Differences in Outcomes Between Initial Responders and Subsequent Responders to Health Questionnaires for Total Hip and Knee Arthroplasty: An Australian Tertiary Institutional Registry Study.

BACKGROUND: Patient-reported outcome measure (PROM) questionnaires in national arthroplasty registries often have low response rates leading to questions about data reliability. In Australia, the SMART (St. Vincent's Melbourne Arthroplasty Outcomes) registry captures all elective total hip (THA) and total knee (TKA) arthroplasty patients with an approximate 98% response rate for preoperative and 12-month PROM scores. This high response rate is due to dedicated registry staff following up patients who do not initially respond (subsequent responders). This study compared initial responders to subsequent responders to find differences in 12-month PROM outcomes for THA and TKA. METHODS: All elective THA and TKA patients for osteoarthritis from 2012 to 2021 captured by the SMART registry were included. In total, 1,333 THA and 1,340 TKA patients were included. The PROM scores were assessed using the Veterans-RAND 12 (VR12) and Western Ontario and McMasters Universities Arthritis Index (WOMAC) questionnaires. The primary outcome was differences in mean 12-month PROM scores between initial and subsequent responders. RESULTS: Baseline characteristics and PROM scores were similar between initial and subsequent responders. However, 12-month PROM scores varied significantly. The adjusted mean difference showed that for the WOMAC pain score, subsequent responders scored 3.4 points higher in the THA cohort and 7.4 points higher in the TKA cohort compared to initial responders. Significant differences were also found in other WOMAC and VR12 scores for both THA and TKA cohorts at the 12-month timepoint. CONCLUSION: This study found that significant differences in PROM outcomes postsurgery occurred in THA and TKA patients based on response to PROM questionnaires, suggesting that loss to follow-up in PROM outcomes should not be treated as missing completely at random (MCAR).

Assessing the Mortality Rate After Primary Total Knee Arthroplasty: An Observational Study to Inform Future Economic Analysis.

BACKGROUND: Previous research has focused on the perioperative or short-term (<1 year) mortality rate of total knee arthroplasty (TKA), leaving the long-term (>1 year) mortality rate unresolved. In this study, we calculated the mortality rate up to 15 years after primary TKA. METHODS: Data from the New Zealand Joint Registry from April 1998 to December 2021 were analyzed. Patients aged 45 years or older who underwent TKA for osteoarthritis were included. Mortality data were linked with national records from births, deaths, and marriages. To determine the expected mortality rates in the general population, age-sex-specific life tables from statistics New Zealand were used. Mortality rate was presented as standardized mortality ratios (SMRs) - a comparison of relative mortality rate between the TKA and general populations. In total, 98,156 patients with a median follow-up of 7.25 years (range, 0.00 to 23.74) were included. RESULTS: Over the entire follow-up period, 22,938 patients (23.4%) had died. The overall SMR for the TKA cohort was 1.08 (95% confidence interval (CI): 1.06 to 1.09), suggesting that TKA patients have an 8% higher mortality rate compared to the general population. However, a reduction in short-term mortality rate was observed for TKA patients up to 5 years post TKA (SMR 5 years post TKA; 0.59 95% CI: 0.57 to 0.60]). On the contrary, a significantly increased long-term mortality rate was observed in TKA patients with greater than 11 years of follow-up, particularly in men over the age of 75 years (SMR 11 to 15 years post TKA for males ≥ 75 years; 3.13 [95% CI: 2.95 to 3.31]). CONCLUSION: The results suggest a reduction in short-term mortality rate for patients who undergo primary TKA. However, there is an increased long-term mortality rate particularly in men over the age of 75 years. Importantly, the mortality rates observed in this study cannot be causally attributed to TKA alone.

Evaluating willingness for surgery using the SMART Choice (Knee) patient prognostic tool for total knee arthroplasty: study protocol for a pragmatic randomised controlled trial.

