Research Priorities to Increase Confidence in and Acceptance of Health Preference Research: What Questions Should be Prioritized Now?

BACKGROUND AND OBJECTIVE

There has been an increase in the study and use of stated-preference methods to inform medicine development decisions. The objective of this study was to identify prioritized topics and questions relating to health preferences based on the perspective of members of the preference research community.

METHODS

Preference research stakeholders from industry, academia, consultancy, health technology assessment/regulatory, and patient organizations were recruited using professional networks and preference-targeted e-mail listservs and surveyed about their perspectives on 19 topics and questions for future studies that would increase acceptance of preference methods and their results by decision makers. The online survey consisted of an initial importance prioritization task, a best-worst scaling case 1 instrument, and open-ended questions. Rating counts were used for analysis. The best-worst scaling used a balanced incomplete block design.

RESULTS

One hundred and one participants responded to the survey invitation with 66 completing the best-worst scaling. The most important research topics related to the synthesis of preferences across studies, transferability across populations or related diseases, and method topics including comparison of methods and non-discrete choice experiment methods. Prioritization differences were found between respondents whose primary affiliation was academia versus other stakeholders. Academic researchers prioritized methodological/less studied topics; other stakeholders prioritized applied research topics relating to consistency of practice.

CONCLUSIONS

As the field of health preference research grows, there is a need to revisit and communicate previous work on preference selection and study design to ensure that new stakeholders are aware of this work and to update these works where necessary. These findings might encourage discussion and alignment among different stakeholders who might hold different research priorities. Research on the application of previous preference research to new contexts will also help increase the acceptance of health preference information by decision makers.

Patient Preferences in Pulmonary Arterial Hypertension, a Latent Class Analysis to Identify Preference Heterogeneity

OBJECTIVES

Pulmonary arterial hypertension (PAH) is a chronic, progressive disease of the pulmonary circulation characterized by vascular remodeling that, if untreated, can lead to right heart dysfunction and death. This analysis measured heterogeneity in patient preferences for PAH-specific treatment regimens.

METHOD

Adult patients with PAH with slight to marked limitations during physical activity were recruited through a patient organization in Germany. Participants completed an online best-worst scaling case 3 survey. Patients chose among 3 hypothetical treatment profiles defined by 6 benefits and risks at varying levels. Participants completed 12 choice tasks. Preference heterogeneity was assessed using latent class analysis.

RESULTS

A total of 83 participants (76% female) completed the survey. Best-fit model revealed 4 classes. Class 1 (19% of participants) assigned importance to multiple attributes particularly side effects, class 2 (34%) to physical activity limitations, class 3 (30%) to survival and physical activity limitations, and class 4 (17%) to survival. No differences in sociodemographic characteristics were observed across classes. Compared with other classes, class 4 was most likely to report having marked physical activity limitations (79%) and needing daily help (100%), while considering higher daily activity levels to be ordinary (walking >1 km [71%] or climbing several flights of stairs [50%]).

CONCLUSION

This first patient preference study in a PAH population suggests that physical activity limitations in addition to survival matter most to patients; however, preference heterogeneity between groups of patients was observed. Patient preferences should be considered in treatment decision making to better balance patient's expectations regarding the known risk-benefit ratio of treatment.

Stated-Preference Survey Design and Testing in Health Applications

Following the conceptualization of a well-formulated and relevant research question, selection of an appropriate stated-preference method, and related methodological issues, researchers are tasked with developing a survey instrument. A major goal of designing a stated-preference survey for health applications is to elicit high-quality data that reflect thoughtful responses from well-informed respondents. Achieving this goal requires researchers to design engaging surveys that maximize response rates, minimize hypothetical bias, and collect all the necessary information needed to answer the research question. Designing such a survey requires researchers to make numerous interrelated decisions that build upon the decision context, selection of attributes, and experimental design. Such decisions include considering the setting(s) and study population in which the survey will be administered, the format and mode of administration, and types of contextual information to collect. Development of a survey is an interactive process in which feedback from respondents should be collected and documented through qualitative pre-test interviews and pilot testing. This paper describes important issues to consider across all major steps required to design and test a stated-choice survey to elicit patient preferences for health preference research.

Patient Preferences for Lung Cancer Interception Therapy

Importance

Interception therapy requires individuals to undergo treatment to prevent a future medical event, but little is known about preferences of individuals at high risk for lung cancer and whether they would be interested in this type of treatment.

