Socioeconomic impact of osteoarthritis in Hong Kong: utilization of health and social services, and direct and indirect costs

The effects of pulsed electromagnetic field therapy on muscle strength and pain in patients with end-stage knee osteoarthritis: a randomized controlled trial

Background

Osteoarthritis (OA) of the knee is one of the most common chronic degenerative joint conditions affecting aging population.

Aim

To investigate the effectiveness of a combination of home-based exercise and pulsed electromagnetic field (PEMF) therapy to improve muscle strength, physical function, and pain.

Methods

Sixty patients were randomly assigned to either home-based exercise alone (control group; n = 30) or combined with PEMF therapy (treatment group; n = 30) twice a week for eight weeks. Knee extension, flexion muscle strength, gait speed (GS), 5 time sit-to-stand test (5STS), Visual Analogue Scale (VAS) pain and Knee Injury and Osteoarthritis Outcome Score (KOOS) were recorded at baseline and 4 and 8 weeks.

Results

Significant improvements in symptomatic knee extension muscle strength (SKE, p = 0.001), flexion strength (SKF, p = 0.011), contralateral knee extension muscle strength (CKE, p = 0.002), and flexion strength (CKF, p = 0.009) were observed for the PEMF treatment group at 8 weeks. Significant reductions in VAS pain scores were observed in both the treatment (p < 0.001, partial η2 = 0.505) and control (p < 0.001, partial η2 = 0.268) groups. Significant differences were reported between groups in the 4 (p = 0.010, partial η2 = 0.111) and 8 (p = 0.046, partial η2 = 0.068) week assessment in VAS pain. A significant time difference was found in GS and 5STS between baseline and week 8 (GS: difference 0.051, p = 0.026; 5STS: difference 2.327, p < 0.001) in the treatment group. The significant group difference at week 8 was observed in SKE (p = 0.013) in female patients while pain in male patients (p = 0.026). Patients aged over 70 years have a significantly superior improvement in SKE, SKF, and CKF after 8 weeks of PEMF therapy.

Conclusion

The combination of PEMF therapy and home-based exercise superiorly improved knee muscle strength and reduced pain in end-stage knee OA subjects and showed a promising tendency to improve performance-based physical function. PEMF therapy was shown to preferentially benefit knee muscle strength in female patients and patients aged over 70 years, whereas male patients were more responsive to PEMF therapy in the form of pain relief.

Clinical trial registration

clinicalTrials.gov, NCT05550428.

Current therapies for osteoarthritis and prospects of CRISPR-based genome, epigenome, and RNA editing in osteoarthritis treatment

Osteoarthritis (OA) is one of the most common degenerative joint diseases worldwide, causing pain, disability, and decreased quality of life. The balance between regeneration and inflammation-induced degradation results in multiple etiologies and complex pathogenesis of OA. Currently, there is a lack of effective therapeutic strategies for OA treatment. With the development of CRISPR-based genome, epigenome, and RNA editing tools, OA treatment has been improved by targeting genetic risk factors, activating chondrogenic elements, and modulating inflammatory regulators. Supported by cell therapy and in vivo delivery vectors, genome, epigenome, and RNA editing tools may provide a promising approach for personalized OA therapy. This review summarizes CRISPR-based genome, epigenome, and RNA editing tools that can be applied to the treatment of OA and provides insights into the development of CRISPR-based therapeutics for OA treatment. Moreover, in-depth evaluations of the efficacy and safety of these tools in human OA treatment are needed.

Adapting a Clinical Practice Guideline for Management of Patients with Knee and Hip Osteoarthritis by Hong Kong Physiotherapists

Knee and hip osteoarthritis are common disabling conditions globally. Although numerous international clinical practice guidelines exist to guide physiotherapy management, not all recommendations issued from these guidelines can be translated to other contexts without considering the cultural acceptability and clinical implementability of targeted countries. Because the ADAPTE framework provides a robust methodology to adapt guidelines to the local context, this study used its methodology to adapt high-quality guideline recommendations to promote optimal physiotherapy care for knee and hip osteoarthritis in Hong Kong. The ADAPTE framework was used and modified to complete the adaptation process. International clinical practice guidelines were identified from eight guideline clearinghouses and six electronic databases. Two independent reviewers critically appraised the eligible guidelines using the AGREE II tool. We extracted and tabulated recommendations from high-quality guidelines. A voting-based consensus among interdisciplinary experts was conducted to decide on suitable recommendations for the Hong Kong context and whether there was a need to modify them. Pertinent recommendations were then translated into the traditional Chinese language. Our team members suggested modifying four tools and adding one to explore the patient's feedback on the recommendations, to the ADAPTE framework. The adaptation was performed on three high-quality guidelines. We adapted 28 and 20 recommendations for treating knee and hip osteoarthritis, respectively. We recommend a multimodal treatment for managing knee and hip osteoarthritis. Land- and aquatic-based exercises, patient education, and self-management were strongly recommended for patients with knee osteoarthritis. Land- and aquatic-based exercises were strongly recommended for patients with hip osteoarthritis. This is the first adaptation study in Hong Kong. It provides guidance to local physiotherapists on managing patients with knee and hip osteoarthritis. Future studies should test the effectiveness of implementing this adapted guideline to improve local physiotherapy care in Hong Kong.

Global, regional, and national burden of osteoarthritis, 1990-2020 and projections to 2050: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND

Osteoarthritis is the most common form of arthritis in adults, characterised by chronic pain and loss of mobility. Osteoarthritis most frequently occurs after age 40 years and prevalence increases steeply with age. WHO has designated 2021-30 the decade of healthy ageing, which highlights the need to address diseases such as osteoarthritis, which strongly affect functional ability and quality of life. Osteoarthritis can coexist with, and negatively effect, other chronic conditions. Here we estimate the burden of hand, hip, knee, and other sites of osteoarthritis across geographies, age, sex, and time, with forecasts of prevalence to 2050.

METHODS

In this systematic analysis for the Global Burden of Disease Study, osteoarthritis prevalence in 204 countries and territories from 1990 to 2020 was estimated using data from population-based surveys from 26 countries for knee osteoarthritis, 23 countries for hip osteoarthritis, 42 countries for hand osteoarthritis, and US insurance claims for all of the osteoarthritis sites, including the other types of osteoarthritis category. The reference case definition was symptomatic, radiographically confirmed osteoarthritis. Studies using alternative definitions from the reference case definition (for example self-reported osteoarthritis) were adjusted to reference using regression models. Osteoarthritis severity distribution was obtained from a pooled meta-analysis of sources using the Western Ontario and McMaster Universities Arthritis Index. Final prevalence estimates were multiplied by disability weights to calculate years lived with disability (YLDs). Prevalence was forecast to 2050 using a mixed-effects model.

