Association between widespread pain and psychosocial factors in people with knee osteoarthritis: a cross-sectional study of patients from primary care in Denmark.

INTRODUCTION: The relationship between psychosocial factors and bodily pain in people with knee osteoarthritis (KOA) is unclear. PURPOSE: To examine whether widespread pain was associated with poorer self-efficacy, more anxiety, depression, and kinesiophobia in people with KOA. METHODS: This was a cross-sectional study based on data from Good Life with osteoArthritis in Denmark (GLA:D®). The association between widespread pain (multiple pain sites) and self-efficacy (Arthritis Self-Efficacy Scale), anxiety and depression (item from the EQ-5D-5 L), and kinesiophobia (yes/no) was examined using multiple linear tobit or logistic regression models. RESULTS: Among 19,323 participants, 10% had no widespread pain, 37% had 2 pain sites, 26% had 3-4 pain sites, and 27% had ≥5 pain sites. Widespread pain was associated with poorer self-efficacy (-0.9 to -8.3 points), and the association was stronger with increasing number of pain sites (p-value <.001). Significant increasing odds ratios (ORs) were observed for having anxiety or depression with 3-4 pain sites (OR 1.29, 95% CI 1.12; 1.49) and ≥5 pain sites (OR 1.80, 95% CI 1.56; 2.07). Having 2 and 3-4 pain sites were associated with lower odds of kinesiophobia compared to having no widespread pain. CONCLUSION: Widespread pain was associated with lower self-efficacy and more anxiety and depression but also lower kinesiophobia in people with KOA.

GLA:D to Be Walking Better: Change in Self-Reported Difficulty Walking After Exercise Therapy and Education in Persons With Knee Osteoarthritis.

OBJECTIVE: Difficulty walking is a primary reason that individuals with knee osteoarthritis (OA) seek care. We examined the change in self-reported difficulty walking after participating in the Good Life With Osteoarthritis in Denmark (GLA:D) 8-week education and exercise program and assessed patient factors associated with improvement in difficulty walking. METHODS: This was a registry-based cohort study of individuals in Denmark with knee OA who enrolled in GLA:D. Assessments were administered at baseline, program completion (~3 months), and 12 months. Our prespecified primary outcome was change in self-reported difficulty walking assessed using the EuroQol 5-dimension 5-level walking item. Exposures included sociodemographic factors, measures of OA illness severity, comorbidities, and psychological factors. In those with baseline moderate/severe difficulty walking, using multivariable regression analysis, we assessed the relationship between exposures of interest and improvement to no/slight difficulty walking. RESULTS: We included 5262 participants. Of 2178 (41.4%) individuals with baseline moderate/severe difficulty walking, 51.4% and 58.3% reported no/slight difficulty walking at 3 and 12 months, respectively. Greater self-efficacy, younger age, female sex, lower BMI, less intense knee pain, and better function at baseline were associated with greater likelihood of improvement in difficulty walking, whereas severe difficulty walking at baseline and back pain intensity were associated with decreased likelihood of improvement. CONCLUSION: More than half of those with baseline difficulty walking experienced substantial improvement after completing GLA:D and this improvement was maintained at 12 months. Several patient factors were associated with the outcome, suggesting that some individuals may require additional support and extended treatment.

Patient Acceptable Symptom State Thresholds for IKDC-SKF and KOOS at the 10-Year Follow-up After Anterior Cruciate Ligament Injury: A Study From the Delaware-Oslo ACL Cohort.

