Do medical house officers value the health of veterans differently from the health of non-veterans? Patient utilities in chronic musculoskeletal pain: how useful is the standard gamble method? Quality of life in epilepsy: comparison of four preference measures Proportional Heuristics in Time Tradeoff and Conjoint Measurement Patient utilities in fibromyalgia and the association with other outcome measures. Measuring preferences for schizophrenia outcomes with the time tradeoff method Scoring the Child Health Utility 9D instrument: estimation of a Chinese child and adolescent-specific tariff Estimating a preference-based index from the Japanese SF-36. Developing a utility index for the Aberrant Behavior Checklist (ABC-C) for fragile X syndrome Comparing Three Versions of the Time Tradeoff Preference-Based Measurement of Health-Related Quality of Life (HRQL) in Children with Chronic Musculoskeletal Disorders (MSKDs) The impact of a revised EQ-5D population scoring on preference-based utility scores in an inflammatory arthritis cohort. Estimation of patient preference-based utility weights from the functional assessment of cancer therapy - general. US Valuation of the EQ-5D Health States: Development and Testing of the D1 Valuation Model Estimating a Preference-Based Index from the Clinical Outcomes in Routine Evaluation–Outcome Measure (CORE-OM) Cost effectiveness of foldable multifocal intraocular lenses compared to foldable monofocal intraocular lenses for cataract surgery Can systematic reviews with sparse data be trusted? Development of the EXACT-U: a preference-based measure to report COPD exacerbation utilities. Holistic Preferences for 1-Year Health Profiles Describing Fluctuations in Health How do the EQ-5D, SF-6D and the well-being rating scale compare in patients with ankylosing spondylitis? Protocol for a systematic review of the diagnostic and prognostic utility of tests currently available for the detection of aspirin resistance in patients with established cardiovascular or cerebrovascular disease Evaluation of the Quality of Prognosis Studies in Systematic Reviews Protocol for a systematic review of time to antibiotics (TTA) in patients with fever and neutropenia during chemotherapy for cancer (FN) and interventions aiming to reduce TTA
Background Little information is available regarding medical residents ' perceptions of patients ' health-related quality of life . Patients cared for by residents have been shown to receive differing patterns of care at Veterans Affairs facilities than at community or university setting s. We therefore examined : 1 ) how resident physicians value the health of patients ; 2 ) whether values differ if the patient is described as a veteran ; and 3 ) whether residency-associated variables impact values . Methods All medicine residents in a teaching hospital were asked to watch a digital video of an actor depicting a 72-year-old patient with mild-moderate congestive heart failure . Residents were r and omized to 2 groups : in one group , the patient was described as a veteran of the Korean War , and in the other , he was referred to only as a male . The respondents assessed the patient 's health state using 4 measures : rating scale ( RS ) , time tradeoff ( TTO ) , st and ard gamble ( SG ) , and willingness to pay ( WTP ) . We also ascertained residents ' demographics , risk attitudes , residency program type , post-graduate year level , current rotation , experience in a Veterans Affairs hospital , and how many days it had been since they were last on call . We performed univariate and multivariable analyses using the RS , TTO , SG and WTP as dependent variables . Results Eighty-one residents ( 89.0 % of eligible ) participated , with 36 ( 44.4 % ) viewing the video of the veteran and 45 ( 55.6 % ) viewing the video of the non-veteran . Their mean ( SD ) age was 28.7 ( 3.1 ) years ; 51.3 % were female ; and 67.5 % were white . There were no differences in residents ' characteristics or in RS , TTO , SG and WTP scores between the veteran and non-veteran groups . The mean RS score was 0.60 ( 0.14 ) ; the mean TTO score was 0.80 ( 0.20 ) ; the mean SG score was 0.91 ( 0.10 ) ; and the median ( 25th , 75th percentile ) WTP was $ 10,000 ( $ 7600 , $ 20,000 ) per year . In multivariable analyses , being a resident in the categorical program was associated with assigning higher RS scores , but no residency-associated variables were associated with the TTO , SG or WTP scores . Conclusion Physicians in training appear not to be biased either in favor of or against military veterans when judging the value of a patient 's health The main goal of current pain management approaches is to increase the patients ' quality of life by improving pain coping skills and by reducing the levels of disability in daily life , often despite persistent pain . Direct measurement of quality of life is of crucial importance in economic evaluation research , in which not only is the estimation of financial costs and benefits included , but so is the evaluation of costs and benefits in terms of changes in health states . The purpose of this study is to compare the psychometric qualities of two instruments for assessing patients ' utilities , the  rating scale ( RS )  and the st and ard gamble ( SG ) . Such instruments are design ed for their application in economic evaluation research , but have seldomly been used in chronic pain trials . Both methods provide a single measure between 0 and 1 . The relationship between these utility measures and descriptive and domain-specific quality of life measures was examined in 133 fibromyalgia patients and 148 patients with chronic non-specific low back pain .  Mean utility score at baseline was 0.43 with the RS and 0.78 for the SG . The correlation between both methods was found to be poor ( r = 0.21 ) . Both measures appeared to be fairly stable in a 2-week test-retest period ( intra class correlation coefficient ( ICC ) = 0.74 and 0.77 ) . Scores on the description of patient 's own health on six domains , global assessment of change and domain specific measures correlated moderately with the RS scores and low with the SG . Multiple regression analyses demonstrated that 32 % of the variance in RS values and only 13 % of the variance in SG utilities could be explained by domain-specific measures . These results suggest an acceptable construct validity for the RS but insufficient construct validity for the SG . Valuations of ones own health appear only partially to be related to the assessment of the pain-specific measures and measures of distress . It can be concluded that the RS and domain-specific measures assess partly different , but nevertheless complementary aspects of health-related quality of life . It is therefore recommended to include in economic evaluation studies both domain-specific measures and valuation measures . Finally , in chronic musculoskeletal pain patients , RS scores were found to be more responsive in detecting significant changes in preferences than SG scores . For use in patients with chronic musculoskeletal pain , the RS is preferred to the SG for establishing accurate decisions about the impact of new interventions on their health outcomes Several specific and general measures are available for the assessment of overall health related quality of life in epilepsy . Few of the commonly used measures provide utility weights for use in cost-utility analyses . This study compares four methods for measuring utility weights : time trade-off ( TTO ) , st and ard gamble ( SG ) , 15D , end the EuroQol visual analog scale .  