Changes in physical activity and the association between pain and physical activity - a longitudinal analysis of 17,454 patients with knee or hip osteoarthritis from the GLA:D® registry.

OBJECTIVE: Investigate change in physical activity following an 8-week education and exercise therapy program for patients with knee/hip osteoarthritis, focusing on those with low physical activity level. Furthermore, to evaluate associations between changes in pain intensity and physical activity. METHOD: Data from the Good Life with osteoArthritis in Denmark (GLA:D®) registry, at baseline, immediately after completion, and 12 months after entering the program was used. Measures of interest were UCLA activity scale (1-10) and Visual Analog Scale for pain intensity (0-100 mm). Changes in physical activity levels (low 1-4, moderate 5-6, and high 7-10) over three time points were investigated. Asymmetric fixed effects regression models were used to evaluate the association between clinically relevant change in pain (≥15 mm) and change in physical activity level from baseline to 12 months. RESULTS: 37% with low activity level at baseline (n = 4,836) and 69% of all patients (n = 17,454) reached or maintained at least a moderate physical activity level at follow-ups. Surprisingly, both an improvement (ß = 1.44, P < 0.001) and a worsening (ß = 1.18, P < 0.001) in pain intensity was associated with increased physical activity in low activity patients. For all patients a similar trend was observed (ß = 0.51, P < 0.001 and ß = 0.11, P = 0.215, respectively). CONCLUSION: In low active knee or hip OA patients, a third of patients participating in an education and exercise therapy program reached and maintained at least a moderate physical activity level for 1 year. The improvement in physical activity was not dependent on pain reduction.

Arthroscopic partial meniscectomy vs non-surgical or sham treatment in patients with MRI-confirmed degenerative meniscus tears: a systematic review and meta-analysis with individual participant data from 605 randomised patients.

OBJECTIVE: To identify subgroups of patients with magnetic resonance imaging (MRI)-confirmed degenerative meniscus tears who may benefit from arthroscopic partial meniscectomy (APM) in comparison with non-surgical or sham treatment. METHODS: Individual participant data (IPD) from four RCTs were pooled (605 patients, mean age: 55 (SD: 7.5), 52.4% female) as to investigate the effectiveness of APM in patients with MRI-confirmed degenerative meniscus tears compared to non-surgical or sham treatment. Primary outcomes were knee pain, overall knee function, and health-related quality of life, at 24 months follow-up (0-100). The IPD were analysed in a one- and two-stage meta-analyses. Identification of potential subgroups was performed by testing interaction effects of predefined patient characteristics (e.g., age, gender, mechanical symptoms) and APM for each outcome. Additionally, generalized linear mixed-model trees were used for subgroup detection. RESULTS: The APM group showed a small improvement over the non-surgical or sham group on knee pain at 24 months follow-up (2.5 points (95% CI: 0.8-4.2) and 2.2 points (95% CI: 0.9-3.6), one- and two-stage analysis, respectively). Overall knee function and health-related quality of life did not differ between the two groups. Across all outcomes, no relevant subgroup of patients who benefitted from APM was detected. The generalized linear mixed-model trees did also not identify a subgroup. CONCLUSIONS: No relevant subgroup of patients was identified that benefitted from APM compared to non-surgical or sham treatment. Since we were not able to identify any subgroup that benefitted from APM, we recommend a restrained policy regarding meniscectomy in patients with degenerative meniscus tears.

Knee and hip osteoarthritis are more alike than different in baseline characteristics and outcomes: a longitudinal study of 32,599 patients participating in supervised education and exercise therapy.