BACKGROUND: Approximately 1 in 5 patients feel unsatisfied after total knee arthroplasty (TKA). Prognostic tools may aid in the patient selection process and reduce the proportion of patients who experience unsatisfactory surgery. This study uses the prognostic tool SMART Choice (Patient Prognostic Tool for Total Knee Arthroplasty) to predict patient improvement after TKA. The tool aims to be used by the patient without clinician input and does not require clinical data such as X-ray findings or blood results. The objective of this study is to evaluate the SMART Choice tool on patient decision making, particularly willingness for surgery. We hypothesise that the use of the SMART Choice tool will influence willingness to undergo surgery, especially when used earlier in the patient TKA journey. METHODS: This is a multicentred, pragmatic, randomised controlled trial conducted in Melbourne, Australia. Participants will be recruited from the St. Vincent's Hospital, Melbourne (SVHM) Orthopaedic Clinic, and the client base of HCF, Australia (private health insurance company). Patients over 45 years of age who have been diagnosed with knee osteoarthritis and considering TKA are eligible for participation. Participants will be randomised to either use the SMART Choice tool or treatment as usual. The SMART Choice tool provides users with a prediction for improvement or deterioration / no change after surgery based on utility score change calculated from the Veterans-RAND 12 (VR-12) survey. The primary outcome of the study is patient willingness for TKA surgery. The secondary outcomes include evaluating the optimal timing for tool use and using decision quality questionnaires to understand the patient experience when using the tool. Participants will be followed up for 6 months from the time of recruitment. DISCUSSION: The SMART Choice tool has the potential to improve patient decision making for TKA. Although many prognostic tools have been developed for other areas of surgery, most are confined within academic bodies of work. This study will be one of the first to evaluate the impact of a prognostic tool on patient decision making using a prospective clinical trial, an important step in transitioning the tool for use in clinical practice. TRIAL REGISTRATION: Australia and New Zealand Clinical Trials Registry (ANZCTR) - ACTRN12622000072718 . Prospectively registered - 21 January 2022.

No Difference in Quality-Of-Life Outcomes in the First 7 Years Following Primary Total Knee Arthroplasty Performed Using Computer Navigation Versus Conventional Referencing: A Propensity Score-Matched Analysis.

BACKGROUND: Computer navigation techniques can potentially improve both the accuracy and precision of prosthesis implantation in total knee arthroplasty (TKA) but its impact on quality-of-life outcomes following surgery remains unestablished. METHODS: An institutional arthroplasty registry was queried to identify patients with TKA performed between January 1, 2007 and December 31, 2019. Propensity score matching based on demographical, medical, and surgical variables was used to match computer-navigated to conventionally referenced cases. The primary outcomes were Veterans RAND 12 Item Health Survey scores (VR-12 PCS and MCS), Short Form 6 Dimension utility values (SF-6D), and quality-adjusted life years (QALYs) in the first 7 years following surgery. RESULTS: A total of 629 computer-navigated TKAs were successfully matched to 1,351 conventional TKAs. The VR-12 PCS improved by a mean of 12.75 and 11.94 points in computer-navigated and conventional cases at 12-month follow-up (P = .25) and the VR-12 MCS by 6.91 and 5.93 points (P = .25), respectively. The mean VR-12 PCS improvement at 7-year follow-up (34.4% of the original matched cohort) for navigated and conventional cases was 13.00 and 12.92 points (P = .96) and for the VR-12 MCS was 4.83 and 6.30 points (P = .47), respectively. The mean improvement in the SF-6D utility score was 0.164 and 0.149 points at 12 months (P = .11) and at 7 years was 0.115 and 0.123 points (P = .69), respectively. Computer-navigated cases accumulated 0.809 QALYs in the first 7 years, compared to 0.875 QALYs in conventionally referenced cases (P = .65). There were no differences in these outcomes among a subgroup analysis of obese patients (body mass index ≥ 30 kg/m2). CONCLUSION: The use of computer navigation did not provide an incremental benefit to quality-of-life outcomes at a mean of 2.9 years following primary TKA performed for osteoarthritis when compared to conventional referencing techniques.

The health and educational costs of preterm birth to 18 years of age in Australia.