All patients aged 18 - 67 years with a diagnosis of epilepsy , who had been admitted to or attended the outpatient clinic at a large county hospital 1987 - 1994 , received a comprehensive question naire . From 397 respondents , 82 patients were r and omly selected . Most of the 57 patients completing the study generally had well-controlled epilepsy , but were still on anti-epileptic medication . Mean age was 44 years . Fourty-one percent were male and 59 % female . The result ing utility weights differed considerably between the measures , both with regard to central tendency and dispersion . Median utility scores : EuroQol visual analog scale 0.75 , 15D 0.90 , TTO 0.98 , SG 0.99 . There was a good association between the EuroQol rating scale and the 15D , and a moderate association between SG and TTO . These preference instruments measure different aspects of health-related quality of life and thus yield different results . Caution should be taken when interpreting cost-utility studies , as results will depend on the choice of utility instrument The time-tradeoff ( TTO ) test is widely used to measure quality of life for different health states . Subjects are asked to equate the value of living a given period in an inferior health state to the value of living a shorter period in good health . Applications of TTOs have been criticized based on the fact that the value of future life duration is taken as the future life duration itself . The authors show that for a health state in which a subject does not want to live longer than a specified amount of time , subjects ' responses do not comply with the assumption that the value of the period in inferior health is equated to the value of the shorter period in good health Actually , preference reversals with respect to such a health state point to the use of a proportional heuristic in the TTO test . Comparisons of the TTO test in these subjects with category scaling and difference measurements also favor a proportional inter pretation of the TTO test . In tests based on conjoint measurement , these subjects also appear to use a proportional heuristic . Consequences of the use of the TTO test and conjoint measurement m quality -of-life models are discussed Key words : utility assessment , QALY , conjoint measurement ; preference reversals ; compatibility effect . ( Med Decis Making 1996;16:36 - 44 OBJECTIVE To compare in patients with fibromyalgia ( FM ) utilities derived by rating scale and st and ard gamble methods ; to gain insight into construct validity by relating utility values to other outcome measures ; to assess the sensitivity to change of utilities . METHODS A total of 73 patients with FM were r and omized into one of 3 groups : low impact fitness training , biofeedback , or controls . At baseline and after 6 mo the Maastricht Utility Measurement Question naire was applied . By means of both the rating scale and st and ard gamble method patients were asked to value their own health status . Construct validity of patient utility measurements was evaluated by Spearman correlation and multiple regression of baseline values with pain , stiffness , patient 's global assessment , Sickness Impact Profile ( SIP ) , modified Health Assessment Question naire and Arthritis Impact Measurement Scale ( AIMS ) . Sensitivity to change was assessed against changes in these outcomes . RESULTS Rating scale utilities correlated significantly ( p < 0.05 ) with patient 's global assessment ( rs = 0.53 ) , pain ( rs = -0.47 ) , SIP ( rs = -0.43 ) , and with 9 of 11 dimensions of the AIMS ( rs ranging from 0.23 to 0.62 ) . St and ard gamble utilities correlated significantly with mobility , pain , and arthritis impact of the AIMS scale ( rs from 0.22 to 0.36 ) and with pain by visual analog scale ( rs = -0.24 ) and patient 's global assessment ( rs = 0.32 ) . Multiple regression analysis showed that patient 's global assessment explained 41 % ( rating scale ) and 10 % ( st and ard gamble ) of total variance in baseline utilities . Also , 16 % of the variance in change in rating scale utility values was explained by changes in patient 's global assessment . In contrast , variance of changes in st and ard gamble utility values was not explained significantly by changes in other disease outcomes . CONCLUSION Rating scale utilities correlated more strongly with disease outcome measures than st and ard gamble utilities . Also , construct validity for the rating scale was better than for the st and ard gamble . In FM , utility measurement is sensitive to the method chosen to elicit patient priorities Measuring preferences for schizophrenia outcomes facilitates meaningful integration of multiple outcome measures and multiple perspectives on treatment outcomes . The Time Tradeoff ( TTO ) technique , specifically developed for measuring health state preferences , is used widely in health research , but some evidence suggests that the TTO may work less well with schizophrenia than with other health conditions . This study tested the hypotheses that tailoring the time frame of the st and ard TTO to the course of schizophrenia and simplifying its presentation fromat would improve its feasibility and efficiency .  