OBJECTIVE: Compare baseline characteristics and change in outcomes in patients with symptomatic knee or hip OA participating in patient education and exercise therapy. DESIGN: Longitudinal cohort study. Good Life with osteoArthritis in Denmark (GLA:D®) is an 8-week patient education and supervised exercise program delivered by certified clinicians. Changes in pain intensity, Knee injury/Hip disability Osteoarthritis Outcome Scores' subscale Quality of Life (K/HOOS QOL), EuroQoL 5-Dimensions 5-Level (EQ-5D) and 40 m walk test at ∼3 and 12 months were compared between knee and hip patients. RESULTS: 24,241 knee and 8,358 hip patients were included, with response rates of 75% and 60% at ∼3 and 12 months. Age, gender, symptom duration, pain medication use, pain intensity, physical function and quality of life were alike. More knee than hip patients were obese and had bilateral symptoms. At 3 months, clinically relevant improvements were seen in both knee and hip OA patients with clinically irrelevant between groups differences; 2.1 (1.5; 2.8) mm in pain intensity, -1.1 (-1.5; -0.7) point in K/HOOS QOL score, -0.010 (-0.013; -0.007) in EQ-5D index score and -0.02 (-0.02; -0.01) m/sec in walking speed. At 12 months the slight immediate differences were equalized. CONCLUSION: Patients presenting with knee and hip OA in primary care were on average more alike than different. Following treatment, clinically relevant improvements were seen in both knee and hip OA patients at 3 and 12 months. Patients with knee and hip OA should be prioritized alike for treatment with patient education and supervised exercise therapy.

Chronic opioid use before and after exercise therapy and patient education among patients with knee or hip osteoarthritis.

OBJECTIVE: To investigate changes in opioid use after supervised exercise therapy and patient education among knee or hip osteoarthritis patients with chronic opioid use. METHOD: In this cohort study, we linked data from the Good Life with osteoArthritis in Denmark register (GLA:D®; standardised treatment program for osteoarthritis; January 2013 to November 2018) with national health registries. Among 35,549 patients, 1,262 were classified as chronic opioid users based on amount and temporal distribution of dispensed opioids the year before the intervention. We investigated changes in opioid use, measured as mg oral morphine equivalents (OMEQs), from the year before the intervention to the year after using generalized estimating equations. RESULTS: We found a 10% decrease in mg OMEQs from the year before to the year after the intervention (incidence rate ratio [IRR]: 0.90, 95% confidence interval [CI]: 0.86, 0.94). Additional analyses suggested this decrease to be mainly attributable to regulatory actions targeting opioid prescribing during the study period (IRR among patients participating in the intervention before: 0.98 [95% CI: 0.89, 1.07] vs after: 0.83 [0.74, 0.93] regulatory actions). In a random general population sample of matched chronic opioid users, a similar opioid use pattern was observed over time, further supporting the impact of regulatory actions on the opioid use in the study population. CONCLUSION: Among patients with knee or hip osteoarthritis and chronic opioid use, a standardised treatment program did not change opioid use when regulatory changes in opioid prescribing were taken into account.

A lifespan approach to osteoarthritis prevention.

Prevention is an attractive solution for the staggering and increasingly unmanageable burden of osteoarthritis. Despite this, the field of osteoarthritis prevention is relatively immature. To date, most of what is known about preventing osteoarthritis and risk factors for osteoarthritis is relative to the disease (underlying biology and pathophysiology) of osteoarthritis, with few studies considering risk factors for osteoarthritis illness, the force driving the personal, financial and societal burden. In this narrative review we will discuss what is known about osteoarthritis prevention, propose actionable prevention strategies related to obesity and joint injury which have emerged as important modifiable risk factors, identify where evidence is lacking, and give insight into what might be possible in terms of prevention by focussing on a lifespan approach to the illness of osteoarthritis, as opposed to a structural disease of the elderly. By targeting a non-specialist audience including scientists, clinicians, students, industry employees and others that are interested in osteoarthritis but who do not necessarily focus on osteoarthritis, the goal is to generate discourse and motivate inquiry which propel the field of osteoarthritis prevention into the mainstream.

The clinical profile of people with knee osteoarthritis and a self-reported prior knee injury: A cross-sectional study of 10,973 people.