BACKGROUND: Preterm birth is the greatest cause of death up to five years of age and an important contributor to lifelong disability. There is increasing evidence that a meaningful proportion of early births may be prevented, but widespread introduction of effective preventive strategies will require financial support. AIMS: This study estimated the economic cost to the Australian government of preterm birth, up to 18 years of age. MATERIALS AND METHODS: A decision-analytic model was developed to estimate the costs of preterm birth in Australia for a hypothetical cohort of 314 814 children, the number of live births in 2016. Costs to Australia's eight jurisdictions included medical expenditures and additional costs to educational services. RESULTS: The total cost of preterm birth to the Australian government associated with the annual cohort was estimated at $1.413 billion (95% CI 1047-1781). Two-thirds of the costs were borne by healthcare services during the newborn period and one-quarter of the costs by educational services providing special assistance. For each child, the costs were highest for those born at the earliest survivable gestational age, but the larger numbers of children born at later gestational ages contributed heavily to the overall economic burden. CONCLUSION: Preterm birth leaves many people with lifelong disabilities and generates a significant economic burden to society. The costs extend beyond those to the healthcare system and include additional educational needs. Assessments of economic costs should inform economic evaluations of interventions aimed at the prevention or treatment of preterm birth.

Placebo Surgery Controlled Trials: Do They Achieve What They Set Out To Do? A Systematic Review.

OBJECTIVE: To explore whether placebo surgery controlled trials achieve what they set out to do by investigating discrepancy between projected and actual design aspects of trials identified through systematic review methods. SUMMARY BACKGROUND: Interest in placebo surgery controlled trials is growing in response to concerns regarding unnecessary surgery and the societal cost of low-value healthcare. As questions about the justifiability of using placebo controls in surgery have been addressed, attention is now being paid to more practical concerns. METHODS: Six databases were searched from inception - May 2020 (MEDLINE, Embase, Emcare, APA PsycInfo, CINAHL, Cochrane Library). Placebo surgery controlled trials with a published protocol were included. Three authors extracted "projected" design aspects from protocols and "actual" design aspects from main findings papers. Absolute and relative difference between projected and actual design aspects were presented for each trial. Trials were grouped according to whether they met their target sample size ("completed") and were concluded in a timely fashion. Pairs of authors assessed risk of bias. RESULTS: Of 24 trials with data available to analyse; 3 were completed and concluded within target timeframe; 10 were completed and concluded outside the target timeline; 4 were completed without clear target timeframes; 2 were incomplete and concluded within the target framework; 5 were incomplete and concluded outside the target timeline. Trials which reached the recruitment target underestimated trial duration by 88% and number of recruitment sites by 87%. CONCLUSIONS: Trialists need to factor additional time and sites into future placebo surgery controlled trials. A robust reporting framework of projected and actual trial design is imperative for trialists to learn from their predecessors. REVIEW REGISTRATION: PROSPERO (CRD42019133296).

Opioid Use and Total Joint Replacement.

PURPOSE OF REVIEW: We provide an overview of recent research into the relationship between preoperative opioid use and total joint replacement outcomes. RECENT FINDINGS: Recent findings indicate that total joint replacement patients with a history of preoperative opioid use experience higher rates of infection, revision, short-term complications, and prolonged postoperative opioid use, along with fewer improvements in pain and function following surgery. These risks are particularly pronounced among chronic opioid users. While the baseline risk profiles of these patients may contribute to higher rates of adverse outcomes, it is also plausible that certain outcomes are directly impacted by opioid use through mechanisms such as opioid-induced hyperalgesia and immunosuppression. There is little available data on the efficacy of interventions that aim to mitigate these risks. Well-designed clinical trials are needed to evaluate the efficacy of targeted perioperative interventions that aim to improve outcomes for this high-risk surgical population. Where such trials are not feasible, additional high-quality observational studies are necessary to further our understanding of the mechanisms underlying the relationships between opioid use and specific adverse outcomes.

Predictors of inpatient rehabilitation after total knee replacement: an analysis of private hospital claims data.

