Comparative outcomes and cost-utility following surgical treatment of focal lumbar spinal stenosis compared with osteoarthritis of the hip or knee: part 2--estimated lifetime incremental cost-utility ratios.

BACKGROUND CONTEXT: Although total hip arthroplasty (THA) and total knee arthroplasty (TKA) have been widely accepted as highly cost-effective procedures, spine surgery for the treatment of degenerative conditions does not share the same perception among stakeholders. In particular, the sustainability of the outcome and cost-effectiveness following lumbar spinal stenosis (LSS) surgery compared with THA/TKA remain uncertain. PURPOSE: The purpose of the study was to estimate the lifetime incremental cost-utility ratios for decompression and decompression with fusion for focal LSS versus THA and TKA for osteoarthritis (OA) from the perspective of the provincial health insurance system (predominantly from the hospital perspective) based on long-term health status data at a median of 5 years after surgical intervention. STUDY DESIGN/SETTING: An incremental cost-utility analysis from a hospital perspective was based on a single-center, retrospective longitudinal matched cohort study of prospectively collected outcomes and retrospectively collected costs. PATIENT SAMPLE: Patients who had undergone primary one- to two-level spinal decompression with or without fusion for focal LSS were compared with a matched cohort of patients who had undergone elective THA or TKA for primary OA. OUTCOME MEASURES: Outcome measures included incremental cost-utility ratio (ICUR) ($/quality adjusted life year [QALY]) determined using perioperative costs (direct and indirect) and Short Form-6D (SF-6D) utility scores converted from the SF-36. METHODS: Patient outcomes were collected using the SF-36 survey preoperatively and annually for a minimum of 5 years. Utility was modeled over the lifetime and QALYs were determined using the median 5-year health status data. The primary outcome measure, cost per QALY gained, was calculated by estimating the mean incremental lifetime costs and QALYs for each diagnosis group after discounting costs and QALYs at 3%. Sensitivity analyses adjusting for +25% primary and revision surgery cost, +25% revision rate, upper and lower confidence interval utility score, variable inpatient rehabilitation rate for THA/TKA, and discounting at 5% were conducted to determine factors affecting the value of each type of surgery. RESULTS: At a median of 5 years (4-7 years), follow-up and revision surgery data was attained for 85%-FLSS, 80%-THA, and 75%-THA of the cohorts. The 5-year ICURs were $21,702/QALY for THA; $28,595/QALY for TKA; $12,271/QALY for spinal decompression; and $35,897/QALY for spinal decompression with fusion. The estimated lifetime ICURs using the median 5-year follow-up data were $5,682/QALY for THA; $6,489/QALY for TKA; $2,994/QALY for spinal decompression; and $10,806/QALY for spinal decompression with fusion. The overall spine (decompression alone and decompression and fusion) ICUR was $5,617/QALY. The estimated best- and worst-case lifetime ICURs varied from $1,126/QALY for the best-case (spinal decompression) to $39,323/QALY for the worst case (spinal decompression with fusion). CONCLUSION: Surgical management of primary OA of the spine, hip, and knee results in durable cost-utility ratios that are well below accepted thresholds for cost-effectiveness. Despite a significantly higher revision rate, the overall surgical management of FLSS for those who have failed medical management results in similar median 5-year and lifetime cost-utility compared with those of THA and TKA for the treatment of OA from the limited perspective of a public health insurance system.

Comparison of lifetime incremental cost:utility ratios of surgery relative to failed medical management for the treatment of hip, knee and spine osteoarthritis modelled using 2-year postsurgical values.

BACKGROUND: Demand for surgery to treat osteoarthritis (OA) of the hip, knee and spine has risen dramatically. Whereas total hip (THA) and total knee arthroplasty (TKA) have been widely accepted as cost-effective, spine surgeries (decompression, decompression with fusion) to treat degenerative conditions remain underfunded compared with other surgeries. METHODS: An incremental cost-utility analysis comparing decompression and decompression with fusion to THA and TKA, from the perspective of the provincial health insurance system, was based on an observational matched-cohort study of prospectively collected outcomes and retrospectively collected costs. Patient outcomes were measured using short-form (SF)-36 surveys over a 2-year follow-up period. Utility was modelled over the lifetime, and quality-adjusted life years (QALYs) were determined. We calculated the incremental cost per QALY gained by estimating mean incremental lifetime costs and QALYs of surgery compared with medical management of each diagnosis group after discounting costs and QALYs at 3%. Sensitivity analyses were also conducted. RESULTS: The lifetime incremental cost:utility ratios (ICURs) discounted at 3% were $5321 per QALY for THA, $11,275 per QALY for TKA, $2307 per QALY for spinal decompression and $7153 per QALY for spinal decompression with fusion. The sensitivity analyses did not alter the ranking of the lifetime ICURs. CONCLUSION: In appropriately selected patients with leg-dominant symptoms secondary to focal lumbar spinal stenosis who have failed medical management, the lifetime ICUR for surgical treatment of.

Developing a decision aid to guide public sector health policy decisions: a study protocol.

