Allopurinol and Renal Outcomes in Adults With and Without Type 2 Diabetes: A Retrospective, Population-Based Cohort Study and Propensity Score Analysis

OBJECTIVES

Elevated uric acid (UA) is common in diabetes and is implicated in the pathogenesis of chronic kidney disease (CKD). Lowering UA with allopurinol may delay CKD progression. We assessed the association between allopurinol and renal outcomes in older adults both with and without diabetes, and whether this differed by diabetes status.

METHODS

We conducted a population-based, retrospective cohort study of older adults ≥66 years of age with a gout flare using administrative data from Ontario, Canada. The primary outcome was doubling of creatinine or kidney failure. Secondary outcomes were a composite of death or kidney failure, decline in estimated glomerular filtration rate by >30%, death and kidney failure. New allopurinol users were compared with nonusers using Cox proportional hazards models and inverse probability of treatment weighting (IPTW). An interaction between allopurinol use and presence or absence of diabetes was assessed.

RESULTS

Among 5,937 older adults with a gout flare (1,911 with diabetes), 1,304 (22%) were newly treated with allopurinol. Median follow-up time was 1.11 (interquartile range, 0.33 to 3.21) years for allopurinol users and 3.38 (interquartile range, 1.42 to 4.43) years for nonusers. There was no association between allopurinol use and the primary outcome (IPTW-adjusted hazard ratio, 0.97; 95% confidence interval, 0.72 to 1.31), and this did not differ by diabetes status. Allopurinol use was not associated with any of the secondary outcomes.

CONCLUSIONS

Allopurinol use was not associated with renal outcomes in older adults with or without diabetes. This supports the interpretation of UA as a biomarker of CKD risk rather than a modifiable target for prevention or treatment of CKD.

The Relationship between Patient-Reported Readiness for Total Knee Arthroplasty and Likelihood of a Good Outcome at One Year

OBJECTIVE

To determine the relationship between patients' pre-operative readiness for total knee arthroplasty (TKA) and surgical outcome at one-year.

METHODS

This prospective cohort study recruited knee osteoarthritis (OA) patients aged 30+ years referred for TKA at two hip/knee surgery centers in Alberta, Canada. Those who received primary, unilateral TKA completed questionnaires pre-TKA to assess WOMAC-pain, KOOS-physical function, Perceived Arthritis Coping Efficacy, General Self-Efficacy, PHQ-8, BMI, comorbidities and TKA readiness (Patient Acceptable Symptom State; willingness to undergo TKA), and one-year post-TKA to assess outcomes. A good TKA outcome was defined as improved knee symptoms (OARSI-OMERACT responder criteria) AND overall satisfaction with results. Poisson regression with robust error estimation was used to estimate relative risk of a good outcome for exposures, before and after controlling for covariates.

RESULTS

Of 1,272 TKA recipients assessed at one year, 1,053 with data for our outcome were included (mean age 66.9 years (SD 8.8); 58.6% female). Most (87.8%) were definitely willing to undergo TKA and had 'unacceptable' knee symptoms (79.7%). 78.1% achieved a good TKA outcome. Controlling for pre-TKA OA-related disability, arthritis coping efficacy, comorbid hip symptoms and depressed mood, definite willingness to undergo TKA and unacceptable knee symptoms were associated with greater likelihood of a good TKA outcome (adjusted RRs 1.18, 95% CI 1.04-1.35, and 1.14, 95% CI 1.02-1.27, respectively).

CONCLUSION

Among TKA recipients for knee OA, patients' psychological readiness and willingness for TKA were associated greater likelihood of a good outcome. Incorporation of these factors in TKA decision-making may enhance patient outcomes and appropriate use of TKA.

Effect of Biomechanical Footwear on Knee Pain in People With Knee Osteoarthritis: The BIOTOK Randomized Clinical Trial

IMPORTANCE

Individually calibrated biomechanical footwear therapy may improve pain and physical function in people with symptomatic knee osteoarthritis, but the benefits of this therapy are unclear.

OBJECTIVE

To assess the effect of a biomechanical footwear therapy vs control footwear over 24 weeks of follow-up.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial conducted at a Swiss university hospital. Participants (N = 220) with symptomatic, radiologically confirmed knee osteoarthritis were recruited between April 20, 2015, and January 10, 2017. The last participant visit occurred on August 15, 2017.