BACKGROUND: Little is known about how a prior knee injury affects the clinical profile of individuals with knee osteoarthritis (KOA) although this is potentially important to personalize care. OBJECTIVES: To compare individual and clinical characteristics of individuals with KOA with and without a self-reported prior knee injury. DESIGN: Secondary data analysis of baseline data from the Good Life with osteoArthritis in Denmark (GLA:D®) registry. METHODS: Individuals with symptomatic KOA, self-reporting a prior knee injury requiring a doctor's assessment, were compared to individuals without prior knee injury on a range of individual and clinical characteristics using multivariable logistic regression. RESULTS: The analysis included 10,973 individuals with KOA of which 54% self-reported a prior knee injury. The average age was 64 years and 73% were female. We found that being male (Odds Ratio (OR): 0.99), having longer symptom duration of knee pain (OR: 1.07), having more painful body sites (OR: 1.03), being able to do more chair rises (OR: 1.02) and being more physically active in a week (2-4 days; OR:1.33) (>4 days; OR: 1.24) were associated with self-reporting a prior knee injury whereas being older (OR: 0.99), having higher BMI (OR: 0.99) and higher quality of life (OR: 0.98) were not associated with reporting a prior knee injury. CONCLUSION: The overall pattern of our findings rather than specific characteristics indicates that individuals with KOA and a history of a self-reported knee injury have a somewhat different clinical profile than their non-injured peers.

Associations between comorbidities and immediate and one-year outcomes following supervised exercise therapy and patient education - A cohort study of 24,513 individuals with knee or hip osteoarthritis.

OBJECTIVE: To investigate if comorbidities are associated with change in health outcomes following an 8-week exercise and education program in knee and hip osteoarthritis (OA). METHODS: We included 24,513 individuals with knee or hip OA from the Good Life with osteoArthritis in Denmark (GLA:D®). GLA:D® consists of two patient education sessions and 12 supervised exercise sessions. Before the program, individuals self-reported having one or more of 11 common comorbidities. Physical function was assessed using the 40-m Fast-Paced Walk Test (FPWT, m/sec) before and immediately after the program. Pain intensity and health-related quality of life was self-reported before, immediately after, and at 12 months post-intervention using a visual analogue scale (VAS, 0-100) and the EQ-5D-5L index (-0.624 to 1.000), respectively. Associations of comorbidity combinations with change in outcomes immediately and at 12 months was estimated using mixed linear regression. RESULTS: Individuals with OA improved on average 0.12 m/s (95%CI 0.12 to 0.13) in 40-m FPWT, -12.7 mm (95%CI -13.2 to -12.2) in VAS, and 0.039 (95%CI 0.036 to 0.041) in EQ-5D-5L from before to immediately after the intervention with minor additional improvements at 12 months. Despite that individuals with comorbidities had worse baseline scores in all outcomes than individuals without comorbidities, they had similar levels of improvement immediately and 12 months after the intervention. CONCLUSION: Comorbidities are not associated with worse nor better health outcomes following an 8-week exercise and education program in individuals with OA, suggesting exercise as a viable treatment option for individuals with OA, irrespective of comorbidities.

Symptoms of lumbar spinal stenosis in people with knee or hip osteoarthritis or low back pain: a cross-sectional study of 10,234 participants in primary care.

OBJECTIVE: The aims of this study were to evaluate: the proportion of people reporting symptoms associated with lumbar spinal stenosis (LSS) in primary care programs for knee or hip osteoarthritis (OA) or persistent low back pain (LBP) and; the prevalence of self-reported clinical LSS in these three cohorts, according to two sets of adapted criteria. METHOD: A cross-sectional analysis of baseline data from the Good Life with osteoArthritis in Denmark primary care programs. Self-report LSS symptom questions were administered to participants with knee OA, hip OA, and persistent LBP. The prevalence of eleven LSS symptoms and clinical LSS were calculated for each cohort. RESULTS: A total of 10,234 participants were included in the analysis. A similar proportion of participants in each cohort were female (69%), with a 6- and 7-year older mean age in the knee and hip cohorts compared to the back cohort. A greater proportion of participants with LBP reported LSS symptoms (range 11-71%) than in the hip (11-50%) and knee (8-40%) cohorts. This pattern was observed for all but one symptom. The same pattern was observed for the prevalence of clinical LSS with less than 10% of people in each cohort satisfying the clinical criteria. CONCLUSION: Self-reported LSS symptoms are commonly reported by people treated in primary care for knee or hip OA, although not as frequently as reported by those with LBP. Despite symptoms of LSS being common, only a small proportion of people were classified as having self-reported clinical LSS.