Background: Clinicians need thresholds for the Patient Acceptable Symptom State (PASS) and Treatment Failure to interpret group-based patient-reported outcome measures after anterior cruciate ligament (ACL) injury. Validated thresholds that are crucial for accurately discerning patient symptom state and facilitating effective interpretation have not been determined for long-term follow-up after ACL injury. Purpose: To calculate and validate thresholds for PASS and Treatment Failure for the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) and the Knee injury and Osteoarthritis Outcome Score (KOOS) subscales at the 10-year follow-up after ACL injury. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 163 participants with unilateral ACL injury (treated with reconstruction or rehabilitation alone) from the Delaware-Oslo ACL Cohort were included. Thresholds for PASS were calculated for IKDC-SKF and KOOS subscales using anchor-based predictive modeling and receiver operating characteristic (ROC) analysis. Too few participants had self-reported Treatment Failure to calculate thresholds for that outcome. Nonparametric bootstrapping was used to derive 95% CIs. The criterion validity of the predictive modeling and ROC-derived thresholds were assessed by comparing actual patient-reported PASS outcome with the calculated PASS outcome for each method of calculation and calculating their positive and negative predictive values with respect to the anchor questions. Results: A total of 127 (78%) participants reported satisfactory symptom state. Predictive modeling PASS thresholds (95% CIs) were 76.2 points (72.1-79.4 points) for IKDC-SKF, 85.4 points (80.9-89.2 points) for KOOS Pain, 76.5 points (67.8-84.7 points) for KOOS Symptoms, 93.8 points (90.1-96.9 points) for KOOS activities of daily living, 71.6 points (63.4-77.7 points) for KOOS Sports, and 59.0 points (53.7-63.9 points) for KOOS quality of life (QoL). Predictive modeling thresholds classified 81% to 93% of the participants as having satisfactory symptom state, whereas ROC-derived thresholds classified >50% as unsatisfied. The thresholds for IKDC-SKF, KOOS Sports, and KOOS QoL resulted in the most accurate percentages of PASS among all identified thresholds and therefore demonstrate the highest validity. Conclusion: Predictive modeling provided valid PASS thresholds for IKDC-SKF and KOOS at the 10-year follow-up after ACL injury. The thresholds for IKDC-SKF, KOOS Sports, and KOOS QoL should be used when determining satisfactory outcomes. ROC-derived thresholds result in substantial misclassification rates of the participants who reported satisfactory symptom state.

Recruitment and baseline characteristics of young adults at risk of early-onset knee osteoarthritis after ACL reconstruction in the SUPER-Knee trial.

Objectives: The study aims to (1) report the process of recruiting young adults into a secondary knee osteoarthritis prevention randomised controlled trial (RCT) after anterior cruciate ligament reconstruction (ACLR); (2) determine the number of individuals needed to be screened to include one participant (NNS) and (3) report baseline characteristics of randomised participants. Methods: The SUpervised exercise-therapy and Patient Education Rehabilitation (SUPER)-Knee RCT compares SUPER and minimal intervention for young adults (aged 18-40 years) with ongoing symptoms (ie, mean score of <80/100 from four Knee injury and Osteoarthritis Outcome Score subscales (KOOS4)) 9-36 months post-ACLR. The NNS was calculated as the number of prospective participants screened to enrol one person. At baseline, participants provided medical history, completed questionnaires (demographic, injury/surgery, rehabilitation characteristics) and underwent physical examination. Results: 1044 individuals were screened to identify 567 eligible people, from which 184 participants (63% male) enrolled. The sample of enrolled participants was multicultural (29% born outside Australia; 2% Indigenous Australians). The NNS was 5.7. For randomised participants, mean±SD age was 30±6 years. The mean body mass index was 27.3±5.2 kg/m2, with overweight (43%) and obesity (21%) common. Participants were, on average, 2.3 years post-ACLR. Over half completed <8 months of postoperative rehabilitation, with 56% having concurrent injury/surgery to meniscus and/or cartilage. The most affected KOOS (0=worst, 100=best) subscale was quality of life (mean 43.7±19.1). Conclusion: Young adults post-ACLR were willing to participate in a secondary osteoarthritis prevention trial. Sample size calculations should be multiplied by at least 5.7 to provide an estimate of the NNS. The SUPER-Knee cohort is ideally positioned to monitor and intervene in the early development and trajectory of osteoarthritis. Trial registration number: ACTRN12620001164987.

Assessing the efficacy of the Stop OsteoARthritis (SOAR) program: A randomized delayed-controlled trial in persons at increased risk of early onset post-traumatic knee osteoarthritis.