FINDINGS

Globally, 595 million (95% uncertainty interval 535-656) people had osteoarthritis in 2020, equal to 7·6% (95% UI 6·8-8·4) of the global population, and an increase of 132·2% (130·3-134·1) in total cases since 1990. Compared with 2020, cases of osteoarthritis are projected to increase 74·9% (59·4-89·9) for knee, 48·6% (35·9-67·1) for hand, 78·6% (57·7-105·3) for hip, and 95·1% (68·1-135·0) for other types of osteoarthritis by 2050. The global age-standardised rate of YLDs for total osteoarthritis was 255·0 YLDs (119·7-557·2) per 100 000 in 2020, a 9·5% (8·6-10·1) increase from 1990 (233·0 YLDs per 100 000, 109·3-510·8). For adults aged 70 years and older, osteoarthritis was the seventh ranked cause of YLDs. Age-standardised prevalence in 2020 was more than 5·5% in all world regions, ranging from 5677·4 (5029·8-6318·1) per 100 000 in southeast Asia to 8632·7 (7852·0-9469·1) per 100 000 in high-income Asia Pacific. Knee was the most common site for osteoarthritis. High BMI contributed to 20·4% (95% UI -1·7 to 36·6) of osteoarthritis. Potentially modifiable risk factors for osteoarthritis such as recreational injury prevention and occupational hazards have not yet been explored in GBD modelling.

INTERPRETATION

Age-standardised YLDs attributable to osteoarthritis are continuing to rise and will lead to substantial increases in case numbers because of population growth and ageing, and because there is no effective cure for osteoarthritis. The demand on health systems for care of patients with osteoarthritis, including joint replacements, which are highly effective for late stage osteoarthritis in hips and knees, will rise in all regions, but might be out of reach and lead to further health inequity for individuals and countries unable to afford them. Much more can and should be done to prevent people getting to that late stage.

FUNDING

Bill & Melinda Gates Foundation, Institute of Bone and Joint Research, and Global Alliance for Musculoskeletal Health.

Progress in osteoarthritis research by the National Natural Science Foundation of China

Osteoarthritis (OA) in China is gradually becoming an important scientific research area that has had a significant impact on research and development (R&D) activities in the OA field worldwide. This article summarizes the R&D progress related to OA in China in recent years. The National Natural Science Foundation of China (NSFC) is a national funding institution for basic research and plays a critical role in promoting and supporting Chinese scholars' R&D activities. We collected and analyzed information on NSFC funding in the field of OA from 2010 to 2019, including the amount, the level and the program categories of the funded projects. The data fully demonstrate the important and positive role of the NSFC in supporting free exploration, cultivating research teams and young talent, and boosting OA R&D. In this article, we outline and discuss hot topics in focused areas, key advances in this field and the prospects for progress in OA research in China.

Prevalence Trends of Site-Specific Osteoarthritis From 1990 to 2019: Findings From the Global Burden of Disease Study 2019

OBJECTIVE

To estimate systematic and anatomic site-specific age-standardized prevalence rates (ASRs) and analyze the secular trends of osteoarthritis (OA) at global, regional, and national levels.

METHODS

Data were derived from the Global Burden of Disease Study 2019. ASRs and their estimated annual percentage changes (EAPCs) were used to describe the secular trends of OA according to age group, sex, region, country, and territory, as well as the joints involved.

RESULTS

Globally, prevalent cases of OA increased by 113.25%, from 247.51 million in 1990 to 527.81 million in 2019. ASRs were 6,173.38 per 100,000 in 1990 and 6,348.25 per 100,000 in 2019, with an average annual increase of 0.12% (95% confidence interval [95% CI] 0.11%, 0.14%). The ASR of OA increased for the knee, hip, and other joints, but decreased for the hand, with EAPCs of 0.32 (95% CI 0.29, 0.34), 0.28 (95% CI 0.26, 0.31), 0.18 (95% CI 0.18, 0.19), and -0.36 (95% CI -0.38, -0.33), respectively. OA prevalence increased with age and revealed female preponderance, geographic diversity, and disparity with regard to anatomic site. OA of the knee contributed the most to the overall burden, while OA of the hip had the highest EAPC in most regions.

CONCLUSION

OA has remained a major public health concern worldwide over the past decades. The prevalence of OA has increased and diversified by geographic location and affected joint. Prevention and early treatment are pivotal to mitigating the growing burden of OA.

Lessons learnt from the impact of COVID-19 on arthroplasty services in Hong Kong: how to prepare for the next pandemic?

BACKGROUND

Arthroplasty services worldwide have been significantly disrupted by the pandemic of coronavirus disease 2019 (COVID-19). This retrospective comparative study aimed to characterize its impact on arthroplasty services in Hong Kong.

METHODS

From January 1 to June 30, 2020, the patients of "COVID-19 cohort" underwent elective total hip or knee replacement in Hong Kong public hospitals. The cohort was compared to the "control cohort" during the same period in 2019. Data analysis was performed to compare the two cohorts' numbers of operations, hospital admission, orthopaedic clinic attendances, and waiting time.

RESULTS

A total of 33,111 patient episodes were analyzed. During the study period, the elective arthroplasty operations and hospitalizations decreased by 53 and 54%, respectively (P < 0.05). Reductions were most drastic from February to April, with surgical volume declining by 86% (P < 0.05). The primary arthroplasty operations decreased by 91% (P < 0.05), while the revision operations remained similar. Nevertheless, 14 public hospitals continued performing elective arthroplasty for patients with semi-urgent indications, including infection, progressive bone loss, prosthesis loosening, dislocation or mechanical failure of arthroplasty, and tumor. At the institution with the highest arthroplasty surgical volume, infection (28%) was the primary reason for surgery, followed by prosthesis loosening (22%) and progressive bone loss (17%). The orthopaedic clinic attendances also decreased by 20% (P < 0.05). Increases were observed in waiting time and the total number of patients on the waiting list for elective arthroplasty.

CONCLUSIONS

Despite the challenges, public hospitals in Hong Kong managed to continue providing elective arthroplasty services for high-priority patients. Arthroplasty prioritization, infection control measures, and post-pandemic service planning can enhance hospital preparedness to mitigate the impact of current and future pandemics.

Clinical and cost-effectiveness of physiotherapy interventions following total hip replacement: a systematic review and meta-analysis

To examine the reported clinical and cost-effectiveness of physiotherapy interventions following total hip replacement (THR). A systematic review was completed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). MEDLINE, CINAHL, AMED, Scopus, DARE, HTA, and NHS EED databases were searched for studies on clinical and cost-effectiveness of physiotherapy in adults with THR published up to March 2020. Studies meeting the inclusion criteria were identified and key data were extracted. Risk of bias was assessed using the Cochrane Risk of Bias Tool and a Consolidated Health Economic Evaluation Reporting Standards (CHEERS). Data were summarised and combined using random-effect meta-analysis. A total of 1263 studies related to the aim of the review were identified, from which 20 studies met the inclusion criteria and were included in the review. These studies were conducted in Australia (n = 3), Brazil (n = 1), United States of America (USA) (n = 2), France (n = 2), Italy (n = 2), Germany (n = 3), Ireland (n = 1), Norway (n = 2), Canada (n = 1), Japan (n = 1), Denmark (n = 1), and United Kingdom (UK) (n = 1). The duration of follow-up of the included studies was ranged from 2 weeks to 12 months. Physiotherapy interventions were found to be clinically effective for functional performance, hip muscle strength, pain, and range of motion flexion. From the National Health Service perspective, an accelerated physiotherapy programme following THR was cost-effective. The findings of the review suggest that physiotherapy interventions were clinically effective for people with THR. However, questions remain on the pooled cost-effectiveness of physiotherapy interventions, and further research is required to examine this in patients with THR. Future studies are required to examine the cost-effectiveness of these interventions from patients, caregivers, and societal perspectives.Registration Prospero (ID: CRD42018096524).