INTERVENTIONS

Participants were randomized to biomechanical footwear involving shoes with individually adjustable external convex pods attached to the outsole (n = 111) or to control footwear (n = 109) that had visible outsole pods that were not adjustable and did not create a convex walking surface.

MAIN OUTCOMES AND MEASURES

The primary outcome was knee pain at 24 weeks of follow-up assessed with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscore standardized to range from 0 (no symptoms) to 10 (extreme symptoms). The secondary outcomes included WOMAC physical function and stiffness subscores and the WOMAC global score, all ranging from 0 (no symptoms) to 10 (extreme symptoms) at 24 weeks of follow-up, and serious adverse events.

RESULTS

Among the 220 randomized participants (mean age, 65.2 years [SD, 9.3 years]; 104 women [47.3%]), 219 received the allocated treatment and 213 (96.8%) completed follow-up. At 24 weeks of follow-up, the mean standardized WOMAC pain subscore improved from 4.3 to 1.3 in the biomechanical footwear group and from 4.0 to 2.6 in the control footwear group (between-group difference in scores at 24 weeks of follow-up, -1.3 [95% CI, -1.8 to -0.9]; P < .001). The results were consistent for WOMAC physical function subscore (between-group difference, -1.1 [95% CI, -1.5 to -0.7]), WOMAC stiffness subscore (between-group difference, -1.4 [95% CI, -1.9 to -0.9]), and WOMAC global score (between-group difference, -1.2 [95% CI, -1.6 to -0.8]) at 24 weeks of follow-up. Three serious adverse events occurred in the biomechanical footwear group compared with 9 in the control footwear group (2.7% vs 8.3%, respectively); none were related to treatment.

CONCLUSIONS AND RELEVANCE

Among participants with knee pain from osteoarthritis, use of biomechanical footwear compared with control footwear resulted in an improvement in pain at 24 weeks of follow-up that was statistically significant but of uncertain clinical importance. Further research would be needed to assess long-term efficacy and safety, as well as replication, before reaching conclusions about the clinical value of this device.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02363712.

How Do Physical Therapists Approach Management of People With Early Knee Osteoarthritis? A Qualitative Study

BACKGROUND

Knee osteoarthritis (OA) is a leading cause of disability. There is increasing emphasis on initiating treatment earlier in the disease. Physical therapists are central to the management of OA through the delivery of exercise programs. There is a paucity of research on physical therapists' perceptions and clinical behaviors related to early knee OA management.

OBJECTIVE

The study aimed to explore how physical therapists approached management of early knee OA, with a focus on evidence-based strategies. This is an important first step to begin to optimize care by physical therapists for this population.

DESIGN

We used a qualitative, descriptive research design.

METHODS

Semistructured interviews were conducted with 33 physical therapists working with people with knee symptoms and/or diagnosed knee OA in community or outpatient settings in Canada. Data were analyzed using thematic analysis.

RESULTS

Five main themes were constructed: (1) Physical therapists' experience and training: clinical experiences and continuing professional development informed clinical decision-making. (2) Tailoring treatment from the physical therapist "toolbox:" participants described their toolbox of therapeutic interventions, highlighting the importance of tailoring treatments to people. (3) The central role of exercise and physical activity in management: exercise was consistently recommended by participants. (4) Variability in support for weight management: there was variation related to how participants addressed weight management. (5) Facilitating "buy-in" to management: physical therapists used a range of strategies to gain "buy-in."

LIMITATIONS

Participants were recruited through a professional association specializing in orthopedic physical therapy and worked an average of 21 years.

CONCLUSIONS

Participants' accounts emphasized tailoring of interventions, particularly exercises, which is an evidence-based strategy for OA. Findings illuminated variations in management that warrant further exploration to optimize early intervention (eg, weight management, behavior change techniques).

Use of Recommended Non-surgical Knee Osteoarthritis Management in Patients prior to Total Knee Arthroplasty: A Cross-sectional Study

OBJECTIVE

Our aim was to assess prior use of core recommended non-surgical treatment among patients with knee osteoarthritis (OA) scheduled for total knee arthroplasty (TKA), and to assess potential patient-level correlates of underuse, if found.

