The standard gamble demonstrated lower reliability than the feeling thermometer

Causal Mediation Analysis with Multiple Time-varying Mediators

In longitudinal studies with time-varying exposures and mediators, the mediational g-formula is an important method for the assessment of direct and indirect effects. However, current methodologies based on the mediational g-formula can deal with only one mediator. This limitation makes these methodologies inapplicable to many scenarios. Hence, we develop a novel methodology by extending the mediational g-formula to cover cases with multiple time-varying mediators. We formulate two variants of our approach that are each suited to a distinct set of assumptions and effect definitions and present nonparametric identification results of each variant. We further show how complex causal mechanisms (whose complexity derives from the presence of multiple time-varying mediators) can be untangled. We implemented a parametric method, along with a user-friendly algorithm, in R software. We illustrate our method by investigating the complex causal mechanism underlying the progression of chronic obstructive pulmonary disease. We found that the effects of lung function impairment mediated by dyspnea symptoms accounted for 14.6% of the total effect and that mediated by physical activity accounted for 11.9%. Our analyses thus illustrate the power of this approach, providing evidence for the mediating role of dyspnea and physical activity on the causal pathway from lung function impairment to health status. See video abstract at, http://links.lww.com/EDE/B988 .

Influence of Psychological Factors on Vaccination Acceptance among Health Care Workers in Slovenia in Three Different Phases of the COVID-19 Pandemic

COVID-19 vaccination acceptance among healthcare workers (HCWs) is very important to control the pandemic and to ensure the safety of HCWs and patients. As psychological factors may affect the decision to be vaccinated, the aim of this study was to investigate the influence of psychological factors on vaccination acceptance in different phases of the COVID-19 pandemic. A cross-sectional study using a web-based survey was conducted among HCWs in Slovenia at the beginning of the pandemic (N = 851), one month later (N = 86), and one year later (N = 145) when vaccines were already available. The results showed that the influence of psychological factors (anxiety, psychological burden, perceived infectability, and germ aversion) was specific for each survey period. At the beginning of the pandemic, vaccination intention was positively associated with anxiety. In the third survey period, anxiety was not exposed as a predictive factor for vaccination intention. However, comparison of vaccination status among groups with different levels of anxiety revealed an interesting distinction within those in favour of vaccination; in the group with minimal levels of anxiety, there was a relatively high share of respondents that were already vaccinated, whereas in the group with severe anxiety, most individuals intended to be vaccinated but hesitated to take action.

A novel approach to increase physical activity in older adults in the community using citizen science: a mixed-methods study

OBJECTIVES

The aims of this study were to implement a novel, community-based physical activity (PA) intervention in a Swiss town with active participation of elderly participants and to evaluate its effectiveness, feasibility, acceptability and sustainability.

METHODS

The CAPACITY intervention combined important determinants of PA, used smartphone apps to provide feedback/facilitate interaction, and followed a citizen science approach to enable participants to organize walking groups. We targeted persons > 60 years from Wetzikon. Assessments took place at baseline and after 6 months, during this intervention period, and 11 months after step-wise withdrawal of the study team.

RESULTS

Twenty-nine persons were included in the study; 25 conducted 6-month follow-up. They had a significant increase in moderate-to-vigorous PA (p = 0.046) but not in daily steps (p = 0.331). After the intervention period, key participants took over organization, independently organized monthly get-togethers, added new walking routes and continuously recruit new participants. Eleven months after withdrawal of the study team, 61 people regularly walk in groups together.

CONCLUSIONS

The novel CAPACITY intervention was successfully implemented, transferred to participants and is now self-sustainable for almost 1 year in the community.

Effects of a long-term home-based exercise training programme using minimal equipment vs. usual care in COPD patients: a study protocol for two multicentre randomised controlled trials (HOMEX-1 and HOMEX-2 trials)

BACKGROUND

Exercise training is an important component of pulmonary rehabilitation (PR) programmes in chronic obstructive pulmonary disease (COPD), but the great majority of COPD patients who would benefit from PR never follow such programmes or fail to maintain exercise training after PR completion. Against this background, we developed an exercise training programme that requires minimal equipment and can be implemented long-term in the patient's home-setting. The aims of the HOMEX-1 and HOMEX-2 trials are to assess the effectiveness of this home-based exercise training programme in two groups of COPD patients over the course of one year: patients who have completed PR (HOMEX-1 trial) and patients who did not enrol in existing PR programmes within the last two years (HOMEX-2 trial).

