Analysis of regional variation in hip and knee joint replacement rates in England using Hospital Episodes Statistics

Is Social Deprivation Associated With Usage, Adverse Events, and Patient-reported Outcome Measures in Total Joint Arthroplasty? A Systematic Review

BACKGROUND

To capture various social determinants of health, recent analyses have used comprehensive measures of socioeconomic disadvantage such as deprivation and vulnerability indices. Given that studies evaluating the effects of social deprivation on total joint arthroplasty (TJA) have yielded mixed results, a systematic review of this relationship might help answer questions about usage, complications, and results after surgery among patients in different socioeconomic groups and help guide targeted approaches to ensure health equity.

QUESTIONS/PURPOSES

We asked: How is social deprivation associated with TJA (1) usage, (2) adverse events including discharge deposition and length of stay, and (3) patient-reported outcome measures (PROMs)?

METHODS

A comprehensive review of the PubMed, EBSCO host, Medline, and Google Scholar electronic databases was conducted to identify all studies that evaluated social deprivation and TJA between January 1, 2000, and March 1, 2022. Studies were included if they evaluated comprehensive measures of socioeconomic deprivation rather than individual social determinants of health. Nineteen articles were included in our final analysis with a total of 757,522 patients. In addition to characteristics of included studies (such as patient population, procedure evaluated, and utilized social deprivation metric), we recorded TJA usage, adverse events, and PROM values as reported by each article. Two reviewers independently evaluated the quality of included studies using the Methodological Index for Nonrandomized Studies (MINORS) tool. The mean ± SD MINORS score was 13 ± 1 of 16, with higher scores representing better study quality. All the articles included are noncomparative studies. Given the heterogeneity of the included studies, a meta-analysis was not performed and results were instead presented descriptively.

RESULTS

Although there were inconsistencies among the included articles, higher levels of social deprivation were associated with lower TJA usage even after controlling for various confounding variables. Similarly, there was agreement among studies regarding higher proportion of nonhome discharge for patients with more social deprivation. Although there was limited agreement across studies regarding whether patients with more social deprivation had differences in their baseline and postoperative PROMs scores, patients with more social deprivation had lower improvements from baseline for most of the included articles.

CONCLUSION

These findings encourage continued efforts focusing on appropriate patient education regarding expectations related to functional improvement and the postoperative recovery process, as well as resources available for further information and social support. We suggest linking patient data to deprivation measures such as the Area Deprivation Index to help encourage shared decision-making strategies that focus on health literacy and common barriers related to access. Given the potential influence social deprivation may have on the outcome and utilization of TJA, hospitals should identify methods to determine patients who are more socially deprived and provide targeted interventions to help patients overcome any social deprivation they are facing. We encourage physicians to maintain close communication with patients whose circumstances include more severe levels of social deprivation to ensure they have access to the appropriate resources. Additionally, as multiple social deprivation metrics are being used in research, future studies should identify a consistent metric to ensure all patients that are socially deprived are reliably identified to receive appropriate treatment.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Explaining regional variation in elective hip and knee arthroplasties in Finland 2010 - 2017-a register-based cohort study

Background

A persistent research finding in industrialised countries has been regional variation in medical practices including elective primary hip and knee arthroplasty. The aim of the study was to examine regional variations in elective total hip and knee arthroplasties over time, and the proportions of these variations which can be explained by individual level or area-level differences in need.

Methods

We obtained secondary data from the Care Register for Health Care to study elective primary hip and knee arthroplasties in total Finnish population aged 25 + years between 2010 and 2017. Two-level Poisson regression models – individuals and hospital regions – were used to study regional differences in the incidence of elective hip and knee arthroplasties in two time periods: 2010 − 2013 and 2014 − 2017. The impact of several individual level explanatory factors (age, socioeconomic position, comorbidities) and area-level factors (need and supply of operations) was measured with the proportional change in variance. Predictions of incidence were measured with incidence rate ratios. The relative differences in risk of the procedures in regions were described with median rate ratios.

Results

We found small and over time relatively stable regional variation in hip arthroplasties in Finland, while the variation was larger in knee arthroplasties and decreased during the study period. In 2010 − 2013 individual socioeconomic variables explained 10% of variation in hip and 4% in knee arthroplasties, an effect that did not emerge in 2014 − 2017. The area-level musculoskeletal disorder index reflecting the need for care explained a further 44% of the variation in hip arthroplasties in 2010 − 2013, but only 5% in 2014 − 2017 and respectively 22% and 25% in knee arthroplasties. However, our final models explained the regional differences only partially.

Conclusions

Our results suggest that eligibility criteria in total hip and knee arthroplasty are increasingly consistent between Finnish hospital districts. Factors related to individual level and regional level need both had an important role in explaining regional variations. Further study is needed on the effect of health policy on equity in access to care in these operations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-08305-7.