Impact of Osteoarthritis on Household Catastrophic Health Expenditures in Korea

BACKGROUND

Osteoarthritis (OA) is a disease of old age whose prevalence is increasing. This study explored the impact of OA on household catastrophic health expenditure (CHE) in Korea.

METHODS

We used data on 5,200 households from the Korea Health Panel Survey in 2013 and estimated annual living expenses and out-of-pocket (OOP) payments. Household CHE was defined when a household's total OOP health payments exceeded 10%, 20%, 30%, or 40% of the household's capacity to pay. To compare the OOP payments of households with OA individuals and those without OA, OA households were matched 1:1 with households containing a member with other chronic disease such as neoplasm, hypertension, heart disease, cerebrovascular disease, diabetes, or osteoporosis. The impact of OA on CHE was determined by multivariable logistic analysis.

RESULTS

A total of 1,289 households were included, and households with and without OA patients paid mean annual OOP payments of $2,789 and $2,607, respectively. The prevalence of household CHE at thresholds of 10%, 20%, 30%, and 40% were higher in households with OA patients than in those without OA patients (P < 0.001). The presence of OA patients in each household contributed significantly to CHE at thresholds of 10% (odds ratio [OR], 1.48; 95% confidence interval [CI], 1.16-1.87), 20% (OR, 1.29; 95% CI, 1.01-1.66), and 30% (OR, 1.37; 95% CI, 1.05-1.78), but not of 40% (OR, 1.17; 95% CI, 0.87-1.57).

CONCLUSION

The presence of OA patients in Korean households is significantly related to CHE. Policy makers should try to reduce OOP payments in households with OA patients.

The impact of osteoarthritis on early exit from work: results from a population-based study

Background

Osteoarthritis (OA) is a leading cause of pain and disability, which may be a source of productivity losses. The objectives of this study were to describe the impact of OA, namely through pain and physical disability, on early exit from work and to calculate its economic burden.

Methods

We analysed data from the national, cross-sectional, population-based EpiReumaPt study (Sep2011–Dec2013) in which 10,661 individuals were randomly surveyed in order to capture all cases of rheumatic diseases. We used all participants aged 50–64, near the official retirement age, who were clinically validated by experienced rheumatologists (n = 1286), including OA cases. A national database was used to calculate productivity values by gender, age and region, using the human capital approach. The impact of OA on the likelihood of early exit from work and the population attributable fractions used to calculate due economic burden (indirect costs) were obtained at the individual level by logistic regression. All results were based on weighted data.

Results

Almost one third of the Portuguese population aged 50–64 had OA (29.7%; men: 16.2% and women: 43.5%) and more than half were out of paid work (51.8%). Only knee OA is associated with early exit from work (OR: 2.25; 95%CI: 1.42–3.59; p = 0.001), whereas other OA locations did not reach any statistical difference. Furthermore, we observed an association between self-reported longstanding musculoskeletal pain (OR: 1.55; 95%CI: 1.07–2.23; p = 0.02) and pain interference (OR: 1.35; 95%CI: 1.13–1.62; p = 0.001) with early exit from work. We also detected a clear relationship between levels of disability, measured by the Health Assessment Questionnaire (HAQ), and the probability of work withdrawal. The estimated annual cost of early exit from work attributable to OA was €656 million (€384 per capita; €1294 per OA patient and €2095 per OA patient out-of-work).

Conclusions

In this study, we observed an association between OA and early exit from work, largely dependent on pain and disability. This relationship translates into a meaningful economic burden amounting to approximately 0.4% of the national Gross Domestic Product (GDP). The high prevalence and the impact of this disabling chronic disease highlight the need to prioritize policies targeting early exit from work in OA.

Personal and Workplace Environmental Factors Associated With Reduced Worker Productivity Among Older Workers With Chronic Knee Pain: A Cross-Sectional Survey

OBJECTIVES

The aim of this study was to explore personal and workplace environmental factors as predictors of reduced worker productivity among older workers with chronic knee pain.

METHODS

A questionnaire-based survey was conducted among 129 older workers who had participated in a randomized clinical trial evaluating dietary supplements. Multivariable analyses were used to explore predictors of reduced work productivity among older workers with chronic knee pain.

RESULTS

The likelihood of presenteeism was higher in those reporting knee pain (≥3/10) or problems with other joints, and lower in those reporting job insecurity. The likelihood of work transitions was higher in people reporting knee pain (≥3/10), a high comorbidity score or low coworker support, and lower in those having an occupation involving sitting more than 30% of the day.

CONCLUSION

Allowing access to sitting and promoting positive affiliations between coworkers are likely to provide an enabling workplace environment for older workers with chronic knee pain.

The effect of Ai Chi aquatic therapy on individuals with knee osteoarthritis: a pilot study

[Purpose] To examine the efficacy of Ai Chi in relieving the pain and stiffness of knee osteoarthritis and improving, physical functioning, proprioception and quality of life. [Subjects and Methods] Twenty-five persons with knee osteoarthritis completed 5 weeks Ai Chi practice (60 minutes per session, twice per week, 10 sessions in total). Knee pain and stiffness were measured before and after the intervention program. [Results] Significant improvements in pain, self-perceived physical functioning and self-perceived stiffness were observed after the Ai-Chi intervention. On average, no significant change in knee range of motion, 6-minute walk test distances or proprioception was observed. [Conclusion] A five-week Ai Chi intervention can improve the pain and stiffness of knee osteoarthritis and self-perceived physical functions and quality of life improvement. Ai Chi may be another treatment choice for people with knee OA to practice in the community.

Economic impact of lower-limb osteoarthritis worldwide: a systematic review of cost-of-illness studies

OBJECTIVE

An overview of the economic consequences - overall costs as well as cost breakdown (direct and indirect) - of hip and knee osteoarthritis (OA) worldwide.

METHODS

A systematic literature search of EMBASE, MEDLINE, Scopus and Cochrane databases for articles was performed independently by two rheumatologists who used the same predefined eligible criteria. Papers without abstracts and in languages other than English or French were excluded. Extracted costs were converted to an annual cost and to 2013 euros (€) by using the Consumer Price Index of the relevant countries and the 2013 Purchasing Power Parities between these countries and the European Union average.

RESULTS

A total of 45 abstracts were selected, and 32 articles were considered for the review. The studied populations were heterogeneous: administrative, hospital and national health survey data. Annual total costs per patient ranged from 0.7 to 12 k€, direct costs per patient from 0.5 to 10.9 k€ and indirect costs per patient from 0.2 to 12.3 k€. The weighted average annual costs per patient living with knee and hip OA were 11.1, 9.5 and 4.4 k€ for total, direct and indirect costs, respectively.

CONCLUSIONS

This review highlights the heterogeneity of studies and lack of methodologic consensus to obtain reliable cost-of-illness estimates for lower-limb OA. However, costs induced by the disease seem substantial and deserve to be more extensively explored.