Objective

To explore preferences of individuals at high risk for lung cancer for potential interception therapies to reduce this risk.

Design, Setting, and Participants

This survey study used a discrete-choice experiment and included hypothetical lung cancer interception treatments with 4 attributes: reduction in lung cancer risk over 3 years, injection site reaction severity, nonfatal serious infection, and death from serious infection. Respondents were assigned to a baseline lung cancer risk of 6%, 10%, or 16% over 3 years. The discrete-choice experiment was administered online (July 13 to September 6, 2022) to US respondents eligible for lung cancer screening according to US Preventive Services Task Force guidelines. Participants included adults aged 50 to 80 years with at least a 20 pack-year smoking history. Statistical analysis was performed from September to December 2022.

Main Outcomes and Measures

Attribute-level preference weights were estimated, and conditional relative attribute importance, maximum acceptable risks, and minimum acceptable benefits were calculated. Characteristics of respondents who always selected no treatment were also explored.

Results

Of the 803 survey respondents, 495 (61.6%) were female, 138 (17.2%) were African American or Black, 55 (6.8%) were Alaska Native, American Indian, or Native American, 44 (5.5%) were Asian or Native Hawaiian or Other Pacific Islander, 104 (13.0%) were Hispanic, Latin American, or Latinx, and 462 (57.5%) were White, Middle Eastern or North African, or a race or ethnicity not listed; and mean (SD) age was 63.0 (7.5) years. Most respondents were willing to accept interception therapy and viewed reduction in lung cancer risk as the most important attribute. Respondents would accept a greater than or equal to a 12.0 percentage point increase in risk of nonfatal serious infection if lung cancer risk was reduced by at least 20.0 percentage points; and a greater than or equal to 1.2 percentage point increase in risk of fatal serious infection if lung cancer risk was reduced by at least 30.0 percentage points. Respondents would require at least a 15.4 (95% CI, 10.6-20.2) percentage point decrease in lung cancer risk to accept a 12.0 percentage point increase in risk of nonfatal serious infection; and at least a 23.1 (95% CI, 16.4-29.8) percentage point decrease in lung cancer risk to accept a 1.2 percentage point increase in risk of death from serious infection. Respondents who were unwilling to accept interception therapy in any question (129 [16.1%]) were more likely to be older and to currently smoke with no prior cessation attempt, and less likely to have been vaccinated against COVID-19 or examined for skin cancer.

Conclusions and Relevance

In this survey study of individuals at high risk of lung cancer, most respondents were willing to consider interception therapy. These results suggest the importance of benefit-risk assessments for future lung cancer interception treatments.

Acceptable risks of treatments to prevent rheumatoid arthritis among first-degree relatives: demographic and psychological predictors of risk tolerance

OBJECTIVES

To quantify tolerance to risks of preventive treatments among first-degree relatives (FDRs) of patients with rheumatoid arthritis (RA).

METHODS

Preventive treatments for RA are under investigation. In a preference survey, adult FDRs assumed a 60% chance of developing RA within 2 years and made choices between no treatment and hypothetical preventive treatment options with a fixed level of benefit (reduction in chance of developing RA from 60% to 20%) and varying levels of risks. Using a probabilistic threshold technique, each risk was increased or decreased until participants switched their choice. Perceived risk of RA, health literacy, numeracy, Brief Illness Perception Questionnaire and Beliefs about Medicines Questionnaire-General were also assessed. Maximum acceptable risk (MAR) was summarised using descriptive statistics. Associations between MARs and participants' characteristics were assessed using interval regression with effects coding.

RESULTS

289 FDRs (80 male) responded. The mean MAR for a 40% reduction in chance of developing RA was 29.08% risk of mild side effects, 9.09% risk of serious infection and 0.85% risk of a serious side effect. Participants aged over 60 years were less tolerant of serious infection risk (mean MAR ±2.06%) than younger participants. Risk of mild side effects was less acceptable to participants who perceived higher likelihood of developing RA (mean MAR ±3.34%) and more acceptable to those believing that if they developed RA it would last for a long time (mean MAR ±4.44%).

CONCLUSIONS

Age, perceived chance of developing RA and perceived duration of RA were associated with tolerance to some risks of preventive RA therapy.