BACKGROUND: Decision aids have been developed in a number of health disciplines to support evidence-informed decision making, including patient decision aids and clinical practice guidelines. However, policy contexts differ from clinical contexts in terms of complexity and uncertainty, requiring different approaches for identifying, interpreting, and applying many different types of evidence to support decisions. With few studies in the literature offering decision guidance specifically to health policymakers, the present study aims to facilitate the structured and systematic incorporation of research evidence and, where there is currently very little guidance, values and other non-research-based evidence, into the policy making process. The resulting decision aid is intended to help public sector health policy decision makers who are tasked with making evidence-informed decisions on behalf of populations. The intent is not to develop a decision aid that will yield uniform recommendations across jurisdictions, but rather to facilitate more transparent policy decisions that reflect a balanced consideration of all relevant factors. METHODS/DESIGN: The study comprises three phases: a modified meta-narrative review, the use of focus groups, and the application of a Delphi method. The modified meta-narrative review will inform the initial development of the decision aid by identifying as many policy decision factors as possible and other features of methodological guidance deemed to be desirable in the literatures of all relevant disciplines. The first of two focus groups will then seek to marry these findings with focus group members' own experience and expertise in public sector population-based health policy making and screening decisions. The second focus group will examine issues surrounding the application of the decision aid and act as a sounding board for initial feedback and refinement of the draft decision aid. Finally, the Delphi method will be used to further inform and refine the decision aid with a larger audience of potential end-users. DISCUSSION: The product of this research will be a working version of a decision aid to support policy makers in population-based health policy decisions. The decision aid will address the need for more structured and systematic ways of incorporating various evidentiary sources where applicable.

A multidisciplinary systematic review of the use of diagrams as a means of collecting data from research subjects: application, benefits and recommendations.

BACKGROUND: In research, diagrams are most commonly used in the analysis of data and visual presentation of results. However there has been a substantial growth in the use of diagrams in earlier stages of the research process to collect data. Despite this growth, guidance on this technique is often isolated within disciplines. METHODS: A multidisciplinary systematic review was performed, which included 13 traditional healthcare and non-health-focused indexes, non-indexed searches and contacting experts in the field. English-language articles that used diagrams as a data collection tool and reflected on the process were included in the review, with no restriction on publication date. RESULTS: The search identified 2690 documents, of which 80 were included in the final analysis. The choice to use diagrams for data collection is often determined by requirements of the research topic, such as the need to understand research subjects' knowledge or cognitive structure, to overcome cultural and linguistic differences, or to understand highly complex subject matter. How diagrams were used for data collection varied by the degrees of instruction for, and freedom in, diagram creation, the number of diagrams created or edited and the use of diagrams in conjunction with other data collection methods. Depending on how data collection is structured, a variety of options for qualitative and quantitative analysis are available to the researcher. The review identified a number of benefits to using diagrams in data collection, including the ease with which the method can be adapted to complement other data collection methods and its ability to focus discussion. However it is clear that the benefits and challenges of diagramming depend on the nature of its application and the type of diagrams used. DISCUSSION/CONCLUSION: The results of this multidisciplinary systematic review examine the application of diagrams in data collection and the methods for analyzing the unique datasets elicited. Three recommendations are presented. Firstly, the diagrammatic approach should be chosen based on the type of data needed. Secondly, appropriate instructions will depend on the approach chosen. And thirdly, the final results should present examples of original or recreated diagrams. This review also highlighted the need for a standardized terminology of the method and a supporting theoretical framework.

Predicting the longer term outcomes of total knee arthroplasty.

We asked the question of what are the patient level predictors (age, gender, body mass index, education, ethnicity, mental health, and comorbidity) for a sustained functional benefit at a minimum of 1 year follow-up after total knee arthroplasty(TKA). Five hundred fifty-one consecutive patients were reviewed from our joint registry between the years of 1998 and 2005. Baseline demographic data and the outcome scores of the Western Ontario McMaster University Osteoarthritis Index (WOMAC) and Medical Outcomes Short-Form 36 (SF36) scores were extracted from the database. Longitudinal regression modeling was performed to identify the predictive factors of interest. We had 27% of data points missing. The mean follow-up in our cohort was 3.0 years (range 1-8 years) and there were no revisions performed during this time. Clinical outcome scores were found to be relatively constant for 3-4 years after surgery and then demonstrated a gradual decline after that. Older age, year of follow-up, greater comorbidity, and a poorer mental health state at time of surgery were identified as negative prognostic factors for a sustained functional outcome following TKR (P<0.05). Knowledge of these factors that predict outcomes should be used in setting appropriate patient expectations of surgery.

Asian ethnicity and the prevalence of metabolic syndrome in the osteoarthritic total knee arthroplasty population.