Development of an arthroscopic ultrasound probe for assessment of articular cartilage degeneration

Quantitative assessment of articular cartilage is important for the early diagnosis of osteoarthritis, intra-operation joint tissue evaluation and judgment of repaired cartilage quality. This technique is also applicable to the cartilage if arthroscopic instrument embedding this technique can be developed. In this study, an arthroscopic water-jet ultrasound indentation probe was developed with the help of a small profile intra-articular ultrasound imaging (IAUS) catheter for the intra-articular measurement of cartilage condition. The probe can provide measurement of morphological, acoustical and mechanical properties of articular cartilage. Preliminary tests were conducted on 10 intact porcine knees with the guide of arthroscopy for the evaluation of cartilage degeneration, which was induced by trypsin digestion. Results showed the cartilage stiffness decreased significantly after the digestion (p < 0.001) with the measurement conducted by the developed probe. In summary, an arthroscopic ultrasound probe has been successfully developed and its utility in detecting the cartilage degeneration was demonstrated in this study. Future work includes the improvement of the probe design and studies on measurement of animal or human samples in vivo.

Socio-economic costs of osteoarthritis: a systematic review of cost-of-illness studies

OBJECTIVE

The burden of illness that can be attributed to osteoarthritis is considerable and ever increasing. The aim of this systematic review is to analyze currently available data derived from cost-of-illness studies on the healthcare and non-healthcare costs of osteoarthritis.

METHODS

PubMed, Index Medicus Español (IME), and the Spanish Database of Health Sciences [Índice Bibliográfico Español en Ciencias de la Salud (IBECS)] were searched up to the end of April 2013. This study adhered to the PRISMA guidelines. Articles were reviewed and the study quality assessed by two independent investigators with consensus resolution of discrepancies.

RESULTS

We identified 39 studies that investigated the socio-economic cost of osteoarthritis. Only nine studies took a social perspective. Rather than estimating the incremental cost of osteoarthritis, nine studies estimated the total cost of treating patients with osteoarthritis without a control for comorbidity. The other 30 studies determined the incremental cost with or without a control group. Only nine studies assessed a comprehensive list of healthcare resources. The annual incremental healthcare costs of generalized osteoarthritis ranged from €705 to €19,715. The annual incremental non-healthcare-related costs of generalized osteoarthritis ranged from €432 to €11,956.

CONCLUSIONS

The study concludes that the social cost of osteoarthritis could be between 0.25% and 0.50% of a country׳s GDP. This should be considered in order to foster studies that take into account both healthcare and non-healthcare costs.

Burden of reduced work productivity among people with chronic knee pain: a systematic review

OBJECTIVE

The aims of this systematic review were to determine the prevalence of reduced work productivity among people with chronic knee pain as well as specifically categorise determinants of work productivity losses into individual, disease and work-related factors, conduct an evaluation of study methodological quality and present a best-evidence synthesis.

METHODS

We searched the literature using combinations of key words such as knee pain, knee osteoarthritis, absenteeism (days taken off work) and presenteeism (reduced productivity while at work) for observational studies published in English. Methodological quality appraisal and a best-evidence synthesis were used to pool the study findings.

RESULTS

The studies were conducted exclusively in high income countries of North America, Western Europe and Hong Kong. 17 studies were included in the review, 10 measuring absenteeism and six measuring presenteeism. Of the 10 studies reporting absenteeism, seven found a 12-month absenteeism prevalence ranging from 5% to 22%. Only two studies evaluated presenteeism prevalence and reported a range from 66% to 71%. Using best-evidence synthesis: three high quality cohort studies and three cross-sectional studies provided strong evidence that knee pain or knee osteoarthritis was associated with absenteeism; two high quality cross-sectional studies and one cohort study provided limited evidence for an association with presenteeism; one cross-sectional study provided limited evidence for an association among age, high job demands and low coworker support and absenteeism among nurses with knee pain. No studies examined individual or work-related factors associated with presenteeism.

CONCLUSIONS

A number of high quality studies consistently demonstrated that chronic knee pain or knee osteoarthritis is associated with absenteeism. However, data are lacking regarding presenteeism and individual or work-related risk factors for reduced work productivity among older workers with chronic knee pain.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO registry number: CRD42013004137.

Patients with knee osteoarthritis demonstrate improved gait pattern and reduced pain following a non-invasive biomechanical therapy: a prospective multi-centre study on Singaporean population

BACKGROUND

Previous studies have shown the effect of a unique therapy with a non-invasive biomechanical foot-worn device (AposTherapy) on Caucasian western population suffering from knee osteoarthritis. The purpose of the current study was to evaluate the effect of this therapy on the level of symptoms and gait patterns in a multi-ethnic Singaporean population suffering from knee osteoarthritis.

METHODS

Fifty-eight patients with bilateral medial compartment knee osteoarthritis participated in the study. All patients underwent a computerized gait test and completed two self-assessment questionnaires (WOMAC and SF-36). The biomechanical device was calibrated to each patient, and therapy commenced. Changes in gait patterns and self-assessment questionnaires were reassessed after 3 and 6 months of therapy.

RESULTS

A significant improvement was seen in all of the gait parameters following 6 months of therapy. Specifically, gait velocity increased by 15.9%, step length increased by 10.3%, stance phase decreased by 5.9% and single limb support phase increased by 2.7%. In addition, pain, stiffness and functional limitation significantly decreased by 68.3%, 66.7% and 75.6%, respectively. SF-36 physical score and mental score also increased significantly following 6 months of therapy (46.1% and 22.4%, respectively) (P < 0.05 for all parameters).

CONCLUSIONS

Singaporean population with medial compartment knee osteoarthritis demonstrated improved gait patterns, reported alleviation in symptoms and improved function and quality of life following 6 months of therapy with a unique biomechanical device.

TRIAL REGISTRATION

Registration number NCT01562652.

Risk factors associated with reduced work productivity among people with chronic knee pain

OBJECTIVE

To determine the burden and risk factors associated with reduced work productivity among people with chronic knee pain.

METHOD

A longitudinal study, nested within a randomised controlled trial (RCT) evaluating the long-term effects of dietary supplements, was conducted among people with chronic knee pain in paid employment (n = 360). Participants recorded days off work (absenteeism) and reduced productivity while at work (presenteeism) for seven days every two months over a 12-month period in a study specific diary. Examined risk factors included knee pain severity, occupational group, radiographic disease severity, physical activity, body mass index (BMI), health-related quality of life (SF-12) and co-morbidity.

RESULTS

Over the 12-month follow up period, 50 (14%) participants reported one or more days off work due to knee problems, while 283 (79%) reported reduced productivity while at work (presenteeism <100%). In multivariate analysis, the only significant risk factor for absenteeism was having an SF-12 Mental Component Summary (MCS) score <40 (OR: 2.49 [95% CI: 1.03-5.98]). Significant risk factors for presenteeism included; reporting an; SF-12 Physical Component Summary (PCS) score <50 (OR: 1.99 [95% CI: 1.05-3.76]), semi-manual labour (OR: 2.23 [1.09-4.59]) or manual labour (OR: 6.40 [1.44-28.35]) or a high maximum knee pain (4-6 out of 10) (OR: 2.29 [1.17-4.46]).