METHODS

HOMEX-1 and HOMEX-2 are multicentre, parallel group, randomised controlled trials. For both trials each, it is planned to include 120 study participants with a diagnosis of COPD. Participants will be randomised with a 1:1 ratio into the intervention group or the control group (usual care/no intervention). The intervention consists of minimal-equipment exercise training elements with progressive level of intensity, conducted by the participant during six days per week and instructed and coached by a trained health care professional during three home visits and regular telephone calls during one year. Primary outcome is change in dyspnoea (domain of Chronic Respiratory Questionnaire) from baseline to 12-months follow-up. Secondary outcomes are change in dyspnoea over the course of the year (assessed at 3, 6 and 12 month) and change in functional exercise capacity, physical activity, health-related quality of life, health status, exacerbations and symptoms from baseline to 12 months follow-up. In addition, explanatory, safety and cost-effectiveness outcomes will be assessed. We will conduct intention-to-treat analyses separately per trial and per protocol analyses as sensitivity analyses.

DISCUSSION

The HOMEX-1 and HOMEX-2 trials assess a novel intervention that provides an innovative way of making exercise training as accessible as possible for COPD patients. If the intervention proves to be effective long-term, it will fill the gap of providing an easily accessible and feasible intervention so that more COPD patients can follow an exercise programme.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: HOMEX-1 NCT03461887 (registration date: March 12, 2018; retrospectively registered); HOMEX-2 NCT03654092 (registration date: August 31, 2018).

Comparison of the Sensitivity to Change of the 36-Item Short Form Health Survey and the Lupus Quality of Life Measure Using Various Definitions of Minimum Clinically Important Differences in Patients With Active Systemic Lupus Erythematosus

OBJECTIVE

The Medical Outcomes Study Short Form 36 (SF-36) and Lupus Quality of Life (LupusQoL) are health-related quality of life questionnaires used in systemic lupus erythematosus (SLE). We first determined the hypothesis-testing construct validity of the SF-36 and LupusQoL against disease activity in patients with active SLE and then compared the sensitivity to change of SF-36 and LupusQoL domains according to different definitions of minimum clinically important differences (MCIDs) for improvement and worsening in the current cohort.

METHODS

Seventy-eight clinically active SLE patients concurrently completed both questionnaires at their baseline and followup visits. Questionnaire domain scores were correlated with the SLE Disease Activity Index 2000 (SLEDAI-2K) and evaluated for floor/ceiling effects. The sensitivity to change of domains in each questionnaire was analyzed first, according to the various MCID definitions and, second, by clinically meaningful changes in disease activity. The magnitudes of change in each domain score between the baseline and followup visit were evaluated using standardized response means.

RESULTS

In the 78 patients, the mean ± SD SLEDAI-2K scores were 9.7 ± 4.8 at baseline and 8.8 ± 5.1 at followup. SF-36/LupusQoL domain scores did not correlate with disease activity. The SF-36 showed floor effects, and ceiling effects were evident in both questionnaires. All domains of both questionnaires showed sensitivity to change over time. Specific domains that reflected worsening or improvement differed according to differing MCID definitions.

CONCLUSION

In SLE patients with active disease, both the SF-36 and LupusQoL are sensitive to change, reflecting both improvement and worsening. More importantly, the LupusQoL SLE-specific domains (planning, burden to others, body image, and intimate relationships) were largely responsive to change.

Benefit-harm analysis and charts for individualized and preference-sensitive prevention: example of low dose aspirin for primary prevention of cardiovascular disease and cancer

BACKGROUND

Clinical practice guidelines provide separate recommendations for different diseases that may be prevented or treated by the same intervention. Also, they commonly provide recommendations for entire populations but not for individuals. To address these two limitations, our aim was to conduct benefit-harm analyses for a wide range of individuals using the example of low dose aspirin for primary prevention of cardiovascular disease and cancer and to develop Benefit-Harm Charts that show the overall benefit-harm balance for individuals.

METHODS

We used quantitative benefit-harm modeling that included 16 outcomes to estimate the probability that low dose aspirin provides more benefits than harms for a wide range of men and women between 45 and 84 years of age and without a previous myocardial infarction, severe ischemic stroke, or cancer. We repeated the quantitative benefit-harm modeling for different combinations of age, sex, and outcome risks for severe ischemic and hemorrhagic stroke, myocardial infarction, cancers, and severe gastrointestinal bleeds. The analyses considered weights for the outcomes, statistical uncertainty of the effects of aspirin, and death as a competing risk. We constructed Benefit-Harm Charts that show the benefit-harm balance for different combinations of outcome risks.

