Applying Trial-Derived Treatment Effects to Real-World Populations: Generalizing Cost-Effectiveness Estimates When Modeling Complex Hazards.

OBJECTIVES: Generalizability of trial-based cost-effectiveness estimates to real-world target populations is important for decision making. In the context of independent aggregate time-to-event baseline and relative effects data, complex hazards can make modeling of data for use in economic evaluation challenging. Our article provides an overview of methods that can be used to apply trial-derived relative treatment effects to external real-world baselines when faced with complex hazards and follows with a motivating example. METHODS: Approaches for applying trial-derived relative effects to real-world baselines are presented in the context of complex hazards. Appropriate methods are applied in a cost-effectiveness analysis using data from a previously published study assessing the real-world cost-effectiveness of a treatment for carcinoma of the head and neck as a motivating example. RESULTS: Lack of common hazards between the trial and target real-world population, a complex baseline hazard function, and nonproportional relative effects made the use of flexible models necessary to adequately estimate survival. Assuming common distributions between trial and real-world reference survival substantially affected survival and cost-effectiveness estimates. Modeling time-dependent vs proportional relative effects affected estimates to a lesser extent, dependent on assumptions used in cost-effectiveness modeling. CONCLUSIONS: Appropriately capturing reference treatment survival when attempting to generalize trial-derived relative treatment effects to real-world target populations can have important impacts on cost-effectiveness estimates. A balance between model complexity and adequacy for decision making should be considered where multiple data sources with complex hazards are being evaluated.

Modelled cost-effectiveness analysis of the Support and Treatment After Replacement (STAR) care pathway for chronic pain after total knee replacement compared with usual care.

BACKGROUND: The aim of the study was to estimate the long-term cost-effectiveness of the Support and Treatment After Replacement (STAR) care pathway for chronic pain after total knee replacement compared with usual postoperative care. METHODS: Study design: A decision-analytic (cohort Markov) model was used for the simulation with time dependent annual transition probabilities and a time horizon of five years. SETTING: Patients treated by National Health Service (NHS) hospitals in England and Wales. STUDY POPULATION: Adults classified as having chronic pain three months after undergoing a total knee replacement. INTERVENTION: The STAR care pathway following a total knee replacement. COMPARATOR: Usual postoperative care following a total knee replacement. PERSPECTIVE: The study was undertaken from the perspective of the NHS. OUTCOME MEASURES: Quality-adjusted life years and healthcare costs. Discounting: A rate of 3.5% for both costs and health utility. RESULTS: Model results indicate that the STAR intervention would dominate current practice by providing a gain in quality-adjusted life years (QALYs) of 0.086 and a reduction of £375 (per person) in costs over the first five years. The incremental net monetary benefit of the STAR intervention was estimated at £2,086 (at a threshold of £20,000 per QALY). Probabilistic sensitivity analysis suggests the STAR intervention is likely to be cost-effective with a probability of 0.62. The results remain robust to changes in model assumptions on comparator utility and the timing of the start of the intervention. If hospital admission costs are assumed not to be reduced by the STAR intervention, it would no longer be cost saving, but it would likely be cost-effective based on probabilistic sensitivity analysis (0.59). CONCLUSION: Evidence from the economic model suggests that the STAR care pathway is likely to be cost-effective and potentially dominant from an NHS perspective. TRIAL REGISTRATION: The STAR trial is registered with ISRCTN, ISRCTN92545361.

Patients' experience on pain outcomes after hip arthroplasty: insights from an information tool based on registry data.

BACKGROUND: Arthroplasty registries are rarely used to inform encounters between clinician and patient. This study is part of a larger one which aimed to develop an information tool allowing both to benefit from previous patients' experience after total hip arthroplasty (THA). This study focuses on generating the information tool specifically for pain outcomes. METHODS: Data from the Geneva Arthroplasty Registry (GAR) about patients receiving a primary elective THA between 1996 and 2019 was used. Selected outcomes were identified from patient and surgeon surveys: pain walking, climbing stairs, night pain, pain interference, and pain medication. Clusters of patients with homogeneous outcomes at 1, 5, and 10 years postoperatively were generated based on selected predictors evaluated preoperatively using conditional inference trees (CITs). RESULTS: Data from 6,836 THAs were analysed and 14 CITs generated with 17 predictors found significant (p < 0.05). Baseline WOMAC pain score, SF-12 self-rated health (SRH), number of comorbidities, SF-12 mental component score, and body mass index (BMI) were the most common predictors. Outcome levels varied markedly by clusters whilst predictors changed at different time points for the same outcome. For example, 79% of patients with good to excellent SRH and less than moderate preoperative night pain reported absence of night pain at 1 year after THA; in contrast, for those with fair/poor SHR this figure was 50%. Also, clusters of patients with homogeneous levels of night pain at 1 year were generated based on SRH, Charnley, WOMAC night and pain scores, whilst those at 10 years were based on BMI alone. CONCLUSIONS: The information tool generated under this study can provide prospective patients and clinicians with valuable and understandable information about the experiences of "patients like them" regarding their pain outcomes.