Geographical and ethnic differences of osteoarthritis-associated hip and knee replacement surgeries in New Zealand: a population-based cross-sectional study

OBJECTIVES

To (1) explore the regional and ethnic differences in rates of publicly funded osteoarthritis-associated hip and knee replacement surgeries and (2) investigate the mortality after surgery.

DESIGN

Population-based, retrospective, cross-sectional study.

SETTING

General population in New Zealand.

PARTICIPANTS

Patients with osteoarthritis who underwent publicly funded primary hip and knee replacement surgeries in 2005-2017. Patients aged 14-99 years were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

Age-standardised rate, standardised mortality ratio (SMR) and 30 days, 90 days and 1 year mortality.

RESULTS

We identified 53 439 primary hip replacements and 50 072 primary knee replacements with a diagnosis of osteoarthritis. The number and age-standardised rates of hip and knee replacements increased over time. Māori had the highest age-standardised rate of hip replacements, followed by European/others and Pacific, and Asian had the lowest rate. Pacific had the highest age-standardised rate of knee replacements, followed by Māori and European/others, and Asian had the lowest rate. The Northern Health Network had the lowest rate of hip surgeries, and the Southern Health Network had the lowest rate of knee surgeries. The SMRs of patients undergoing hip and knee replacements were lower than the general population: 0.92 (95% CI 0.89 to 0.95) for hip and 0.79 (95% CI 0.76 to 0.82) for knee. The SMRs were decreasing over time. The patterns of 30 days, 90 days and 1 year mortality were similar to the SMR.

CONCLUSIONS

The numbers of publicly funded osteoarthritis-associated primary hip and knee replacements are steadily increasing. Māori people had the highest age-standardised rate of hip replacements and Pacific people had the highest rate of knee replacements. The Northern Health Network had the lowest rate of hip surgeries, and the Southern Health Network had the lowest rate of knee surgeries. Compared with the general population, patients who had hip and knee replacements have a better life expectancy.

Geographical variation in musculoskeletal surgical care in public hospitals in Ireland: a repeated cross-sectional study

OBJECTIVE

To examine the extent of geographical variation across musculoskeletal surgical procedures and associated factors in Ireland.

DESIGN

Repeated cross-sectional study.

SETTING

36 public hospitals in Ireland.

PARTICIPANTS

Adult admissions for hip fracture, hip and knee replacement, knee arthroscopy and lumbar spine interventions over 5 years (2012-2016).

PRIMARY OUTCOME MEASURE

Standardised discharge rate (SDR).

ANALYSIS

Age and sex SDRs were calculated for 21 geographical areas. Extremal quotients, coefficients of variation and systematic components of variance were calculated. Linear regression analyses were conducted exploring the relationship between SDRs and year, unemployment, % urban population, number of referral hospitals, % on waiting lists>6 months and % with private health insurance for each procedure.

RESULTS

Across 36 public hospitals, n=102 756 admissions were included. Hip fracture repair showed very low variation. Elective hip and knee procedures showed high variation in particular years, while variation for lumbar interventions was very high. Knee arthroscopy rates decreased over time. Higher unemployment was associated with knee and hip replacement rates and urban areas had lower hip replacement rates. Spinal procedure rates were associated with a lower number of referral hospitals in a region and spinal injection rates were associated with shorter waiting lists. A higher proportion of patients having private health insurance was associated with higher rates of hip and knee replacement and lumbar spinal procedures.

CONCLUSIONS

Variation and factors associated with SDRs for publicly funded hip and knee procedures are consistent with similar international research in this field. Further research should explore reasons for high rates of spinal injections and the impact of private practice on musculoskeletal procedure variation.

Lower limb arthroplasty: can we produce a tool to predict outcome and failure, and is it cost-effective? An epidemiological study

Background

Although hip and knee arthroplasties are considered to be common elective cost-effective operations, up to one-quarter of patients are not satisfied with the operation. A number of risk factors for implant failure are known, but little is known about the predictors of patient-reported outcomes.

Objectives

(1) Describe current and future needs for lower limb arthroplasties in the UK; (2) describe important risk factors for poor surgery outcomes and combine them to produce predictive tools (for hip and knee separately) for poor outcomes; (3) produce a Markov model to enable a detailed health economic analysis of hip/knee arthroplasty, and for implementing the predictive tool; and (4) test the practicality of the prediction tools in a pragmatic prospective cohort of lower limb arthroplasty.

Design

The programme was arranged into four work packages. The first three work packages used the data from large existing data sets such as Clinical Practice Research Datalink, Hospital Episode Statistics and the National Joint Registry. Work package 4 established a pragmatic cohort of lower limb arthroplasty to test the practicality of the predictive tools developed within the programme.