RESULTS

The Benefit-Harm Charts ( http://www.benefit-harm-balance.com ) we have created show that the benefit-harm balance differs largely across a primary prevention population. Low dose aspirin is likely to provide more benefits than harms in men, elderly people, and in those at low risk for severe gastrointestinal bleeds. Individual preferences have a major impact on the benefit-harm balance. If, for example, it is a high priority for individuals to prevent stroke and severe cancers while severe gastrointestinal bleeds are deemed to be of little importance, the benefit-harm balance is likely to favor low dose aspirin for most individuals. Instead, if severe gastrointestinal bleeds are judged to be similarly important compared to the benefit outcomes, low dose aspirin is unlikely to provide more benefits than harms.

CONCLUSIONS

Benefit-Harm Charts support individualized benefit-harm assessments and decision making. Similarly, individualized benefit-harm assessments may allow guideline developers to issue more finely granulated recommendations that reduce the risk of over- and underuse of interventions. The example of low dose aspirin for primary prevention of cardiovascular disease and cancer shows that it may be time for guideline developers to provide combined recommendations for different diseases that may be prevented or treated by the same intervention.

A methodological analysis of the plastic surgery cost-utility literature using established guidelines

BACKGROUND

Cost-utility studies, common in medicine, are rare within plastic surgery despite their capability of measuring the value of procedures by considering the societal costs of improving quality of life. The objectives of this study were to analyze the design quality of the plastic surgery cost-utility literature and to identify areas of needed improvement for future studies.

METHODS

A scoring tool was constructed based on the Recommendations of the Panel on Cost-Effectiveness in Health and Medicine. A PubMed search through October of 2012 was conducted for English-language plastic surgery utility studies. Articles were selected using two inclusion criteria and evaluated using the scoring tool.

RESULTS

A 9-point scoring tool was created, and 37 publications were selected. Their average score was 3 out of 9 points. Thirty studies (81 percent) used population preferences in utility measurements. Fifteen studies (41 percent) measured costs, but only four (11 percent) included indirect costs and only five (14 percent) applied discount rates to calculate the value of treatments over time. Three studies (8 percent) earned zero points. The highest scoring study earned 8 points.

CONCLUSIONS

The identified studies manifest the potential of cost-utility analyses in plastic surgery. Nonetheless, they are inconsistent in applying established cost-utility guidelines, especially in measuring costs and conducting recommended sensitivity analysis. Following this simple scoring tool can help future studies achieve some necessary improvements.

Evaluating patient values and preferences for thromboprophylaxis decision making during pregnancy: a study protocol

BACKGROUND

Pregnant women with prior venous thromboembolism (VTE) are at risk of recurrence. Low molecular weight heparin (LWMH) reduces the risk of pregnancy-related VTE. LMWH prophylaxis is, however, inconvenient, uncomfortable, costly, medicalizes pregnancy, and may be associated with increased risks of obstetrical bleeding. Further, there is uncertainty in the estimates of both the baseline risk of pregnancy-related recurrent VTE and the effects of antepartum LMWH prophylaxis. The values and treatment preferences of pregnant women, crucial when making recommendations for prophylaxis, are currently unknown. The objective of this study is to address this gap in knowledge.

METHODS

We will perform a multi-center cross-sectional interview study in Canada, USA, Norway and Finland. The study population will consist of 100 women with a history of lower extremity deep vein thrombosis (DVT) or pulmonary embolism (PE), and who are either pregnant, planning pregnancy, or may in the future consider pregnancy (women between 18 and 45 years). We will exclude individuals who are on full dose anticoagulation or thromboprophylaxis, who have undergone surgical sterilization, or whose partners have undergone vasectomy. We will determine each participant's willingness to receive LMWH prophylaxis during pregnancy through direct choice exercises based on real life and hypothetical scenarios, preference-elicitation using a visual analog scale ("feeling thermometer"), and a probability trade-off exercise. The primary outcome will be the minimum reduction (threshold) in VTE risk at which women change from declining to accepting LMWH prophylaxis. We will explore possible determinants of this choice, including educational attainment, the characteristics of the women's prior VTE, and prior experience with LMWH. We will determine the utilities that women place on the burden of LMWH prophylaxis, pregnancy-related DVT, pregnancy-related PE and pregnancy-related hemorrhage. We will generate a "personalized decision analysis" using participants' utilities and their personalized risk of recurrent VTE as inputs to a decision analytic model. We will compare the personalized decision analysis to the participant's stated choice.