METHODS

This was a cross-sectional study of patients undergoing TKA for primary knee OA at 2 provincial central intake hip and knee clinics in Alberta, Canada. Standardized questionnaires assessed sociodemographic characteristics, social support, coexisting medical conditions, OA symptoms and coping, and previous non-surgical management. Multivariable logistic regression was used to assess the patient-level variables independently associated with receipt of recommended non-surgical knee OA treatment, defined as prior use of pharmacotherapy for pain, rehabilitation strategies (exercise or physiotherapy), and weight loss if overweight or obese (body mass index ≥ 25 kg/m²).

RESULTS

There were 1273 patients included: mean age 66.9 years (SD 8.7), 39.9% male, and 44.1% had less than post-secondary education. Recommended non-surgical knee OA treatment had been used by 59.7% of patients. In multivariable modeling, the odds of having received recommended non-surgical knee OA treatment were significantly and independently lower among individuals who were older (OR 0.97, 95% CI 0.95-0.99), male (OR 0.33, 0.25-0.45), and who lacked post-secondary education (OR 0.70, 0.53-0.93).

CONCLUSION

In a large cross-sectional analysis of knee OA patients scheduled for TKA, 40% of individuals reported having not received core recommended non-surgical treatments. Older individuals, men, and those with less education had lower odds of having used recommended non-surgical OA treatments.

Osteoarthritis is a serious disease

Osteoarthritis (OA) is the most common form of arthritis, affecting 1 in 3 people over age 65 and women more so than men. The prevalence of OA is rising due, in part, to the increasing prevalence of OA risk factors, including obesity, physical inactivity, and joint injury. OA-related joint pain causes functional limitations, poor sleep, fatigue, depressed mood and loss of independence. Compared to age and sex-matched peers, OA patients incur higher out of pocket health-related expenditures and substantial costs due to lost productivity. Most people with OA (59-87%) have at least one other chronic condition, especially cardiometabolic conditions. Symptomatic OA may impair the ability of people with cardiometabolic conditions to exercise and lose weight, resulting in increased risk for poor outcomes. People with OA and other chonic conditions are less likely to receive a diagnosis or recommended treatment. Further, in these individuals the most effective and safest treatment is physical activity/exercise coupled with self-management strategies, which is only moderately effective. Given the already high, and growing, burden of OA, enhanced effort is required to identify better - more effective and safe - treatments for the majority of people with OA who are living with other chronic conditions.

Uptake of the OMERACT-OARSI Hip and Knee Osteoarthritis Core Outcome Set: Review of Randomized Controlled Trials from 1997 to 2017

OBJECTIVE

To assess the uptake of the OMERACT-OARSI (Outcome Measures in Rheumatology- Osteoarthritis Research Society International) core outcome set (COS) domains in hip and/or knee osteoarthritis (OA) trials.

METHODS

There were 382 trials of hip and/or knee OA identified from the ClinicalTrial.gov registry from 1997 to 2017. Frequency of COS adoption was assessed by year and per 5-yearly phases.

RESULTS

COS adoption decreased from 61% between 1997 and 2001 to 38% between 2012 and 2016. Pain (95%) and physical function (86%) were most consistently adopted. Patient's global assessment (48%) was the principal missing domain.

CONCLUSION

Limited adoption of the COS domains indicates that further consideration to improve uptake is required.

The OMERACT-OARSI Core Domain Set for Measurement in Clinical Trials of Hip and/or Knee Osteoarthritis

OBJECTIVE

To update the 1997 OMERACT-OARSI (Outcome Measures in Rheumatology-Osteoarthritis Research Society International) core domain set for clinical trials in hip and/or knee osteoarthritis (OA).

METHODS

An initial review of the COMET database of core outcome sets (COS) was undertaken to identify all domains reported in previous COS including individuals with hip and/or knee OA. These were presented during 5 patient and health professionals/researcher meetings in 3 continents (Europe, Australasia, North America). A 3-round international Delphi survey was then undertaken among patients, healthcare professionals, researchers, and industry representatives to gain consensus on key domains to be included in a core domain set for hip and/or knee OA. Findings were presented and discussed in small groups at OMERACT 2018, where consensus was obtained in the final plenary.