CONCLUSIONS

This longitudinal study found that among this cohort of people with chronic knee pain, the burden of reduced work productivity is mainly attributable to presenteeism rather absenteeism. This study demonstrated that effective strategies to increase work productivity should focus on reducing knee pain or physical disability especially among workers in manual or semi-manual labour.

Comparison of health-related quality of life, work status, and health care utilization and costs according to hip and knee joint disease severity: a national Australian study

BACKGROUND

No population-based studies have investigated how the impact of hip and knee joint disease may vary with increasing severity.

OBJECTIVE

The purpose of this study was to evaluate health-related quality of life (HRQoL), work status, and health service utilization and costs according to severity of hip and knee joint disease.

DESIGN

A national cross-sectional survey was conducted.

METHODS

Five thousand individuals were randomly selected from the Australian electoral roll and invited to complete a questionnaire to screen for doctor-diagnosed hip arthritis, hip osteoarthritis (OA), knee arthritis, and knee OA. Severity was classified by means of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores (range=0-100): <7=asymptomatic, 7-38=mild-moderate, and ≥39=severe. Health-related quality of life was evaluated by means of the Assessment of Quality of Life (AQoL) instrument (range=-0.04 to 1.00; scored worst-best). Self-reported data on work status and health service utilization were collected, with health care costs estimated with the use of government data.

RESULTS

Data were available for 1,157 participants, with 237 (20%) reporting hip or knee joint disease. Of these, 16% (n=37) were classified as asymptomatic, 51% (n=120) as mild-moderate, and 27% (n=64) as severe. The severe group reported very low HRQoL (adjusted mean AQoL=0.43, 95% confidence interval [95% CI]=0.38-0.47) compared with the mild-moderate group (adjusted mean AQoL=0.72, 95% CI=0.69-0.75) and the asymptomatic group (adjusted mean AQoL=0.80, 95% CI=0.74-0.86). Compared with the asymptomatic group, the severe group was >3 times less likely to undertake paid work (adjusted odds ratio=0.28, 95% CI=0.09-0.88) and >4 times less likely to undertake unpaid work (adjusted odds ratio=0.24, 95% CI=0.10-0.62). Although physical therapy services were used infrequently, primary and specialist care utilization and costs were highest for the severe group.

LIMITATIONS

Other costs (including physical therapy consultations) were unavailable.

CONCLUSIONS

A clear pattern of worsening HRQoL, reduced work participation, and higher medical care utilization was seen with increasing severity of joint disease.

Associations of educational attainment, occupation, and community poverty with hip osteoarthritis

OBJECTIVE

To examine cross-sectional baseline data from the Johnston County Osteoarthritis Project for the association between individual and community socioeconomic status (SES) measures with hip osteoarthritis (OA) outcomes.

METHODS

We analyzed data on 3,087 individuals (68% white and 32% African American). Educational attainment and occupation were used as individual measures of SES. Census block group household poverty rate was used as a measure of community SES. Hip OA outcomes included radiographic OA and symptomatic OA in one or both hip joints. Multivariable logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs) for the association of each hip OA outcome with each SES variable separately, and then with all SES measures simultaneously. Associations between hip OA outcomes and SES variables were evaluated for effect modification by race and sex.

RESULTS

Living in a community of high household poverty rate showed independent associations with hip radiographic OA in one or both hips (OR 1.50, 95% CI 1.18-1.92) and bilateral (both hips) radiographic OA (OR 1.87, 95% CI 1.32-2.66). Similar independent associations were found between low educational attainment among those with symptomatic OA in one or both hips (OR 1.44, 95% CI 1.09-1.91) or bilateral symptomatic OA (OR 1.91, 95% CI 1.08-3.39), after adjusting for all SES measures simultaneously. No significant associations were observed between occupation and hip OA outcomes, nor did race or sex modify the associations.

CONCLUSION

Our data provide evidence that hip OA outcomes are associated with both education and community SES measures, associations that remained after adjustment for covariates and all SES measures.

Risk of sick leave and disability pension in working-age women and men with knee osteoarthritis

OBJECTIVES

To investigate sick leave and disability pension in working-age subjects with knee osteoarthritis (OA) compared with the general population.

METHODS

Population-based cohort study: individual-level inpatient and outpatient Skåne Health Care Register data were linked with data from the Swedish Social Insurance Agency. In 2009 all working-age (16-64 years) Skåne County residents who in 1998-2009 had been diagnosed with knee OA (International Classification of Diseases-10 code M17) were identified and their sick leave and disability pension in 2009 related to those of the general working-age population (n=789 366) standardised for age.

RESULTS

15 345 working-age residents (49.6% women) with knee OA were identified. Compared with the general population, the RR (95% CI) of having had one or more episodes of sick leave during the year was 1.82 (1.73 to 1.91) for women and 2.03 (1.92 to 2.14) for men with knee OA. The corresponding risk for disability pension was 1.54 (1.48 to 1.60) for women and 1.36 (1.28 to 1.43) for men with knee OA. The annual mean number of sick days was 87 for each patient with knee OA and 57 for the general population (age- and sex-standardised). Of all sick leave and disability pension in the entire population, 2.1% of days were attributable to knee OA or associated comorbidity in the patients with knee OA (3.1% for sick leave and 1.8% for disability pension).

CONCLUSIONS

Subjects with doctor-diagnosed knee OA have an almost twofold increased risk of sick leave and about 40-50% increased risk of disability pension compared with the general population. About 2% of all sick days in society are attributable to knee OA.

Ensuring face validity in patient-related outcome scores--a matter of content

BACKGROUND

Patient reported outcome (PRO) questionnaires are increasingly used to measure treatment effect in patients with knee pathology. PROs commonly used to assess outcome in patients with knee conditions can be generic, knee-specific, or condition-specific. Most PROs have been created based on clinician-based consensus and are not patient-centered. Items (questions plus their response options) in PROs can be generated by clinicians or through patient interviews. Items created by clinicians possess face validity. The objective of this study was to find all existing PRO items with potentially relevant content for patients with knee pathology.

METHODS

An exhaustive literature search was conducted for PRO questionnaires in English, German, and Scandinavian languages used to assess outcome in patients with knee pathology. The items from the collected PROs were assessed for content redundancy and item reduction was carried out to isolate items of unique content. These items were grouped into one of the components of the ICF classification system.

RESULTS

Thirty-one PROs used for assessment of patients with knee problems were identified, yielding 539 items. Approximately 70% of these items consisted of redundant content matter. The item pool was reduced to a pool of 157 items.

CONCLUSION

The search yielded 157 items of unique content.

CLINICAL RELEVANCE

The identified items can be used to build condition-specific PRO questionnaires for patients with knee pathology.

The Global Economic Cost of Osteoarthritis: How the UK Compares

Aims. To examine all relevant literature on the economic costs of osteoarthritis in the UK, and to compare such costs globally. Methods. A search of MEDLINE was performed. The search was expanded beyond peer-reviewed journals into publications by the department of health, national orthopaedic associations, national authorities and registries, and arthritis charities. Results. No UK studies were identified in the literature search. 3 European, 6 North American, and 2 Asian studies were reviewed. Significant variation in direct and indirect costs were seen in these studies. Costs for topical and oral NSAIDs were estimated to be £19.2 million and £25.65 million, respectively. Cost of hip and knee replacements was estimated to exceed £850 million, arthroscopic surgery for osteoarthritis was estimated to be £1.34 million. Indirect costs from OA caused a loss of economic production over £3.2 billion, £43 million was spent on community services and £215 million on social services for osteoarthritis. Conclusions. While estimates of economic costs can be made using information from non-published data, there remains a lack of original research looking at the direct or indirect costs of osteoarthritis in the UK. Differing methodology in calculating costs from overseas studies makes direct comparison with the UK difficult.