DISCUSSION

The preferences of pregnant women at risk of VTE with respect to the use of antithrombotic therapy remain unexplored. This research will provide explicit, quantitative expressions of women's valuations of health states related to recurrent VTE and its prevention with LMWH. This information will be crucial for both guideline developers and for clinicians.

Characteristics of Dutch and Swiss primary care COPD patients - baseline data of the ICE COLD ERIC study

Introduction

International Collaborative Effort on Chronic Obstructive Lung Disease: Exacerbation Risk Index Cohorts (ICE COLD ERIC) is a prospective cohort study with chronic obstructive pulmonary disease (COPD) patients from Switzerland and The Netherlands designed to develop and validate practical COPD risk indices that predict the clinical course of COPD patients in primary care. This paper describes the characteristics of the cohorts at baseline.

Material and methods

Standardized assessments included lung function, patient history, self-administered questionnaires, exercise capacity, and a venous blood sample for analysis of biomarkers and genetics.

Results

A total of 260 Dutch and 151 Swiss patients were included. Median age was 66 years, 57% were male, 38% were current smokers, 55% were former smokers, and 76% had at least one and 40% had two or more comorbidities with cardiovascular disease being the most prevalent one. The use of any pulmonary and cardiovascular drugs was 84% and 66%, respectively. Although lung function results (median forced expiratory volume in 1 second [FEV₁] was 59% of predicted) were similar across the two cohorts, Swiss patients reported better COPD-specific health-related quality of life (Chronic Respiratory Questionnaire) and had higher exercise capacity.

Discussion

COPD patients in the ICE COLD ERIC study represent a wide range of disease severities and the prevalence of multimorbidity is high. The rich variation in these primary care cohorts offers good opportunities to learn more about the clinical course of COPD.

[Outcome assessment in geriatric trauma]

The number of elderly and old patients with fractures is steadily increasing. Identification of relevant functional deficits and comorbidities is crucial for an efficient treatment strategy and outcome assessment in this patient group. For this reason the integration of a geriatric assessment in every orthopedic traumatology practice seems recommendable. Assessing the outcome of frequent fragility fractures (hip, radius) requires instruments oriented to the International Classification of Functioning, Disability and Health (ICF) which allow analysis of bodily function and structure as well as activity and participation. A combination of disease and body region-specific scores with generic scores seems to be reasonable. It can also be sensible to include instruments for health economic analyses.

An instrument to assess quality of life in relation to nutrition: item generation, item reduction and initial validation

Background

It is arguable that modification of diet, given its potential for positive health outcomes, should be widely advocated and adopted. However, food intake, as a basic human need, and its modification may be accompanied by sensations of both pleasure and despondency and may consequently affect to quality of life (QoL). Thus, the feasibility and success of dietary changes will depend, at least partly, on whether potential negative influences on QoL can be avoided. This is of particular importance in the context of dietary intervention studies and in the development of new food products to improve health and well being. Instruments to measure the impact of nutrition on quality of life in the general population, however, are few and far between. Therefore, the aim of this project was to develop an instrument for measuring QoL related to nutrition in the general population.

Methods and results

We recruited participants from the general population and followed standard methodology for quality of life instrument development (identification of population, item selection, n = 24; item reduction, n = 81; item presentation, n = 12; pretesting of questionnaire and initial validation, n = 2576; construct validation n = 128; and test-retest reliability n = 20). Of 187 initial items, 29 were selected for final presentation. Factor analysis revealed an instrument with 5 domains. The instrument demonstrated good cross-sectional divergent and convergent construct validity when correlated with scores of the 8 domains of the SF-36 (ranging from -0.078 to 0.562, 19 out of 40 tested correlations were statistically significant and 24 correlations were predicted correctly) and good test-retest reliability (intra-class correlation coefficients from 0.71 for symptoms to 0.90).

Conclusions

We developed and validated an instrument with 29 items across 5 domains to assess quality of life related to nutrition and other aspects of food intake. The instrument demonstrated good face and construct validity as well as good reliability. Future work will focus on the evaluation of longitudinal construct validity and responsiveness.