Forty clinicians provided  TTO ratings using 1 of 4 combinations of time frame and presentation format . Numeric ratings and quantitative and qualitative measures of feasibility showed that while participants preferred the simpler format , none of the alterations improved feasibility . Participants ' ratings were prone to logical inconsistencies and participants found all 4 versions of the TTO confusing and poorly suited to the context of schizophrenia treatment Purpose To derive children and adolescents ’ preferences for health states defined by the Chinese version of Child Health Utility 9D ( CHU9D-CHN ) instrument in China that can be used to estimate quality -adjusted life years ( QALYs ) for economic evaluation . Methods A profile case best – worst scaling ( BWS ) and a time trade-off ( TTO ) method were combined to derive a Chinese-specific tariff for the CHU9D-CHN . The BWS survey  recruited students from primary and high schools using a multi-stage r and om sampling method and was administered in a classroom setting , whilst the TTO survey adopted an interviewer-administrated conventional TTO task and was administered to a convenience sample of undergraduate students . A latent class modelling framework was adopted for analysing the BWS data . Results Two independent surveys were conducted in Nanjing , China , including a valid sample of 902 students ( mean age 13 years ) from the BWS survey and a valid sample of 38 students ( mean age 18 years ) from the TTO survey . The poolability of the best and the worst responses was rejected and the optimal result based on the best responses only . The optimal model suggests the existence of two latent classes . The BWS estimates were further re-anchored onto the QALY scale using the TTO generated health state values via a mapping approach . Conclusion This study provides further insights into the use of the BWS method to generate health state values with young people and highlights the potential different decision rules that young people may employ for determining best vs. worst choices in this context OBJECTIVE The main objective of the study was to estimate a preference-based Short Form (SF)-6D index from the SF-36 for Japan and compare it with the UK results . STUDY DESIGN AND SETTING The SF-6D was translated into Japanese . Two hundred and forty-nine health states defined by this version of the SF-6D were then valued by a representative sample of 600 members of the Japanese general population using st and ard gamble ( SG ) . These health-state values were modeled using classical parametric r and om-effect methods with individual-level data and ordinary least squares ( OLS ) on mean health-state values , together with a new nonparametric approach using Bayesian methods of estimation . RESULTS All parametric models estimated on Japanese data were found to perform less well than their UK counterparts in terms of poorer goodness of fit , more inconsistencies , larger prediction errors and bias , and evidence of systematic bias in the predictions . Nonparametric models produce a substantial improvement in out-of- sample predictions . The physical , role , and social dimensions have relatively larger decrements than pain and mental health compared with those in the United Kingdom . CONCLUSION The differences between Japanese and UK valuations of the SF-6D make it important to use the Japanese valuation data set estimated using the nonparametric Bayesian technique presented in this article Purpose This study aim ed to develop a utility index ( the ABC-UI ) from the Aberrant Behavior Checklist-Community ( ABC-C ) , for use in quantifying the benefit of emerging treatments for fragile X syndrome ( FXS ) . Methods The ABC-C is a proxy-completed assessment of behaviour and is a widely used measure in FXS . A subset of ABC-C items across seven dimensions was identified to include in health state descriptions . This item reduction process was based on item performance , factor analysis and Rasch analysis performed on an observational study data set , and consultation with five clinical experts and a method ological expert . Dimensions were combined into health states using an orthogonal design and valued using time trade-off ( TTO ) , with lead-time TTO methods used where TTO indicated a state valued as worse than dead . Preference weights were estimated using mean , individual level , ordinary least squares and r and om-effects maximum likelihood estimation [ RE ( MLE ) ] regression models . Results A representative sample of the UK general public ( n = 349 ; mean age 35.8 years , 58.2 % female ) each valued 12 health states . Mean observed values ranged from 0.92 to 0.16 for best to worst health states . The RE ( MLE ) model performed best based on number of significant coefficients and mean absolute error of 0.018 . Mean utilities predicted by the model covered a similar range to that observed . Conclusions The ABC-UI estimates a wide range of utilities from patient-level FXS ABC-C data , allowing estimation of FXS health-related quality of life impact for economic evaluation from an established FXS clinical trial instrument This paper reports a comparative study of three formulations of the time-tradeoff ( TTO ) method of health valuation . One asks people to consider giving up time each day in exchange for better health . The second asks people to consider giving up time during a 12-month interval . The third is the more conventional TTO in which people are asked to contemplate a reduction in life expectancy . Question naires were sent to 4,087 adults selected at r and om from the population of Scotl and . Each respondent provided a de scription of his or her health , and was asked to value an improvement in that health , using all three formulations of the TTO . The daily TTO appeared to be an improvement on the conventional formulation , correlating more strongly with health , eliciting re sponses that appeared to be more precise , and obtaining information about the value of health from a far greater number of respondents . The performance of the annual TTO appeared to be only slightly inferior to that of the daily TTO . Key words : time tradeoff ; quality of life ; health valuation . ( Med Decis Making 1996;16:335 - 347 Background . Health-related quality of life can be measured by patients ' health preferences ( utilities or values ) . No method for measuring health state preferences has been st and ardized for children with arthritis or other musculoskeletal disorders ( MSKDs ) . Such a method is needed for economic evaluations of current and new pediatric treatments . Objectives . 