to -2.9 (moderate OFI), and ≤ -3 (severe OFI). CONCLUSIONS: The smartphone app-based self-measurement of the 6WT is a convenient, reliable, and valid way to determine OFI in patients with lumbar DDD. The 6WT app facilitates the digital evaluation and monitoring of patients with lumbar DDD.

Longitudinal smartphone-based self-assessment of objective functional impairment in patients undergoing surgery for lumbar degenerative disc disease: initial experience.

BACKGROUND: The worldwide spread of smartphone usage enables new possibilities for longitudinal monitoring of objective functional impairment (OFI) in patients undergoing surgery for lumbar degenerative disc disease (DDD). METHODS: Three patients, undergoing elective surgery for lumbar DDD, self-assessed OFI using a recently validated 6-min walking test (6WT) smartphone application. Results are presented as raw 6-min walking distance (6WD) as well as in reference to age- and sex-specific healthy population reference values using standardized z-scores (number of standard deviations). In parallel, patient-reported outcome measures (PROMs), including numeric rating scale (NRS) leg-pain and Core Outcome Measures Index (COMI) were obtained before (pre) and 6 weeks (6 W) as well as 3 months (3 M) after surgery. Descriptive analyses were used to compare PROMs with repeated 6WT measurements over time. The feasibility and benefits of the longitudinal OFI measurements using the 6WT app are discussed. RESULTS: One patient presented a favorable outcome, reflected by a clinically meaningful improvement in PROMs. Correspondingly, the 6WT distance gradually improved above the normal population values ((pre 399 m (z-score - 1.96) vs. 6 W 494 m (- 0.85) vs. 3 M 557 m (- 0.1)). One patient experienced initial improvement at 6 W, followed by a decline in 6WD at 3 M which promoted further interventions with subsequent recovery ((358 m (z-score - 3.29) vs 440 m (- 2.2) vs 431 m (- 2.32) vs 471 m (- 1.78)). The last patient showed a lack of improvement in PROMs as well as in OFI (360 m (z-score 0.0) vs 401 m (0.30) vs 345 m (- 0.11)) resulting in secondary surgery. CONCLUSION: The longitudinal assessment of OFI using the 6WT app was feasible and provided the physician with a detailed history of patients' postoperative walking capacity complementing commonly used PROMs.

Normative data of a smartphone app-based 6-minute walking test, test-retest reliability, and content validity with patient-reported outcome measures.

OBJECTIVE: The 6-minute walking test (6WT) is used to determine restrictions in a subject's 6-minute walking distance (6WD) due to lumbar degenerative disc disease. To facilitate simple and convenient patient self-measurement, a free and reliable smartphone app using Global Positioning System coordinates was previously designed. The authors aimed to determine normative values for app-based 6WD measurements. METHODS: The maximum 6WD was determined three times using app-based measurement in a sample of 330 volunteers without previous spine surgery or current spine-related disability, recruited at 8 centers in 5 countries (mean subject age 44.2 years, range 16-91 years; 48.5% male; mean BMI 24.6 kg/m2, range 16.3-40.2 kg/m2; 67.9% working; 14.2% smokers). Subjects provided basic demographic information, including comorbidities and patient-reported outcome measures (PROMs): visual analog scale (VAS) for both low-back and lower-extremity pain, Core Outcome Measures Index (COMI), Zurich Claudication Questionnaire (ZCQ), and subjective walking distance and duration. The authors determined the test-retest reliability across three measurements (intraclass correlation coefficient [ICC], standard error of measurement [SEM], and mean 6WD [95% CI]) stratified for age and sex, and content validity (linear regression coefficients) between 6WD and PROMs. RESULTS: The ICC for repeated app-based 6WD measurements was 0.89 (95% CI 0.87-0.91, p < 0.001) and the SEM was 34 meters. The overall mean 6WD was 585.9 meters (95% CI 574.7-597.0 meters), with significant differences across age categories (p < 0.001). The 6WD was on average about 32 meters less in females (570.5 vs 602.2 meters, p = 0.005). There were linear correlations between average 6WD and VAS back pain, VAS leg pain, COMI Back and COMI subscores of pain intensity and disability, ZCQ symptom severity, ZCQ physical function, and ZCQ pain and neuroischemic symptoms subscores, as well as with subjective walking distance and duration, indicating that subjects with higher pain, higher disability, and lower subjective walking capacity had significantly lower 6WD (all p < 0.001). CONCLUSIONS: This study provides normative data for app-based 6WD measurements in a multicenter sample from 8 institutions and 5 countries. These values can now be used as reference to compare 6WT results and quantify objective functional impairment in patients with degenerative diseases of the spine using z-scores. The authors found a good to excellent test-retest reliability of the 6WT app, a low area of uncertainty, and high content validity of the average 6WD with commonly used PROMs.