OBJECTIVE: Assess the efficacy of an 8-week virtual, physiotherapist (PT)-guided knee health program (Stop OsteoARthritis (SOAR)) to improve knee extensor strength in individuals at risk of post-traumatic knee osteoarthritis (PTOA). METHOD: In this superiority, randomized delayed-control trial, persons aged 16-35 years, 1-4 years after a self-reported knee joint injury were randomly assigned (1:1) to receive the SOAR program immediately (experimental group) or after a 9-week delay (control group). SOAR includes 1) one-time Knee Camp (virtual PT-guided group education, knee assessment, 1:1 exercise and physical activity (PA) goal-setting); 2) Weekly personalized home-based exercise and PA program with tracking; 3) Weekly 1:1 PT counseling (virtual). The primary outcome was a change in isokinetic knee extensor strength (baseline to 9-weeks). Additional outcomes included change in self-reported knee-related quality-of-life (QOL), self-efficacy, self-management and kinesiophobia, and PA (accelerometer) at 9 and 18-weeks. Linear regression models estimated the effect of the 8-week intervention at the primary endpoint (9-week). RESULTS: 49 of 54 randomized participants completed the study (91%). Participants were a mean ± standard deviation age of 27 ± 5.0 years, and 2.4 ± 0.9 years post-injury. No mean between group differences for the primary (0.05; 95% confidence interval (CI): -0.10, 0.19) or other outcomes were seen at 9 weeks except for greater improvements in perceived self-management (Partner in Health Scale; 11.3/96, 95%CI: 5.5, 17.1) and kinesiophobia (Tampa Scale of Kinesiophobia; -4.4/33, 95%CI: -7.0, -1.8). CONCLUSION: For active persons with elevated risk of PTOA, an 8-week SOAR program did not change knee-related strength, QOL, self-efficacy, or PA, on average, but may benefit the ability to self-manage knee health and kinesiophobia.

Are Outcomes From an Exercise Therapy and Patient Education Program for Osteoarthritis Associated With Hip and Knee Replacement Within Two Years? A Register-Based Study of 9,339 Patients With Osteoarthritis.

OBJECTIVE: The objective of this study was to determine whether short-term outcomes from exercise therapy and patient education for osteoarthritis (OA) are associated with hip or knee replacement within two years. METHODS: Individual-level data from the Good Life with osteoArthritis in Denmark (GLA:D) Registry were linked to the Danish National Patient Registry and other national registries. Cox proportional hazards models were used to investigate associations between program outcomes (baseline to three-month changes) and time to primary hip or knee replacement. Patients who did not receive joint replacement were censored at two years, time of death, or emigration. RESULTS: A total of 2,304 and 7,035 patients with clinically diagnosed hip and knee OA, respectively, were included. Of these, 30% with hip OA and 10% with knee OA had joint replacement within two years. Postprogram improvements in hip-related quality of life and arthritis self-efficacy (pain subscale) were associated with a reduced hazard of hip replacement (adjusted hazard ratios [HRs] for a 10-unit improvement: 0.74 [95% confidence interval (CI) 0.69-0.80] and 0.90 [95% CI 0.85-0.96], respectively). Improvements in knee pain, knee-related quality of life, and arthritis self-efficacy (pain subscale) were associated with a lower hazard of knee replacement (adjusted HRs for 10-unit improvement: 0.81 [95% CI 0.76-0.86] to 0.90 [95% CI 0.86-0.95], 0.70 [95% CI 0.63-0.78] to 0.79 [95% CI 0.72-0.86], and 0.89 [95% CI 0.83-0.94], respectively). CONCLUSION: The magnitude of improvement in key measures after exercise therapy and education was significantly associated with the likelihood of surgery. Progression to hip replacement was three times higher than progression to knee replacement. This information can guide patient-clinician conversations around anticipated program outcomes.

Use of prescribed analgesics before and after exercise therapy and patient education in patients with knee or hip osteoarthritis.