Results

The estimated number of total knee replacements (TKRs) and total hip replacements (THRs) performed in the UK in 2015 was 85,019 and 72,418, respectively. Between 1991 and 2006, the estimated age-standardised rates (per 100,000 person-years) for a THR increased from 60.3 to 144.6 for women and from 35.8 to 88.6 for men. The rates for TKR increased from 42.5 to 138.7 for women and from 28.7 to 99.4 for men. The strongest predictors for poor outcomes were preoperative pain/function scores, deprivation, age, mental health score and radiographic variable pattern of joint space narrowing. We found a weak association between body mass index (BMI) and outcomes; however, increased BMI did increase the risk of revision surgery (a 5-kg/m2rise in BMI increased THR revision risk by 10.4% and TKR revision risk by 7.7%). We also confirmed that osteoarthritis (OA) severity and migration pattern of the hip predicted patient-reported outcome measures. The hip predictive tool that we developed performed well, with a correctedR2of 23.1% and had good calibration, with only slight overestimation of Oxford Hip Score in the lowest decile of outcome. The knee tool developed performed less well, with a correctedR2of 20.2%; however, it had good calibration. The analysis was restricted by the relatively limited number of variables available in the extant data sets, something that could be addressed in future studies. We found that the use of bisphosphonates reduced the risk of revision knee and hip surgery by 46%. Hormone replacement therapy reduced the risk by 38%, if used for at least 6 months postoperatively. We found that an increased risk of postoperative fracture was prevented by bisphosphonate use. This result, being observational in nature, will require confirmation in a randomised controlled trial. The Markov model distinguished between outcome categories following primary and revision procedures. The resulting outcome prediction tool for THR and TKR reduced the number and proportion of unsatisfactory outcomes after the operation, saving NHS resources in the process. The highest savings per quality-adjusted life-year (QALY) forgone were reported from the oldest patient subgroups (men and women aged ≥ 80 years), with a reported incremental cost-effectiveness ratio of around £1200 saved per QALY forgone for THRs. In the prospective cohort of arthroplasty, the performance of the knee model was modest (R2 = 0.14) and that of the hip model poor (R2 = 0.04). However, the addition of the radiographic OA variable improved the performance of the hip model (R2 = 0.125 vs. 0.110) and high-sensitivity C-reactive protein improved the performance of the knee model (R2 = 0.230 vs. 0.216). These data will ideally need replication in an external cohort of a similar design. The data are not necessarily applicable to other health systems or countries.

Conclusion

The number of total hip and knee replacements will increase in the next decade. High BMI, although clinically insignificant, is associated with an increased risk of revision surgery and postoperative complications. Preoperative pain/function, the pattern of joint space narrowing, deprivation index and level of education were found to be the strongest predictors for THR. Bisphosphonates and hormone therapy proved to be beneficial for patients undergoing lower limb replacement. The addition of new predictors collected from the prospective cohort of arthroplasty slightly improved the performance of the predictive tools, suggesting that the potential improvements in both tools can be achieved using the plethora of extra variables from the validation cohort. Although currently it would not be cost-effective to implement the predictive tools in a health-care setting, we feel that the addition of extensive risk factors will improve the performances of the predictive tools as well as the Markov model, and will prove to be beneficial in terms of cost-effectiveness. Future analyses are under way and awaiting more promising provisional results.

Future work

Further research should focus on defining and predicting the most important outcome to the patient.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Differences in presentation, progression and rates of arthroplasty between hip and knee osteoarthritis: Observations from an osteoarthritis cohort study-a clear role for conservative management

Aim

To describe the natural progression and the rates of arthroplasty of a cohort of hip and knee osteoarthritis (OA) patients.

Methods

An observational study of 247 consecutive patients who attended an OA clinic between May 2008 and August 2009. Follow‐up survey was conducted from July 2014 to December 2014, with the primary end point being joint replacement surgery.

Results

One hundred and sixty‐seven patients had knee OA and 80 patients had hip OA. When adjusted for other variables (age, gender, body mass index, Kellgren‐Lawrence stage, symptom duration, presence of OA elsewhere and pain score), patients with hip OA demonstrated 86% increased hazard of surgery compared to knee OA patients (95% CI increase of 19% to 193%). At 6 years after initial consultation, 67% of patients with knee OA did not require a knee replacement surgery, while 40% (30, 51) of hip OA patients did not undergo surgery (95% CI: 59–74%). Overall at 6 years, 58% of patients (95% CI: 51–64%) did not undergo joint replacement surgery.

Conclusion

Knee and hip OA patients appear to behave differently, with hip OA patients more likely to undergo arthroplasty. There is a significant number of both hip OA and knee OA patients who did not require arthroplasty at the end of 6 years, suggesting a major role for conservative therapy.

Socioeconomic inequality in small area use of elective total hip replacement in the English National Health Service in 1991 and 2001

Objectives

To compare socioeconomic inequality in small area use of elective total hip replacement in the English National Health Service (NHS) in 1991 and 2001.