Smartphone-Based Self-Assessment of Objective Functional Impairment (6-Minute Walking Test) in Patients Undergoing Epidural Steroid Injection.

Epidural steroid injection (ESI) represents a popular treatment option in patients with lumbar degenerative disc disease (DDD). The main objective of the article was to determine whether the 6-minute walking test (6WT) could assist in the discrimination between ESI responders and nonresponders. We used a validated 6WT smartphone application to assess self-measured objective functional impairment (OFI) in 3 patients with DDD undergoing ESI. Patient-reported outcome measures (PROMs), including the Core Outcome Measures Index and the Oswestry Disability Index, were obtained at baseline and at the 3-, 7-, and 28-day follow-up. Descriptive analyses were used to compare PROMs with OFI over time. Two patients responded well to the ESI, illustrated by clinically meaningful improvements in PROMs. This improvement was accompanied by a substantial increase in the 6WT distance (case I: 358 m vs. 517 m and case II: 296 m vs. 625 m). One patient reported only moderate improvement in leg pain and conflicting results in the other PROMs. The 6WT demonstrated a persistent OFI (487 m vs. 488 m). This patient was considered a nonresponder and underwent surgical treatment. This case series illustrates the feasibility of the smartphone-based 6WT as a tool to assess OFI in patients undergoing ESI for lumbar DDD.

Gender differences in the surgical management of lumbar degenerative disease: a scoping review.

OBJECTIVE: Despite efforts toward achieving gender equality in clinical trial enrollment, females are often underrepresented, and gender-specific data analysis is often unavailable. Identifying and reducing gender bias in medical decision-making and outcome reporting may facilitate equitable healthcare delivery. Gender disparity in the utilization of surgical therapy has been exemplified in the orthopedic literature through studies of total joint arthroplasty. A paucity of literature is available to guide the management of lumbar degenerative disease, which stratifies on the basis of demographic factors. The objective of this study was to systematically map and synthesize the adult surgical literature regarding gender differences in pre- and postoperative patient-reported clinical assessment scores for patients with lumbar degenerative disease (disc degeneration, disc herniation, spondylolisthesis, and spinal canal stenosis). METHODS: A systematic scoping review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines. MEDLINE, Embase, and the Cochrane Registry of Controlled Trials were searched from inception to September 2018. Study characteristics including patient demographics, diagnoses, procedures, and pre- and postoperative clinical assessment scores (pain, disability, and health-related quality of life [HRQoL]) were collected. RESULTS: Thirty articles were identified, accounting for 32,951 patients. Six studies accounted for 84% of patients; 5 of the 6 studies were published by European groups. The most common lumbar degenerative conditions were disc herniation (59.0%), disc degeneration (20.3%), and spinal canal stenosis (15.9%). The majority of studies reported worse preoperative pain (93.3%), disability (81.3%), and HRQoL (75%) among females. The remainder reported equivalent preoperative scores between males and females. The majority of studies (63.3%) did not report preoperative duration of symptoms, and this represents a limitation of the data. Eighty percent of studies found that females had worse absolute postoperative scores in at least one outcome category (pain, disability, or HRQoL). The remainder reported equivalent absolute postoperative scores between males and females. Seventy-three percent of studies reported either an equivalent or greater interval change for females. CONCLUSIONS: Female patients undergoing surgery for lumbar degenerative disease (disc degeneration, disc herniation, spondylolisthesis, and spinal canal stenosis) have worse absolute preoperative pain, disability, and HRQoL. Following surgery, females have worse absolute pain, disability, and HRQoL, but demonstrate an equal or greater interval change compared to males. Further studies should examine gender differences in preoperative workup and clinical course.

Lower Extremity Motor Deficits Are Underappreciated in Patient-Reported Outcome Measures: Added Value of Objective Outcome Measures.