The older worker with osteoarthritis of the knee

BACKGROUND

Changing demographics mean that many patients with large joint arthritis will work beyond traditional retirement age. This review considers the impact of knee osteoarthritis (OA) on work participation and the relation between work and total knee replacement (TKR).

SOURCES

Two systematic searches in Embase and Medline, supplemented by three systematic reviews.

AREAS OF AGREEMENT

Probably, although evidence is limited, knee OA considerably impairs participation in work (labour force participation, work attendance and work productivity). AREAS OF UNCERTAINTY/RESEARCH NEED: Little is known about effective interventions (treatments, work changes and policies) to improve vocational participation in patients with knee OA; or how type of work affects long-term clinical outcomes (e.g. pain, function and the need for revision surgery) in patients with TKRs. The need for such research is pressing and opportune, as increasing numbers of patients with knee OA or TKR expect to work on.

The association between socioeconomic status and traditional chinese medicine use among children in Taiwan

Background

Traditional Chinese medicine (TCM) utilization is common in Asian countries. Limited studies are available on the socioeconomic status (SES) associated with TCM use among the pediatric population. We report on the association between SES and TCM use among children and adolescents in Taiwan.

Methods

A National Health Interview Survey was conducted in Taiwan in 2001 that included 5,971 children and adolescents. We assessed the children's SES using the head of household's education, occupation and income. This information was used to calculate pediatric SES scores, which in turn were divided into quartiles. Children and adolescents who visited TCM in the past month were defined as TCM users.

Results

Compared to children in the second SES quartile, children in the fourth SES quartile had a higher average number of TCM visits (0.12 vs. 0.06 visits, p = 0.027) and higher TCM use prevalence (5.0% vs. 3.6%, p = 0.024) within the past month. The adjusted odds ratio (OR) for TCM use was higher for children in the fourth SES quartile than for those in the first SES quartile (OR 1.49; 95% confidence interval [CI] 1.02-2.17). The corresponding OR was 2.17 for girls (95% CI 1.24-3.78). The highest-SES girls (aged 10-18 years) were most likely to visit TCM practices (OR 2.47; 95% CI 1.25-4.90).

Conclusions

Children and adolescents with high SES were more likely to use TCM and especially girls aged 10-18 years. Our findings point to the high use of complementary and alternative medicine among children and adolescents.

The epidemiology of osteoarthritis in Asia

Worldwide, osteoarthritis (OA) is estimated to be the fourth leading cause of disability. Most of this disability burden is attributable to the involvement of the hips or the knees. OA is strongly associated with ageing and the Asian region is ageing rapidly. Further, OA has been associated with heavy physical occupational activity, a required livelihood for many people living in rural communities in developing countries. Unfortunately, joint replacement surgery, an effective intervention for people with severe OA involving the hips or knees, is inaccessible to most people in these regions. On the other hand, obesity, another major risk factor, may be less prevalent, although it is on the increase. Determining region-specific OA prevalence and risk factor profiles will provide important information for planning future cost-effective preventive strategies and health care services. An update of what is currently known about the prevalence of hip and knee OA from population-based studies conducted in the Asian region is presented in this review. Many of the recent studies have conducted comparisons between urban and rural areas and poor and affluent communities. The results of Asian-based studies evaluating risk factors from population-based cohorts or case-control studies, and the current evidence on OA morbidity burden in Asia is also outlined.

The Effect of Osteoarthritis of the Hip or Knee on Work Participation

In our systematic literature search, we included studies involving patients with hip or knee osteoarthritis (OA) and outcome measures of work participation. Methodological quality was assessed using 11 criteria; a qualitative data analysis was performed. Fifty-three full-text articles were selected out of 1861 abstracts; finally, data were extracted from 14 articles. Design, populations, definitions, and measurements in the studies showed large variations; work outcomes were often only secondary objectives. The outcomes were summarized as showing a mild negative effect of OA on work participation. Many patients had paid work and managed to stay at work despite limitations. However, research on the effect of OA on work participation is scarce and the methodological quality is often insufficient. The longitudinal course of work participation in individuals with OA has not been described completely.

An overview of OA research in two urban APLAR populations

Osteoarthritis (OA), the most prevalent type of arthritis in the elderly, is also among the first five leading causes of disability in developed countries. With the 'Westernized' living environment and lifestyle among Southeast Asian urbanized cities, where obesity is on the rise and the populations are ageing, the incidence of OA is expected to rise in the next decades. There is need to summarize research work within these places. This article summarizes some of the research aspects of OA in Southeast Asian cities. These data may form a useful basis for future planning of medical resource and needs.

Use of a disease-specific instrument in economic evaluations: mapping WOMAC onto the EQ-5D utility index

OBJECTIVE

To map the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) onto the EuroQol 5 Dimension (EQ-5D) utility index in patients with knee osteoarthritis (OA).

METHODS

A consecutive sample of patients (n=258) diagnosed with knee OA completed both the WOMAC and the EQ-5D. Regression models with the ordinary least squares (OLS) or the censored least absolute deviations as the estimator were used to establish the mapping function. The WOMAC was represented as explanatory variables in four ways: 1) total score; 2) domain scores (i.e., pain, stiffness, and physical function); 3) domain scores plus pair-wise interaction terms to account for possible nonlinearities; and 4) individual item scores. Goodness-of-fit criteria included the mean absolute error (the primary criterion) and the root mean squared error, and were obtained using an iterative random sampling procedure. Prediction precision was evaluated at individual patient level and at the group level.

RESULTS

The model using the OLS estimator and the WOMAC domain scores as explanatory variables had the best fit and was chosen as the preferred mapping model. The prediction error at the individual level exceeded the maximal tolerance value (i.e., the minimally important difference of the EQ-5D) in about 16% of the patients. At the group level, the width of the 95% confidence interval of prediction errors varied from 0.0176 at a sample size of 400 to 0.0359 at a sample size of 100.

CONCLUSIONS

EQ-5D scores can be predicted using WOMAC domain scores with an acceptable precision at both individual and group levels in patients with mild to moderate knee OA.

What are the important components of the clinical assessment of hand problems in older adults in primary care? Results of a Delphi study

BACKGROUND

To identify clinical questions and assessments regarded by health care practitioners as important when assessing undifferentiated hand pain or problems in adults aged 50 years and over presenting to primary care.

METHODS

A purposively selected panel of 26 UK-based Health Care Practitioners comprising occupational therapists, physiotherapists, rheumatologists and general practitioners, were invited to take part in a consensus study involving three postal rounds of a Delphi questionnaire with accompanying case scenarios. Participants were asked to generate questions and assessments (round 1), rate their importance (round 2), and vote on which items were most important (round 3).