Shoulder replacement surgery's rising demand, inequality of provision, and variation in outcomes: cohort study using Hospital Episode Statistics for England.

BACKGROUND: The aim of this study was to forecast future patient demand for shoulder replacement surgery in England and investigate any geographic and socioeconomic inequalities in service provision and patient outcomes. METHODS: For this cohort study, all elective shoulder replacements carried out by NHS hospitals and NHS-funded care in England from 1999 to 2020 were identified using Hospital Episode Statistics data. Eligible patients were aged 18 years and older. Shoulder replacements for malignancy or acute trauma were excluded. Population estimates and projections were obtained from the Office for National Statistics. Standardised incidence rates and the risks of serious adverse events (SAEs) and revision surgery were calculated and stratified by geographical region, socioeconomic deprivation, sex, and age band. Hospital costs for each admission were calculated using Healthcare Resource Group codes and NHS Reference Costs based on the National Reimbursement System. Projected rates and hospital costs were predicted until the year 2050 for two scenarios of future growth. RESULTS: A total of 77,613 elective primary and 5847 revision shoulder replacements were available for analysis. Between 1999 and 2020, the standardised incidence of primary shoulder replacements in England quadrupled from 2.6 to 10.4 per 100,000 population, increasing predominantly in patients aged over 65 years. As many as 1 in 6 patients needed to travel to a different region for their surgery indicating inequality of service provision. A temporal increase in SAEs was observed: the 30-day risk increased from 1.3 to 4.8% and the 90-day risk increased from 2.4 to 6.0%. Patients from the more deprived socioeconomic groups appeared to have a higher risk of SAEs and revision surgery. Shoulder replacements are forecast to increase by up to 234% by 2050 in England, reaching 20,912 procedures per year with an associated annual cost to hospitals of £235 million. CONCLUSIONS: This study reports a rising incidence of shoulder replacements, regional disparities in service provision, and an overall increasing risk of SAEs, especially in more deprived socioeconomic groups. These findings highlight the need for better healthcare planning to match local population demand, while more research is needed to understand and prevent the increase observed in SAEs.

Impact of fragility fractures on activities of daily living and productivity in community-dwelling women: a multi-national study.

We estimated the short-term impact of fragility fractures on community-dwelling women in five countries. Women with fragility fractures reported significantly more difficulties performing activities of daily living and significantly higher levels of lost productivity and caregiver support than those without fractures; results highlight the multi-country indirect burden of fragility fractures. INTRODUCTION: To estimate the impact of fragility fractures on activities of daily living (ADL), productivity loss and caregiver support in women with a recent fragility fracture. METHODS: This multi-centre cross-sectional study enrolled community-dwelling women aged ≥ 50 years in South Korea, Spain, Germany, Australia and the United States. The fragility fracture cohort consisted of women with an index fragility fracture in the past 12 months; the fracture free cohort consisted of women with no fracture in the 18 months prior to study enrolment. Study participants completed three validated questionnaires: Lawton Instrumental ADL (IADL), Physical Self-Maintenance Scale (PSMS) and iMTA Productivity Cost Questionnaire (iPCQ). RESULTS: In total, 1,253 participants from 41 sites across the five countries were included. Compared with the fracture free cohorts, fragility fracture cohorts had significantly lower function and were more dependent on support (p < 0.05 in all countries for Lawton IADL, and in South Korea, Spain, Australia and the United States for PSMS), significantly higher hours of paid absenteeism (p < 0.05, Spain, Germany, Australia), significantly higher unpaid lost productivity (p < 0.05, South Korea, Spain, Germany), significantly more days of paid help received in the home (p < 0.05 South Korea, Spain and the United States), and significantly more days of unpaid help from family members or friends (p < 0.05, all countries). CONCLUSION: In this multi-national study, fragility fractures in community-dwelling ≥ 50 years women were associated with several outcomes indicating higher indirect burden and lower quality of life, including more difficulties performing ADL and higher levels of lost productivity and caregiver support.