OBJECTIVE: The patient-reported outcome measure (PROM)-based evaluation in lumbar degenerative disc disease (DDD) is today's gold standard but has limitations. We studied the impact of lower extremity motor deficits (LEMDs) on PROMs and a new objective outcome measure. METHODS: We evaluated patients with lumbar DDD from a prospective 2-center database. LEMDs were graded according to the British Medical Research Council (BMRC; 5 [normal] -0 [no movement]). The PROM-based evaluation included pain (visual analogue scale), disability (Oswestry Disability Index [ODI] & Roland-Morris Disability Index [RMDI]), and health-related quality of life (HRQoL; Short-Form 12 physical component summary/mental component summary & EuroQol-5D index). Objective functional impairment (OFI) was determined as age- and sex-adjusted Timed-Up and Go (TUG) test value. RESULTS: One hundred five of 375 patients (28.0%) had a LEMD. Patients with LEMD had slightly higher disability (ODI: 52.8 vs. 48.2, p = 0.025; RMDI: 12.6 vs. 11.3, p = 0.034) but similar pain and HRQoL scores. OFI T-scores were significantly higher in patients with LEMD (144.2 vs. 124.3, p = 0.006). When comparing patients with high- (BMRC 0-2) vs. low-grade LEMD (BMRC 3-4), no difference was evident for the PROM-based evaluation (all p > 0.05) but patients with high-grade LEMD had markedly higher OFI T-scores (280.9 vs. 136.0, p = 0.001). Patients with LEMD had longer TUG test times and OFI T-scores than matched controls without LEMDs. CONCLUSION: Our data suggest that PROMs fail to sufficiently account for LEMD-associated disability, which is common and oftentimes bothersome to patients. The objective functional evaluation with the TUG test appears to be more sensitive to LEMD-associated disability. An objective functional evaluation of patients with LEMD appears reasonable.

Objective functional impairment in lumbar degenerative disease: concurrent validity of the baseline severity stratification for the five-repetition sit-to-stand test.

OBJECTIVE: The five-repetition sit-to-stand (5R-STS) test provides a new dimension of clinical assessment by capturing objective functional impairment (OFI). Through the utilization of data from two prospective studies, the authors sought to evaluate the concurrent validity of the proposed 5R-STS baseline severity stratification (BSS) for OFI with the following levels based on time to completion in seconds: none, ≤ 10.4; mild, 10.5-15.2; moderate, 15.3-22.0; and severe, > 22.0 seconds. METHODS: Patients with degenerative diseases of the spine performed the 5R-STS test and completed visual analog scales (VASs) for back and leg pain, the Oswestry Disability Index (ODI), the Roland-Morris Disability Questionnaire (RMDQ), and EQ-5D questionnaires. The degree of OFI severity was assessed based on the previously proposed BSS, and its association with patient-reported scales was evaluated using ANOVA as well as crude and adjusted linear regression models. RESULTS: Our sample included 240 patients, of whom 101 exhibited no OFI, whereas 80, 34, and 25 were judged to have mild, moderate, and severe OFI, respectively. A higher baseline severity was strongly associated with loss of working ability (p < 0.001), as well as results of all patient-reported scales (p ≤ 0.001), with the exception of the VAS for leg pain (p = 0.556). Crude and adjusted regression analyses corroborated these findings, although only patients with moderate and severe OFI as judged by using the 5R-STS BSS demonstrated clinically relevant differences compared with patients without OFI. CONCLUSIONS: The degree of OFI-based on the 5R-STS BSS-is strongly associated with measures of back pain, subjective functional impairment, and health-related quality of life. However, leg pain severity is not reflected within the dimension of OFI measured by the 5R-STS. The proposed BSS appears to be a concurrently valid and clinically relevant measure of OFI in patients with degenerative spinal pathologies.

Reliability of the 6-minute walking test smartphone application.