Methods

Hospital Episode Statistics and Census data were aggregated to a common geography of ‘frozen’ 1991 English electoral wards. The Townsend deprivation score was used as the primary indicator of socioeconomic status for each ward, and the sensitivity analysis used other Census indicators. Two main measures of inequality were examined: the indirectly age-sex standardized utilization rate ratio between most and least deprived quintile groups, and the concentration index of deprivation-related inequality in age-sex standardized utilization ratios between small areas. Each standardized utilization ratio is the observed use divided by the expected use, if each age and sex group in the study population had the same use rate as the national population.

Results

In both years, observed use was below expected use for the bottom third of areas by socioeconomic status. The standardized utilization rate ratio between top and bottom Townsend quintiles fell from 1.41 (95% confidence interval [CI] 1.36-1.47) in 1991 to 1.27 (95% CI 1.23-1.32) in 2001. The proportionate increase in use required to bring the bottom quintile to the level of top thus fell significantly from 41% to 27%. The Town-send-based concentration index also fell from 0.069 (95% CI 0.059-0.079) in 1991 to 0.060 (95% CI 0.050-0.071) in 2001, although this fall was not statistically significant (P=0.085). Other socioeconomic indicators yielded a similar pattern.

Conclusions

Socioeconomic small area inequality in use of total hip replacement appears to have fallen between 1991 and 2001. One possible explanation is that increased hip replacement rates in the 1990s may have lowered barriers to access, thus allowing this health technology to diffuse further among lower socio-economic groups.

Variations in hospital billing for total joint arthroplasty

Although regional variations in Medicare spending are known, it is not clear whether regional variations exist in hospital charges for total joint arthroplasty. Data from Centers for Medicare and Medicaid Services (CMS) on Diagnosis Related Groups 469 and 470 (Major Joint with and without Major Complicating or Comorbid Condition) from 2011 were analyzed for variation by region. Drastic variations in charges between institutions were apparent with significant differences between regions for hospital charges and payments. The median hospital charge nationwide was $71,601 and $46,219 for Diagnosis Related Groups 469 and 470, respectively, with corresponding median payments of $21,231 and $13,743. Weak to no correlation was found between hospital charges and payments despite adjustments for wage index, cost of living, low-income care and teaching institution status.

National Health Systems

Health care systems ideally include universal access to comprehensive prepaid medical care along with health promotion and disease prevention. National health insurance and national health services of various models have evolved in the developed world and increasingly in developing countries as well. Some models, such as the Bismarckian social security model and the Bereidge National Health Service model, or National Health insurance such as in pioneered in Canada, are used by a number of countries. The common features are based on principles of national responsibility and solidarity for health, social solidarity for providing funding and searching for effective ways of providing care. Various universal systems of health coverage exist in all industrialized countries, except in the United States which has a mix of public and private insurance but with high percentages of uninsured and poorly insured. Health reform is a continuing process as all countries aspire to assure health care for all. Aging populations, increasing costs, advancing and increasing technology all require nations to modify and adapt organization and financing systems of health care, health protection and promotion.

Identifying the medical practice after total hip arthroplasty using an integrated hybrid approach

A critical option of total hip arthroplasty (THA) is considered only when tried more conservative treatments but continued to have pain, stiffness, or problems with the function of ones hip. THA plays one of major concerns under the waves of the rapid growth of aging populations and the constrained health care resources in Taiwan. Moreover, prior studies indicated that imbalanced class distribution problems do exist in the constructed classification model and cause seriously negative effects on model performances in the health care industry. Therefore, this study proposes an integrated hybrid approach to provide an alternate method for classifying the quality (e.g., the staying length in hospital) of medical practice with an imbalanced class problem after performing a THA procedure for hip replacement patients and their doctors in the health care industry. The proposed approach is constituted by seven components: expert knowledge, global discretization, imbalanced bootstrap technique, reduct and core methods, rough sets, rule induction, and rule filter. The proposed approach is illustrated in practice by examining an experimental dataset from the National Health Insurance Research Database (NHIRD) in Taiwan. The experimental results reveal that the proposed approach has better performance than the listed methods under evaluation criteria. The output created by the rough set LEM2 algorithm is a comprehensible decision rule set that can be applied in knowledge-based health care services as desired. The analytical results provide useful THA information for both academics and practitioners and these results could be applicable to other diseases or to other countries with similar social and cultural practices.

Drivers of surgery for the degenerative hip, knee, and spine: a systematic review

BACKGROUND

Surgical treatment for degenerative conditions of the hip, knee, and spine has an impact on overall healthcare spending. Surgical rates have increased dramatically and considerable regional variation has been observed. The reasons behind these increasing rates and variation across regions have not been well elucidated.

QUESTIONS/PURPOSES

We therefore identified demographic (D), social structure (SS), health belief (HB), personal (PR) and community resources (CR), and medical need (MN) factors that drive rates of hip, knee, and spine surgery.