RESULTS

Sixteen Health Care Practitioners agreed to participate with 11 completing all three rounds. The first round of the Delphi study generated 156 questions and 143 assessments. After three rounds agreement was reached on the importance of 25 questions and 19 assessments. Questions were weighted towards current symptoms, but also included the history of previous hand problems, self-reported hand function, co-morbidity and general health. Observation and palpation of features predominated in the choice of assessment, but specific tests, grip strength, evaluation of sensation and hand function were also included.

CONCLUSIONS

A pool of clinical questions and assessments were generated by Health Care Practitioners, and those considered most important for assessing older adults presenting with undifferentiated hand pain and hand problems in primary care were identified. Further evaluation is required to establish the reliability and feasibility of using these questions and assessments in primary care. In particular, the relative contribution of these questions and assessments in evaluating the nature and severity of hand problems, assisting diagnosis, indicating appropriate management, and predicting future course requires further investigation.

Osteoarthritis and absenteeism costs: evidence from US National Survey Data

OBJECTIVE

This study seeks to quantify the effects of osteoarthritis on the cost of absenteeism from work.

METHODS

This study performs multivariable analyses to examine the relationships between osteoarthritis and annual cost to employers that is associated with absenteeism. The cost is measured as the probability of absenteeism, days missed from work, and their dollar values, all indirect costs.

RESULTS

Osteoarthritis leads to a significantly higher probability of absenteeism and more days missed from work. Osteoarthritis increases annual per capita absenteeism costs by $469 for female workers and by $520 for male workers. This is equivalent to approximately 3 lost workdays. Aggregate annual absenteeism costs are $10.3 billion (women = $5.5 billion; men = $4.8 billion).

CONCLUSIONS

Aggregate annual absenteeism costs of osteoarthritis are quite substantial as measured by the probability of absenteeism, days missed from work, and their dollar values, compared with other major chronic diseases.

Socioeconomic Burden of Psoriatic Arthritis in Hong Kong: Direct and Indirect Costs and the Influence of Disease Pattern

Objective.

To estimate the direct costs and indirect costs of patients with psoriatic arthritis (PsA) in Hong Kong.

Methods.

A retrospective cost-of-illness study was performed on 125 patients with PsA. Participants completed questionnaires on demographics, employment status, and out of pocket expenses. Health resources consumption was recorded by chart review and patient self-report questionnaire. Patients were grouped according to disease pattern, i.e., peripheral and axial disease. Multiple regression was used to determine the predictors of the costs.

Results.

The average annual direct costs were $4,141 (2006 US dollars) per patient. Costs of inpatient care accounted for 27% of direct costs, followed by costs of visits to healthcare providers (25%). The estimated average indirect costs were $3,127 per patient-year. Forty-eight (42%) patients had no indirect costs. Sixty percent of patients with peripheral disease were still employed, compared to 39% of patients with axial disease. Patients with axial disease had almost twice the indirect costs compared to those with peripheral disease (p = 0.005). Increased pain and poor function were independently associated with increased direct costs. Worse physical health status, determined by indirect costs borne by the patient, and poor function and old age predicted high costs.

Conclusion.

PsA imposes substantial economic burden. Pain and function are significantly associated with costs. Improvements in treatments to reduce pain and restore function are likely to reduce the costs incurred by these patients.

Creation of a reflecting formula to determine a patient's indication for undergoing total knee arthroplasty

BACKGROUND

The aim of this study was to develop, from patients' characteristics and radiography, a formula reflecting the decision for total knee arthroplasty (TKA) in patients with a painful osteoarthritic knee.

METHODS

We reviewed medical records of 193 consecutive patients who had knee osteoarthritis and underwent primary TKA surgery and 133 consecutive patients with knee osteoarthritis who did not have surgery in one institution during the preceding 5 years. Two skeletal radiologists graded, from 0 to 3, radiographic joint space narrowing (JSN), osteophytes, subchondral sclerosis, and subchondral cysts. The association between the variables and outcome were calculated by the chi-squared test and multivariable logistic regression.

RESULTS

Women had more TKAs than men (P = 0.002), and the TKA and non-TKA groups differed in terms of self-care ability (P < 0.001). There were no significant differences in age or body mass index between the two groups. The relevant factors in the reflective formula were age, sex, self-care ability, JSN, and osteophytes in the medial compartment. The retrospective sensitivity and specificity for patients who underwent TKA surgery were 84% and 83%, respectively. The diagnostic efficacy in retrospect evaluated by a receiver operating characteristic curve was 0.92.

CONCLUSIONS

A formula reflecting the decision for TKA surgery in patients with a painful osteoarthritic knee has been developed with acceptable diagnostic efficacy obtained retrospectively. The formula should be validated by further study.

The impact of flare on disease costs of patients with systemic lupus erythematosus

OBJECTIVE

To evaluate both direct and indirect costs of systemic lupus erythematosus (SLE) patients with and without flares from a societal perspective, and to investigate the impact of the severity and clinical manifestations of flares on direct/indirect costs.

METHODS

A retrospective cost-of-illness study was performed on 306 SLE patients. Participants completed questionnaires on sociodemographics, employment status, and out-of-pocket expenses. Health resources consumption was recorded by chart review and patient self-reported questionnaire. The total number of flares and involved organs during the preceding 12 months were recorded. Multiple linear regression was performed to determine the cost predictors.

RESULTS

Patients with flares were younger, had shorter disease duration, and had higher disease activity at the time of the assessment. The overall incidence of lupus flares was 0.24 episodes per patient-year. Patients with flares used more health care resources and incurred significantly higher annual direct and indirect costs. The mean total costs per patient-year were 2-fold higher for patients with flares ($22,580 versus $10,870 [2006 US dollars]; P < 0.0005). Multiple regression analysis showed that the number of flares was an independent explanatory variable associated with increased direct costs. Patients with multiorgan flares or renal/neuropsychiatric flares incurred higher direct costs compared with those with single-organ flares or with other organ flares.

CONCLUSION

Patients with flares incur higher direct and indirect costs compared with those without flares. Major organ flares incur higher disease costs than other organ flares. Treatments that effectively control disease activity and prevent flares, especially major organ flares, may reduce the high costs associated with flare in SLE.

Work in inflammatory and degenerative joint diseases

This article focuses on work disability and sick leave and their cost; it also discusses the value of vocational rehabilitation programmes in rheumatic conditions such as rheumatoid arthritis, ankylosing spondylitis, hip and knee osteoarthritis. It acknowledges the importance of work not only for the worker who has one of these diseases but also for the public purse. Much can be done to improve the health of the persons and reduce their disability and its impact in the workplace which will have an important effect on their and their family's quality of life. It is important that neither rehabilitation nor vocational rehabilitation are regarded as bolt-on activities after drug treatment but are seen as an integral part of effective management. Publications dealing with return to work are relatively common in rheumatoid arthritis, less common in ankylosing spondylitis and relatively rare in osteoarthritis. Vocational rehabilitation programmes should aim to facilitate job retention or, failing that, to improve the ability to return to work. The process must be started with in the health arena and it has to be recognised that slow or poor practice in the health service can jeopardise the patient's work potential.