OBJECTIVE: Objective functional measures such as the 6-minute walking test (6WT) are increasingly applied to evaluate patients with degenerative diseases of the lumbar spine before and after (surgical) treatment. However, the traditional 6WT is cumbersome to apply, as it requires specialized in-hospital infrastructure and personnel. The authors set out to compare 6-minute walking distance (6WD) measurements obtained with a newly developed smartphone application (app) and those obtained with the gold-standard distance wheel (DW). METHODS: The authors developed a free iOS- and Android-based smartphone app that allows patients to measure the 6WD in their home environment using global positioning system (GPS) coordinates. In a laboratory setting, the authors obtained 6WD measurements over a range of smartphone models, testing environments, and walking patterns and speeds. The main outcome was the relative measurement error (rME; in percent of 6WD), with |rME| < 7.5% defined as reliable. The intraclass correlation coefficient (ICC) for agreement between app- and DW-based 6WD was calculated. RESULTS: Measurements (n = 406) were reliable with all smartphone types in neighborhood, nature, and city environments (without high buildings), as well as with unspecified, straight, continuous, and stop-and-go walking patterns (ICC = 0.97, 95% CI 0.97-0.98, p < 0.001). Measurements were unreliable indoors, in city areas with high buildings, and for predominantly rectangular walking courses. Walking speed had an influence on the ME, with worse accuracy (2% higher rME) for every kilometer per hour slower walking pace (95% CI 1.4%-2.5%, p < 0.001). Mathematical adjustment of the app-based 6WD for velocity-dependent error mitigated the rME (p < 0.011), attenuated velocity dependence (p = 0.362), and had a positive effect on accuracy (ICC = 0.98, 95% CI 0.98-0.99, p < 0.001). CONCLUSIONS: The new, free, spine-specific 6WT smartphone app measures the 6WD conveniently by using GPS coordinates, empowering patients to independently determine their functional status before and after (surgical) treatment. Measurements of 6WD obtained for the target population under the recommended circumstances are highly reliable.

Objective functional assessment using the "Timed Up and Go" test in patients with lumbar spinal stenosis.

OBJECTIVEPatient-reported outcome measures (PROMs) are standard of care for the assessment of functional impairment. Subjective outcome measures are increasingly complemented by objective ones, such as the "Timed Up and Go" (TUG) test. Currently, only a few studies report pre- and postoperative TUG test assessments in patients with lumbar spinal stenosis (LSS).METHODSA prospective two-center database was reviewed to identify patients with LSS who underwent lumbar decompression with or without fusion. The subjective functional status was estimated using PROMs for pain (visual analog scale [VAS]), disability (Roland-Morris Disability Index [RMDI] and Oswestry Disability Index [ODI]), and health-related quality of life (HRQoL; 12-Item Short-Form Physical Component Summary [SF-12 PCS] and the EQ-5D) preoperatively, as well as on postoperative day 3 (D3) and week 6 (W6). Objective functional impairment (OFI) was measured using age- and sex-standardized TUG test results.RESULTSSixty-four patients (n = 32 [50%] male, mean age 66.8 ± 11.7 years) were included. Preoperatively, they reported a mean VAS back pain score of 4.1 ± 2.7, VAS leg pain score of 5.4 ± 2.7, RMDI of 10.4 ± 5.3, ODI of 41.9 ± 16.2, SF-12 PCS score of 32.7 ± 8.3, and an EQ-5D index of 0.517 ± 0.226. The preoperative rates of severe, moderate, and mild OFI were 4.7% (n = 3), 12.5% (n = 8), and 7.8% (n = 5), respectively, and the mean OFI T-score was 116.3 ± 23.7. At W6, 60 (93.8%) of 64 patients had a TUG test result within the normal population range (no OFI); 3 patients (4.7%) had mild and 1 patient (1.6%) severe OFI. The mean W6 OFI T-score was significantly decreased (103.1 ± 13.6; p < 0.001). Correspondingly, the PROMs showed a decrease in subjective VAS back pain (1.6 ± 1.7, p < 0.001) and leg pain (1.0 ± 1.8, p < 0.001) scores, disability (RMDI 5.3 ± 4.7, p < 0.001; ODI 21.3 ± 16.1, p < 0.001), and increase in HRQoL (SF-12 PCS 40.1 ± 8.3, p < 0.001; EQ-5D 0.737 ± 0.192, p < 0.001) at W6. The W6 responder status (clinically meaningful improvement) ranged between 81.3% (VAS leg pain) and 29.7% (EQ-5D index) of patients.CONCLUSIONSThe TUG test is a quick and easily applicable tool that reliably measures OFI in patients with LSS. Objective tests incorporating longer walking time should be considered if OFI is suspected but fails to be proven by the TUG test, taking into account that neurogenic claudication may not clinically manifest during the brief TUG examination. Objective tests do not replace the subjective PROM-based assessment, but add valuable information to a comprehensive patient evaluation.

Objective measures of functional impairment for degenerative diseases of the lumbar spine: a systematic review of the literature.