Immediate outcomes following the GLA:D® program in Denmark, Canada and Australia. A longitudinal analysis including 28,370 patients with symptomatic knee or hip osteoarthritis.

OBJECTIVE: To report outcomes across three countries for patients with symptomatic knee or hip OA attending the evidence-based education and exercise therapy program Good Life with osteoArthritis from Denmark (GLA:D®). DESIGN: GLA:D® is a structured treatment program including 2-3 patient education sessions and 12 supervised exercise sessions delivered over 8 weeks by certified health care practitioners. The program was introduced in Denmark in 2013, in Canada 2015 and in Australia 2016. Absolute mean change in pain intensity, number of chair stands in 30 s, 40 m walk test time and Knee injury and Osteoarthritis Outcome Score (KOOS)/Hip dysfunction and Osteoarthritis Outcome Score (HOOS) QOL subscale scores from baseline to immediately after treatment were reported as means and 95 % CIs and proportion of responders for each country. RESULTS: Patients from the three countries improved 26-33% in mean pain intensity, 8-12% in walking speed, 18-30% in chair stand ability and 12-26% in joint-related quality of life from baseline to immediately after treatment, with no clinically relevant differences between patients with hip and knee OA. These improvements correspond with moderate to large within-group effect sizes and 43-47 % of the patients experienced clinically relevant pain reductions. CONCLUSION: About half or more of patients across the three countries were categorized as responders for pain and objective function following the implementation of GLA:D®. These findings indicate positive patient outcomes associated with GLA:D® participation across varying health care systems from implementation of guideline-based patient education and exercise therapy for knee and hip OA.

Percentile curves for the knee injury and osteoarthritis outcome score in the middle-aged Dutch population.

OBJECTIVE: To improve the interpretation of the Knee injury and Osteoarthritis Outcome Score (KOOS) in individual patients, we explored associations with age, sex, BMI, history of knee injury and presence of clinical knee osteoarthritis, and developed percentile curves. METHODS: We used cross-sectional data of middle-aged individuals from the population-based Netherlands Epidemiology of Obesity (NEO) study. Clinical knee osteoarthritis was defined using the ACR classification criteria. KOOS scores were handled according to the manual (zero = extreme problems, 100 = no problems). Patient characteristics associated with KOOS were explored using ordered logistic regression, and sex and body mass index (BMI)-specific percentile curves were developed using quantile regression with fractional polynomials. The curves were applied as a benchmark for comparison of KOOS scores of participants with knee osteoarthritis and comorbidities. RESULTS: The population consisted of 6,643 participants (56% women, mean (SD) age 56(6) years). Population-based KOOS subscale scores (median; interquartile range) near optimum: pain (100;94-100), symptoms (96;86-100), ADL function (100;96-100), sport/recreation function (100;80-100), quality of life (100;75-100). Worse KOOS scores were observed in women and in participants with higher BMI. Clinical knee osteoarthritis was defined in 15% of participants, and was, in comparison to other patient characteristics, associated with the highest odds of worse KOOS scores. Furthermore, presence of any comorbidity and cardiovascular disease specifically, was associated with worse KOOS scores, particularly in women. CONCLUSIONS: In the middle-aged Dutch population KOOS scores were generally good, but worse in women and with higher BMI. These percentile curves may be used as benchmarks in research and clinical practice.

Individualized predictions of changes in knee pain, quality of life and walking speed following patient education and exercise therapy in patients with knee osteoarthritis - a prognostic model study.