Mapping the Oxford Shoulder Score onto the EQ-5D utility index.

PURPOSE: In order to enable cost-utility analysis of shoulder pain conditions and treatments, this study aimed to develop and evaluate mapping algorithms to estimate the EQ-5D health index from the Oxford Shoulder Score (OSS) when health outcomes are only assessed with the OSS. METHODS: 5437 paired OSS and EQ-5D questionnaire responses from four national multicentre randomised controlled trials investigating different shoulder pathologies and treatments were split into training and testing samples. Separate EQ-5D-3L and EQ-5D-5L analyses were undertaken. Transfer to utility (TTU) regression (univariate linear, polynomial, spline, multivariable linear, two-part logistic-linear, tobit and adjusted limited dependent variable mixture models) and response mapping (ordered logistic regression and seemingly unrelated regression (SUR)) models were developed on the training sample. These were internally validated, and their performance evaluated on the testing sample. Model performance was evaluated over 100-fold repeated training-testing sample splits. RESULTS: For the EQ-5D-3L analysis, the multivariable linear and splines models had the lowest mean square error (MSE) of 0.0415. The SUR model had the lowest mean absolute error (MAE) of 0.136. Model performance was greatest in the mid-range and best health states, and lowest in poor health states. For the EQ-5D-5L analyses, the multivariable linear and splines models had the lowest MSE (0.0241-0.0278) while the SUR models had the lowest MAE (0.105-0.113). CONCLUSION: The developed models now allow accurate estimation of the EQ-5D health index when only the OSS responses are available as a measure of patient-reported health outcome.

Association between outpatient follow-up and incidence of revision after knee and hip replacements: a population-based cohort study.

BACKGROUND: Follow-up visits 5 or 7 years after surgery were recommended for people having primary hip or knee replacement. The benefits of this practice to patients and the healthcare system, however, have not yet been specifically examined. The aim of this study was to investigate the association between long-term follow-up outpatient hospital visits and revision rates for patients who undergo primary knee or hip replacement surgery. METHODS: Cohorts were identified for patients undergoing knee or hip replacement surgery using medical records from primary care practices within the UK Clinical Practice Research Datalink (CPRD) GOLD dataset linked to hospital records from the English Hospital Episodes Statistics (HES) data. Two groups of patients were compared in terms of revision and mortality rates: those with at least one long-term (between five and 10 years since primary surgery) follow-up visit at the orthopaedic department ('Follow-up' group), and those without ('No follow-up' group). RESULTS: A total of 9856 (4349 in the Follow-up group) patients with knee replacement and 10,837 (4870 in the Follow-up group) with hip replacement were included in the analysis. For knee replacement, the incidence of revision was 3.6% for those followed-up and 0.6% for those not followed-up. An adjusted regression model confirmed the difference in the hazard ratio (HR) for revision was statistically significant (HR: 5.65 [95% CI 3.62 to 8.81]). Mortality at 4 years was lower for the Follow-up (17%) compared to the No follow-up group (21%), but this difference was not statistically significant (HR: 0.95 [0.84 to 1.07]). For hip replacement, the incidence of revision rates were 3.2 and 1.4% for the follow-up and not follow-up groups, respectively, the difference being statistically significant (HR: 2.34 [1.71 to 3.20]). Mortality was lower for the Follow-up (15%) compared to the No follow-up group (21%), but the difference was not statistically significant (HR: 0.91 [0.81 to 1.02]). CONCLUSION: Patients attending follow-up orthopaedic consultations show a higher risk of revision surgery compared to those who are not followed-up. A cause for this difference could not be identified in this study but a likely explanation is that surgeons play an effective role as ultimate arbitrators when identifying patients to be included in long-term follow-up lists.

Primary care consultations and pain medicine prescriptions: a comparison between patients with and without chronic pain after total knee replacement.