METHODS

We conducted a systematic review to include all observational, population-based studies that compared surgical rates with potential drivers (D, SS, HB, PR, CR, MN). We searched PubMed combining key words focusing on (1) disease and procedure; (2) study methodology; and (3) explanatory models. Independent investigators selected potentially eligible studies from abstract review and abstracted methodological and outcome data. From an initial search of 256 articles, we found 37 to be potentially eligible (kappa 0.86) but only 28 met all our inclusion criteria.

RESULTS

Age, nonminority, insurance coverage, and surgeon enthusiasm all increased surgical rates. Rates of arthroplasty were higher for females with higher education, income, obesity, rurality, willingness to consider surgery, and prevalence of disease, whereas spinal rates increased with male gender, lower income, and the availability of advanced imaging.

CONCLUSIONS

Regional variation in these procedures exists because they are examples of preference-sensitive care. With strategies that may affect change in factors that are potentially modifiable by behavior or resources, extreme variation in rates may be reduced.

Who should have knee joint replacement surgery for osteoarthritis?

Knee joint replacement is an effective and cost-effective intervention for severe symptomatic osteoarthritis of the knee joint. However, utilisation rates vary hugely, there are no indications, it is difficult to know when (in the course of arthritis) it is best to operate, and some 10-20% of people who have this surgery are unhappy with the outcome, and have persistent pain. In this article we briefly discuss the variations in utilization of knee joint replacement, and then outline four different approaches to the selection and prioritisation of patients for this procedure. Consensus criteria, including appropriateness criteria are available, but if produced by professionals alone, they may conflict with the views of patients and the public. Databases and cohort studies can be used to attempt relating outcomes to baseline characteristics, but at present we can only account for a small percentage of the variance with this technique. Finally, we propose use of the 'capacity to benefit framework' to attempt providing guidance to both patients and healthcare professionals.

The impact of new hospital orthopaedic surgery programs on total joint arthroplasty utilization

BACKGROUND

Utilization of arthroplasty is increasing, but there are little data exploring the causes of this increase. The objective of this study was to examine the relationship between new programs for arthroplasty of the lower extremity joints and the utilization of arthroplasty.

METHODS

We identified twenty-four markets (hospital referral regions) that experienced the entry of new physician-owned specialty hospitals, using 1991 to 2005 Medicare data. We matched each market with a new specialty hospital to two different control markets (one market with a new arthroplasty program in a general hospital and one market without a new arthroplasty program), using a propensity score that accounted for market supply and demand for orthopaedic surgery and the regulatory environment. We compared the utilization of arthroplasty of the lower extremity joints (total hip arthroplasty and total knee arthroplasty) in each group of markets over a five-year window, extending from two years before to three years after the entry of new orthopaedic surgery programs.

RESULTS

The twenty-four markets with new specialty orthopaedic hospitals had higher utilization of arthroplasty at baseline (10.9 arthroplasties per 1000 Medicare beneficiaries per year) and follow-up (12.7 per 1000 beneficiaries) compared with the twenty-four markets with new arthroplasty programs in general hospitals (9.7 and 11.4, respectively) and the twenty-four markets with no new programs (9.9 and 11.3), although the differences were not significant (p > 0.05). Growth in the utilization of arthroplasty was similar in markets with new specialty hospitals before (an increase of 0.63 procedure per 1000 beneficiaries per year) and after the entry of new specialty hospitals (an increase of 0.39) compared with markets with new surgery programs in general hospitals (an increase of 0.24 before and 0.43 after) and markets with no new programs (an increase of 0.38 before and 0.33 after the entry of new specialty hospitals) (p > 0.05 for all comparisons).

CONCLUSIONS

The utilization of arthroplasty is increasing at similar rates in markets with and without new arthroplasty programs.

Geographical variation in incidence of primary total hip arthroplasty: a population-based analysis of 34,642 replacements

BACKGROUND

Considerable variation in total hip arthroplasty (THA) incidence between regions has been described. The aim of this study was to evaluate geographical variation in the incidence of primary THA for OA in Finland and to analyze variables associated with this variation.

METHODS

Using Hospital Discharge Register, 34,642 THAs performed for primary OA over the 1998 and 2005 period were identified. Incidence indices for 21 hospital administrative regions were determined. Logistic regression analysis and generalized linear models were used for studying the association of potential explanatory factors for the variation in the incidence of THA.

RESULTS

Incidence indices of THA varied from 1.9- to 3.0-fold during the study period. A high ratio of primary THA for primary OA to primary THA for any reason was associated with a high absolute incidence of primary THA (P < 0.001). Neither average incomes nor morbidity were associated with the incidence of THA.