Development of a severity scale to assess chronic lung disease after extremely preterm birth

OBJECTIVE

Chronic lung disease of prematurity (CLDP) is a frequent complication of prematurity. We aimed to identify what clinicians believe are the most important factors determining the severity of CLDP in extremely preterm infants (<28 weeks gestational age) after discharge from the neonatal intensive care unit (NICU) through 12 months corrected age (CA), and to evaluate how these factors should be weighted for scoring, to develop a CLDP severity scale.

STUDY DESIGN

Clinicians completed a three-round online survey utilizing Delphi methodology. Clinicians rated the importance of various factors used to evaluate the severity of CLDP, from 0 (not at all important) to 10 (very important) for the period between discharge home from the NICU and 12 months CA. Fourteen factors were considered in Round 1; 13 in Rounds 2 and 3. The relative importance of factors was explored via a set of 16 single-profile tasks (i.e., hypothetical patient profiles with varying CLDP severity levels).

RESULTS

Overall, 91 clinicians from 11 countries who were experienced in treating prematurity-related lung diseases completed Round 1; 88 completed Rounds 2 and 3. Based on Round 3, the most important factors in determining CLDP severity were mechanical ventilation (mean absolute importance rating, 8.89), supplemental oxygen ≥2 L/min (8.49), rehospitalizations (7.65), and supplemental oxygen <2 L/min (7.56). Single-profile tasks showed that supplemental oxygen had the greatest impact on profile classification.

CONCLUSION

The most important factors for clinicians assigning CLDP severity during infancy were mechanical ventilation, supplemental oxygen ≥2 L/min, and respiratory-related rehospitalizations.

Evaluating Patient Preferences of Maintenance Therapy for the Treatment of Chronic Obstructive Pulmonary Disease: A Discrete Choice Experiment in the UK, USA and Germany

Introduction

With increasing availability of different treatments for chronic obstructive pulmonary disease (COPD), we sought to understand patient preferences for COPD treatment in the UK, USA, and Germany using a discrete choice experiment (DCE).

Methods

Qualitative research identified six attributes associated with COPD maintenance treatments: ease of inhaler use, exacerbation frequency, frequency of inhaler use, number of different inhalers used, side effect frequency, and out-of-pocket costs. A DCE using these attributes, with three levels each, was designed and tested through cognitive interviews and piloting. It comprised 18 choice sets, selected using a D-efficient experimental design. Demographics and disease history were collected and the final DCE survey was completed online by participants recruited from panels in the UK, USA and Germany. Responses were analyzed using mixed logit models, with results expressed as odds ratios (ORs).

Results

Overall, 450 participants (150 per country) completed the DCE; most (UK and Germany, 97.3%; USA, 98.0%) were included in the final analysis. Based on relative attribute importance, avoidance of side effects was found to be most important (UK: OR 11.65; USA: OR 7.17; Germany: OR 11.45; all p<0.0001), followed by the likelihood of fewer exacerbations (UK: OR 2.22; USA: OR 1.63; Germany: OR 2.54; all p<0.0001) and increased ease of use (UK: OR 1.84; USA: OR 1.84; Germany: OR 1.60; all p<0.0001). Number of inhalers, out-of-pocket costs, and frequency of inhaler use were found to be less important. Preferences were relatively consistent across the three countries. All participants required a reduction in exacerbations to accept more frequent inhaler use or use of more inhalers.

Conclusion

When selecting COPD treatment, individuals assigned the highest value to the avoidance of side effects, experiencing fewer exacerbations, and ease of inhaler use. Ensuring that patients’ preferences are considered may encourage treatment compliance.

Cost of behavioral weight loss programs implemented in clinical practice: The POWER trial at Johns Hopkins