OBJECTIVE: To investigate inpatient rehabilitation rates after private total knee replacements (TKRs) in Australia since 2009; to quantify the contributions of hospital-, surgeon- and patient-related factors to predicting inpatient rehabilitation. DESIGN: Retrospective cohort study; multivariate linear regression analysis of linked, de-identified Medibank administrative claims data and hospital casemix protocol data, adjusted for patient-related characteristics. Setting, participants: 35 389 patients undergoing Medibank-funded TKRs in 170 private hospitals in Australia, 2009-2016. MAIN OUTCOME MEASURES: Hospital inpatient rehabilitation rate; relative contributions of patient- and provider-related characteristics to variation in inpatient rehabilitation rates. RESULTS: The overall inpatient rehabilitation rate increased from 31% in 2009 to 45% in 2016, but varied between hospitals (range, 0-100%). The reduction in mean acute length of stay during this period explained about 15% of this increase, and about 30% was explained by patient-related factors; more than half of the increase was explained by neither reduced length of stay or patient-related factors. Patient-related characteristics explained little of the variation in rates between hospitals. Rates at 27% of hospitals lay above the 95% confidence limit for the mean inpatient rehabilitation rate in private hospitals (38%), both before and after adjusting for patient-related factors. Provider characteristics explained three times as much of the variation as patient characteristics (75% v 25%); hospital-related factors made the largest contribution to variation (47%). CONCLUSION: Inpatient rehabilitation after TKR has increased in private health care during the past 8 years. Substantial variation in inpatient rehabilitation rates is not explained by patient-related factors, suggesting that some inpatient rehabilitation is low value care.

Transitions in Smoking Across a Pregnancy: New Information from the Growing Up in New Zealand Longitudinal Study.

Introduction Maternal smoking remains a modifiable cause of adverse maternal and child health outcomes. This study investigated smoking transitions across pregnancy. Methods Data from the contemporary child cohort study Growing Up in New Zealand (n = 6822) were used to analyse smoking status across three points across a pregnancy: pre-pregnancy, during pregnancy and after pregnancy. Odds-ratios (OR) were calculated for maternal, socio-economic and pregnancy-related factors associated with each transition using multivariate logistic regression. Results The prevalence of smoking pre-pregnancy was 20.3%. The cessation rate during pregnancy was 48.5%, while the postpartum relapse rate was 36.0%. Heavy smokers were less likely to quit during pregnancy (OR 0.13, 95% CI 0.08-0.20), and more likely to relapse at 9 months (OR 2.63, CI 1.60-4.32), relative to light smokers. Women in households with another smoker were less likely to quit during pregnancy (OR 0.35, CI 0.25-0.48), and more likely to relapse postpartum (OR 2.00, CI 1.14-3.51), relative to women in a smoke-free household. Women without high school qualifications were less likely to quit during pregnancy than women with bachelor degrees (OR 0.21, CI 0.11-0.41) but no more likely to relapse. Maori women were less likely to quit during pregnancy than European women (OR 0.35, CI 0.25-0.49) but no more likely to relapse. Conclusion Heavy smokers and those with another smoker in the household are at high risk of smoking during pregnancy or relapsing after pregnancy. Decreasing smoking across a pregnancy therefore requires a focus on cessation in all households with heavy smokers of child-bearing age. The association between smoking and ethnicity may be confounded as it not consistent across the pregnancy.

The Impact of Regression to the Mean on Economic Evaluation in Quasi-Experimental Pre-Post Studies: The Example of Total Knee Replacement Using Data from the Osteoarthritis Initiative.

Many treatments are evaluated using quasi-experimental pre-post studies susceptible to regression to the mean (RTM). Ignoring RTM could bias the economic evaluation. We investigated this issue using the contemporary example of total knee replacement (TKR), a common treatment for end-stage osteoarthritis of the knee. Data (n = 4796) were obtained from the Osteoarthritis Initiative database, a longitudinal observational study of osteoarthritis. TKR patients (n = 184) were matched to non-TKR patients, using propensity score matching on the predicted hazard of TKR and exact matching on osteoarthritis severity and health-related quality of life (HrQoL). The economic evaluation using the matched control group was compared to the standard method of using the pre-surgery score as the control. Matched controls were identified for 56% of the primary TKRs. The matched control HrQoL trajectory showed evidence of RTM accounting for a third of the estimated QALY gains from surgery using the pre-surgery HrQoL as the control. Incorporating RTM into the economic evaluation significantly reduced the estimated cost effectiveness of TKR and increased the uncertainty. A generalized ICER bias correction factor was derived to account for RTM in cost-effectiveness analysis. RTM should be considered in economic evaluations based on quasi-experimental pre-post studies. Copyright © 2017 John Wiley & Sons, Ltd.