RESULTS

Four previous COS were identified. Using these, and the patient and health professionals/researcher meetings, 50 potential domains formed the Delphi survey. There were 426 individuals from 25 different countries who contributed to the Delphi exercise. OMERACT 2018 delegates (n = 129) voted on candidate domains. Six domains gained agreement as mandatory to be measured and reported in all hip and/or knee OA clinical trials: pain, physical function, quality of life, and patient's global assessment of the target joint, in addition to the mandated core domain of adverse events including mortality. Joint structure was agreed as mandatory in specific circumstances, i.e., depending on the intervention.

CONCLUSION

The updated core domain set for hip and/or knee OA has been agreed upon. Work will commence to determine which outcome measurement instrument should be recommended to cover each core domain.

Association between allopurinol and cardiovascular outcomes and all-cause mortality in diabetes: A retrospective, population-based cohort study

AIM

To assess the association between allopurinol and mortality and cardiovascular outcomes in an allopurinol-treated diabetes cohort.

MATERIALS AND METHODS

We conducted a population-based retrospective cohort study in Ontario, Canada. Eligible subjects were ≥ 66 years old with diabetes and a first prescription for allopurinol between 1 April, 2002 and 31 March, 2012 and were followed until 31 March, 2016. The primary outcome was a composite: all-cause mortality, non-fatal cardiovascular event (myocardial infarction, revascularization procedure, or stroke) or congestive heart failure (CHF). Secondary outcomes were components of the primary outcome and pneumonia as a negative tracer. Allopurinol was modelled as time-varying exposed versus unexposed, daily dose category and cumulative dose using sex-specific multivariable Cox proportional hazards models.

RESULTS

Over a median follow-up of 4.65 years (interquartile range 1.79-7.81), 16 266/23 103 males and 10 571/15 313 females experienced the primary outcome. Allopurinol was associated with a reduction in the primary outcome [adjusted hazard ratios (aHR) 0.77 (95% confidence interval 0.75-0.80) and 0.81 (0.78-0.84) for males and females, respectively], driven by marked reductions in all-cause mortality and modest reductions in cardiovascular events/CHF. There was no effect of cumulative allopurinol dose on any outcome, and allopurinol was also associated with reduced risk of pneumonia in males [aHR 0.88 (0.83, 0.93)].

CONCLUSIONS

Allopurinol was associated with reduced mortality and cardiovascular outcomes. However, lack of cumulative dose effect and a positive tracer outcome in males suggests residual bias. Future research assessing whether allopurinol prevents vascular complications in diabetes requires a clinical trial.

Engaging primary care physicians in care coordination for patients with complex medical conditions

OBJECTIVE

To explore the dynamics of primary care physicians' (PCPs') engagement with the Seamless Care Optimizing the Patient Experience (SCOPE) project.

DESIGN

Qualitative study using semistructured interviews.

SETTING

Solo and small group primary care practices in urban Toronto, Ont.

PARTICIPANTS

A total of 22 of the 29 SCOPE PCPs (75.8%) were interviewed 14 to 19 months after the initiation of SCOPE.

METHODS

Qualitative semistructured interviews were conducted to examine influencing factors associated with PCPs' engagement in SCOPE. Transcripts were analyzed using a grounded theory-informed approach and key themes were identified.

MAIN FINDINGS

The SCOPE project provided practical mechanisms through which PCPs could access information and connect with resources. Contextual and historical factors including strained relationships between hospital specialists and community PCPs and PCPs' feelings of responsibility, isolation, disconnection, and burnout influenced readiness to engage. Provision of clinically useful supports in a trusting, collaborative manner encouraged PCPs' engagement in newer, more collaborative ways of working.

CONCLUSION

The SCOPE project provided an opportunity for PCPs to build meaningful relationships, reconnect to the broader health care system, and redefine their roles. For many PCPs, reestablishing connections reaffirmed their role in the system and enabled a more collaborative care model. Strategies for connecting community-based PCPs to the broader system need to consider contextual factors and the effects of new linkages and coordination on the identities and relationships of PCPs.

A multifaceted primary care practice-based intervention to reduce ED visits and hospitalization for complex medical patients: A mixed methods study

BACKGROUND

The management of complex, multi-morbid patients is challenging for solo primary care providers (PCPs) with limited access to resources. The primary objective of the intervention was to reduce the overall rate of Emergency Department (ED) visits among patients in participating practices.