Obesity presents an important public health problem that affects more than a third of the U.S. adult population and that is associated with increased morbidity, mortality, and costs. Previously, we documented that two primary care-based weight loss interventions were clinically effective. To encourage the implementation of and reimbursement for these interventions, we evaluated their relative cost-effectiveness. We performed a cost analysis of the Practice-based Opportunities for Weight Reduction (POWER) trial, a three-arm trial that enrolled 415 patients with obesity from six primary care practices. Trial participants were randomized to a control arm, an in-person support intervention, or a remote support intervention; in the two intervention arms, behavioral interventions were delivered over 24 months, in two phases. Weight loss was measured at 6, 12, and 24 months. Using timesheets and empirical data, we evaluated the cost of the in-person and remote support interventions from the perspective of a health care system delivering the interventions. A univariate sensitivity analysis was conducted to evaluate uncertainty around model assumptions. All comparisons were tested using independent t-tests. Cost of the in-person intervention was higher at 6 months ($113 per participant per month and $117 per kg lost) than the remote support intervention ($101 per participant per month and $99 per kg lost; p < .001). Costs were also higher for the in-person support intervention at 24 months ($73 per participant per month and $342 per kg lost) than for the remote support intervention ($53 per participant per month and $275 per kg lost; p < .001). In the sensitivity analyses, cost ranged from $274/kg lost to $456/kg lost for the in-person support intervention and from $218/kg to $367/kg lost for the remote support intervention. A primary care weight loss intervention administered remotely was relatively more cost-effective than an in-person intervention. Expanding the scope of reimbursable programs to include other cost-effective interventions could help ensure that a broader range of patients receive the type of support needed.

Analysis of Patient Preferences in Lung Cancer - Estimating Acceptable Tradeoffs Between Treatment Benefit and Side Effects

OBJECTIVE

Increased treatment options and longer survival for lung cancer have generated increased interest in patient preferences. Previous studies of patient preferences in lung cancer have not fully explored preference heterogeneity. We demonstrate a method to explore preference heterogeneity in the willingness of patients with lung cancer and caregivers to trade progression-free survival (PFS) with side effects.

PATIENTS AND METHODS

Patients and caregivers attending a national lung cancer meeting completed a discrete-choice experiment (DCE) designed through a collaboration with patients. Participants answered 13 choice tasks described across PFS, short-term side effects, and four long-term side effects. Side effects were coded as a one-level change in severity (none-mild, mild-moderate, or moderate-severe). A mixed logit model in willingness-to-pay space estimated preference heterogeneity in acceptable tradeoffs (time equivalents) between PFS and side effects. The study was reported following quality indicators from the United States Food and Drug Administration's patient preference guidance.

RESULTS

A total of 87 patients and 24 caregivers participated in the DCE. Participants would trade 3.7 month PFS (95% CI (CI): 3.3-4.1) for less severe functional long-term treatment side effects, 2.3 months for less severe physical long-term effects (CI: 1.9-2.8) and cognitive long-term effects (CI: 1.8-2.8), 0.9 months (CI: 0.4-1.4) for less severe emotional long-term effects, and 1.8 months (CI: 1.4-2.3) for less severe short-term side effects. Most participants (90%) would accept treatment with more severe functional long-term effects for 8.4 additional month PFS.

CONCLUSION

Participants would trade PFS for changes in short-term side effects and long-term side effects, although preference heterogeneity existed. Lung cancer treatments that offer less PFS but also less severe side effects might be acceptable to some patients.

Examining Generalizability of Older Adults' Preferences for Discussing Cessation of Screening Colonoscopies in Older Adults with Low Health Literacy

BACKGROUND/OBJECTIVES

Many older adults receive unnecessary screening colonoscopies. We previously conducted a survey using a national online panel to assess older adults' preferences for how clinicians can discuss stopping screening colonoscopies. We sought to assess the generalizability of those results by comparing them to a sample of older adults with low health literacy.

DESIGN

Cross-sectional survey.

SETTING

Baltimore metropolitan area (low health literacy sample) and a national, probability-based online panel-KnowledgePanel (national sample).

PARTICIPANTS

Adults 65+ with low health literacy measured using a single-question screen (low health literacy sample, n = 113) and KnowledgePanel members 65+ who completed survey about colorectal cancer screening (national sample, n = 441).

MEASUREMENTS

The same survey was administered to both groups. Using the best-worst scaling method, we assessed relative preferences for 13 different ways to explain stopping screening colonoscopies. We used conditional logistic regression to quantify the relative preference for each explanation, where a higher preference weight indicates stronger preference. We analyzed each sample separately, then compared the two samples using Spearman's correlation coefficient, the likelihood ratio test to assess for overall differences between the two sets of preference weights, and the Wald test to assess differences in preference weights for each individual phrases.