INTERPRETATION

When hip surgery was performed on a larger scale, threshold for performing THAs due to primary OA was higher. Socio-economic status had no apparent effect on THA rate. Surgeon decision-making related factors influence THA rates when there are only a few surgeons responsible for performing THAs in a region.

2009 survey results: surgeon practice patterns regarding arthroscopic surgery

A survey was conducted to collect information on the surgical management and practice preferences of the audience members at a recent continuing medical education conference. Participants were polled on a variety of surgical topics, and their responses were recorded using a wireless audience response system. The answers were tabulated and are presented in this report. The majority of respondents preferred an arthroscopic repair for rotator cuff tears (52%) and shoulder instability (71%). Most (50%) perform single-row repair; 33% perform double-row repair. For simple knee arthroscopy, most use preoperative antibiotics (85%), no tourniquet (53%), and no chemical anticoagulation or only compression boots (69%). For cruciate ligament reconstruction, the majority preferred only a preoperative antibiotic (67%), no chemical anticoagulation or only compression boots (56%), and single-bundle reconstruction (88%) using a transtibial femoral tunnel (78%). Most (47%) prefer an all inside suture-based meniscus repair device.

The Alberta Hip and Knee Replacement Project: a model for health technology assessment based on comparative effectiveness of clinical pathways

BACKGROUND

The Alberta Hip and Knee Replacement Project developed a new evidence-based clinical pathway (NCP) for total hip (THR) and knee (TKR) replacement. The aim was to facilitate the delivery of services in a timely and cost-effective manner while achieving the highest quality of care for the patient across the full continuum of care from patient referral to an orthopedic surgeon through surgery, recovery, and rehabilitation. The purpose of this article is to provide an overview of the study design, rationale, and execution of this project as a model for health technology assessment based on comparative effectiveness of alternative clinical pathways.

METHODS

A pragmatic randomized controlled trial study design was used to evaluate the NCP compared with the standard of care (SOC) for these procedures. The pragmatic study design was selected as a rigorous approach to produce high quality evidence suitable for informing decisions between relevant interventions in real clinical practice. The NCP was evaluated in three of the nine regional health authorities (RHAs) in Alberta with dedicated central intake clinics offering multidisciplinary care teams, constituting 80 percent of THR and TKR surgeries performed annually in Alberta. Patients were identified in the offices of twenty orthopedic surgeons who routinely performed THR or TKR surgeries. Evaluation outcome measures were based on the six dimensions of the Alberta Quality Matrix for Health (AQMH): acceptability, accessibility, appropriateness, effectiveness, efficiency and safety. Data were collected prospectively through patient self-completed questionnaires at baseline and 3 and 12 months after surgery, ambulatory and inpatient chart reviews, and electronic administrative data.

RESULTS

The trial design was successful in establishing similar groups for rigorous evaluation. Of the 4,985 patients invited to participate, 69 percent of patients consented. A total of 3,434 patients were randomized: 1,712 to SOC and 1,722 to the NCP. The baseline characteristics of patients in the two study arms, including demographics, comorbidity as measured by CDS and exposure to pain medications, and health-related quality of life, as measured by Western Ontario and McMaster Universities Osteoarthritis Index and Short Form-36, were similar.

CONCLUSIONS

The Alberta Hip and Knee Replacement Project demonstrates the feasibility and advantages of applying a pragmatic randomized controlled trial to ascertain comparative effectiveness. This is a model for health technology assessment that incorporates how clinical pathways can be effectively evaluated.

Regional variation in orthopedic surgery in Switzerland

The study systematically describes the frequency and geographic variability of major surgical interventions for musculoskeletal disorders in Switzerland. Age- and sex-standardized rates for joint replacements, arthroscopies, spine surgery and hip fracture repair were calculated for hospital service regions. Various statistical analyses were used to measure the extent of variation. The authors argue that the surgery of hip fractures can be used as index surgery in the context of analyzing variations in orthopedic surgery. Temporal trends imply that patient demand and supply factors related to clinical ambiguity and non-medical incentives of providers are far more important components leading to increased use than the sole effect of an aging population.

Knee arthroscopy in England and Ontario: patterns of use, changes over time, and relationship to total knee replacement

BACKGROUND

The role of knee arthroscopy in the management of osteoarthritis is unclear. The purpose of this study was to examine patterns of use of knee arthroscopy, overall and by diagnostic and sociodemographic subgroups, in countries with comparable health-care systems.

METHODS

Administrative databases were used to construct cohorts of adults, twenty years of age or older, who had undergone their first knee arthroscopy in 1993, 1997, 2002, or 2004 either in Ontario, Canada, or in England. For each year, age and sex-standardized rates of knee arthroscopy per 100,000 population were determined overall and by diagnosis, sex, age, and income quintile. Regression analysis, with control for confounders, was used to examine predictors of readmission for primary total knee replacement up to five years after an index knee arthroscopy performed in 1993 or 1997. We also analyzed the records of patients who had undergone primary knee replacement in 2002 to determine the rates of knee arthroscopy in the two years prior to that replacement.