BACKGROUND: Approximately 20% of patients experience chronic pain after total knee replacement (TKR). The impact of chronic pain after TKR on primary care services in the UK is currently unknown. The aim of this study was to compare primary care consultations and pain medicine prescriptions between patients with and without chronic pain after TKR. METHODS: Data from 5,055 patients who received TKR between 2009 and 2016 with anonymised linked data from the Clinical Practice Research Datalink Gold (CPRD) and English Hospital Episode Statistics (HES) Patient Reported Outcome Measures (PROMs) programme were analysed. The exposure time was from 10 years pre-operative to eight years post-operative. Patients with a score ≤ 14 on the Oxford Knee Score pain component scale at 6 months post-operative were classified as having chronic pain after TKR. Primary care consultations and prescribed pain medicines were quantified, and costs calculated based on national cost data. RESULTS: 721 patients (14%) had chronic pain after TKR. The prevalence and costs of primary care consultations and pain medicine prescriptions per year were consistently higher for patients with chronic pain after TKR compared with those without chronic pain after TKR; these differences were observed both before and after surgery. There was a substantial and sustained increase in the cost of opioid prescriptions after surgery for patients with chronic pain after TKR, peaking at seven years post-operative. CONCLUSIONS: Increased primary care consultations and pain medicine prescriptions associated with chronic pain after TKR represent a considerable financial cost to primary care services. Evaluation of interventions to reduce the risk of developing this pain condition and improve the early management of pain after TKR are needed to improve outcomes for patients and reduce costs to healthcare services.

Higher prevalence of non-skeletal comorbidity related to X-linked hypophosphataemia: a UK parallel cohort study using CPRD.

OBJECTIVES: X-Linked hypophosphataemic rickets (XLH) is a rare multi-systemic disease of mineral homeostasis that has a prominent skeletal phenotype. The aim of this study was to describe additional comorbidities in XLH patients compared with general population controls. METHODS: The Clinical Practice Research Datalink (CPRD) GOLD was used to identify a cohort of XLH patients (1995-2016), along with a non-XLH cohort matched (1 : 4) on age, sex and GP practice. Using the CALIBER portal, phenotyping algorithms were used to identify the first diagnosis (and associated age) of 273 comorbid conditions during patient follow-up. Fifteen major disease categories were used and the proportion of patients having ≥1 diagnosis was compared between cohorts for each category and condition. Main analyses were repeated according to the Index of Multiple Deprivation (IMD). RESULTS: There were 64 and 256 patients in the XLH and non-XLH cohorts, respectively. There was increased prevalence of endocrine [OR 3.46 (95% CI: 1.44, 8.31)] and neurological [OR 3.01 (95% CI: 1.41, 6.44)] disorders among XLH patients. Across all specific comorbidities, four were at least twice as likely to be present in XLH cases, but only depression met the Bonferroni threshold: OR 2.95 (95% CI: 1.47, 5.92). Distribution of IMD among XLH cases indicated greater deprivation than the general population. CONCLUSION: We describe a higher risk of mental illness in XLH patients compared with matched controls, and greater than expected deprivation. These findings may have implications for clinical practice guidelines and decisions around health and social care provision for these patients.

Association of sleep, screen time and physical activity with overweight and obesity in Mexico.

PURPOSE: Approximately 70% of adults in Mexico are overweight or obese. Unhealthy lifestyle behaviors are also prevalent. We examined the association of three lifestyle behaviors with body mass index (BMI) categories in adults from Mexico. METHODS: We used publicly available data from the ENSANUT 2016 survey (n = 6419). BMI was used to categorize participants. Differences in sleep duration, suffering from symptoms of insomnia, TV watching time, time in front of any screen, vigorous physical activity (yes vs no), moderate physical activity (> 30 min/day-yes vs. no) and walking (> 60 min/day-yes vs. no) were compared across BMI groups using adjusted linear and logistic regression analyses. RESULTS: Thirty-nine percent of participants were overweight and 37% obese. Time in front of TV, in front of any screen, sleep duration and physical activity were significantly associated with overweight and obesity. Compared to normal weight participants, participants in the obese II category spend on average 0.60 h/day (95% CI 0.36-0.84, p = 0.001) and participants in the obese III category 0.54 h/day (95% CI 0.19-0.89, p < 0.001) more in front of any screen; participants in the obese II category reported 0.55 h/day less sleep (95% CI - 0.67 to - 0.43, p < 0.001); participants in the obese III category were less likely to engage in vigorous activity (OR = 0.60, 95% CI 0.43-0.84, p ≤ 0.003), or walking (OR = 0.65, 95% CI 0.49-0.88, p = 0.005). CONCLUSION: Screen time, sleeping hours, and physical activity were associated with overweight and obesity. However, these associations were not consistent across all BMI categories. Assuming established causal connections, overweight individuals and individuals with obesity would benefit from reduced screen time and engaging in moderate/vigorous physical activity. LEVEL OF EVIDENCE: Level III: observational case-control analytic study.