The aim of this study was to investigate utilisation patterns of prescribed analgesics before, during, and after an exercise therapy and patient education program among patients with knee or hip osteoarthritis. This cohort study is based on data from the nationwide Good Life with osteoarthritis in Denmark (GLA:D®) patient-register linked with national health registries including data on prescribed analgesics. GLA:D® consists of 8-12 weeks of exercise and patient education. We included 35,549 knee/hip osteoarthritis patients starting the intervention between January 2013 and November 2018. Utilisation patterns the year before, 3 months during, and the year after the intervention were investigated using total dispensed defined daily doses (DDDs) per month per 1000 population as outcome. During the year before the intervention, use of prescribed paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), and opioids increased with 85%, 79% and 22%, respectively. During the intervention, use of paracetamol decreased with 16% with a stable use the following year. Use of NSAIDs and opioids decreased with 38% and 8%, respectively, throughout the intervention and the year after. Sensitivity analyses indicated that the prescription of most analgesics changed over time. For paracetamol, NSAIDs, and opioids, 10% of analgesic users accounted for 45%, 50%, and 70%, respectively, of the total DDDs dispensed during the study period. In general, analgesic use increased the year before the intervention followed by a decrease during the intervention and the year after. A small proportion of analgesic users accounted for half or more of all paracetamol, NSAIDs, and opioids dispensed during the study period.

30 years with the Knee injury and Osteoarthritis Outcome Score (KOOS).

This narrative review describes the development and use of patient-reported outcomes over 30 years, focusing on the Knee injury and Osteoarthritis Outcome Score (KOOS). KOOS is a five-subscale patient-reported instrument intended for use from the time of knee injury to the development of osteoarthritis. Numerous studies have confirmed that the psychometric properties of the KOOS and its short-form KOOS-12 are acceptable. More recent research has focused on the use and interpretation of KOOS scores in clinical trials using thresholds, such as minimal important differences, patient-acceptable symptom states, and treatment failure. As an indication of KOOS's popularity, the total 3854 PubMed results for KOOS have increased exponentially since the first KOOS paper was published 25 years ago and now seem to have plateaued at around 650 annually. The selected articles are not based on a systematic search, but on the author's own publications, reading, and literature search that grew organically from that.

Foot and Ankle Outcome Score (FAOS): Reference Values From a National Representative Sample.

Background: The Foot and Ankle Outcome Score (FAOS) is widely used in clinical practice and research. However, FAOS reference values are missing to aid interpretation. This study aimed to establish national record-based reference values for the FAOS. Methods: A national representative sample of 9996 adult Danish citizens was derived from the Danish Civil Registration System. The FAOS questionnaire was sent to all participants, including 2 supplemental questions regarding previous foot and ankle problems and body mass index (BMI). A threshold of 10 FAOS points was predefined as a clinically relevant difference across all 5 subscales. Results: A total of 2759 participants completed the FAOS. Mean age of participants was 60.5 years, and 51% were women. The mean FAOS subscale scores were as follows: pain, 87.1 (95% CI 86.4-87.8); symptoms, 85.1 (95% CI 84.5-85.8); activity of daily living (ADL), 88.9 (95% CI 88.2-89.6); sport and recreation function 78.5 (95% CI 77.4-79.6); and quality of life (QOL), 79.9 (95% CI 79.0-80.9). The mean difference between men and women was small and not clinically relevant (ranged from 0.9 in ADL to 3.4 in QOL). The largest differences in mean scores between age groups ranged from 4.3 in symptoms to 16.4 in sport/rec. Except for the subscale sport/rec, all age-related differences were below the predefined threshold of 10 for clinical relevance. The difference in mean subscale scores between the lowest BMI group (<24.7) and the obese group (>30) ranged from 19.6 in ADL to 39.1 in sport/rec. Conclusion: We found in our population that BMI severely impacted FAOS scores. We recommend using BMI-specific reference FAOS values. Separate FAOS reference values for men and women appear not needed. Stratifying reference values for age is likely not needed except for the subscale sport and recreation function. Level of evidence: Level III, cohort study.

The prevalence of foot pain and association with baseline characteristics in people participating in education and supervised exercise for knee or hip osteoarthritis: a cross-sectional study of 26,003 participants from the GLA:D® registry.

