***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The objective of this study was to assess the association between changes in joint space width ( JSW , i.e. , structure ) or Western Ontario and McMaster Universities ( WOMAC ) score ( i.e. , symptoms ) over 3 years in patients with knee osteoarthritis and the occurrence of knee replacement over 8 years . We followed 133 subjects with primary knee osteoarthritis prospect ively for a mean of 8 years .  JSW ( st and ard radiography ) and symptoms ( total WOMAC score ) were assessed every year for 3 years . The rate of knee replacement  was recorded for the following 5 years . Logistic regressions were performed according to the intention-to-treat principle . After 8 years ’ follow-up , ten patients ( 7.5 % ) had undergone a knee replacement . The changes in JSW or WOMAC score over 3 years were significantly associated with the occurrence of knee replacement during the following 5 years ( p = 0.02 and p = 0.03 , respectively ) . Each 0.1-mm narrowing of JSW over 3 years was associated with a 14 % ( 95 % CI 3–25 % ) increased risk for knee replacement . For every 10 % increase in WOMAC score , the risk for joint replacement was increased by 16 % ( 95 % CI 1–33 % ) . When JSW and WOMAC score were included in the same statistical model , they were still significantly associated with risk for knee replacement ( p = 0.02 and p = 0.03 , respectively ) , but JSW change was the only variable that remained significant after adjusting for all potential confounders . Our results suggest that changes in symptoms and , more particularly , in structure over 3 years in patients with osteoarthritis reflect a clinical ly relevant progression of the disease Background The Arthroplasty Pain Experience ( APEX ) studies are two r and omised controlled trials in primary total hip ( THR ) and total knee replacement ( TKR ) at a large UK orthopaedics centre . APEX investigated the effect of local anaesthetic wound infiltration ( LAI ) , administered before wound closure , in addition to st and ard analgesia , on pain severity at 12 months . This article reports results of the within-trial economic evaluations . Methods Cost-effectiveness was assessed from the health and social care payer perspective in relation to quality adjusted life years ( QALYs ) and the primary clinical outcome , the WOMAC Pain score at 12-months follow-up . Re source use was collected from hospital records and patient-completed postal question naires , and valued using unit cost estimates from local NHS Trust finance department and national tariffs . Missing data were addressed using multiple imputation chained equations . Costs and outcomes were compared per trial arm and plotted in cost-effectiveness planes . If no arm was dominant ( i.e. , more effective and less expensive than the other ) , incremental cost-effectiveness ratios were estimated . The economic results were bootstrapped incremental net monetary benefit statistics ( INMB ) and cost-effectiveness acceptability curves . One-way deterministic sensitivity analyses explored any method ological uncertainty . Results In both the THR and TKR trials , LAI was the dominant treatment : cost-saving and more effective than st and ard care , in relation to QALYs and WOMAC Pain . Using the £ 20,000 per QALY threshold , in THR , the INMB was £ 1,125 ( 95 % BCI , £ 183 to £ 2,067 ) and the probability of being cost-effective was over 98 % . In TKR , the INMB was £ 264 ( 95 % BCI , −£710 to £ 1,238 ) , but there was only 62 % probability of being cost-effective . When considering an NHS perspective only , LAI was no longer dominant in THR , but still highly cost-effective , with an INMB of £ 961 ( 95 % BCI , £ 50 to £ 1,873 ) . Conclusions Administering LAI is a cost-effective treatment option in THR and TKR surgeries . The evidence , because of larger QALY gain , is stronger for THR . In TKR , there is more uncertainty around the economic result , and smaller QALY gains . Results , however , point to LAI being cheaper than st and ard analgesia , which includes a femoral nerve block . Trial registration IS RCT N96095682 , 29/04/2010 This prospect i ve longitudinal multicenter study of ambulatory children with cerebral palsy ( CP ) examined changes in outcome tool score over time , tool responsiveness , and used a systematic method for defining minimum clinical ly important differences ( MCIDs ) . Three hundred and eighty-one participants with CP ( Gross Motor