BACKGROUND CONTEXT: The accurate determination of a patient's functional status is necessary for therapeutic decision-making and to critically appraise treatment efficacy. Current subjective patient-reported outcome measure (PROM)-based assessments have limitations and can be complimented by objective measures of function. PURPOSE: To systematically review the literature and provide an overview on the available objective measures of function for patients with degenerative diseases of the lumbar spine. STUDY DESIGN/SETTING: Systematic review of the literature. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Two reviewers independently searched the PubMed, Web of Science, EMBASE, and SCOPUS databases for permutations of the words "objective," "assessment," "function," "lumbar," and "spine" including articles on human subjects with degenerative diseases of the lumbar spine that reported on objective measures of function, published until September 2018. Risk of bias was not assessed. No funding was received. The authors report no conflicts of interest. RESULTS: Of 2,389 identified articles, 82 were included in the final analysis. There was a significant increase of 0.12 per year in the number of publications dealing with objective measures of function since 1989 (95% CI 0.08-0.16, p<.001). Some publications studied multiple diagnoses and objective measures. The United States was the leading nation in terms of scientific output for objective outcome measures (n=21; 25.6%), followed by Switzerland (n=17; 20.7%), Canada, Germany, and the United Kingdom (each n=6; 7.3%). Our search revealed 21 different types of objective measures, predominantly applied to patients with lumbar spinal stenosis (n=67 publications; 81.7%), chronic/unspecific low back pain (n=28; 34.2%) and lumbar disc herniation (n=22; 26.8%). The Timed-Up-and-Go test was the most frequently applied measure (n=26 publications; 31.7%; cumulative number of reported subjects: 5,181), followed by the Motorized Treadmill Test (n=25 publications; 30.5%, 1,499 subjects) and with each n=9 publications (11.0%) the Five-Repetition Sit-To-Stand test (955 subjects), as well as accelerometry analyses (336 subjects). The reliability and validity of many of the less-applied objective measures was uncertain. There was profound heterogeneity in their application and interpretation of results. CONCLUSIONS: Clinical studies on patients with lumbar degenerative diseases increasingly employ objective measures of function, which offer high potential for improving the quality of outcome measurement in patient-care and research. This review provides an overview on available options. Our findings call for an agreement and standardization in terms of test selection, conduction and analysis to facilitate comparison of results across cohorts. PROSPERO REGISTRATION NUMBER: CRD42019122622.

Can objective functional impairment in lumbar degenerative disease be reliably assessed at home using the five-repetition sit-to-stand test? A prospective study.

PURPOSE: Objective functional tests like the five-repetition sit-to-stand test (5R-STS) can supplement an objective dimension to conventional patient-reported outcome measures. The reliability of unsupervised obtainment of 5R-STS performance is currently unknown. METHODS: We included patients with degenerative pathologies of the lumbar spine. Patients performed the 5R-STS during the initial clinical visit (supervised), as well as at home after instruction by a physiotherapist. At home, patients were first timed by a relative (unsupervised) and subsequently produced a video recording of themselves performing the 5R-STS for digital measurement (telesupervised). Two raters independently assessed the recordings. RESULTS: One hundred and twenty-one patients were recruited, of which 100 were eligible. Eighty-eight reported unsupervised results. Sixty-four returned recordings, of which 61 were ratable. Both unsupervised (r: 0.94, 95% CI 0.91-0.96, p < 0.001) and telesupervised (r: 0.90, 95% CI 0.83-0.94, p < 0.001) measurements demonstrated excellent correlation with clinical test times. Patients did not perform more slowly at home (p > 0.05). The interrater agreement for digital judgement of the telesupervised recording was excellent (ICC: 0.996, 95% CI 0.993-0.998, p < 0.001). We confirmed convergent validity with self-reported disability, back pain, and quality of life (all p < 0.05), but not with leg pain (p = 0.189). CONCLUSIONS: Unsupervised at-home assessment using the 5R-STS is highly reliable. There does not appear to be a specific need for patients to return for a supervised 5R-STS follow-up. Rather, instructions can be provided, and the test performed and rated by a partner or family member at home. This is logistically and economically advantageous for patients, clinicians, and researchers. TRIAL REGISTRY NUMBER: ClinicalTrials.gov Identifier: NCT03321357. These slides can be retrieved under Electronic Supplementary Material.