1 ) To assess the feasibility of utility measurements in children with MSKDs , 2 ) to test the validity of the Health Utility Index ( HUI ) for these children , 3 ) to assess whether rating scale values can be mathematically converted into meaningful st and ard gamble ( SG ) utilities , and 4 ) to study whether parents can act as proxies for their children with respect to health state preferences . Methods . Eighty parents of children with MSKDs were consecutively sample d. Their children , if 8 years of age or older ( n = 55 ) , were studied concurrently . Utilities of current health states were obtained by using the SG and the HUI in r and om order . In addition , health state preferences were assessed using categorical and analog rating scales . Traditional nonutility measures of health status ( the Childhood Health Assessment Question naire [ CHAQ ] and the Activities Scale for Kids [ ASK ] ) were also completed . Intraclass correlation coefficients ( ICCs ) were calculated to assess concordance between the different utility measures and also between the ratings of the parents and their children . Results . Children 8 years of age or older were able to express the strength of their health state preferences using the HUI and rating scales . Children older than 10 years of age were able to use the SG method . The health state utilities of the parents were higher than those of their children . The utilities varied widely depending on the elicitation method . The expected high agreement between the SG and the HUI was not found ( ICC = 0.028 for parents , ICC = 0.016 for patients ) . Unlike the SG , the global utilities derived from the HUI agreed better with preferences derived from rating scales ( ICC = 0.23 - 0.25 ) and correlated with traditional health status measures ( with CHAQ , r = -0.56 ; with ASK , r = 0.46 ) both for parents and children . It was not possible to mathematically convert rating scale preferences into SG utilities . The SG utilities were unrelated to results from the rating scales , the CHAQ , and the ASK . Especially for parents , the SG utilities were very high , even when ratings of the other measures indicated poor health . Conclusions . Although it is possible to measure health utilities for children with MSKDs , the results are highly method dependent . The properties of the HUI in this population are more like those of the traditional health status measures rather than those of the SG . Preferences derived from rating scales , although easily performed , can not readily be converted into SG utilities . Parents ' ratings for their children are impaired by risk aversion BACKGROUND AND OBJECTIVE It is well established that there are problems with the EQ-5D . This is due to the original scoring methods used and how negative time trade-off ( TTO ) values were treated . A revised scoring method has been published . This article applies this to an inflammatory arthritis cohort . The objective is to examine the impact of a revised scoring system for the EQ-5D ( UK ) TTO on the utility estimates and in the case of rheumatoid arthritis , to explore the impact of using different utility metrics on the incremental cost-effectiveness ratio ( ICER ) results of an economic model . METHODS A total of 504 patients with inflammatory arthritis were rescored using revised EQ-5D scoring , which uses an episodic r and om utility model to deal with negative TTO values . Differences in utility scores were compared and the new mapping coefficients were obtained . These were then used in an economic model to examine the impact on the ICER . RESULTS In rheumatoid arthritis , the overall change is less for the revised EQ-5D scoring than with the original EQ-5D ( TTO ) but greater than the SF-6D : EQ-5D UK -0.22 ( 95 % confidence interval [ CI ] -0.30 to -0.15 ) , revised EQ-5D UK -0.16 ( 95 % CI -0.21 to -0.10 ) and SF-6D -0.08 ( 95 % CI -0.11 to -0.05 ) . A similar trend is seen in the psoriatic arthritis group . The economic model produced different ICERs , when different utility measures were used ; EQ-5D ( TTO ) € 42,402 , SF-6D € 111,788 , and revised EQ-5D ( TTO ) € 57,747 . CONCLUSION In the context of inflammatory arthritis , this article demonstrates that a revised scoring for EQ-5D may have a significant impact on utility estimates and on the output of the economic model OBJECTIVE The goal of this study was to estimate an algorithm to convert responses to the Functional Assessment of Cancer Therapy - General ( FACT-G ) to time trade-off ( TTO ) utilities based on utilities for current health elicited from cancer patients . METHODS Data for 1433 cancer patients were r and omly separated into construction and validation sample s. Four FACT-G questions were selected for inclusion based on correlation with Eastern Clinical Oncology Group - Performance Status ( ECOG-PS ) scores and TTO utilities . Item response theory was used to collapse response categories . Ordinary least squares regression with the constant constrained to one was used to estimate the algorithm . RESULTS The algorithm estimated mean utility for the full validation sample within three points of observed mean utility ( 0.805 vs. 0.832 , P < 0.01 ) . Mean utilities were well predicted ( mean absolute difference < 0.03 , P > 0.05 ) for most subgroups defined by ECOG-PS and Short Form-36 physical functioning scores , and responses to the FACT-G overall quality of life item . Nevertheless , the algorithm systematic ally overpredicted utilities for poorer health states . CONCLUSIONS A FACT-G-based algorithm of cancer patient utilities was developed that estimates group mean utility scores with accuracy comparable to other indirect preference-based measures of health-related quality of life . Patient-based preferences for health outcomes of cancer treatment may be useful in multiple situations , such as managing re sources within cancer centers and in underst and ing health states preferences among cancer experienced patients before and after treatment Purpose : The EQ-5D is a brief , multiattribute , preference-based health status measure . This article describes the development of a statistical model for generating US population -based EQ-5D preference weights . Methods : A multistage probability sample was selected from the US adult civilian noninstitutional population . Respondents valued 13 of 243 EQ-5D health states using the time trade-off ( TTO ) method . Data for 12 states were used in econometric modeling . The TTO valuations were linearly transformed to lie on the interval [ −1 , 1 ] . Methods were investigated to account for interaction effects caused by having problems in multiple EQ-5D dimensions . Several alternative model specifications ( eg , pooled least squares , r and om effects ) also were considered . A modified split- sample approach was used to evaluate the predictive accuracy of the models . All statistical analyses took into account the clustering and disproportionate selection probabilities inherent in our sampling design . Results : Our D1 model for the EQ-5D included ordinal terms to capture the effect of departures from perfect health as well as interaction effects . A r and om effects specification of the D1 model yielded a good fit for the observed TTO data , with an overall R2 of 0.38 , a mean absolute error of 0.025 , and 7 prediction