Older patients can accurately recall their preoperative health status six weeks following total hip arthroplasty

BACKGROUND

In clinical trials, use of patient recall data would be beneficial when the collection of baseline data is impossible, such as in trauma situations. We investigated the ability of older patients to accurately recall their preoperative quality of life, function, and general health status at six weeks following total hip arthroplasty.

METHODS

We randomized consecutive patients who were fifty-five years of age or older into two groups. At each assessment, patients completed self-report questionnaires (at four weeks preoperatively, on the day of surgery, and at six weeks and three months postoperatively for Group 1 and at six weeks and three months postoperatively for Group 2). At six weeks postoperatively, all patients completed the questionnaires on the basis of their recollection of their preoperative health status. We evaluated the validity and reliability of recall ratings, the degree of error in recall ratings, and the effects of the use of recall data on power and sample size requirements.

RESULTS

A total of 174 patients (mean age, seventy-one years) who were undergoing either primary or revision total hip arthroplasty were randomized and included in the analysis (118 patients were in Group 1 and fifty-six were in Group 2). Agreement between actual and recalled data was excellent for disease-specific questionnaires (intraclass correlation coefficient, 0.86, 0.87, and 0.88) and moderate for generic health measures (intraclass correlation coefficient, 0.48, 0.58, and 0.60). Increased error associated with recalled ratings compared with actual ratings necessitates minimal increases in sample size or results in small decreases in power.

CONCLUSIONS

Patients undergoing total hip arthroplasty can accurately recall their preoperative health status at six weeks postoperatively.

Selection of outcome measures for patients with hip fracture

In designing a study protocol relating to hip fracture treatment and outcomes, it is important to select appropriate outcome instruments. Before beginning the process of instrument selection, investigators must gain a comprehensive understanding of the condition of interest and have a thorough knowledge of the expected benefits and harms of the proposed intervention. Adequate evidence of an intervention's effectiveness includes indication of impact on the patient's health. We provide a brief discussion about different ways that health and health measurement have been defined, including the International Classification of Function, Disability and Health (ICF), health-related quality of life (HRQOL), and cost-to-benefit analyses. We outline important properties (reliability, validity, sensitivity to change, and responsiveness) that a measurement instrument must demonstrate before being considered an acceptable means to measure outcome. Potential outcome measures relevant to patients with hip fracture are summarized, and important points to consider in the selection of outcome measures for a hypothetical research question in a hip fracture population are discussed.

ICE COLD ERIC--International collaborative effort on chronic obstructive lung disease: exacerbation risk index cohorts--study protocol for an international COPD cohort study

Background

Chronic Obstructive Pulmonary Disease (COPD) is a systemic disease; morbidity and mortality due to COPD are on the increase, and it has great impact on patients' lives. Most COPD patients are managed by general practitioners (GP). Too often, GPs base their initial assessment of patient's disease severity mainly on lung function. However, lung function correlates poorly with COPD-specific health-related quality of life and exacerbation frequency. A validated COPD disease risk index that better represents the clinical manifestations of COPD and is feasible in primary care seems to be useful. The objective of this study is to develop and validate a practical COPD disease risk index that predicts the clinical course of COPD in primary care patients with GOLD stages 2–4.

Methods/Design

We will conduct 2 linked prospective cohort studies with COPD patients from GPs in Switzerland and the Netherlands. We will perform a baseline assessment including detailed patient history, questionnaires, lung function, history of exacerbations, measurement of exercise capacity and blood sampling. During the follow-up of at least 2 years, we will update the patients' profile by registering exacerbations, health-related quality of life and any changes in the use of medication. The primary outcome will be health-related quality of life. Secondary outcomes will be exacerbation frequency and mortality. Using multivariable regression analysis, we will identify the best combination of variables predicting these outcomes over one and two years and, depending on funding, even more years.

Discussion

Despite the diversity of clinical manifestations and available treatments, assessment and management today do not reflect the multifaceted character of the disease. This is in contrast to preventive cardiology where, nowadays, the treatment in primary care is based on patient-specific and fairly refined cardiovascular risk profile corresponding to differences in prognosis. After completion of this study, we will have a practical COPD-disease risk index that predicts the clinical course of COPD in primary care patients with GOLD stages 2–4. In a second step we will incorporate evidence-based treatment effects into this model, such that the instrument may guide physicians in selecting treatment based on the individual patients' prognosis.