Hospitalization in fibromyalgia: a cohort-level observational study of in-patient procedures, costs and geographical variation in England.

OBJECTIVES: Fibromyalgia is a complex, debilitating, multifactorial condition that can be difficult to manage. Recommended treatments are usually delivered in outpatient settings; evidence suggests that significant inpatient care occurs. We describe the scale and cost of inpatient care with a primary diagnostic code of fibromyalgia within the English National Health Service. METHODS: We conducted a cohort-level observational study of all patients admitted to hospital due to a diagnosis of fibromyalgia, between 1 April 2014 and 31 March 2018 inclusive, in the National Health Service in England. We used data from Hospital Episode Statistics Admitted Patient Care to study: the age and sex of patients admitted, number and costs of admissions, length of stay, procedures undertaken, class and type of admission, and distribution of admissions across clinical commissioning groups. RESULTS: A total of 24 295 inpatient admissions, costing £20 220 576, occurred during the 4-year study period. Most patients were women (89%) with peak age of admission of between 45 and 55 years. Most admissions were elective (92%). A number of invasive therapeutic procedures took place, including a continuous i.v. infusion (35%). There was marked geographical variation in the prevalence and cost of inpatient fibromyalgia care delivered across the country, even after accounting for clinical commissioning group size. CONCLUSIONS: Many patients are admitted for treatment of their fibromyalgia and given invasive procedures for which there is weak evidence, with significant variation in practice and cost across the country. This highlights the need to identify areas of resource use that can be rationalized and diverted to provide more effective, evidence-based treatment.

Threshold for Computer- and Robot-Assisted Knee and Hip Replacements in the English National Health Service.

OBJECTIVES: To estimate threshold prices for computer- and robot-assisted knee and hip replacement. METHODS: A lifetime cohort Markov model provided the framework for analysis. Linked primary care and inpatient hospital records informed estimates of outcomes under current practice. Outcomes were estimated under a range of hypothetical relative improvements in quality of life if unrevised and in revision risk after computer or robot-assisted surgery. Threshold prices, a price at which the net health benefit from funding the intervention would be zero, for these improvements were estimated for a cost-effectiveness threshold of £20 000 per additional quality-adjusted life-year (QALY) gained. RESULTS: For average patient profiles under current knee and hip replacement practice, lifetime QALYs were 10.3 (9.9 to 10.7) and 11.0 (10.6 to 11.4), with costs of £6060 (£5947 to £6203) and £6506 (£6335 to £6710) for knee and hip replacement, respectively. A combined 50% relative reduction in risk of revision and 5% improvement in postoperative quality of life if unrevised would, for example, result in QALYs increasing to 10.9 (10.4 to 11.3) and 11.6 (11.2 to 12.0), and costs falling to £5880 (£5816 to £5956) and £6258 (£6149 to £6376) after knee and hip replacement, respectively. These particular improvements would have an associated threshold price of £11 182 (£10 691 to £11 721) for knee replacement and £12 134 (£11 616 to £12 701) for hip replacement. The 50% reduction in revision rate alone would have associated threshold prices of £1094 (£788 to £1488) and £1347 (£961 to £1842), and the 5% improvement in quality of life alone would have associated threshold prices of £9911 (£9476 to £10 296) and £10 578 (£10 171 to £10 982). CONCLUSIONS: At current prices, computer- and robot-assisted knee and hip replacement will likely need to lead to improvements in patient-reported outcomes in addition to any reduction in the risk revision.

Lifetime risk of knee and hip replacement following a diagnosis of RA: findings from a cohort of 13 961 patients from England.