errors exceeding 0.05 in absolute magnitude . Conclusions : The D1 model best predicts the values for observed health states . The result ing preference weight estimates represent a significant enhancement of the EQ-5D 's utility for health status assessment and economic analysis in the US Background . The Clinical Outcomes in Routine Evaluation– Outcome Measure ( CORE-OM ) is used to evaluate the effectiveness of psychological therapies in people with common mental disorders . The objective of this study was to estimate a preference-based index for this population using CORE-6D , a health state classification system derived from the CORE-OM consisting of a 5-item emotional component and a physical item , and to demonstrate a novel method for generating states that are not orthogonal . Methods . Rasch analysis was used to identify 11 emotional health states from CORE-6D that were frequently observed in the study population and are , thus , plausible ( in contrast , conventional statistical design might generate implausible states ) . Combined with the 3 response levels of the physical item of CORE-6D , they generate 33 plausible health states , 18 of which were selected for valuation . A valuation survey of 220 members of the public in South Yorkshire , United Kingdom , was undertaken using the time tradeoff ( TTO ) method . Regression analysis was subsequently used to predict values for all possible states described by CORE-6D . Results . A number of multivariate regression models were built to predict values for the 33 health states of CORE-6D , using the Rasch logit value of the emotional state and the response level of the physical item as independent variables . A cubic model with high predictive value ( adjusted R2 = 0.990 ) was selected to predict TTO values for all 729 CORE-6D health states . Conclusion . The CORE-6D preference-based index will enable the assessment of cost-effectiveness of interventions for people with common mental disorders using existing and prospect i ve CORE-OM data sets . The new method for generating states may be useful for other instruments with highly correlated dimensions Aim : To analyse the cost effectiveness of foldable monofocal intraocular lenses ( IOLs ) compared to foldable multifocal IOLs in cataract surgery alongside a prospect i ve , multicentre r and omised clinical trial ( RCT ) . Methods : Patients underwent cataract surgery with bilateral monofocal ( n = 97 ) or multifocal ( n = 93 ) IOL implantation .  Cost data and patient preferences , using the visual analogue scale ( VAS ) , the time trade-off ( TTO ) , and the st and ard gamble ( SG ) technique were obtained preoperatively and postoperatively by structured interviews . The incremental costs ( multifocal minus monofocal ) , mean costs per patient , and differences in preferences were computed . Results : Mean costs for glasses per patient in the monofocal group were € 41.67 and in the multifocal group € 149.58 . The difference in costs between the multifocal and monofocal group was € −92.09 and was statistically significant ( p = 0.008 ) . No significant differences were found in total costs or in effectiveness between the monofocal and multifocal IOL group . Conclusion : The cost effectiveness  of multifocal IOLs is reduced to a cost minimisation analysis , because of the inability to demonstrate significant differences in effects . The use of multifocal IOLs in cataract surgery result ed in a significant reduction in costs for patient ’s postoperative spectacles Systematic review s are increasingly used to answer clinical questions . Their popularity is partly attributable to their apparent clinical superiority in providing quick summaries of evidence from the ever-growing medical literature ( more than 750,000 items annually [ 1 ] ) , but also thanks to the great impact of the Cochrane Collaboration in promoting the use of the systematic review [ 2 ] . We also note that many scientific journals favour systematic review s because they tend to contribute to higher journal impact factors . However , the rise of systematic review s should give cause for concern ; more than 8000 are being indexed in MEDLINE annually , reflecting a three-fold increase over the last decade [ 3 ] . We write ‘ concern ’ , because many of these review s across healthcare seem to fall short of essential requirements such as incorporating risk of bias assessment in meta-analyses ( only 16 % ) , search ing for unpublished data ( only 7 % ) , or not fully following a protocol ( only one-third [ 3 ] ) . A recent study of review s published in anaesthetic journals revealed similar shortfalls [ 4 ] . Further more , the quality of reporting is lower in some countries and in journals with lower impact factors [ 5 , 6 ] . The apparent poor quality of many published systematic review s greatly increases the risk of misleading conclusions , which ultimately could harm our patients [ 7 ] . Despite their veneer of sophistication , one has to bear in mind that systematic review s are , in essence , retrospective appraisal s of the evidence . Editors , writers and readers should exercise great caution when interpreting conclusions of review s that only include very few trials , even when they fulfill the required st and ards [ 3 ] . Despite great efforts to promote adequate quality of review s through international guidelines such as PRISMA , GRADE and the Cochrane H and book [ 8 ] , the majority of review s may suffer from threats to the validity of their findings due to risk of systematic errors ( bias ) , design errors ( i.e. , erroneous selection of patients , doses of medication , comparators , analyses , outcomes ) and r and om error ( play of chance ) [ 9 ] . In a previous publication in this journal , some of the method ological issues and requirements for authors and editors were thoroughly discussed [ 10 ] . But we believe that other issues need to be addressed , in particular the amount of information included in meta-analyses from systematic review s , with the power this brings BACKGROUND The exacerbations of chronic obstructive pulmonary disease tool ( EXACT ) is a condition-specific daily diary recently developed to evaluate the frequency , severity , and duration of chronic obstructive pulmonary disease ( COPD ) exacerbations . A preference-based algorithm for the EXACT would allow utilities to be reported from patients during an exacerbation when EQ-5D data are not available . OBJECTIVE To develop the exacerbations of chronic obstructive pulmonary disease tool-utility ( EXACT-U ) , a condition-specific preference-based measure to report utilities from the EXACT for use in cost-effectiveness studies . METHODS Five