BACKGROUND: Osteoarthritis (OA) affecting the knee or hip is highly prevalent in the general population and has associated high disease burden. Early identification of modifiable risk factors that prevent, limit, or resolve disease symptoms is critical. Foot pain may represent a potentially modifiable factor however little is known about the prevalence of foot pain in people with knee or hip OA nor whether foot pain is associated with clinical characteristics. The main aim of this study was therefore to determine the prevalence of foot pain in people with knee or hip OA attending an education and supervised exercise-based intervention in Denmark (GLA:D®) and determine if baseline demographic or clinical characteristics are associated with foot pain. METHODS: Analysis was conducted on baseline data of 26,003 people with symptomatic knee or hip OA completing a pain mannequin as part of the Good Life with osteoArthritis in Denmark (GLA:D®) primary care programme. Odds Ratios (OR) and 95% confidence intervals (CI) were calculated to estimate the strength of association between baseline clinical characteristics (including pain severity in worst knee/hip joint, number of painful knee/hip joints, pain medication use and physical activity level) and the presence of baseline foot pain. RESULTS: Twelve percent of participants (n = 3,049) reported foot pain. In those people with index knee OA (n = 19,391), knee pain severity (OR 1.01 CI 1.00, 1.01), number of painful knee/hip joints (OR 1.67 CI 1.58, 1.79), and use of pain medication (OR 1.23 CI 1.12, 1.36) were statistically associated with foot pain. Excluding use of pain medication, similar associations were seen in those with index hip OA. CONCLUSION: Twelve percent of people with knee or hip OA participating in GLA:D® had foot pain. Those with worse knee/hip pain, and greater number of painful joints were more likely to report foot pain. This study is the first to demonstrate a significant relationship between clinical characteristics and foot pain in people with knee or hip OA participating in education and supervised exercise. Future investigation should consider the role that foot pain may play on knee and hip related outcomes following therapeutic intervention.

Knee Injury and Osteoarthritis Outcome Score Interpretation Thresholds at 3 and 12 Months After Arthroscopic Meniscal Surgery. What Changes, and What Stays the Same?

OBJECTIVE: To evaluate the change in minimal important change (MIC), patient acceptable symptom state (PASS), and treatment failure (TF) thresholds for the Knee injury and Osteoarthritis Outcome Score (KOOS) from 3 to 12 months following arthroscopic meniscus surgery. DESIGN: Retrospective cohort study. METHODS: We included patients from the Knee Arthroscopy Cohort Southern Denmark who had meniscus surgery between 2013 and 2015. We calculated the interpretation threshold values for MIC, PASS, and TF using an anchor-based adjusted predictive modeling method. Thresholds at 3 and 12 months postoperatively were compared to evaluate changes over time. RESULTS: The proportions of people who reported a clinically relevant improvement, or their symptoms being acceptable, increased by 10% to 15% points from 3 to 12 months after surgery. MIC thresholds for the 5 KOOS subscales remained stable from 3 to 12 months with statistically nonsignificant differences (95% confidence intervals) ranging from -0.3 (-3.0, 2.6) to -2.4 (-6.1, 1.3). All PASS thresholds except for quality of life (QOL) decreased by -6.5 (-11.8, -1.5) to -3.7 (-7.1, -0.4) points, indicating that higher symptom levels were accepted at 12 months. In contrast, the proportion reporting their treatment to have failed remained stable over time (19% and 17%). For QOL, a 7.4 (2.0, 13.2) higher TF threshold at 12 months suggested that improved QOL was required to not consider that the treatment had failed. CONCLUSION: More patients reported being improved at 1 year compared to at 3 months following meniscus surgery. The KOOS MIC thresholds were stable over time, whereas time-specific PASS values should be applied after meniscus surgery. J Orthop Sports Phys Ther 2023;53(11):685-702. Epub 3 October 2023. doi:10.2519/jospt.2023.11993.

An early care void: The injury experience and perceptions of treatment among knee-injured individuals and healthcare professionals - A qualitative interview study.