RESULTS

The responses from the two samples were highly correlated (Spearman's coefficient 0.92, p < 0.0001). The most preferred phrase to explain stopping screening colonoscopy was "Your other health issues should take priority" in both groups. The three least preferred options were also the same for both groups, with the least preferred being "The doctor does not give an explanation." The explanation that referred to "quality of life" was more preferred by the low health literacy group whereas explanations that mentioned "unlikely to benefit" and "high risk for harms" were more preferred by the national survey group (all p < 0.001).

CONCLUSION

Among two different populations of older adults with different health literacy levels, the preferred strategies for clinicians to discuss stopping screening colonoscopies were highly correlated. Our results can inform effective communication about stopping screening colonoscopies in older adults across different health literacy levels.

Prioritizing outcome preferences in patients with ocular hypertension and open-angle glaucoma using best-worst scaling

Purpose

To quantify patients' preferences for glaucoma outcomes and use this information to prioritize outcomes that are important to patients.

Design

A cross-sectional study using best-worst scaling object case (BWS).

Participants

Two hundred seventy-four participants newly diagnosed with ocular hypertension or mild to moderate open angle glaucoma from three private practices and one academic medical center in the United States.

Methods

We designed a preference-elicitation survey based on findings from 25 semi-structured, qualitative interviews with patients with glaucoma (reported elsewhere). The survey asked participants to rate the importance of 13 glaucoma outcomes on a Likert scale as a warm-up exercise followed by completion of 13 BWS tasks. For each task, we presented participants a subset of four outcomes from the possible thirteen, and participants chose the most important and least important outcome. Outcomes included in the survey pertain to maintaining ability to perform vision-dependent activities of daily living (e.g., driving), maintaining visual function and perception (e.g., depth perception), minimizing need to take glaucoma drops, not experiencing ocular surface symptoms (e.g., red eyes, teary eyes), and having adequate control of intraocular pressure (IOP). We administered the survey online and analyzed response patterns using conditional logistic regression to determine the relative importance of different outcomes.

Main outcome

Ordinal ranking of glaucoma outcomes based on preference weights.

Results

Between September 1, 2017 and February 28, 2018, we invited 1035 patients to complete our survey, among whom 274 (26%) responded. Most participants were older than 65 years of age (146/274, 53%) and currently on IOP-lowering drops (179/274, 65%). Participants identified that outcomes with the largest relative importance weight were having "adequate IOP control" and ability to "drive a car during the day," and the outcomes with the smallest relative importance weights were "maintaining appearance of the eye" and "reducing the number of IOP-lowering drops".

Conclusions

Determining the relative importance of glaucoma outcomes to patients can help researchers design studies that may better inform clinical and regulatory decision-making. Although IOP is an outcome that researchers often measure in glaucoma clinical trials, patients also prioritized outcomes related to the ability to perform vision-dependent activities such as driving.

Patient preferences for attributes of tyrosine kinase inhibitor treatments for EGFR mutation-positive non-small-cell lung cancer

Aim: EGFR-tyrosine kinase inhibitors (TKIs) vary in efficacy, side effects (SEs) and dosing regimen. We explored EGFR-TKI treatment attribute preferences in EGFR mutation-positive metastatic non-small-cell lung cancer. Materials & methods: Patients completed a survey utilizing preference elicitation methods: direct elicitation of four EGFR-TKI profiles describing progression-free survival (PFS), severe SE risk, administration; discrete choice experiment involving 12 choice tasks. Results: 90 participated. The preferred profile (selected 89% of times) had the longest PFS (18 months) and the lowest severe SE risk (5%). Patients would need compensation with ≥three-times longer PFS for severe SEs. Patients would accept ≤7 months PFS reduction for oral treatments versus intravenous. Conclusion: Patients preferred longer PFS but were willing to accept reduced PFS for more favorable SEs and dosing convenience.