items with three to five levels comprise the EXACT-U. Two groups of health states and respondents were constructed to allow for model development ( Development group ) and predictive validity testing ( Validation group ) using independent sample s. Members of the UK general public each valued 11 r and omized health states using time trade-offs ( TTOs ) scaled from full health/dead with 10-year duration s. Regression models estimated from the Development group using individual data , mean data , and panel design s. Models assessed by number of inconsistent coefficients estimated and R(2 ) and tested against observed utilities from the Validation group using mean absolute error ( MAE ) and root mean squared error ( RMSE ) . RESULTS A total of 55 health states , including the best and worst states , were valued in TTO interviews conducted with 400 respondents . Ten models were developed . The final preferred model contained no logical inconsistencies and found MAE = 0.04 and RMSE = 0.05 with a predicted utility range from 0.09 to 0.95 . CONCLUSIONS The EXACT-U is a condition-specific preference-based measure with strong predictive validity to report daily utilities during an exacerbation Abstract Background : There are few empirical studies on the valuation of health profiles that describe the short-term fluctuations of chronic diseases . Objective : This study aim ed to value  chronic obstructive pulmonary disease ( COPD ) health profiles  , which describe the health of these patients over the course of 1 year from a societal perspective . Methods : We developed  16 COPD health profiles .  Each profile combined a description of the severity of COPD during the stable phase with a description of the exacerbation profile in terms of severity , frequency and duration . These profiles were valued by a representative sample of 239 Dutch adults using the visual analogue scale ( VAS ) and time trade-off ( TTO ) methods . Value functions were estimated using r and om effects regression analysis . Results : Both VAS and TTO values consistently decreased as severity of the COPD profiles increased . Estimated TTO values ranged from 0.97 for mild COPD without exacerbations to 0.43 for very severe COPD with one non-serious and one serious exacerbation per year . The estimated decrements in TTO values ranged from 0.010 for having one non-serious exacerbation to 0.088 for having one non-serious plus one serious exacerbation per year . Conclusions : The value function may be an alternative way to model the joint impact of COPD severity and exacerbations on utility values in health economic modelling studies Purpose : To compare aspects of validity of EuroQol—5 Dimensions ( EQ-5D ) and Short-Form—6 Dimensions ( SF-6D ) , two indirect utility instruments , and the well-being rating scale ( RS ) in ankylosing spondylitis ( AS ) . Methods : EQ-5D , SF-6D and RS were available for 254 patients fulfilling modified New York criteria . 134 patients were part of an observational cohort and 120 were part of a r and omised controlled trial ( RCT ) . Aspects of validity assessed were truth ( agreement and correlation with external health measures ) and discrimination ( differentiation between health states , repeatability and detection of treatment effect ) . Results : Median ( range ) values were 0.69 ( −0.08–1.00 ) for the EQ-5D , 0.65 ( 0.35–0.95 ) for the SF-6D and 0.65 ( 0.14–1.00 ) for the RS . Agreement ( intraclass correlation coefficient ) was moderate ( 0.46–0.55 ) . Instruments correlated equally with disease activity , functioning and quality of life . The SF-6D showed smaller average differences in utility between patients with better and worse disease compared with the EQ-5D and the RS . The smallest detectable difference ( SDD ) ( in the control group of RCT ) was 0.36 , 0.17 and 0.33 for EQ-5D , SF-6D and RS , respectively . The ability to detect treatment effect ( in the intervention trial ) showed st and ardised effect sizes that were moderate for EQ-5D and SF-6D ( 0.63 and 0.64 ) and low for the RS ( 0.23 ) . Conclusion : In patients with AS , EQ-5D , SF-6D and the RS correlate equally well with external measures of health , but have different psychometric properties . The SDD is most favourable for the SF-6D , but it discriminates less well between patients with different disease severities . The RS has a poorer ability to detect treatment effects . It is difficult to recommend one of the instruments Background The benefits of aspirin as an anti-platelet agent are well established ; however , there has been much debate about the lack of uniformity in the efficacy of aspirin to inhibit platelet function . In some patients , aspirin fails to inhibit platelets even where compliance has been verified , a phenomenon which has been termed “ aspirin resistance ” . These patients may in turn be at a higher risk of future vascular events . The proportion of “ resistant ” patients identified depends on the type of platelet function test . Therefore , the aim of this systematic review is to determine which , if any , platelet function test has utility in terms of identifying patients with a high risk of vascular events . The review has been registered with PROSPERO ( CRD42012002151 ) . Methods Relevant studies will be sought from bibliographic data bases . Trials registers will be search ed for ongoing studies . Reference lists will be checked and subject experts contacted . There will be no date or language restrictions . St and ard review ing methodology to minimise bias will be employed . Any prospect i ve studies in patients on aspirin therapy and assessing platelet function in relation to relevant clinical outcomes will be included , as will studies reporting prognostic models . Risk of bias assessment will be based on the Quality Assessment of Diagnostic Accuracy Studies guidelines , and suitable criteria for assessing quality of prognostic studies . Data on test accuracy measures , relative risks , odds or hazard ratios will be extracted and meta-analysed , where possible , using a r and om-effects model to account for between- study heterogeneity . Where appropriate , the causes of heterogeneity will be explored through meta-regression and sub-group or sensitivity analyses . If platelet function testing is demonstrated to have diagnostic/predictive utility in a specific population , the potential for a cost-effectiveness analysis will be considered and , if possible , an economic model constructed . This will be supported by a systematic review of existing economic evaluation studies . Discussion The results of the review could indicate if platelet function test(s ) could lead to a reliable prediction of the risk