OBJECTIVES: To better comprehend the initial injury experience and care requirements of knee-injured individuals, as well as healthcare professionals' interactions with early care. DESIGN: Qualitative interviews. SETTING: Public healthcare in Denmark. PARTICIPANTS: Ten individuals (6 women) with major knee injuries (6 anterior cruciate ligament (ACL) and meniscal tears, 2 isolated ACL tears, 1 isolated meniscal tear, 1 patella dislocation), aged 16-33 years (median 19 years), 1-26 months post-injury (median 3 months). Thirteen HCPs (5 physiotherapists, 5 orthopedic surgeons, 3 general practitioners). MAIN OUTCOME MEASURE: Semi-structured individual and focus group interviews, transcribed verbatim and with latent thematic analysis. RESULTS: The three main themes were: 1) Emotional struggles in solitude - knee-injured individuals dealing with emotions alone due to limited HCP resources for emotional support. 2) Blurry beginning - knee-injured individuals finding initial care frustrating, a sentiment shared by HCPs. 3) A journey with no map - knee-injured individuals holding varied outcome expectations, while HCPs hesitate to discuss long-term knee health. CONCLUSION: Early care for knee-injured individuals is filled with worries and unmet emotional and information support needs. HCPs need more support and training to deliver timely and appropriate care.

Does the one-leg rise test reflect quadriceps strength in individuals following anterior cruciate ligament reconstruction?

OBJECTIVE: To explore if one-leg rise test performance is associated with quadriceps strength following anterior cruciate ligament reconstruction (ACLR). DESIGN: Cross-sectional. PARTICIPANTS: 100 individuals (50 females, 50 males) aged 18-40 years, 9-36 months post-ACLR with ongoing knee symptoms (KOOS4 <80/100). MAIN OUTCOME MEASURES: Number of one-leg rise repetitions (using an adjustable-height plinth) and isometric quadriceps strength using isokinetic dynamometry (60° flexion, normalised to body mass). Multivariable fractional polynomial regression models adjusted for sex explored relationships between one-leg rise performance (repetitions) and quadriceps strength (Nm/kg) for each limb. RESULTS: A non-linear, increasing association between one-leg rise performance and quadriceps strength was observed, with the rate of increase attenuating at higher values of one-leg rise performance. Similar relationships were observed in the ACLR (ß = 0.15, 95%CI 0.10 to 0.20; adjusted r2 = 0.51) and contralateral limb (ß = 0.14, 95%CI 0.08 to 0.19; r2 = 0.42). CONCLUSION: The one-leg rise test can be an indicator of quadriceps strength in individuals after ACLR, enabling clinicians to easily monitor quadriceps strength recovery without specialised equipment. With the relationship between one-leg rise performance and quadriceps strength attenuating with a larger number of one-leg rises achieved, other factors (e.g., motivation, endurance) likely contribute to one-leg rise performance at higher values.

Knee injury and osteoarthritis outcome score (KOOS) - National record-based reference values.

BACKGROUND: Knee Injury and Osteoarthritis Outcome Score (KOOS) and the short form KOOS-12 are commonly used in clinical practice and research but there are no national record-based reference values to aid interpretation. The aim of this study was to establish national record-based reference values for the KOOS and its short form KOOS-12. PATIENTS AND METHODS: A national record-based representative sample of 9996 adult citizens were derived from the Danish Civil Registration System. The selection of citizens was based on seven predefined age groups with an equal sex distribution across each age strata. The KOOS questionnaire was sent to all participants, together with two supplemental questions regarding previous knee problems and body mass index (BMI). RESULTS: A total of 2842 participants completed the KOOS, 1463 women (51.4%) and 1379 men (48.6%). The mean KOOS subscale scores were: pain 85.3 (95% confidence interval (CI): 84.6-85.9), symptoms 85.1 (95% CI: 84.5-85.8), activities of daily living (ADL) 86.7 (95% CI: 86.0-87.3), sport and recreation function 70.9 (95% CI: 69.8-72.0), quality of life (QOL) 74.9 (95% CI: 73.9-75.8).Age- and sex-specific reference values showed small differences in mean scores between the five KOOS subscales and all were below the threshold for clinically relevant improvement (10 points).Knee problems were associated with worse KOOS scores across all subscales. The difference in the mean subscale scores between the lowest (<24.9) and highest (>40) BMI groups ranged from 12.9 to 24.1. Comparable results were observed for KOOS-12. CONCLUSION: KOOS and KOOS-12 reference values can, in most situations, be used without stratification for age and sex. Sport/recreation reference values stratified for age and BMI may be of importance.