OBJECTIVE: To facilitate shared decision-making for patients with knee osteoarthritis (OA), we aimed at building clinically applicable models to predict the individual change in pain intensity (VAS scale 0-100), knee-related quality of life (QoL) (KOOS QoL score 0-100) and walking speed (m/sec) immediately following two educational and 12 supervised exercise therapy sessions. METHODS: We used data from patients with knee OA from the 'Good Life with osteoArthritis in Denmark' (GLA:D®) registry (n = 6,767). From 51 patient characteristics, we selected the best performing variables to predict the outcomes via random forest regression. We evaluated model performance via R2. Lastly, we validated and compared our models with the average improvements via the mean differences in an independent validation data set from the GLA:D® registry (n = 2,896) collected 1 year later than the data used to build the models. RESULTS: Validating our models including the best performing variables yielded R2s of 0.34 for pain intensity, 0.18 for knee-related QoL, and 0.07 for walking speed. The absolute mean differences between model predictions and the true outcomes were 14.65 mm, 10.32 points, and 0.14 m/s, respectively, and similar to the absolute mean differences of 17.64, 11.28 and 0.14 observed when we subtracted the average improvements from the true outcomes. CONCLUSION: Despite including 51 potential predictors, we were unable to predict changes in individuals' pain intensity, knee-related QoL and walking speed with clinically relevant greater precision than the respective group average outcomes. Therefore, average prediction values can be used to inform patients about expected outcomes.

Comparison of three sets of clinical classification criteria for knee osteoarthritis: a cross-sectional study of 13,459 patients treated in primary care.

OBJECTIVE: To determine and compare the proportion of patients treated in a primary care setting that have knee osteoarthritis (OA) according to the European League Against Rheumatism (EULAR), the American College of Rheumatology (ACR), and the National Institute for Health and Care Excellence (NICE) clinical classification criteria. DESIGN: A cross-sectional analysis of baseline data from 13,459 patients with knee symptoms or functional limitations associated with OA participating in the Good Life with osteoArthritis in Denmark (GLA:D®) treatment program. The prevalence of knee OA according to the EULAR, ACR and NICE criteria were calculated in all participants and in the subgroup of patients with self-reported radiographic changes associated with knee OA (n = 10,651 or 79%). RESULTS: Mean age (SD) was 65.3 (9.8) years, median (IQR) duration of symptoms 12 (6-36) months and mean pain intensity (0-100; SD) 46.5 (22.1) mm. 39% fulfilled all three sets of criteria. 48%, 52% and 89% fulfilled the EULAR, ACR, and NICE criteria for having knee OA, respectively. In the subgroup with self-reported radiographic changes, the corresponding numbers were 49%, 54% and 90%. CONCLUSIONS: While the EULAR and ACR criteria only identified around half of those, with or without self-reported radiographic knee OA, that were treated because of symptoms or functional limitations associated with knee OA, the NICE criteria identified most patients. The results indicate that the NICE criteria are relevant and appropriate to identify individuals treated for knee OA in primary care.

Cost-effectiveness of 12 weeks of supervised treatment compared to written advice in patients with knee osteoarthritis: a secondary analysis of the 2-year outcome from a randomized trial.

OBJECTIVE: To assess the 24-month cost-effectiveness of supervised treatment compared to written advice in knee osteoarthritis (OA). DESIGN: 100 adults with moderate-severe OA not eligible for total knee replacement (TKR) randomized to a 12-week individualized, supervised treatment (exercise, education, diet, insoles and pain medication) or written advice. Effectiveness was measured as change in quality-adjusted life years (QALYs) from baseline to 24 months, including data from baseline, 3, 6, 12 and 24 months, while healthcare costs and transfer payments were derived from national registries after final follow-up. Incremental costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) were calculated. A sensitivity analysis resampling existing data was conducted and the probability of cost-effectiveness was estimated using a 22,665 Euros/QALY threshold. In a sensitivity analysis, cost-effectiveness was calculated for different costs of the supervised treatment (actual cost in study; cost in private practice; and in-between cost). RESULTS: Average costs were similar between groups (6,758 Euros vs 6,880 Euros), while the supervised treatment were close to being more effective (incremental effect (95% CI) of 0.075 (-0.005 to 0.156). In the primary analysis excluding deaths, this led the supervised treatment to be cost-effective, compared to written advice. The sensitivity analysis demonstrated that the results were sensitive to changes in the cost of treatment, but in all scenarios the supervised treatment was cost-effective (ICERs of 6,229 to 20,688 Euros/QALY). CONCLUSIONS: From a 24-month perspective, a 12-week individualized, supervised treatment program is cost-effective compared to written advice in patients with moderate-severe knee OA not eligible for TKR. TRIAL REGISTRATION: ClinicalTrials.gov number: NCT01535001.