METHODS AND FINDINGS

An interrupted time series design and qualitative interviews were used to evaluate a multifaceted intervention, SCOPE (Seamless Care Optimizing the Patient Experience), offered to solo PCPs whose patients were frequent users of the ED. The intervention featured a navigation hub (nurse, homecare coordinator) to link PCPs with hospital and community resources, a general internist on-call to provide phone advice or urgent assessments, and access to patient results on-line. Continuous quality improvement (QI) strategies were employed to optimize each component of the intervention. The primary outcome was the relative pre-post intervention change in ED visit rate for patients of participating practices compared with that for a propensity-matched control group of physicians over the contemporaneous period. Themes were identified from semi-structured interviews on PCP's experiences and influential factors in their engagement. Twenty-nine physicians agreed to participate and were provided access to the intervention over an 18-month time period. There were a total of 1,525 intervention contacts over the 18-months (average: 50.6±60.8 per PCP). Both intervention and control groups experienced a trend towards lower rates of ED use by their patients over the study time period. The pre-post difference in trend for the intervention group compared to the controls was not significant at 1.4% per year (RR = 1.014; p = 0.59). Several themes were identified from qualitative interviews including: PCPs felt better supported in the care of their patients; they experienced a greater sense of community, and; they were better able to provide shared primary-specialty care.

CONCLUSIONS

This multifaceted intervention to support solo PCPs in the management of their complex patients did not result in a reduced rate of ED visits compared to controls, likely related to variable uptake among PCPs. It did however result in more comprehensive and coordinated care for their patients. Future directions will focus on increasing uptake by improving ease of use, increasing the range of services offered and expanding to a larger number of PCPs.

Applied Bayesian Methods in the Rheumatic Diseases

The use of applied Bayesian methods is increasing in rheumatology. Using the Bayes theorem, past evidence is updated with new data. Preexisting data are expressed as a prior probability distribution or prior. New observations are expressed as a likelihood. Through explicit incorporation of preexisting data and new data, this process informs how this new information should change the way we think. In this article, the authors highlight the use of applied Bayesian methods in the study of rheumatic diseases.

Qualitative study exploring the factors influencing physical therapy management of early knee osteoarthritis in Canada

OBJECTIVES

Increasingly, there is emphasis on identifying and initiating treatment of osteoarthritis (OA) in the early phases of the disease. This study aimed to identify the perceived barriers and facilitators to managing clients with early knee OA and the contextual factors affecting implementation of care by physical therapists (PTs).

DESIGN

Qualitative study using in-depth semistructured interviews with 33 PTs. The interviews were audio-recorded, transcribed verbatim and analysed inductively using thematic analysis.

SETTING

Canada.

PARTICIPANTS

A purposive sample of PTs who managed clients with knee symptoms and/or diagnosed knee OA in community/outpatient settings in three provinces in Canada (Ontario, Alberta, British Columbia).

RESULTS

Factors that affected physical therapy management of early knee OA were identified at four levels: the community, healthcare system, healthcare provider and client level. Some healthcare provider factors acted primarily as enablers of management, such as PTs' confidence in their ability to manage perceived early knee OA, PTs' beliefs about consequences of OA and the PT scope of practice. However, the study illuminated a range of modifiable factors that can act as barriers to management. These factors included access to services in the community and healthcare system; healthcare provider factors such as time, access to evidence and physician's role in referrals and messaging; and client factors related to client characteristics (eg, general health, socioeconomic status), engagement in management and beliefs about OA.

CONCLUSION

These findings provide us with a basis to begin to address specific barriers and to optimise care for early knee OA.

Validation of a new symptom outcome for knee osteoarthritis: the Ambulation Adjusted Score for Knee pain

OBJECTIVE

Validation of a symptom measure for early knee OA may help identify new treatments and modifiable risk factors. Symptom measures that consider pain in the context of activity level may provide better discrimination than pain alone. Therefore, we aimed to compare sensitivity to change for radiographic progression between Ambulation Adjusted Score for Knee pain (AASK), which accounts for self-reported ambulation, and Western Ontario McMaster Osteoarthritis (WOMAC) knee pain score.

DESIGN

Participants were assessed annually up to 48 months using WOMAC, Physical Activity Scale for the Elderly (PASE) ambulation, and knee radiographs. AASK was defined as ((WOMAC pain) + 1)/((average daily hours of walking) + 1). Radiographs were scored for Kellgren-Lawrence (KL) grade. Linear regression, stratified by OA status, evaluated relationships between changes in AASK and WOMAC pain and KL grade over time.