How Do Older Adults Consider Age, Life Expectancy, Quality of Life, and Physician Recommendations When Making Cancer Screening Decisions? Results from a National Survey Using a Discrete Choice Experiment

Background. Older adults with limited life expectancy frequently receive cancer screening, although on average, harms outweigh benefits. We examined the influence of life expectancy on older adults' cancer screening decisions relative to three other factors. Methods. Adults aged 65+ years (N = 1272) were recruited from a national online survey panel. Using a discrete choice experiment, we systematically varied a hypothetical patient's life expectancy, age, quality of life, and physician's recommendation and asked whether the participant would choose screening. Participants were randomized to questions about colonoscopy or prostate-specific antigen/mammography screenings. Logistic regression produced preference weights that quantified the relative influence of the 4 factors on screening decisions. Results. 879 older adults completed the survey, 660 of whom varied their screening choices in response to the 4 factors we tested. The age of the hypothetical patient had the largest influence on choosing screening: the effect of age being 65 versus 85 years had a preference weight of 2.44 (95% confidence interval [CI]: 2.22, 2.65). Life expectancy (10 versus 1 year) had the second largest influence (preference weight: 1.64, CI: 1.41, 1.87). Physician recommendation (screen versus do not screen) and quality of life (good versus poor) were less influential, with preference weights of 0.90 (CI: 0.72, 1.08) and 0.68 (CI: 0.52, 0.83), respectively. Conclusions. While clinical practice guidelines increasingly use life expectancy in addition to age to guide screening decisions, we find that age is the most influential factor, independent of life expectancy, quality of life, and physician recommendation, in older adults' cancer screening choices. Strategies to reduce overscreening should consider the importance patients give to continuing screening at younger ages, even when life expectancy is limited.

Exploring variation in parental worries about HPV vaccination: a latent-class analysis

Background. Prior research has identified diverse worries that parents have about HPV vaccination. We sought to understand how parents prioritize worries and to identify subgroups of parents according to shared patterns of worry. Methods. We surveyed a national sample of 431 U.S. parents of adolescents who reported never having talked to their child's healthcare provider about HPV vaccination. Parents completed a best-worst scaling experiment designed to prioritize 11 common worries about HPV vaccination. The experiment used a balanced incomplete block design to present 11 choice tasks consisting of repeated subsets of worries. We used conditional logistic regression to prioritize worries and latent class models with 1-10 classes to identify subgroups of parents with shared worries. Results. Parents most often worried about long-term side effects of HPV vaccination, which about one-third (36%) ranked as their top worry. Other common top-ranked worries were how new the vaccine is (12%), motives of drug companies (12%), short-term side effects (10%), and that it may be unnecessary (10%). Latent class analyses suggested a relatively large number of distinct worry profiles, with most classes characterized by a worry about long-term side effects in combination with one other worry. Discussion. Our findings suggest that providers should be prepared to address concerns about long-term side effects, as this worry was prioritized across many subgroups of parents. However, to best address worry, a tailored, rather than targeted, communication approach may be needed.

Demographic, health, and attitudinal factors predictive of cancer screening decisions in older adults

Many older adults receive routine cancer screening even when it is no longer recommended. We sought to identify demographic, health-related, and attitudinal factors that are most predictive of continued breast, colorectal, and prostate cancer screening decisions in older adults under various scenarios. A sample of adults age 65+ (n = 1272) were recruited from a nationally representative panel in November 2016, of which 881 (69.3%) completed our survey. Participants were presented vignettes in which we experimentally varied a hypothetical patient's life expectancy, age, quality of life, and physician screening recommendation. The dependent variable was the choice to continue cancer screening in the vignette. Classification and regression tree (CART) analysis was used to identify characteristics most predictive of screening decisions; both the participants' characteristics and the hypothetical patient's characteristics in the vignettes were included in the analysis. CART analysis uses recursive partitioning to create a classification tree in which variables predictive of the outcome are included as hierarchical tree nodes. We used automated ten-fold cross-validation to select the tree with lowest misclassification and highest predictive accuracy. Participants' attitude towards cancer screening was most predictive of choosing screening. Among those who agreed with the statement "I plan to get screened for cancer for as long as I live" (n = 300, 31.9%), 73.2% chose screening and 57.2% would still choose screening if hypothetical patient had 1-year life expectancy. For this subset of older adults with enthusiasm towards screening even when presented with scenario involving limited life expectancy, efforts are needed to improve informed decision-making about screening.

AcroVoice: eliciting the patients' perspective on acromegaly disease activity

PURPOSE

To determine how patients define acromegaly disease activity and treatment success and to quantify from the patients' perspective the relative importance of each disease parameter included in the ACRODAT®.