Predicting the Long-Term Gains in Health-Related Quality of Life After Total Knee Arthroplasty.

BACKGROUND: We investigated the predictors of long-term gains in quality-adjusted life years (QALYs) from total knee arthroplasty (TKA) and the patient attributes that predicted cost-effective TKA. METHODS: Data on TKA patients (n = 570) from 2006 to 2007 were extracted from a single-institution registry. QALY gains over 7 years post surgery were calculated from health-related quality of life (HrQoL) scores measured preoperatively and annually postoperatively using the short-form health survey (SF-12) instrument. Multivariate linear regression analysis investigated the predictors of QALY gain from TKA from a broad range of preoperative patient characteristics and was used to predict QALY gains for each individual. Patients were grouped into deciles according to their predicted QALY gain, and the cost-effectiveness of each decile was plotted on the cost-effectiveness plane. Patient attribute differences between deciles were decomposed. RESULTS: After exclusions and dropout, data were available for 488 patients. The average estimated QALY gain over 7 years was 0.77 (95% confidence interval [CI] 0.70-0.83). Predictors significantly associated with smaller QALY gains were comorbidities (Charlson comorbidity index 3+ coefficient -0.54 CI -0.15 to -0.92), the absence of severe osteoarthritis in the ipsilateral knee (-0.51 CI -0.16 to -0.85), preoperative HrQoL (standardized coefficient -0.34 CI -0.26 to -0.43), the requirement for an interpreter (-0.24 CI -0.05 to -0.44), and age (-0.01 CI -0.01 to -0.02). The largest difference between cost-effective and non-cost-effective deciles was relatively high preoperative HrQoL in the non-cost-effective decile. CONCLUSION: TKA is likely to be cost-effective for most patients except those with unusually high preoperative HrQoL or a lack of severe osteoarthritis. The poorer outcomes for those requiring an interpreter requires further research.

The Cost Differential Between Warfarin Versus Aspirin Treatment After a Fontan Procedure.

BACKGROUND: The use of aspirin versus warfarin for treatment of patients after a Fontan procedure remains contentious. Current preference-based models of treatment across Australia and New Zealand show variation in care that is unlikely to reflect patient differences and/or clinical risk. METHODS: We combine data from the Australian and New Zealand Fontan Registry and a home INR (International Normalised Ratio) monitoring program (HINRMP) from the Royal Children's Hospital (RCH) Melbourne, to estimate the cost difference for Fontan recipients receiving aspirin versus warfarin for 2015. We adopt a societal perspective to costing which includes cost to the health system (e.g. medical consults, pathology tests) and costs to patients and carers (e.g. travel and time), but excludes costs of adverse events. Costs are presented in Australian 2015 dollars; any costs from previous years have been inflated using appropriate rates from the Australian Bureau of Statistics. RESULTS: We find that warfarin patients face additional costs of $825 per annum, with the majority ($584 or 71%) of those borne by the patient or family. If aspirin is as clinically as effective as warfarin, Fontan recipients could be enjoying far less costly, invasive and time-consuming treatment. While achieving such clinical consensus can be difficult, economics shows us that there are large costs associated with a failure to achieve it.

Using Patient-Reported Outcomes for Economic Evaluation: Getting the Timing Right.