Trial registration

ClinicalTrials.gov Archive NCT00706602

Health state utilities in latent and active tuberculosis

BACKGROUND

Tuberculosis (TB) remains a major public health threat worldwide. Numerous cost-effectiveness analyses of TB screening and treatment strategies have been recently published, but none have utilized quality-adjusted life-years as recommended because of the lack of utilities for TB health states.

OBJECTIVE

To characterize and compare utility scores from either active TB or latent TB infection (LTBI) participants.

METHODS

Consenting patients attending a population-based screening and treatment clinic were administered the Short Form 36 (SF-36), the Health Utilities Index 2/3 (HUI2/3), and a general health visual analog scale (VAS) along with demographic questions. SF-36 scores were converted to Short Form 6D (SF-6D) utility scores using an accepted algorithm. Utility results were compared across scales, and construct validity was assessed.

RESULTS

A total of 162 TB patients (78 LTBI and 84 active TB) with available SF-36 and all four utility scores (Health Utilities Index 2, Health Utilities Index 3, SF-6D and VAS) were included in the analysis. Those with active TB had significantly lower SF-36 and utility scores than those with LTBI. Although all appeared to exhibit construct validity, the HUI2/3 and the VAS appeared to have significant ceiling effects, whereas the SF-6D had significant floor effects.

CONCLUSIONS

Health state utility values for active TB and LTBI have been determined using different instruments. The three measures did not generate identical utility scores. The HUI2/3 was limited by ceiling effects, whereas the SF-6D appeared to display floor effects.

Marker states and a health state prompt provide modest improvements in the reliability and validity of the standard gamble and rating scale in prostate cancer patients

PURPOSE

To evaluate the combined effect of marker states and a prompt on the reliability and validity of direct utility assessment.

METHODS

In a structured interview, 141 prostate cancer (PC) patients provided rating scale (RS) and standard gamble (SG) utilities for their "own health" (RS-/SG-). Following self-completion of comparison instruments (two generic utility and one disease-specific psychometric), they answered a checklist of PC-related items (a prompt to consider self-health) and provided utilities for self-health and mild and severe PC marker states (RS+/SG+). The interview was repeated 5 weeks later, but without comparison instruments. Using Bayesian modeling, we computed and compared correlation coefficients to assess RS and SG test-retest reliability and validity and the effects of the prompt and marker states.

RESULTS

RS and SG had acceptable test-retest reliability (intraclass correlation coefficients = 0.57-0.63). The prompt and marker states decreased the reliability of the RS by 0.01 (from 0.58 to 0.57) but increased the reliability of the SG by 0.05 (from 0.58 to 0.63). The probability that the reliability of the SG+ was greater than that of the SG- was very high (0.96). Correlations with comparison instruments were higher by 0.01-0.06 for RS+ vs RS-, and higher by 0.03-0.06 for SG+ vs SG-. The probabilities that the prompt and marker states improved validity ranged from 0.55 to 0.74 (RS), and from 0.61 to 0.70 (SG).

CONCLUSIONS

A self-health description prompt and marker states modestly improved the reliability and validity of direct utility elicitation.

The standard gamble showed better construct validity than the time trade-off

BACKGROUND AND OBJECTIVE

There is little evidence for the relative cross-sectional validity of the standard gamble (SG) and time trade-off (TTO). We compared these preference-based instruments in patients with Irritable Bowel Syndrome (IBS).

METHODS

Patients rated their own health on the SG and TTO and completed the disease-specific IBS questionnaire, the Brief Pain Inventory, the SF-36, the Sickness Impact Profile, and a global rating of disease severity.

RESULTS

Mean scores of the 96 enrolled patients (mean age 39.5 years, 84.4% women) were 0.84 (standard deviation 0.16) for the SG and 0.76 (0.22) for the TTO. The correlation of the SG with the TTO was 0.36. For the SG, correlation coefficients with the IBS questionnaire domain scores ranged from 0.36 to 0.47, whereas those of the TTO were substantially lower (0.15-0.42). The SG also had higher correlations than the TTO with generic questionnaires (0.18-0.34 versus 0.13-0.26), Brief Pain Inventory (0.27 versus 0.11), global rating of disease severity (0.22 versus 0.10) as well as with SF-36-derived patient preferences (0.31-0.43 versus 0.27-0.31).