National population-based reference data for the Hip Disability and Osteoarthritis Outcome Score (HOOS).

INTRODUCTION: Interpretation of patient-reported outcome scores such as the Hip Disability and Osteoarthritis Outcome Score (HOOS) can be improved with use of reference values. The aim of the study was to establish population-based reference values for the HOOS' five subscales and its short-form HOOS-12. MATERIALS AND METHODS: A representative sample of 9997 Danish citizens 18 years and older were identified. The population record-based sample was based on seven predefined age groups and an equal sex distribution within each age group. A national secure electronic system was used to send the HOOS questionnaire and one supplementary question regarding previous hip complaints to all participants. RESULTS: 2277 participants completed the HOOS, 947 women (42%) and 1330 men (58%). The mean HOOS subscale scores were: pain 86.9 (95% CI 86.1-87.7), symptoms 83.7 (95% CI 82.9-84.5), ADL 88.2 (95% CI 87.5-89.0), sport and recreation function 83.1 (95% CI 82.0-84.1), QOL 82.7 (95% CI 81.8-83.6). The youngest age group reported better mean scores in four subscales compared to the oldest age group (pain 91.7 vs. 84.5, mean difference 7.2 95% CI 0.4-14.0), (ADL 94.6 points vs. 83.2, mean difference 11.4 95% CI 4.9-17.8), (sport and recreation function 91.5 points vs. 73.8 points, mean difference 17.7 95% CI 9.0-26.4), (QOL 88.9 points vs. 78.8, mean difference 10.1 points 95% CI 2.0-18.2). Participants with a self-reported hip complaint had worse HOOS scores across all subscales (mean difference range 22.1-34.6). Super obese patients (BMI > 40) had > 12.5 points worse scores across the five HOOS subscales. Results were similar for the HOOS-12. CONCLUSION: This study provides reference values for the HOOS and its short form HOOS-12. Results show that older patients and patients with a BMI over 40 have worse HOOS and HOOS-12 scores that may be of clinical importance in the interpretation of scores both when evaluating potential for improvement and post-treatment results.

Suitability of the animated activity questionnaire for use as computer adaptive test: establishing the AAQ-CAT.

PURPOSE: The animated activity questionnaire (AAQ) is a computer-based measure of activity limitations. To answer a question, patients choose the animation of a person performing an activity that matches their own level of limitation. The AAQ has not yet been tested for suitability to be applied as computer-adaptive test (CAT). Thus, the objective of this study was to develop and evaluate an AAQ-based CAT to facilitate the application of the AAQ in daily clinical care. METHODS: Patients (n = 1408) with hip/knee osteoarthritis from Brazil, Denmark, France, The Netherlands, Norway, Spain, and the UK responded to all 17 AAQ items. Assumptions of item-response theory (IRT) modelling were investigated. To establish item parameters for the CAT, a graded response model was estimated. To evaluate the performance of post-hoc simulated AAQ-based CATs, precision, test length, and construct validity (correlations with well-established measures of activity limitations) were evaluated. RESULTS: Unidimensionality (CFI = 0.95), measurement invariance (R2-change < 2%), and IRT item fit (S-X2 p > .003) of the AAQ were supported. Performing simulated CATs, the mean test length was more than halved (≤ 8 items), while the range of precise measurement (standard error ≤ 0.3) was comparable to the full AAQ. The correlations between original AAQ scores and three AAQ-CAT versions were ≥ 0.95. Correlations of AAQ-CAT scores with patient-reported and performance measures of activity limitations were ≥ 0.60. CONCLUSION: The almost non-verbal AAQ-CAT is an innovative and efficient tool in patients with hip/knee osteoarthritis from various countries, measuring activity limitations with lower respondent burden, but similar precision and construct validity compared to the full AAQ.