BACKGROUND: Patient-reported outcome measures (PROMs) are becoming increasingly popular in orthopedic surgery. Preoperative and postoperative follow-up often elicit PROMs in the form of generic quality-of-life instruments (e.g., Short Form health survey SF-12 [SF-12]) that can be used in economic evaluation to estimate quality-adjusted life-years (QALYs). However, the timing of postoperative measurement is still under debate. OBJECTIVES: To explore the timing of postoperative PROMs collection and the implications for bias in QALY estimation for economic evaluation. METHODS: We compared the accuracy of QALY estimation on the basis of utilities derived from the SF-12 at one of 6 weeks, 3 months, 6 months, and 12 months after total knee arthroplasty, under different methods of interpolation between points. Five years of follow-up data were extracted from the St. Vincent's Melbourne Arthroplasty Outcomes (SMART) registry (n = 484). The SMART registry collects follow-up PROMs annually and obtained more frequent outcomes on subset of patients (n = 133). RESULTS: Postoperative PROM collection at 6 weeks, 6 months, or 12 months biased the estimation of QALY gain from total knee arthroplasty by -41% (95% confidence interval [CI] -59% to -22%), 18% (95% CI 4%-32%), and -8% (95% CI -18% to -2%), respectively. This bias was minimized by collecting PROMs at 3 months postoperatively (6% error; 95% CI -9% to 21%). CONCLUSIONS: The timing of PROM collection and the interpolation assumptions between measurements can bias economic evaluation. In the case of total knee arthroplasty, we recommend a postoperative measurement at 3 months with linear interpolation between preoperative and postoperative measures. The design of economic evaluations should consider timing and interpolation issues.

Predictive Tool Use and Willingness for Surgery in Patients With Knee Osteoarthritis: A Randomized Clinical Trial.

Importance: Despite the increasing number of tools available to predict the outcomes of total knee arthroplasty (TKA), the effect of these predictive tools on patient decision-making remains uncertain. Objective: To assess the effect of an online predictive tool on patient-reported willingness to undergo TKA. Design, Setting, and Participants: This parallel, double-masked, 2-arm randomized clinical trial compared predictive tool use with treatment as usual (TAU). The study was conducted between June 30, 2022, and July 31, 2023. Participants were followed up for 6 months after enrollment. Participants were recruited from a major Australian private health insurance company and from the surgical waiting list for publicly funded TKA at a tertiary hospital. Eligible participants had unilateral knee osteoarthritis, were contemplating TKA, and had previously tried nonsurgical interventions, such as lifestyle modifications, physiotherapy, and pain medications. Intervention: The intervention group was provided access to an online predictive tool at the beginning of the study. This tool offered information regarding the likelihood of improvement in quality of life if patients chose to undergo TKA. The predictions were based on the patient's age, sex, and baseline symptoms. Conversely, the control group received TAU without access to the predictive tool. Main Outcomes and Measures: The primary outcome measure was the reduction in participants' willingness to undergo surgery at 6 months after tool use as measured by binomial logistic regression. Secondary outcome measures included participant treatment preference and the quality of their decision-making process as measured by the Knee Decision Quality Instrument. Results: Of 211 randomized participants (mean [SD] age, 65.8 [8.3] years; 118 female [55.9%]), 105 were allocated to the predictive tool group and 106 to the TAU group. After adjusting for baseline differences in willingness for surgery, the predictive tool did not significantly reduce the primary outcome of willingness for surgery at 6 months (adjusted odds ratio, 0.85; 95% CI, 0.42-1.71; P = .64). Conclusions and Relevance: Despite the absence of treatment effect on willingness for TKA, predictive tools might still enhance health outcomes of patients with knee osteoarthritis. Additional research is needed to optimize the design and implementation of predictive tools, address limitations, and fully understand their effect on the decision-making process in TKA. Trial Registration: ANZCTR.org.au Identifier: ACTRN12622000072718.

Pre- and postnatal drivers of childhood intelligence: evidence from Singapore.

This study seeks to investigate what influences intelligence in early childhood. The Singapore Cohort Study of the Risk Factors of Myopia (SCORM) is used to assess determinants of childhood IQ and changes in IQ. This longitudinal data set, collected in 1999, includes a wealth of demographic, socioeconomic and prenatal characteristics. The richness of the data allows various econometric approaches to be employed, including the use of ordered and multinomial logit analysis. Mother's education is found to be a consistent and key determinant of childhood IQ. Father's education and school quality are found to be key drivers for increasing IQ levels above the average sample movement.

The impact of cost on quality of surgical management in non-metastatic extremity sarcoma: A cross-country narrative literature review with a systematic approach.