CONCLUSIONS

The higher correlations of the SG with validation measures indicate that the SG better reflects health-related quality of life and patient preferences compared to the TTO.

Application of generalizability theory confirmed lower reliability of the standard gamble than the feeling thermometer

OBJECTIVES

Recent studies suggest that rating clinical marker states (CMS) does not improve the measurement properties of the standard gamble (SG) and only slightly improves those of the feeling thermometer (FT). The poor intrarater (test-retest) reliability of CMS may explain their meager performance. Further, lack of interrater reliability may compromise the use of CMS in interpreting health state ratings. The aim of this study was to assess the reliability of CMS ratings for the SG and the FT.

STUDY DESIGN AND SETTING

Two similar studies in patients with chronic obstructive pulmonary disease (COPD, n=91) and in patients with gastroesophageal reflux disease (GERD, n=112) provided data for this analysis. Patients rated three different CMS (mild, moderate, and severe disease) twice several weeks apart. We used generalizability theory to calculate reliability coefficients.

RESULTS

Test-retest reliability for CMS ratings was higher for the FT compared to the SG (COPD: 0.86 vs. 0.67; GERD: 0.86 vs. 0.67). Interrater reliability was much higher for the FT compared to the SG (COPD: 0.78 vs. 0.46; GERD: 0.71 vs. 0.26).

CONCLUSIONS

These results suggest that the markedly poorer reliability of CMS for the SG than the FT is driven largely by poor interrater reliability.

Changes in preferences for life-sustaining treatment among older persons with advanced illness

BACKGROUND

There are conflicting assumptions regarding how patients' preferences for life-sustaining treatment change over the course of serious illness.

OBJECTIVE

To examine changes in treatment preferences over time.

DESIGN

Longitudinal cohort study with 2-year follow-up.

PARTICIPANTS

Two hundred twenty-six community-dwelling persons age > or =60 years with advanced cancer, congestive heart failure, or chronic obstructive pulmonary disease.

MEASUREMENTS

Participants were asked, if faced with an illness exacerbation that would be fatal if untreated, whether they would: a) undergo high-burden treatment at a given likelihood of death and b) undergo low-burden treatment at a given likelihood of severe disability, versus a return to current health.

RESULTS

There was little change in the overall proportions of participants who would undergo therapy at a given likelihood of death or disability from first to final interview. Diversity within the population regarding the highest likelihood of death or disability at which the individual would undergo therapy remained substantial over time. Despite a small magnitude of change, the odds of participants' willingness to undergo high-burden therapy at a given likelihood of death and to undergo low-burden therapy at a given likelihood of severe cognitive disability decreased significantly over time. Greater functional disability, poorer quality of life, and lower self-rated life expectancy were associated with decreased willingness to undergo therapy.

CONCLUSIONS

Diversity among older persons with advanced illness regarding treatment preferences persists over time. Although the magnitude of change is small, there is a decreased willingness to undergo highly burdensome therapy or to risk severe disability in order to avoid death over time and with declining health status.

Do Clinical Marker States Improve Responsiveness and Construct Validity of the Standard Gamble and Feeling Thermometer: A Randomized Multi-Center Trial in Patients with Chronic Respiratory Disease

BACKGROUND

Optimizing the validity and responsiveness of utility measures will enhance their usefulness in randomized trials. We evaluated the impact of clinical marker state (CMS) rating prior to patients' rating their own health on two utility instruments (feeling thermometer (FT) and standard gamble (SG)) in patients with chronic respiratory disease (CRD).

METHODS

We randomized 182 patients with CRD to complete the FT (self-administered) and SG with CMS (FT+/SG+, n=91) or without marker states (FT-/SG-, n=91) before and after undergoing respiratory rehabilitation in a multi-center trial.

RESULTS

Use of CMS did not influence baseline utility scores. Improvement after therapy on the scale from 0 (dead) to 1.0 (full health) was 0.04 both in FT+ (p=0.03) and FT- (p=0.02; the difference between FT+ and FT- was 0.00, p=0.83). Improvement on the SG was 0.05 in both SG+ (p=0.08) and SG- (p=0.04; difference between SG+ and SG- 0.00, p=0.95). Correlations with other health related quality of life scores were highest for FT+.

CONCLUSION

Administration of CMS did not improve responsiveness of the FT but may have improved construct validity. The SG showed limited construct validity and responsiveness that was not influenced by CMS use.