OBJECTIVE: To estimate the lifetime risk of knee and hip replacement following a diagnosis of RA. METHODS: The analysis was undertaken using routinely collected data from the English NHS. Diagnosis of RA was identified using primary care records, with knee and hip replacement observed in linked hospital records. Parametric survival models were fitted for up to 15 years of follow-up, with age, sex, Charlson comorbidity score, socioeconomic status, BMI and smoking status included as explanatory variables. A decision model was used to combine and extrapolate survival models to estimate lifetime risk. RESULTS: The number of individuals with a diagnosis of RA and included in the study was 13 961. Lifetime risk of knee replacement and hip replacement was estimated to be 22% (95% CI: 16, 29%) and 17% (95% CI: 11, 26%) following a diagnosis of RA for the average patient profile (non-smoking women aged 64 with no other comorbidities, BMI of 27 and in the top socioeconomic quintile). Risks were higher for younger patients. CONCLUSION: The lifetime risk of knee and hip replacement for individuals with a diagnosis of RA is approximately double that of the general population. These findings allow for a better understanding of long-term prognosis and healthcare resource use, and highlight the importance of timely diagnosis and effective treatment.

The effect of rheumatoid arthritis on patient-reported outcomes following knee and hip replacement: evidence from routinely collected data.

OBJECTIVES: To compare outcomes of total knee replacement (TKR) and total hip replacement (THR) for individuals with RA and OA. METHODS: We performed a cohort study using routinely collected data. Oxford Knee Score, Oxford Hip Score, and EuroQol 5-dimension 3-level (EQ-5D-3L) questionnaires were collected before and 6 months after surgery. Multivariable regressions were used to estimate the association between diagnosis and post-operative scores after controlling for pre-operative scores and patient characteristics. RESULTS: Study cohorts included 2070 OA and 142 RA patients for TKR and 2030 OA and 98 RA patients for THR. Following TKR, the median Oxford Knee Score was 37 [interquartile range (IQR) 29-43] for OA and 36 (27-42) for RA while the median EQ-5D-3L was 0.76 (0.69-1.00) and 0.69 (0.52-0.85), respectively. After THR, the Oxford Hip Score was 42 (IQR 36-46) for OA and 39 (30-44) for RA while the EQ-5D-3L was 0.85 (0.69-1.00) and 0.69 (0.52-1.00), respectively. The estimated effect of RA, relative to OA, on post-operative scores was -0.05 (95% CI -1.57, 1.48) for the Oxford Knee Score, -0.09 (-0.13, -0.06) for the EQ-5D-3L following TKR, -1.35 (-2.93, -0.22) for the Oxford Hip Score, and -0.08 (-0.12, -0.03) for the EQ-5D-3L following THR. CONCLUSION: TKR and THR led to substantial improvements in joint-specific scores and overall quality of life. While diagnosis had no clinically meaningful effect on joint-specific outcomes, improvements in general quality of life were somewhat less for those with RA, which is likely due to the systemic and multijoint nature of rheumatoid disease.

Health Care Costs Associated With Muscle Weakness: A UK Population-Based Estimate.

Sarcopenia and muscle weakness are responsible for considerable health care expenditure but little is known about these costs in the UK. To address this, we estimated the excess economic burden for individuals with muscle weakness regarding the provision of health and social care among 442 men and women (aged 71-80 years) who participated in the Hertfordshire Cohort Study (UK). Muscle weakness, characterised by low grip strength, was defined according to the Foundation for the National Institutes of Health criteria (men < 26 kg, women < 16 kg). Costs associated with primary care consultations and visits, outpatient and inpatient secondary care, medications, and formal (paid) as well as informal care for each participant were calculated. Mean total costs per person and their corresponding components were compared between groups with and without muscle weakness. Prevalence of muscle weakness in the sample was 11%. Mean total annual costs for participants with muscle weakness were £4592 (CI £2962-£6221), with informal care, inpatient secondary care and primary care accounting for the majority of total costs (38%, 23% and 19%, respectively). For participants without muscle weakness, total annual costs were £1885 (CI £1542-£2228) and their three highest cost categories were informal care (26%), primary care (23%) and formal care (20%). Total excess costs associated with muscle weakness were £2707 per person per year, with informal care costs accounting for 46% of this difference. This results in an estimated annual excess cost in the UK of £2.5 billion.

Modelling cost-effectiveness of tenofovir for prevention of mother to child transmission of hepatitis B virus (HBV) infection in South Africa.