RESULTS

In both countries, the proportion of arthroscopic procedures performed to treat internal derangement or dislocation of the knee increased over time; the rates were highest in the highest income quintiles. The study revealed that 4.8% of the patients in England and 8.5% of those in Ontario who had an arthroscopy to treat osteoarthritis in 1997 received a knee replacement within one year after that procedure. The risk of readmission for knee replacement was greater in association with a diagnosis of osteoarthritis, female sex, and an older age at the time of the arthroscopy. Of the patients who had a primary knee replacement in 2002, 2.7% in England and 5.7% in Ontario had undergone a knee arthroscopy in the previous year; the likelihood of the patient having had a prior arthroscopy increased with higher income and increasing age.

CONCLUSIONS

Variations in knee arthroscopy rates according to age, sex, income, and diagnosis were identified in both countries. Research to determine if these differences are consistent with need is warranted.

MOBILE and the provision of total joint replacement

Modern joint replacements have been available for 45 years, but we still do not have clear indications for these interventions, and we do not know how to optimize the outcome for patients who agree to have them done. The MOBILE programme has been investigating these issues in relation to primary total hip and knee joint replacements, using mixed methods research.

There have been five main strands: (1) Epidemiological investigations to find out who is receiving total hip and knee replacements in the National Health Service (NHS). This has shown that there are extensive variations in different regions of the UK, with inequalities and probable inequities in the provision of these operations; (2) Epidemiological work to ascertain the population-based needs for the operations, showing under-provision of knee joint replacements, and a relative reluctance of both patients and GPs to consider knee surgery; (3) Quantitative and qualitative research into the views of patients, health care professionals and the public on the indications for, and prioritization of, total hip and knee joint replacements. This has shown lack of agreement within or between professional groups, as well as a mismatch between the views of patients and the public, and those of professionals; (4) Theoretical and experimental work on patient-related outcome measures, and the development of new instruments to assess both pain and function in people with osteoarthritis, based on the International Classification of Function, as well as a new integrated model of function; (5) Cohort studies of patients undergoing hip or knee joint replacements to find out what the determinants of good and bad outcomes are. These studies have emphasized the huge variation in disease severity at the time of surgery.

The challenge now is to use and implement our findings for maximum patient benefit.

Management of chronic knee pain: a survey of patient preferences and treatment received

Background

A range of interventions exist for the management of knee pain, but patient preferences for treatment are not clear. In this study the management received by people with chronic knee pain, their management preferences and reasons for these preferences were recorded.

Methods

At baseline assessment of a clinical trial of rehabilitation for chronic knee pain, 415 participants were asked about their i) previous management, ii) preferred treatment, if any, iii) whether they would undergo knee surgery and iv) reasons for their preferences.

Results

Previous management – Medication was the most common treatment, followed by physiotherapy, 39 participants had received no treatment. Preferences – 166 patients expressed no treatment preference. Of those who expressed a preference the most popular option was physiotherapy, whilst not having surgery was the third most frequent response. The most common reason for preferring physiotherapy and not wanting surgery was prior experience.

Willingness to accept surgery – 390 participants were not waiting for knee replacement surgery, and overall 81% would not accept surgery if offered, usually because pain was not perceived to be severe enough to warrant surgery.

Conclusion

Most chronic knee pain is managed with medication despite concerns about safety, efficacy and cost, management guidelines recommendations and people's management preferences. Previous experience and perceptions of need were major determinants of people's preferences, but many people were unaware of management options. Appreciating patient preferences and provision of more information about management options are important in facilitating informed patient/clinician discussion and agreement.

Trial Registration

Current Controlled Trials, ISRCTN 94658828

Characteristics of evolving models of care for arthritis: a key informant study

BACKGROUND

The burden of arthritis is increasing in the face of diminishing health human resources to deliver care. In response, innovative models of care delivery are developing to facilitate access to quality care. Most models have developed in response to local needs with limited evaluation. The primary objective of this study is to a) examine the range of models of care that deliver specialist services using a medical/surgical specialist and at least one other health care provider and b) document the strengths and challenges of the identified models. A secondary objective is to identify key elements of best practice models of care for arthritis.

METHODS

Semi-structured interviews were conducted with a sample of key informants with expertise in arthritis from jurisdictions with primarily publicly-funded health care systems. Qualitative data were analyzed using a constant comparative approach to identify common types of models of care, strengths and challenges of models, and key components of arthritis care.

RESULTS

Seventy-four key informants were interviewed from six countries. Five main types of models of care emerged. 1) Specialized arthritis programs deliver comprehensive, multidisciplinary team care for arthritis. Two models were identified using health care providers (e.g. nurses or physiotherapists) in expanded clinical roles: 2) triage of patients with musculoskeletal conditions to the appropriate services including specialists; and 3) ongoing management in collaboration with a specialist. Two models promoting rural access were 4) rural consultation support and 5) telemedicine. Key informants described important components of models of care including knowledgeable health professionals and patients.