Development of osteoarthritis in patients with degenerative meniscal tears treated with exercise therapy or surgery: a randomized controlled trial.

OBJECTIVE: To evaluate progression of individual radiographic features 5 years following exercise therapy or arthroscopic partial meniscectomy as treatment for degenerative meniscal tear. DESIGN: Randomized controlled trial including 140 adults, aged 35-60 years, with a magnetic resonance image verified degenerative meniscal tear, and 96% without definite radiographic knee osteoarthritis. Participants were randomized to either 12-weeks of supervised exercise therapy or arthroscopic partial meniscectomy. The primary outcome was between-group difference in progression of tibiofemoral joint space narrowing and marginal osteophytes at 5 years, assessed semi-quantitatively by the OARSI atlas. Secondary outcomes included incidence of radiographic knee osteoarthritis and symptomatic knee osteoarthritis, medial tibiofemoral fixed joint space width (quantitatively assessed), and patient-reported outcome measures. Statistical analyses were performed using a full analysis set. Per protocol and as treated analysis were also performed. RESULTS: The risk ratios (95% CI) for progression of semi-quantitatively assessed joint space narrowing and medial and lateral osteophytes for the surgery group were 0.89 (0.55-1.44), 1.15 (0.79-1.68) and 0.77 (0.42-1.42), respectively, compared to the exercise therapy group. In secondary outcomes (full-set analysis) no statistically significant between-group differences were found. CONCLUSION: The study was inconclusive with respect to potential differences in progression of individual radiographic features after surgical and non-surgical treatment for degenerative meniscal tear. Further, we found no strong evidence in support of differences in development of incident radiographic knee osteoarthritis or patient-reported outcomes between exercise therapy and arthroscopic partial meniscectomy. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT01002794).

Item selection for 12-item short forms of the Knee injury and Osteoarthritis Outcome Score (KOOS-12) and Hip disability and Osteoarthritis Outcome Score (HOOS-12).

OBJECTIVE: To develop 12-item short forms (KOOS-12, HOOS-12) of the 42-item Knee injury and Osteoarthritis Outcome Score (KOOS) and 40-item Hip disability and Osteoarthritis Outcome Score (HOOS) that represent the full-length instruments sufficiently to provide joint-specific pain, function and quality of life (QOL) domain and summary joint impact scores. This paper describes KOOS-12 and HOOS-12 item selection. Subsequent papers will examine KOOS-12 and HOOS-12 reliability, validity and responsiveness. DESIGN: Items were selected based on qualitative information from patients, clinicians and KOOS/HOOS translators and analysis of data from 1,395 knee osteoarthritis (OA) and 1,281 hip OA patients from the FORCE-TJR cohort who completed KOOS or HOOS before and after total joint replacement (TJR). Item response theory models and computerized adaptive test (CAT) simulations were used to identify items that best measured patients' levels of pain and function pre- and post-TJR. KOOS-12/HOOS-12 items were selected based on content, coverage of a wide measurement range, high item information, item usage in CAT simulations, scale-level properties (reliability, validity, responsiveness), and qualitative information. RESULTS: KOOS-12 and HOOS-12 each included a pain frequency item and three items measuring pain during increasingly difficult activities (sitting/lying, walking, up/down stairs); function items about standing, rising from sitting, getting in/out of a car, and twisting/pivoting (KOOS-12) or walking on an uneven surface (HOOS-12); and the original 4-item QOL scale. CONCLUSIONS: This study demonstrated the benefits of examining patient-reported outcome measures using modern psychometric methods, to create short forms with diverse content that provide domain-specific and summary joint impact scores.

A 12-item short form of the Hip disability and Osteoarthritis Outcome Score (HOOS-12): tests of reliability, validity and responsiveness.