Characteristics associated with comorbid lumbar spinal stenosis symptoms in people with knee or hip osteoarthritis: an analysis of 9,136 good life with osteoArthritis in Denmark (GLA:D®) participants.

BACKGROUND: Previous studies have found that lumbar spinal stenosis (LSS) often co-occurs with knee or hip OA and can impact treatment response. However, it is unclear what participant characteristics may be helpful in identifying individuals with these co-occurring conditions. The aim of this cross-sectional study was to explore characteristics associated with comorbid symptoms of lumbar spinal stenosis (LSS) in people with knee or hip osteoarthritis (OA) enrolled in a primary care education and exercise program. METHODS: Sociodemographic, clinical characteristics, health status measures, and a self-report questionnaire on the presence of LSS symptoms was collected at baseline from the Good Life with osteoArthritis in Denmark primary care program for knee and hip OA. Cross-sectional associations between characteristics and the presence of comorbid LSS symptoms were assessed separately in participants with primary complaint of knee and hip OA, using domain-specific logistic models and a logistic model including all characteristics. RESULTS: A total of 6,541 participants with a primary complaint of knee OA and 2,595 participants with a primary complaint of hip OA were included, of which 40% and 50% reported comorbid LSS symptoms, respectively. LSS symptoms were associated with similar characteristics in knee and hip OA. Sick leave was the only sociodemographic variable consistently associated with LSS symptoms. For clinical characteristics, back pain, longer symptom duration and bilateral or comorbid knee or hip symptoms were also consistently associated. Health status measures were not consistently related to LSS symptoms. CONCLUSION: Comorbid LSS symptoms in people with knee or hip OA undergoing a primary care treatment program of group-based education and exercise were common and associated with a similar set of characteristics. These characteristics may help to identify people with co-occurring LSS and knee or hip OA, which can be used to help guide clinical decision-making.

Online and onsite supervised exercise therapy and education for individuals with knee osteoarthritis - A before and after comparison of two different care delivery models.

OBJECTIVE: To compare the 3 and 12-month changes on pain, function and quality of life between online and onsite delivery of Good Life with Osteoarthritis in Denmark (GLA:D® ) in individuals with knee osteoarthritis (OA). DESIGN: Non-inferior comparison of individuals with knee OA receiving physiotherapist-supervised online (TeleGLA:D) or onsite (GLA:D®) (12 exercise and 2 education sessions). The primary outcome was the baseline-to-3-month change on KOOS-12 summary score. Secondary outcomes were changes in KOOS-12 subscales pain, function and quality of life and pain intensity (Visual Analog Scale (VAS 0-100)) at 3 and 12 months; 40 m fast-paced walk and 30 s chair-stand at 3 months. Using mixed linear regressions, comparisons were adjusted for age, sex, BMI, comorbidities and number of knees and hips with OA. RESULTS: Over a 1-year period (May 2020-May 2021), we included data from 3789 participants (3701 GLA:D®; 88 TeleGLA:D). At 3 months, TeleGLA:D showed non-inferior change-scores to GLA:D® on KOOS-12 summary score; adjusted mean difference (90% Confidence Intervals (CI)) -2.40 (-5.55 to 0.75). For secondary outcomes, there was a statistically significant difference in change-scores, favouring TeleGLA:D in gait speed; adjusted mean difference (90%CI) 0.23 m/s (0.18-0.27). TeleGLA:D remained non-inferior to GLA:D® at 12 months. CONCLUSIONS: Online delivery of physiotherapist-supervised neuromuscular exercise and education for individuals with knee OA may be non-inferior to traditional onsite delivery in reducing pain and improving function and quality of life. The wide confidence intervals, baseline imbalance, loss to follow-up and the non-randomized design highlight the need for a confirmatory randomized controlled trial.