Metabolic syndrome (MS) is a known risk factor for the development of osteoarthritis (OA). We asked whether the prevalence of MS varies across ethnicity among patients who undergo total knee arthroplasty for end-stage OA. In our population of 1460 patients undergoing primary knee arthroplasty, MS was defined as body mass index greater than 30 kg/m(2), diabetes, hypertension, and hypercholesterolemia. Among the 1334 white patients, 114 (8.5%) had MS as compared with 3 of 36 (8.3%) blacks and 18 of 90 (20%) Asians (P = .006) Adjusted analysis showed that those of Asian ethnicity had a 2.0 (95% confidence interval, 1.1-3.8; P = .03) times greater odds of MS as compared with those of other ethnicity. Metabolic syndrome is a risk factor for OA, and Asians demonstrate a greater prevalence of MS as compared with whites and blacks in this population.

Outcomes of total joint arthroplasty in academic versus community hospitals.

BACKGROUND: Most joint-replacement surgeries are currently performed in community hospitals. We sought to determine whether the functional outcomes of joint-replacement surgery differ between academic and community hospitals. METHODS: We surveyed 471 patients for demographic data, Western Ontario McMaster University Osteoarthritis Index (WOMAC) scores and Medical Outcomes Study Short Form 36 (SF-36) scores at baseline and at 3-month and 1-year follow-up. We assessed patient satisfaction at 1 year with a single survey question. RESULTS: Community hospital patients (n = 269) were significantly older and had greater comorbidity than academic hospital patients (n = 202; p < 0.05). We found no difference in WOMAC scores, SF-36 scores or in patient satisfaction between hospitals at 1-year follow-up (p > 0.05). Adjusted analysis showed that patients undergoing surgery in an academic or community hospitals have the same functional outcomes. CONCLUSION: There is no significant difference in the functional outcomes of joint-replacement surgery between academic and community hospitals. Further work will involve evaluating cost of care differences between these types of hospitals.

Metabolic syndrome and the incidence of symptomatic deep vein thrombosis following total knee arthroplasty.

OBJECTIVE: We asked if patients with metabolic syndrome undergoing total knee replacement (TKR) have an increased risk for symptomatic deep vein thrombosis (DVT) at 3 months followup. METHODS: We reviewed 1460 patients from our joint registry undergoing primary, unilateral TKR between 1998-2006. Demographic variables of age, sex, comorbidity, and education were retrieved. Metabolic syndrome was defined as body mass index above 30 kg/m(2), diabetes, hypertension, and hypercholesterolemia. Logistic regression was used to examine the relationship of metabolic syndrome on the incidence of DVT. RESULTS: The overall incidence of symptomatic DVT was 4.4% (65/1460). Patients with metabolic syndrome had an increased incidence of DVT compared to those without metabolic syndrome (15.5% vs 3.4%). Adjusted analysis showed that the risk of symptomatic DVT in patients with metabolic syndrome was 3.2 times [odds ratio 3.2, 95% CI (1.0,15.4), p = 0.04] the risk in those without metabolic syndrome. CONCLUSION: Hospital protocols developed for prophylactic anticoagulation following TKR should give special consideration to patients with metabolic syndrome.

Greater perceived helplessness in osteoarthritis predicts outcome of joint replacement surgery.

OBJECTIVE: To determine if there is a difference between male and female patients in their perceived control of osteoarthritis (OA) symptoms at the time of joint replacement surgery, as measured by the Arthritis Helplessness Index (AHI), and how this helplessness affects surgical outcomes at 1 year. METHODS: From a joint replacement registry, 70 male and 70 female patients were randomly selected and matched for age, body mass index, comorbidity, procedure, and education. Patients completed the AHI prior to surgery. Functional status was assessed at baseline and 1-year followup with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. Linear regression modeling was used to determine the effect of sex on predicting AHI scores. A second model was constructed to examine the effect of AHI on the 1-year WOMAC change score. RESULTS: There were no statistically significant differences in demographic data or clinically significant differences in AHI scores between sexes. Linear regression modeling showed that female sex was a significant predictor of a greater AHI score prior to surgery (p < 0.05). Moreover, a greater AHI score was an independent predictor of a lower WOMAC change score at 1 year (p = 0.01). CONCLUSION: Interventions to improve control over arthritis symptoms should be studied with the goal of improving surgical outcomes.

High-flexion implants in primary total knee arthroplasty: a meta-analysis.

BACKGROUND: We asked whether a high-flexion design implant improves patient functional outcomes or range of motion (ROM) after primary knee arthroplasty. METHODS: We searched the major medical databases for randomized trials and comparison observational studies comparing high-flexion and conventional knee implants. After testing for publication bias and heterogeneity, the data were aggregated by random effect modeling. We estimated the weighted mean differences of functional outcomes scores and ROM with 95% confidence intervals. RESULTS: Six studies met our inclusion criteria for review. We found no evidence of publication bias. The pooled mean difference for KSS scores was 0.144 (95% CI: -0.018 to 0.306), p=0.081. The pooled mean difference for the mean changes in ROM was 0.404 (95% CI: 0.139 to 0.669), p=0.003. CONCLUSION: High-flexion implant design improves overall ROM as compared to traditional implants but offers no clinical advantage over traditional implant designs in primary knee arthroplasty.