METHODS

One hundred acromegaly patients on medical therapy (mean age = 47.1 years; SD = 11.96) completed an online preference study evaluating hypothetical patient profiles described in terms of insulin-like growth factor-I (IGF-I) levels, tumor size, comorbid conditions, signs/symptoms, and quality of life (QoL). Participants first completed a single-profile task experiment by rating 20 single patient profiles as exhibiting stable, mild, or significant disease activity based on treatment success. Next, participants completed a double-profile discrete choice experiment (DCE) by selecting the patient that was doing "better" from 15 profile pairs. Results were analyzed using logistic and conditional logistic models.

RESULTS

When choosing between stable vs. mild or significant disease activity, signs/symptoms, tumor size, and IGF-I levels were weighted equally; IGF-I and signs and symptoms were valued equally when selecting mild vs. significant disease activity. The DCE showed that, statistically, all disease parameters, except comorbid conditions, predicted health status equally. Tumor size and IGF-I levels each accounted for 23% of the decision-making process; QoL, signs/symptoms, and comorbid conditions accounted for 21%, 19%, and 14%, respectively.

CONCLUSION

All five ACRODAT® parameters had some influence on disease activity from the patients' perspective. To account for patients' preferences and optimize treatment and outcomes, a holistic disease management approach should be employed.

Older Adults' Preferences for Discussing Long-Term Life Expectancy: Results From a National Survey

PURPOSE

Clinical practice guidelines recommend incorporating long-term life expectancy to inform a number of decisions in primary care. We aimed to examine older adults' preferences for discussing life expectancy in a national sample.

METHODS

We invited 1,272 older adults (aged 65 or older) from a national, probability-based online panel to participate in 2016. We presented a hypothetical patient with limited life expectancy who was not imminently dying. We asked participants if they were that patient, whether they would like to talk with the doctor about how long they may live, whether it was acceptable for the doctor to offer this discussion, whether they want the doctor to discuss life expectancy with family or friends, and when it should be discussed.

RESULTS

The 878 participants (69.0% participation rate) had a mean age of 73.4 years. The majority, 59.4%, did not want to discuss how long they might live in the presented scenario. Within this group, 59.9% also did not think that the doctor should offer the discussion, and 87.7% also did not want the doctor to discuss life expectancy with family or friends. Fully 55.8% wanted to discuss life expectancy only if it were less than 2 years. Factors positively associated with wanting to have the discussion included higher educational level, believing that doctors can accurately predict life expectancy, and past experience with either a life-threatening illness or having discussed life expectancy of a loved one. Reporting that religion is important was negatively associated.

CONCLUSIONS

The majority of older adults did not wish to discuss life expectancy when we depicted a hypothetical patient with limited life expectancy. Many also did not want to be offered discussion, raising a dilemma for how clinicians may identify patients' preferences regarding this sensitive topic.

Project Transform: engaging patient advocates to share their perspectives on improving research, treatment and policy

OBJECTIVE

Incorporating the patient perspective into lung cancer research, policy and treatment is becoming increasingly recognized as important. This project sought to create an engagement partnership with lung cancer patient advocates and to explore their views on transforming lung cancer healthcare systems, treatment and policy to be more patient centered.

METHODS

A patient action committee (PAC) of patient advocates living with lung cancer was engaged through group meetings, in-person and phone interviews, and email correspondence. Group meetings (two 1 hour meetings, one 3 hour meeting) served to discuss engagement strategies and project goals, while individual interviews (n = 19) (30-75 minutes) provided in-depth exploration of individuals' perspectives. Meetings and interviews were recorded to identify priorities for addressing issues within lung cancer research, treatment and policy. PAC members corroborated the results through email and in-person meetings.

RESULTS

PAC members identified three general objectives: (i) for healthcare systems, increasing access to care through accessible, coordinated and affordable care, (ii) for treatment, addressing patient needs in treatment and research through patient education, shared decisions and clinical trials, and (iii) for policy, shining a light on lung cancer through screening policies, public awareness and research funding.

CONCLUSION

Patient advocates expressed their views that lung cancer is a neglected disease that is not highly prioritized in healthcare systems, treatment approaches and public perceptions. This project represents an integral step in developing an ongoing partnership between researchers and these advocates.

Conducting a Discrete-Choice Experiment Study Following Recommendations for Good Research Practices: An Application for Eliciting Patient Preferences for Diabetes Treatments

OBJECTIVES

To consolidate and illustrate good research practices in health care to the application and reporting of a study measuring patient preferences for type 2 diabetes mellitus medications, given recent methodological advances in stated-preference methods.