of clinical ly important events in a defined population , and thus support investigations into adjustments to therapy in order to compensate for a predicted poor response to st and ard aspirin Prognosis studies are investigations of future events or the evaluation of associations between risk factors and health outcomes in population s of patients ( 1 ) . The results of such studies improve our underst and ing of the clinical course of a disease and assist clinicians in making informed decisions about how best to manage patients . Prognostic research also informs the design of intervention studies by helping define subgroups of patients who may benefit from a new treatment and by providing necessary information about the natural history of a disorder ( 2 ) . There has recently been a rapid increase in the use of systematic review methods to synthesize the evidence on research questions related to prognosis . It is essential that investigators conducting systematic review s thoroughly appraise the method ologic quality of included studies to be confident that a study 's design , conduct , analysis , and interpretation have adequately reduced the opportunity for bias ( 3 , 4 ) . Caution is warranted , however , because inclusion of method ologically weak studies can threaten the internal validity of a systematic review ( 4 ) . This follows abundant empirical evidence that inadequate attention to biases can cause invalid results and inferences ( 5 - 9 ) . However , there is limited consensus on how to appraise the quality of prognosis studies ( 1 ) . A useful framework to assess bias in such studies follows the basic principles of epidemiologic research ( 10 , 11 ) . We focus on 6 areas of potential bias : study participation , study attrition , prognostic factor measurement , confounding measurement and account , outcome measurement , and analysis . The main objectives of our review of review s are to describe methods used to assess the quality of prognosis studies and to describe how well current practice s assess potential biases . Our secondary objective is to develop recommendations to guide future quality appraisal , both within single studies of prognostic factors and within systematic review s of the evidence . We hope this work facilitates future discussion and research on biases in prognosis studies and systematic review s. Methods Literature Search and Study Selection We identified systematic review s of prognosis studies by search ing MEDLINE ( 1966 to October 2005 ) using the search strategy recommended by McKibbon and colleagues ( 12 ) . This strategy combines broad search terms for systematic review s ( systematic review .mp ; meta- analysis .mp ) and a sensitive search strategy for prognosis studies ( cohort , incidence , mortality , follow-up studies , prognos * , predict * , or course ) . We also search ed the reference lists of included review s and method ologic papers to identify other relevant publications . We restricted our search to English- language publications . One review er conducted the search and selected the studies . Systematic review s , defined as review s of published studies with a comprehensive search and systematic selection , were included if they assessed the method ologic quality of the included studies by using 1 or more explicit criteria . We excluded studies if they were meta-analyses of independent patient data only , if their primary goal was to investigate the effectiveness of an intervention or specific diagnostic or screening tests , or if they included studies that were not done on humans . Data Extraction and Synthesis Individual items included in the quality assessment of the systematic review s were recorded as they were reported in the publication ( that is , the information that would be available to readers and future review ers ) . We review ed journal Web sites and contacted the authors of the systematic review s for additional information when authors made such an offer in their original papers . When review s assessed different study design s by using different sets of quality items , we extracted only those items used to assess cohort studies . We constructed a comprehensive list of distinct items that the review s used to assess the quality of their included studies . The full text of each review was screened . All items used by the review authors to assess the quality of studies were extracted into a computerized spreadsheet by 1 review er . Two experienced review ers , a clinical epidemiologist and an epidemiologist , independently synthesized the quality items extracted from the prognosis review s to determine how well the systematic review s assessed potential biases . We did this in 3 steps : 1 ) identified distinct concepts or domains addressed by the quality items ; 2 ) grouped each extracted quality item into the appropriate domain or domains ; and 3 ) identified the domains necessary to assess potential biases in prognosis studies . We then used this information to assess how well the review s ' quality assessment included items from the domains necessary to assess potential biases . After completing each of the first 3 steps , the review ers met to attempt to reach a consensus . The consensus process involved each review er presenting his or her observations and results , followed by discussion and debate . A third review er was available in cases of persistent disagreement or uncertainty . In the first step , all domains addressed by the quality items were identified . The first review er iteratively and progressively defined the domains as items were extracted from the included review s. The second review er defined domains from a r and om list of all extracted quality items . Limited guidance was provided to the review ers so that their assessment s and definitions of domains would be independent . The review ers agreed on a final set of domains that adequately and completely defined all of the extracted items . In the second step , review ers independently grouped each extracted item into the appropriate domains . Review ers considered each extracted item by asking , What is each particular quality item addressing ? or What are the review 's authors getting at with the particular quality assessment item ? . Items were grouped into the domain or domains that best represented the concepts being addressed . For example , the extracted items at least 80 % of the group originally identified was located for follow-up and follow-up was sufficiently complete or does n't jeopardize validity were each independently classified by both review ers as assessing the domain completeness of follow-up adequate , whereas the extracted item