BACKGROUND: International sustainable development goals for the elimination of viral hepatitis as a public health problem by 2030 highlight the need to optimize strategies for prevention, diagnosis and treatment of hepatitis B virus (HBV) infection. An important priority for Africa is to have affordable, accessible and sustainable prevention of mother to child transmission (PMTCT) programmes, delivering screening and treatment for antenatal women and implementing timely administration of HBV vaccine for their babies. METHODS: We developed a decision-analytic model simulating 10,000 singleton pregnancies to assess the cost-effectiveness of three possible strategies for deployment of tenofovir in pregnancy, in combination with routine infant vaccination: S1: no screening nor antiviral therapy; S2: screening and antiviral prophylaxis for all women who test HBsAg-positive; S3: screening for HBsAg, followed by HBeAg testing and antiviral prophylaxis for women who are HBsAg-positive and HBeAg-positive. Our outcome was cost per infant HBV infection avoided and the analysis followed a healthcare perspective. RESULTS: Based on 10,000 pregnancies, S1 predicts 45 infants would be HBV-infected at six months of age, compared to 21 and 28 infants in S2 and S3, respectively. Relative to S1, S2 had an incremental cost of $3940 per infection avoided. S3 led to more infections and higher costs. CONCLUSION: Given the long-term health burden for individuals and economic burden for society associated with chronic HBV infection, screening pregnant women and providing tenofovir for all who test HBsAg+ may be a cost-effective strategy for South Africa and other low/middle income settings.

Identifying individuals with chronic pain after knee replacement: a population-cohort, cluster-analysis of Oxford knee scores in 128,145 patients from the English National Health Service.

BACKGROUND: Approximately one in five patients undergoing knee replacement surgery experience chronic pain after their operation, which can negatively impact on their quality of life. In order to develop and evaluate interventions to improve the management of chronic post-surgical pain, we aimed to derive a cut-off point in the Oxford Knee Score pain subscale to identify patients with chronic pain following knee replacement, and to characterise these patients using self-reported outcomes. METHODS: Data from the English Patient-Reported Outcome Measures (PROMs) programme were used. This comprised patient-reported data from 128,145 patients who underwent primary knee replacement surgery in England between 2012 and 2015. Cluster analysis was applied to derive a cut-off point on the pain subscale of the Oxford Knee Score. RESULTS: A high-pain group was identified, described by a maximum of 14 points in the Oxford Knee Score pain subscale six months after surgery. The high-pain group, comprising 15% of the sample, was characterised by severe and frequent problems in all pain dimensions, particularly in pain severity, night pain and limping, as well as in all dimensions of health-related quality of life. CONCLUSIONS: Patients with Oxford Knee Score pain subscale scores of 14 or less at six months after knee replacement can be considered to be in chronic pain that is likely to negatively affect their quality of life. This derived cut-off can be used for patient selection in research settings to design and assess interventions that support patients in their management of chronic post-surgical pain.

Ten-year patient-reported outcomes following total and minimally invasive unicompartmental knee arthroplasty: a propensity score-matched cohort analysis.

PURPOSE: For patients with medial compartment arthritis who have failed non-operative treatment, either a total knee arthroplasty (TKA) or a unicompartmental knee arthroplasty (UKA) can be undertaken. This analysis considers how the choice between UKA and TKA affects long-term patient-reported outcome measures (PROMs). METHODS: The Knee Arthroplasty Trial (KAT) and a cohort of patients who received a minimally invasive UKA provided data. Propensity score matching was used to identify comparable patients. Oxford Knee Score (OKS), its pain and function components, and the EuroQol 5 Domain (EQ-5D) index, estimated on the basis of OKS responses, were then compared over 10 years following surgery. Mixed-effects regressions for repeated measures were used to estimate the effect of patient characteristics and type of surgery on PROMs. RESULTS: Five-hundred and ninety UKAs were matched to the same number of TKAs. Receiving UKA rather than TKA was found to be associated with better scores for OKS, including both its pain and function components, and EQ-5D, with the differences expected to grow over time. UKA was also associated with an increased likelihood of patients achieving a successful outcome, with an increased chance of attaining minimally clinically important improvements in both OKS and EQ-5D, and an 'excellent' OKS. In addition, for both procedures, patients aged between 60 and 70 and better pre-operative scores were associated with better post-operative outcomes. CONCLUSION: Minimally invasive UKAs performed on patients with the appropriate indications led to better patient-reported pain and function scores than TKAs performed on comparable patients. UKA can lead to better long-term quality of life than TKA and this should be considered alongside risk of revision when choosing between the procedures. LEVEL OF EVIDENCE: II.