OBJECTIVE: To evaluate reliability, validity and responsiveness of HOOS-12, a 12-item short form of the 40-item Hip disability and Osteoarthritis Outcome Score (HOOS). HOOS-12 provides Pain, Function and Quality of Life (QOL) scale scores and a summary hip impact score. DESIGN: Data from 1,273 FORCE-TJR hip osteoarthritis (OA) patients who completed HOOS before and six and 12 months after total hip replacement (THR) were analyzed. HOOS-12 includes a pain frequency item and three items measuring pain during increasingly difficult (sitting/lying, walking, stairs) activities; function items about standing, rising from sitting, getting in/out of a car, and walking on an uneven surface; and the 4-item HOOS QOL scale. Percent computable scale scores, floor and ceiling effects, internal consistency reliability, validity (scale correlations, tests of known groups validity using one-way analysis of variance (ANOVA)), and responsiveness (effect sizes (ES), standardized response means (SRM)) were compared for HOOS-12, full-length HOOS, HOOS-PS and HOOS, JR. RESULTS: Internal consistency reliability was above 0.70 for all HOOS-12 scales and above 0.90 for the HOOS-12 Summary score. Validity and responsiveness of HOOS-12 Pain, Function and QOL scales were satisfactory and reached similar conclusions as comparable full-length HOOS scales. The HOOS-12 Summary score was highly responsive in discriminating between groups who differed in global ratings of post-THR change in physical capabilities and had high ES and SRM standardized response means. CONCLUSIONS: HOOS-12 was a reliable and valid alternative to HOOS in THR patients with moderate to severe OA and provided three domain-specific and summary hip impact scores with substantially reduced respondent burden.

A 12-item short form of the Knee injury and Osteoarthritis Outcome Score (KOOS-12): tests of reliability, validity and responsiveness.

OBJECTIVE: To evaluate reliability, validity and responsiveness of KOOS-12, a 12-item short form of the 42-item Knee injury and Osteoarthritis Outcome Score (KOOS) that provides Pain, Function and Quality of Life (QOL) scale scores and a summary knee impact score. DESIGN: Data from 1,392 knee osteoarthritis (OA) patients from the FORCE-TJR research cohort who completed KOOS before and 6 and 12 months after total knee replacement (TKR) were analyzed. KOOS-12 includes a pain frequency item and three items measuring pain during increasingly difficult (sitting/lying, walking, stairs) activities; function items about standing, rising from sitting, getting in/out of a car, and twisting/pivoting; and the 4-item KOOS QOL scale. Percent computable scale scores, floor and ceiling effects, internal consistency reliability, validity (scale correlations, tests of known groups validity using one-way analysis of variance (ANOVA)) and responsiveness (effect sizes, standardized response means) were compared for the KOOS-12, full-length KOOS, KOOS-PS and KOOS, JR. RESULTS: Internal consistency reliability was above 0.70 for all KOOS-12 scales and ≥0.90 for the KOOS-12 Summary score. Validity and responsiveness of KOOS-12 Pain, Function and QOL scales was satisfactory and reached similar conclusions as comparable full-length KOOS scales. The KOOS-12 Summary score was most responsive in discriminating between groups who differed in global ratings of post-TKR change in physical capabilities and had the highest effect sizes and standardized response means. CONCLUSIONS: KOOS-12 was a reliable and valid alternative to KOOS in TKR patients with moderate to severe OA and provided three domain-specific and summary knee impact scores with substantially reduced respondent burden.

The impact of physical activity level on the short- and long-term pain relief from supervised exercise therapy and education: a study of 12,796 Danish patients with knee osteoarthritis.

OBJECTIVES: It is unknown if people with knee osteoarthritis (OA) who are already physically active benefit from exercise therapy. To study the impact of physical activity level on pain relief, post-intervention and 12 months following exercise therapy and education. METHOD: The analyses included 12,796 patients with knee OA from the Good Life with osteoArthritis in Denmark (GLA:D®) program. GLA:D® consists of 12 sessions of supervised neuromuscular exercise and two sessions of education delivered by trained physical therapists. The impact of physical activity level on change in knee pain intensity (0-100) immediately post-intervention and at 12 months was estimated using a mixed-effects model adjusted for age, sex, body mass index (BMI), educational level and comorbidity. Physical activity level was assessed using the University of California, Los Angeles (UCLA) activity scale. RESULTS: Physically inactive patients had worse baseline pain compared to patients with low to very high physical activity level (6-15 points worse; P < 0.001). Pain decreased by 13.4 points (95% CI; 9.7 to 17.1) following the treatment program and by 12.8 points (7.7-18.0) at 12 months in the inactive patients, with similar improvements in patients with higher levels of physical activity (P = 0.278 to 0.851). CONCLUSION: In patients with knee OA, similar and persistent long-term pain relief was found from supervised exercise therapy and education regardless of the initial physical activity level. Patients with high to very high levels of physical activity can expect pain relief from supervised exercise therapy and education similar to that of more physically inactive patients.