CONCLUSION

A range of models of care for arthritis have been developed. This classification can be used as a framework for discussing care delivery. Areas for development include integration of care across the continuum, including primary care.

Epidemiology and health services: year in review

PURPOSE OF REVIEW

Epidemiology began as the study of the occurrence of disease in populations. Initial studies focused on the presence of diseases by person, place, and time to identify risk factors for disease. The field has grown to include many subfields recognizing the contributions of multiple factors to disease susceptibility.

RECENT FINDINGS

This review will focus on articles published October 2005-November 2006 relevant to genetic epidemiology, pharmacoepidemiology, and social determinants of health and health disparities.

SUMMARY

Genetic epidemiology is the study of genetic contributions to disease occurrence, and of population-based genetic risks for disease. Genetics influences not only susceptibility to disease, but also the phenotype and severity of disease. Pharmacoepidemiology examines the outcomes of medication use, including clinical benefits and adverse effects. Gene-environment interactions are also included in this area. Typical topics in pharmacoepidemiology include studies of medication use, risks, benefits and genetic factors influencing the metabolism of medications. Social epidemiology is the study of social determinants of health, including psychosocial behaviors, socioeconomic status, interactions of individuals, the collective health of the community in which a person lives, and the position of the individual within society. Social epidemiology is directly relevant to studies of socioeconomic and ethnic disparities.

The influence of socioeconomic status on utilization and outcomes of elective total hip replacement: a multicity population-based longitudinal study

OBJECTIVE

In countries with universal health coverage, socioeconomic status is not expected to influence access to effective treatment and its prognosis. We tested whether socioeconomic status affects the rates of elective total hip replacement and whether it plays a role in early and late outcomes.

DESIGN

Multicity population-based longitudinal study.

SETTING AND PARTICIPANTS

From Hospital Registries of four Italian cities (Rome, Milan, Turin, and Bologna), we identified 6140 residents aged 65+ years undergoing elective total hip replacement in 1997-2000.

MAIN OUTCOME MEASURES

An area-based (census block) income index was used for each individual. Poisson regression yielded rate ratios (RR) of population occurrence by income level. Logistic regression estimated odds ratios (OR) of selected outcomes within 90 days. Cox proportional hazard models evaluated effects of income on rates of revision of total hip replacement and mortality up to 31 December 2004. Analyses were adjusted for age, gender, city of residence, and coexisting medical conditions.

RESULTS

Low-income people were less likely than high-income counterparts to undergo total hip replacement [RR = 0.87, 95% confidence interval (CI) 0.81-0.95]; the effect was stronger among those aged 75+ years (RR = 0.76, 95% CI = 0.66-0.86). Low income was associated with higher risk of acute adverse medical events (P trend = 0.05) and of general infections and decubitus ulcer (P trend = 0.02) within 90 days. The effects were even higher among those aged 75+ years. No effects were found either for orthopaedic complications within 90 days or for revision and mortality.

CONCLUSIONS

Total hip replacement is underutilized among elderly deprived individuals. Disadvantaged patients seem more vulnerable to acute adverse medical events after surgery. The evidence of unmet need and poor prognosis of low social class people has important implications for health care policy.

Standardized incidence rates of total hip replacement for primary hip osteoarthritis in the 5 Nordic countries: similarities and differences

BACKGROUND

The national hip registers of the Nordic countries provide an opportunity to compare age- and sex-standardized annual incidence of primary total hip replacement (THR) and types of implants used for primary hip osteoarthritis (OA) in Denmark, Finland, Iceland, Norway and Sweden.

METHODS

The data on THR were from the national total hip replacement registries, and population data were from the national statistics agencies. Annual incidence density per 100,000 was calculated for each 5-year age group and it was age-standardized using the WHO European standard population.

RESULTS

Crude country-specific annual incidence (all ages) for 1996-2000 varied between 73 and 90. WHO age-standardized annual incidence (all ages) varied between 61 (Finland) and 84 (Iceland). For the ages 50-89, comprising 94-98% of all THRs for OA, annual incidence varied between 217 (Finland) and 309 (Iceland). For Norway, the sex incidence ratio (women/men) was 2, and for the other countries it was between 1.1 and 1.3. The use of uncemented and hybrid replacements was considerably higher in Finland and Denmark than in the other countries.

INTERPRETATION

We found overall similarity in THR incidence between the 5 Nordic countries, but substantial differences between women and men, and in the use of different types of implant. Population-based, age-standardized and disease-specific information on THR incidence is required in order to properly explore the causes of differences in provision and practice of THR in different countries, regions and groups, and it will aid in projecting future needs.