RESULTS

For 4191 people (8030 knees), the mean age was 61.2 (+ 9.2) years old and BMI was 28.6 (+ 4.8) kg/m²; 58% female. Over 40% of knees had WOMAC pain scores of 0; by design, no knees had AASK scores of 0. Annual changes in AASK were more sensitive to changes in KL than changes in WOMAC in those without baseline OA (0.20 and 0.16 change per unit KL change, p = 0.005 and 0.070 respectively), but performed similarly in knees with OA.

CONCLUSION

AASK is simple to assess using existing validated questionnaires. AASK performs well in individuals with and without OA and should be considered in clinical trials and observational studies of early knee OA.

The impact of hip and knee osteoarthritis on the subsequent risk of incident diabetes: a population-based cohort study

AIMS/HYPOTHESIS

This study examined the relationship between hip/knee osteoarthritis and incident diabetes. We hypothesised that hip/knee osteoarthritis would be independently related to an increased risk of incident diabetes and that this relationship would be due, at least in part, to walking difficulty. We also hypothesised a stronger relationship with incident diabetes for knee than hip osteoarthritis because of the higher prevalence in the former of obesity/the metabolic syndrome.

METHODS

A population cohort aged ≥55 years recruited from 1996 to 1998 was followed through provincial health administrative data to 2014. Participants with baseline diabetes were excluded. Hip/knee osteoarthritis was defined as swelling, pain or stiffness in any joint lasting 6 weeks in the past 3 months and indication on a joint homunculus that a hip/knee was 'troublesome'. Walking limitation was defined as self-reported difficulty standing or walking in the last 3 months (yes/no). Using Cox regressions, we examined the relationship of baseline hip/knee osteoarthritis with incident diabetes as defined from health administrative data, controlling for age, sex, BMI, income, prior hypertension, cardiovascular disease and primary care exposure. We tested whether the observed effect was mediated through walking limitation.

RESULTS

In total, 16,362 participants were included: median age 68 years and 61% female. Of these, 1637 (10%) individuals met the criteria for hip osteoarthritis, 2431 (15%) for knee osteoarthritis and 3908 (24%) for walking limitation. Over a median follow-up of 13.5 years (interquartile range 7.3-17.8), 3539 individuals (22%) developed diabetes. Controlling for confounders, a significant relationship was observed between number of hip/knee joints with osteoarthritis and incident diabetes: HR for two vs no osteoarthritic hips 1.25 (95% CI 1.08, 1.44); HR for two vs no osteoarthritic knees 1.16 (95% CI 1.04, 1.29). From 37% to 46% of this relationship was explained by baseline walking limitation.

CONCLUSIONS/INTERPRETATION

In a large population cohort aged ≥55 years who were free of diabetes at baseline, and controlling for confounders, the presence and burden of hip/knee osteoarthritis was a significant independent predictor of incident diabetes. This association was partially explained by walking limitation. Increased attention to osteoarthritis and osteoarthritis-related functional limitations has the potential to reduce diabetes risk.

Utilization and Short-Term Outcomes of Primary Total Hip and Knee Arthroplasty in the United States and Canada: An Analysis of New York and Ontario Administrative Data

OBJECTIVE

Total knee arthroplasty (TKA) and total hip arthroplasty (THA) are common and effective surgical procedures. This study sought to compare utilization and short-term outcomes of primary TKA and THA in adjacent regions of Canada and the United States.

METHODS

The study was designed as a retrospective cohort study of patients who underwent primary TKA or THA, comparing administrative data from New York and Ontario in 2012-2013. Demographic features of the TKA and THA patients, per capita utilization rates, and short-term outcomes were compared between the jurisdictions.