Function Classification System [ GMFCS ] Levels I-III ; age range 4 - 18y , mean age 11y [ SD 4y 4mo ] ; 265 diplegia , 116 hemiplegia ; 230 males , 151 females ) . At baseline and follow-up at least 1 year later , Functional Assessment Question naire , Gross Motor Function Measure , Pediatric Quality of Life Inventory , Pediatric Outcomes Data Collection Instrument , Pediatric Functional Independence Measure , temporal-spatial gait parameters , and oxygen cost were collected . Adjusted st and ardized response means determined tool responsiveness for nonsurgical ( n=292 ) and surgical ( n=87 ) groups at GMFCS Levels I to III . Most scores reaching medium or large effect sizes were for GMFCS Level III . Nonsurgical group change scores were used to calculate MCID thresholds for ambulatory children with CP . These values were verified by examining participants who changed GMFCS levels . Tools measuring function were responsive when a change large enough to cause a change in GMFCS level occurred . MCID thresholds assess change in study population s over time , and serve as the basis for design ing prospect i ve intervention studies Objectives To assess how costs and quality of life ( measured by EuroQoL-5 Dimensions ( EQ-5D ) ) before and after total hip replacement ( THR ) and total knee replacement ( TKR ) vary with age , gender and preoperative Oxford hip score ( OHS ) and Oxford knee score ( OKS ) . Design Regression analyses using prospect ively collected data from clinical trials , cohort studies and administrative data bases . Setting UK secondary care . Participants Men and women undergoing primary THR or TKR . The Hospital Episode Statistics data linked to patient-reported outcome measures included 602 176 patients undergoing hip or knee replacement who were followed up for up to 6 years . The Knee Arthroplasty Trial included 2217 patients undergoing TKR who were followed up for 12 years . The Clinical Outcomes in Arthroplasty Study cohort included 806 patients undergoing THR and 484 patients undergoing TKR who were observed for 1 year . Outcome measures EQ-5D-3L quality of life before and after surgery , costs of primary arthroplasty , costs of revision arthroplasty and the costs of hospital readmissions and ambulatory costs in the year before and up to 12 years after joint replacement . Results Average postoperative utility for patients at the 5th percentile of the OHS/OKS distribution was 0.61/0.5 for THR/TKR and 0.89/0.85 for patients at the 95th percentile . The difference between postoperative and preoperative EQ-5D utility was highest for patients with preoperative OHS/OKS lower than 10 . However , postoperative EQ-5D utility was higher than preoperative utility for all patients with OHS≤46 and those with OKS≤44 . In contrast , costs were generally higher for patients with low preoperative OHS/OKS than those with high OHS/OKS . For example , costs of hospital readmissions within 12 months after primary THR/TKR were £ 740/£888 for patients at the 5th percentile compared with £ 314/£404 at the 95th percentile of the OHS/OKS distribution . Conclusions Our findings suggest that costs and quality of life associated with total joint replacement vary systematic ally with preoperative symptoms measured by OHS/OKS Background For the majority of patients with osteoarthritis ( OA ) , joint replacement is a successful intervention for relieving chronic joint pain . However , between 10 - 30 % of patients continue to experience chronic pain after joint replacement . Evidence suggests that a risk factor for chronic pain after joint replacement is the severity of acute post-operative pain . The aim of this r and omised controlled trial ( RCT ) is to determine if intra-operative local anaesthethic wound infiltration additional to a st and ard anaethesia regimen can reduce the severity of joint pain at 12-months after total knee replacement ( TKR ) and total hip replacement ( THR ) for OA . Methods 300 TKR patients and 300 THR patients are being recruited into this single-centre double-blind RCT . Participants are recruited before surgery and r and omised to either the st and ard care group or the intervention group . Participants and outcome assessors are blind to treatment allocation throughout the study . The intervention consists of an intra-operative local anaesthetic wound infiltration , consisting of 60 mls of 0.25 % bupivacaine with 1 in 200,000 adrenaline . Participants are assessed on the first 5 days