Systemic lupus erythematosus with neuropsychiatric manifestation incurs high disease costs: a cost-of-illness study in Hong Kong

OBJECTIVE

To determine the direct and indirect costs of SLE in Hong Kong, and to ascertain the relationship between neuropsychiatric SLE (NPSLE) and disease costs.

METHODS

A retrospective, cross-sectional, non-randomized cost-of-illness study was performed in a tertiary rheumatology specialty centre in Hong Kong. Participants completed questionnaires on sociodemographics, employment status and out-of-pocket expenses. Healthcare resources consumption was recorded by chart review. The occurrence of NPSLE since onset of SLE was determined using the 1999 ACR nomenclature and standard definitions. Mann-Whitney U-test was used to compare disease costs between patients with and without NPSLE. Multiple linear regression was used to determine the predictors of the costs.

RESULTS

Three hundred and six Chinese patients were recruited, with a mean age of 41 years and mean disease duration of 9.6 years. A total of 108 NPSLE events were recorded by 83 patients. The most common manifestations were seizure and cardiovascular disease. The mean annual total costs were USD 13,307 per patient. The direct costs dominated the total costs, and the costs of inpatient care contributed 52% of the direct costs. Patients with NPSLE incurred significantly higher direct and indirect costs compared with those without NPSLE. The number of NPSLE events was an independent explanatory variable associated with both direct and indirect costs.

CONCLUSION

The economic impact of SLE in Hong Kong is considerable and patients with NPSLE incur higher disease costs compared with those without NPSLE. Improvement in prevention of end-organ damage, especially neuropsychiatric manifestation, may reduce costs of SLE patients.

A study on indirect and intangible costs for patients with knee osteoarthritis in Singapore

OBJECTIVES

To estimate indirect costs through human capital approach and intangible costs through willingness-to-pay (WTP), and identify factors potentially affecting these costs in multiethnic Asian patients with knee osteoarthritis (OA).

METHODS

Data were collected through face-to-face interviews among knee OA patients. Human capital approach was used to estimate indirect costs by multiplying: 1) days of absence from work because of OA, with average earnings per capita per day for working patients; or 2) productivity loss with the market price of housekeeping for retirees/homemakers. A closed-ended iterative bidding contingent valuation method was used to elicit willingness-to-pay for a hypothetical cure of OA as a proxy for intangible costs. Mann-Whitney U or Kruskal-Wallis H-tests were performed in univariate analyzes, and linear regression in multivariate analyses.

RESULTS

Indirect costs per year and intangible costs were estimated at US$1008 and US$1200, accounting for 2.8% and 3.3% of annual household income, respectively. The indirect costs were significantly higher for male or working patients, while intangible costs were higher for Chinese, working patients, with higher income, or worse global well-being.

CONCLUSION

This study demonstrated that eliciting indirect costs through human capital approach and intangible costs through WTP are acceptable and feasible in Asian patients with knee OA. Besides the direct costs, the indirect and intangible costs for the OA patients could be substantial.

Electrical impedance signal analysis in assessing the possibility of non-invasive diagnosis of knee osteoarthritis

Knee osteoarthritis (OA) is a degenerating disorder that leads to pain, disability and dependence. Although significant numbers of elderly people are affected by this irreversible damage, not many non-invasive methods have been found that can detect onset of OA. The traditional x-ray has the disadvantage of detecting a problem only after many changes have taken place. Others, such as MRI and ultrasound, are either expensive or unsuitable for mass screening and repeated use. In this paper, an attempt has been made to study the usefulness of electrical impedance plethysmography (EIP) in non-invasive diagnosis of knee OA. In two experiments on 10 OA knees and eight control knees in groups aged 45 - 65 years (OA group: 62.40 +/- 3.47 years, controls: 53.38 +/- 8.55 years), knee swing (active flexion and extension of leg in sitting position, KS) and normal walking (WN) electrical impedance changes (DeltaZ) around the knee were analysed. The results indicate that there is significant difference in amplitudes of signals. Difference in mean of variances of two groups was significant (p < 0.05) for KS and WN. The difference in the mean rms values was also significant (p < 0.05) for KS and WN. Impedance changes suggest that EIP signal around the knee have the potential for non-invasive diagnosis of knee OA.

True difference or something else? Problems in cost of osteoarthritis studies

OBJECTIVES

To identify the commonalities and discrepancies among the published cost of osteoarthritis (OA) studies and to further propose some potential improvements for this type of research.

METHODS

A systematic literature review was performed on MEDLINE (1966 to April 2006) by using 2 overlapping search strategies to identify cost of illness studies in OA based on the predefined eligible criteria. Direct and indirect costs per patient per annum were separately summarized across studies and countries. The sample size-weighted mean was calculated when there were 2 or more studies from the same country. Discount rates of 3% and appropriate exchange rates were used in conversion of the costs reported in different years and different currencies to 2005 US dollars.

RESULTS

Ten articles fulfilling the eligible criteria were included in the literature synthesis. Of these, 4 were from the USA, 2 each from Canada and France, and 1 each from Italy and Hong Kong. After adjusted to 2005 US dollars, annual direct costs per patient (in descending order) were $9147 in Hong Kong, $4792 in USA, $2878 in Canada, $1271 in Italy, and $345 in France. In contrast, indirect costs were only reported by 5 studies in 4 countries. The highest indirect costs were $9847 per patient per annum in Canada and the lowest were $864 in Hong Kong.

CONCLUSIONS

The observed substantial variations in costs of OA across studies and countries may not reflect the true differences among them. The comparability across these identified studies is quite limited, which highlights the importance of standardization in cost of OA studies.

Impact of an Arthritis Self-Management Programme with an added exercise component for osteoarthritic knee sufferers on improving pain, functional outcomes, and use of health care services: An experimental study

OBJECTIVE

The aim of this study was to assess the effect of an adopted Arthritis Self-Management Programme (ASMP) with an added exercise component among osteoarthritic knee sufferers in Hong Kong.

METHODS

An experimental study with 88 participants assigned to an intervention group and 94 participants to a control group. One hundred and forty-nine participants (81.9%) completed the 1 week and 120 participants (65.6%) the 16 week post-intervention assessments. Participants in the intervention group received a 6-week ASMP with an added exercise component. Outcome measures included arthritic pain and fatigue rating, practice of light exercise routines, functional status, and number of unplanned arthritis-related medical consultations. To assess the programme's effect on outcome measures, the between-groups and within-group mean changes were compared using Mann-Whitney U-test and Friedman test.

RESULTS

At 16 weeks, there were significant mean changes between groups in four outcome measures: reduction in arthritis pain (p=0.0001) and fatigue (p=0.008), and increased duration of weekly light exercise practice (p=0.0001) and knee flexion (p=0.004). The ability to perform daily activities and the number of unplanned arthritis-related medical consultations show statistically significant improvements between three time-points within the intervention group only (p=0.0001 and p=0.005, respectively), but not between-groups (p=0.14 and p=0.86, respectively). Both groups apparently had no changes in muscle strength.

CONCLUSION

Our findings suggest that the intervention had a positive effect in reducing pain, fatigue, knee range of motion, the practice of exercise routines, the number of medical consultations and in improving functional status and over a 16-week period.

PRACTICE IMPLICATIONS

The self-management programme we applied took into account the local context and the ethnicity of the group. This process is worth further exploration and testing in different groups.