quantification and description of all subjects lost to follow-up was classified as assessing the domain completeness of follow-up described . In the third step , we identified the domains necessary to assess potential biases . Each review er considered the ability of the identified domains to adequately address , at least in part , 1 of the following 6 potential biases : 1 ) study participation , 2 ) study attrition , 3 ) prognostic factor measurement , 4 ) confounding measurement and account , 5 ) outcome measurement , and 6 ) analysis . Domains were considered to adequately address part of the framework if information garnered from that domain would inform the assessment of potential bias . For example , both review ers judged that the identified domain study population represents source population or population of interest assessed potential bias in a prognosis study , whereas the domain research question definition did not , although the latter is an important consideration in assessing the inclusion of studies in a systematic review . Finally , on the basis of our previous ratings , we looked at whether each review included items from the domains necessary to assess the 6 potential biases . We calculated the frequency of systematic review s by assessing each potential bias and the number of review s that adequately assessed bias overall . From this systematic synthesis , we developed recommendations for improving quality appraisal in future systematic review s of prognosis studies . We used Microsoft Access and Excel 2002 ( Microsoft Corp. , Redmond , Washington ) for data management and SAS for Windows , version 9.1 ( SAS Institute , Inc. , Cary , North Carolina ) for descriptive statistics . Role of the Funding Sources The funding sources , the Canadian Institutes of Health Research , the Canadian Chiropractic Research Foundation , the Ontario Chiropractic Association , and the Ontario Ministry of Health and Long Term Care , did not have a role in the collection , analysis , or interpretation of the data or in the decision to su bmi t the manuscript for publication . Results We identified 1384 potentially relevant articles . Figure 1 shows a flow chart of studies that were included and excluded . Figure 2 shows the number of review s identified by year of publication . We excluded 131 systematic review s of prognosis studies that did not seem to include any quality assessment of the included studies ; this represented 44 % of prognosis review s. We included 163 review s of prognosis studies in our analysis ( 13 - 175 ) . The most common topics were cancer ( 15 % ) , musculoskeletal disorders and rheumatology ( 13 % ) , cardiovascular ( 10 % ) , neurology ( 10 % ) , and obstetrics ( 10 % ) . Other review s included a wide range of health and health care topics . Sixty-three percent of the review s investigated the association between a specific prognostic factor and a particular outcome ; the remainder investigated multiple prognostic factors or models . The number of primary studies included in each systematic review ranged from 3 to 167 ( median , 18 [ interquartile range , 12 to 31 ] ) . A complete description of the included review s is available from the authors on request . Figure 1 . Flow diagram of inclusion and exclusion criteria of systematic review s. Figure 2 . Number of systematic review s of prognosis studies identified over time . Quality Items One hundred fifty-three review s provided adequate detail to allow extraction of quality items . Eight hundred eighty-two distinct quality items were extracted from the review s. Most review s developed their own set of quality items , with only a few applying criteria from previous review s. Most quality items Background Fever and  neutropenia ( FN ) is a common complication of chemotherapy for cancer . Prompt empiric broad-spectrum antibiotic therapy in FN is typically considered st and ard of care , but the definition of prompt is not clear . We seek to systematic ally review the available data on the association between time to antibiotics ( TTA ) administration and clinical outcomes in patients with FN being treated with chemotherapy .  There have been several efforts to reduce TTA in patients with FN , by implementing specific interventions , presuming there will be a beneficial effect on patient-important outcomes . This systematic review will also collect data on such interventions and their effect to reduce TTA and potentially change clinical outcomes . Methods / design The search will cover MEDLINE , MEDLINE In-Process & Other Non-Indexed Citations , EMBASE , CINAHL , CDSR , CENTRAL , and LILACS . A full- search strategy is provided . Lists of studies identified by references cited and forward citation search ing of included articles will also be review ed . Studies will be screened , and data extracted by one research er and independently checked by a second . Confounding biases and quality of studies will be assessed with the risk of bias in non-r and omised studies -of interventions ( ROBINS-I ) tool . Data will be presented in narrative and tabular forms ; in addition , if appropriate data is available , r and om effects meta- analysis will be used to examine TTA.A detailed analysis plan , including an assessment of heterogeneity and publication bias , is provided . Discussion This study aims to evaluate the association between TTA and patient-important clinical outcomes . Additionally , it will identify , critically appraise , and synthesis e information on performed interventions and its effect to reduce TTA as a way of gaining insight into the potential use of these approaches . This will provide better knowledge for an adjusted treatment approach of FN . Systematic review registration PROSPERO [ CRD42018092948
The results of this study do not support the common view that RS values are lower than TTO values , may suggest that TTO biases largely cancel , and support the validity of formulas for correcting SG bias
Background .
A common assertion is that rating scale ( RS ) values are lower than both st and ard gamble ( SG ) and time tradeoff ( TTO ) values .
However , differences among these methods may be due to method specific bias .
Although SG and TTOs suffer systematic bias , RS responses are known to depend on the range and frequency of other health states being evaluated .
Over many diverse studies this effect is predicted to diminish .
Thus , a systematic review and data synthesis of RS-TTO and RS-SG difference scores may better reveal persistent dissimilarities .
The purpose of this study was to establish through systematic review and meta- analysis the net effect of biases that endure over many studies of utilities .