post-operative , and then at 3-months , 6-months and 12-months . The primary outcome is the WOMAC Pain Scale , a vali date d measure of joint pain at 12-months . Secondary outcomes include pain severity during the in-patient stay , post-operative nausea and vomiting , satisfaction with pain relief , length of hospital stay , joint pain and disability , pain sensitivity , complications and cost-effectiveness . A nested qualitative study within the RCT will examine the acceptability and feasibility of the intervention for both patients and healthcare professionals . Discussion Large-scale RCTs assessing the effectiveness of a surgical intervention are uncommon , particulary in orthopaedics . The results from this trial will inform evidence -based recommendations for both short-term and long-term pain management after lower limb joint replacement . If a local anaesthetic wound infiltration is found to be an effective and cost-effective intervention , implementation into clinical practice could improve long-term pain outcomes for patients undergoing lower limb joint replacement . Trial registration Current Controlled Trials IS RCT Background The number of prosthesis br and s used for hip replacement has increased rapidly , but there is little evidence on their effectiveness . We compared patient-reported outcomes , revision rates , and mortality for the three most frequently used br and s within each prosthesis type : cemented ( Exeter V40 Contemporary , Exeter V40 Duration and Exeter V40 Elite Plus Ogee ) , cementless ( Corail Pinnacle , Accolade Trident , and Taperloc Exceed ) , and hybrid ( Exeter V40 Trilogy , Exeter V40 Trilogy , and CPT Trilogy ) . Methods and Findings We used three national data bases of patients who had hip replacements between 2008 and 2011 in the English NHS to compare functional outcome ( Oxford Hip Score ( OHS ) ranging from 0 ( worst ) to 48 ( best ) ) in 43,524 patients at six months . We analysed revisions and mortality in 187,201 patients . We used multiple regression to adjust for pre-operative differences . Prosthesis type had an impact on post-operative OHS and revision rates ( both p<0.001 ) . Patients with hybrid prostheses had the best functional outcome ( mean OHS 39.4 , 95%CI 39.1 to 39.7 ) and those with cemented prostheses the worst ( 37.7 , 37.3 to 38.1 ) . Patients with cemented prostheses had the lowest reported 5-year revision rates ( 1.3 % , 1.2 % to 1.4 % ) and those with cementless prostheses the highest ( 2.2 % , 2.1 % to 2.4 % ) . Differences in mortality according to prosthesis type were small and not significant ( p = 0.06 ) . Functional outcome varied according to br and among cemented ( p = 0.05 , with Exeter V40 Duration having the best ) and cementless prostheses ( p = 0.01 , with Corail Pinnacle having the best ) . Revision rates varied according to br and among hybrids ( p = 0.05 , with Exeter V40 Trident having the lowest ) . Conclusions Functional outcomes were better with cementless cups and revision rates were lower with cemented stems , which underlies the good overall performance of hybrids . The hybrid Exeter V40 Trident seemed to produce the best overall results . This br and should be considered as a benchmark in r and omised trials PURPOSE We report on a clinical trial developed to compare four different instruments that provide overall quality -of-life ( QOL ) scores , ranging from a simple , one-item instrument to more detailed instruments . Two issues addressed were ( 1 ) Will QOL tools suffer from missing data when used in a community-based cooperative group setting ? , and ( 2 ) Are there additional data generated by a more detailed multiitem instrument over that provided by a single-item global QOL question ? MATERIAL S AND METHODS A four-arm r and omized trial was design ed to compare four instruments that provide overall QOL scores in patients with advanced colorectal cancer . Patients and physicians completed the single-item Spitzer Uniscale ( UNISCALE ) at baseline and monthly . Patients were r and omly assigned to complete , in addition , either the 22-item Functional Living Index-Can 
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LIMITATIONS The ACHE tool supports but does not replace the shared decision-making process required before an individual decides whether or not to undergo surgery .
At a population level , both hip and knee arthroplasty are highly cost-effective right up to the absolute threshold for intervention .