BACKGROUND: Extremity sarcoma surgery entails significant costs for patients, governments and insurers. Multiple studies have described individual costs, however, the overall impact of cost on the quality of surgical care remains unclear. OBJECTIVES: A narrative review with a systematic approach was undertaken to compare the impact of cost on the quality of extremity sarcoma care across low-middle-income and high-income countries. DATA SOURCES: MEDLINE, EMBASE, Cochrane, PsycInfo, DARE, NHS-EED, HTA. METHODS: A systematic search was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Inclusion criteria were: discussion of costs and the surgical management of primary extremity sarcoma. There were no restrictions on study design, publication type, date, geographic location or publication status. A data extraction table was used to identify study location, type and findings. RESULTS: 1012 studies were retrieved and 44 met the inclusion criteria. Four additional studies were identified from the reference lists of included articles. 27 studies were published in high-income countries (HIC) including all four full health economic analyses and 20 studies were published in low-middle income countries (LMC). Within LMC, cost impeded access to diagnosis, resection and options for reconstruction. In HIC, cost varied with choice of management, particularly during the long-term postoperative period. CONCLUSIONS: Within LMC, cost impaired the provision of quality, curative care for patients with extremity sarcoma. Within HIC, while costs varied with chosen management, they were not prohibitive to the provision of quality care. Further research is required, specific to both socioeconomic contexts, to further describe the long-term cost-utility of different methods for the surgical management of extremity sarcoma.

SMART choice (knee) tool: a patient-focused predictive model to predict improvement in health-related quality of life after total knee arthroplasty.

BACKGROUND: Current predictive tools for TKA focus on clinicians rather than patients as the intended user. The purpose of this study was to develop a patient-focused model to predict health-related quality of life outcomes at 1-year post-TKA. METHODS: Patients who underwent primary TKA for osteoarthritis from a tertiary institutional registry after January 2006 were analysed. The primary outcome was improvement after TKA defined by the minimal clinically important difference in utility score at 1-year post-surgery. Potential predictors included demographic information, comorbidities, lifestyle factors, and patient-reported outcome measures. Four models were developed, including both conventional statistics and machine learning (artificial intelligence) methods: logistic regression, classification tree, extreme gradient boosted trees, and random forest models. Models were evaluated using discrimination and calibration metrics. RESULTS: A total of 3755 patients were included in the study. The logistic regression model performed the best with respect to both discrimination (AUC = 0.712) and calibration (intercept = -0.083, slope = 1.123, Brier score = 0.202). Less than 2% (n = 52) of the data were missing and therefore removed for complete case analysis. The final model used age (categorical), sex, baseline utility score, and baseline Veterans-RAND 12 responses as predictors. CONCLUSION: The logistic regression model performed better than machine learning algorithms with respect to AUC and calibration plot. The logistic regression model was well calibrated enough to stratify patients into risk deciles based on their likelihood of improvement after surgery. Further research is required to evaluate the performance of predictive tools through pragmatic clinical trials. LEVEL OF EVIDENCE: Level II, decision analysis.

Net cost savings arising from patient completion of an active self-management program.

OBJECTIVE: The objective of this study is to investigate changes in willingness for total knee replacement (TKR) surgery following a randomised control trial (RCT) of an osteoarthritis management program, and to extrapolate orthopaedic cost consequences for private health insurers (PHI). METHODS: Willingness for surgery data from the RCT is analysed using a multinomial logistic regression model. A decision analytic model is used to conduct a break-even cost benefit analysis of the intervention from a PHI payer perspective. The analysis estimates the minimum probability of progression to surgery required for the intervention to be cost-neutral when considering savings limited to reduced orthopaedic costs. Cost data and orthopaedic pathway probabilities are sourced from payer data. RESULTS: At baseline, 39% of participants in the treatment and control group were willing for surgery. At 12 months, 16% of participants in the treatment group remained willing for surgery, versus 36% in the control group. Participants in the treatment group are 2.96 (95% CI: 1.01-8.66) times more likely than those in the control group to move from initially willing for surgery, to unsure or unwilling at 12 months. The analysis indicates that the intervention is likely to be cost saving when at least 60% of initially willing participants progress to surgery over a 5-year time horizon. CONCLUSION: Our study estimates that an education, exercise and weight loss intervention can deliver both improved participant outcomes and a return on investment to Australian PHIs through a reduction in TKR surgery incidence.