RESULTS

A higher percentage of New York hospitals performed TKA compared to Ontario hospitals (75.7% versus 42.1%; P < 0.001), and the mean annual procedural volume for TKAs was lower in New York hospitals (mean 179 versus 327 in Ontario hospitals; P < 0.001). After direct standardization, utilization was significantly lower in New York compared to Ontario, both for TKA (16.1 TKAs versus 21.4 TKAs per 10,000 population per year; P < 0.001) and for THA (10.5 THAs versus 11.5 THAs per 10,000 population per year; P < 0.001). For those who underwent TKA, the length of stay in Ontario hospitals was significantly longer (mean 3.7 days versus 3.4 days in New York hospitals; P < 0.001). A smaller percentage of New York patients were discharged directly home (46.2% versus 90.9% of Ontario patients; P < 0.001), but 30-day and 90-day readmission rates were higher in New York compared to Ontario (30-day rates, 4.6% versus 3.9% [P < 0.001]; 90-day rates, 8.4% versus 6.7% [P < 0.001]). For the THA cohorts, the results with regard to length of stay, discharge disposition, and readmission rates were similar to those for TKA.

CONCLUSION

Ontario has higher utilization of total joint arthroplasty than New York but has a smaller percentage of hospitals performing these procedures. Patients are more likely to be discharged home and less likely to be readmitted in Ontario. Our results suggest areas where each jurisdiction could improve.

Impact of Osteoarthritis on Difficulty Walking: A Population-Based Study

OBJECTIVE

To assess the relationship of hip and knee osteoarthritis (OA) to walking difficulty.

METHODS

A population cohort ages ≤55 years recruited from 1996 to 1998 (n = 28,451) completed a standardized questionnaire assessing demographics, health conditions, joint symptoms, and functional limitations, including difficulty walking in the past 3 months. Survey data were linked to health administrative databases; self-report and administrative data were used to identify health conditions. Hip/knee OA was defined as self-reported swelling, pain, or stiffness in a hip or knee lasting ≥6 weeks in the past 3 months without an inflammatory arthritis diagnosis. Using multivariable logistic regression, we examined the determinants of walking difficulty and constructed a clinical nomogram.

RESULTS

A total of 18,490 cohort participants were eligible (mean age 68 years, 60% women), and 25% reported difficulty walking. Difficulty walking was significantly and independently associated with older age, female sex, body mass index, and several health conditions. Of the conditions examined, the likelihood of walking difficulty was greatest with hip and knee OA and increased with the number of hip/knee joints affected. The predicted probability of difficulty walking for a 60-year-old middle-income, normal-weight woman was 5-10% with no health conditions, 10-20% with diabetes mellitus and cardiovascular (CV) disease, 40% with OA in 2 hips/knees, 60-70% with diabetes mellitus, CV disease, and OA in 2 hips/knees, and 80% with diabetes mellitus, CV disease, and OA in all hips/knees.

CONCLUSION

In a population cohort, symptomatic hip/knee OA was the strongest contributor to walking difficulty. Given the importance of walking to engagement in physical activity for chronic disease management, greater attention to OA is warranted.

The longitudinal relationship between hand, hip and knee osteoarthritis and cardiovascular events: a population-based cohort study

OBJECTIVE

In this population-based cohort study, we examined the association between the presence of symptomatic osteoarthritis (OA) and risk for cardiovascular (CV) events.

METHOD

A cohort aged ≥55 years recruited from 1996 to 98 was followed through provincial health administrative data to 2014. Demographics, joint complaints and functional limitations were collected. Hip, knee and hand OA were defined using a validated definition. Using Cox-regressions, the relationship between OA and a composite CV outcome (myocardial infarction (MI), stroke, angina, heart failure, revascularization) was assessed controlling for age, body mass index (BMI), sex, pre-existing metabolic factors, comorbidities, income status, primary care exposure and functional limitations.

RESULTS

18,490 participants were included: median age was 68 years, 60.3% were female; 24.4% met criteria for OA (10.0% hip, 15.3% knee, 16.0% hand), 16.3% self-reported limitation in grip and 25.4% in walking. Over a median 13.4 years, 31.9% experienced a CV event. Controlling for all but walking limitation, a dose-response relationship was observed between number of joints affected by knee/hip OA and CV risk (HR 2 hips/knees vs none: 1.13, 95% CI 1.03-1.23; 3+ hips/knees: 1.22, 95% CI 1.09-1.36). This relationship became non-significant additionally controlling for difficulty walking. Self-reported difficulty walking was associated with a 30% increased hazard for CV events. The effect of hand OA was not significant.

CONCLUSION

In a large population cohort, a greater burden of hip/knee OA was associated with higher CV risk; the relationship was explained by OA-related difficulty walking. Increased attention to management of OA with a view to improving mobility has potential to reduce CV events.