One year effectiveness of neuromuscular exercise compared with instruction in analgesic use on knee function in patients with early knee osteoarthritis: the EXERPHARMA randomized trial.

OBJECTIVE: To test long-term effectiveness of neuromuscular exercise (NEMEX) with instructions in optimized pharmacological treatment (PHARMA) on activities of daily living (ADL) in patients with early knee osteoarthritis. DESIGN: 12-months follow-up from a randomized controlled trial. Participants with mild-to-moderate medial tibiofemoral knee osteoarthritis were randomly allocated to 8 weeks NEMEX or PHARMA. The primary outcome measure was the ADL-subscale of the Knee Injury and Osteoarthritis Outcome Score (KOOS). Secondary outcome measures included the other four KOOS-subscales, the University of California Activity Score (UCLA) and the European Quality of Life-5 Dimensions. RESULTS: Ninety-three patients (57% women, 58 ± 8 years, body mass index 27 ± 4 kg/m2) were randomized to NEMEX (n = 47) or PHARMA group (n = 46) with data from 85% being available at 12-months follow-up. Good compliance was achieved for 49% of the participants in NEMEX (≥12 sessions) and 7% in PHARMA (half the daily dose of acetaminophen/NSAIDs ≥ 28 days). Within-group improvements in NEMEX were considered to be clinically relevant (≥10 points) for all KOOS-subscales, except Sport/Rec whereas, no between-groups difference in the primary outcome KOOS ADL (3.6 [-2.1 to 9.2]; P = 0.216) was observed. For KOOS Symptoms, a statistically significant difference of 7.6 points (2.6-12.7; P = 0.004) was observed in favor of NEMEX with 47% improving ≥10 points. CONCLUSIONS: No difference in improvement in difficulty with ADL was observed. NEMEX improved knee symptoms to a greater extent with half of patients reporting clinically relevant improvements. CLINICALTRIALS. GOV IDENTIFIER: NCT01638962 (July 3, 2012). ETHICAL COMMITTEE: S-20110153.

Total knee replacement and non-surgical treatment of knee osteoarthritis: 2-year outcome from two parallel randomized controlled trials.

OBJECTIVES: To compare 2-year outcomes of total knee replacement (TKR) followed by non-surgical treatment to that of non-surgical treatment alone and outcomes of the same non-surgical treatment to that of written advice. DESIGN: In two randomized trials, 200 (mean age 66) adults with moderate to severe knee osteoarthritis (OA), 100 eligible for TKR and 100 not eligible for TKR, were randomized to TKR followed by non-surgical treatment, non-surgical treatment alone, or written advice. Non-surgical treatment consisted of 12 weeks of supervised exercise, education, dietary advice, use of insoles, and pain medication. The primary outcome was the mean score of the Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales, covering pain, symptoms, activities of daily living (ADL), and quality of life (QOL). RESULTS: Patients randomized to TKR had greater improvements than patients randomized to non-surgical treatment alone (difference of 18.3 points (95% CI; 11.3 to 25.3)), who in turn improved more than patients randomized to written advice (difference of 7.0 points (95% CI; 0.4 to 13.5)). Among patients eligible for TKR, 16 (32%) from the non-surgical group underwent TKR during 2 years and among those initially ineligible, seven patients (14%) from the non-surgical group and ten (20%) from the written advice group underwent TKR. CONCLUSIONS: TKR followed by non-surgical treatment is more effective on pain and function than non-surgical treatment alone, which in turn is more effective than written advice. Two out of three patients with moderate to severe knee OA eligible for TKR delayed surgery for at least 2 years following non-surgical treatment. TRIAL REGISTRATION: ClinicalTrials.gov numbers NCT01410409 and NCT01535001.