METHODS

The International Society for Pharmacoeconomics and Outcomes Research good research practices and other recommendations were used to conduct a discrete-choice experiment. Members of a US online panel with type 2 diabetes mellitus completed a Web-enabled, self-administered survey that elicited choices between treatment pairs with six attributes at three possible levels each. A D-efficient experimental design blocked 48 choice tasks into three 16-task surveys. Preference estimates were obtained using mixed logit estimation and were used to calculate choice probabilities.

RESULTS

A total of 552 participants (51% males) completed the survey. Avoiding 90 minutes of nausea was valued the highest (mean -10.00; 95% confidence interval [CI] -10.53 to -9.47). Participants wanted to avoid low blood glucose during the day and/or night (mean -3.87; 95% CI -4.32 to -3.42) or one pill and one injection per day (mean -7.04; 95% CI -7.63 to -6.45). Participants preferred stable blood glucose 6 d/wk (mean 4.63; 95% CI 4.15 to 5.12) and a 1% decrease in glycated hemoglobin (mean 5.74; 95% CI 5.22 to 6.25). If cost increased by $1, the probability that a treatment profile would be chosen decreased by 1%.

CONCLUSIONS

These results are consistent with the idea that people have strong preferences for immediate consequences of medication. Despite efforts to produce recommendations, ambiguity surrounding good practices remains and various judgments need to be made when conducting stated-preference studies. To ensure transparency, these judgments should be described and justified.

Live, Learn, Pass It on: A Patient Advocacy Engagement Project on the Lived Experience of Lung Cancer Survivors

Introduction:

The objective of this project was to engage survivor–advocates by describing their experiences living with lung cancer in an era of increasing treatment options.

Methods:

This was a qualitative engagement project with participants from a lung cancer advocacy organization’s survivor advisory board. Interviews were conducted, transcribed, and analyzed for stages and associated experiences using interpretive phenomenological analysis and elements of narrative analysis, in partnership with the patient advocacy organization.

Results:

Of 27 engaged members, interviews were conducted with 19, mostly long-term survivors with stage 3 or 4 lung cancer. Within the quest for patient-centeredness, we identified 3 stages of the patient experience. The stage Live describes the journey of the lived experience; Learn describes the quest for knowledge, empowerment, and skills; and Pass it on describes making a difference through guiding others, building awareness, and community.

Conclusions:

Lung cancer survivor–advocates have an intertwined experience of their personal journey, the quest for knowledge, and developing advocacy. Future patient engagement can incorporate these findings into increasing the survivor-centeredness of partnerships and research, particularly for quality of life and shared decision-making.

A cost analysis of implementing a behavioral weight loss intervention in community mental health settings: Results from the ACHIEVE trial

OBJECTIVE

In the ACHIEVE randomized controlled trial, an 18-month behavioral intervention accomplished weight loss in persons with serious mental illness who attended community psychiatric rehabilitation programs. This analysis estimates costs for delivering the intervention during the study. It also estimates expected costs to implement the intervention more widely in a range of community mental health programs.

METHODS

Using empirical data, costs were calculated from the perspective of a community psychiatric rehabilitation program delivering the intervention. Personnel and travel costs were calculated using time sheet data. Rent and supply costs were calculated using rent per square foot and intervention records. A univariate sensitivity analysis and an expert-informed sensitivity analysis were conducted.

RESULTS

With 144 participants receiving the intervention and a mean weight loss of 3.4 kg, costs of $95 per participant per month and $501 per kilogram lost in the trial were calculated. In univariate sensitivity analysis, costs ranged from $402 to $725 per kilogram lost. Through expert-informed sensitivity analysis, it was estimated that rehabilitation programs could implement the intervention for $68 to $85 per client per month.

CONCLUSIONS

Costs of implementing the ACHIEVE intervention were in the range of other intensive behavioral weight loss interventions. Wider implementation of efficacious lifestyle interventions in community mental health settings will require adequate funding mechanisms.

Caregiver Treatment Preferences for Children with a New Versus Existing Attention-Deficit/Hyperactivity Disorder Diagnosis

OBJECTIVES

Parental experiences with managing their child's attention-deficit/hyperactivity disorder (ADHD) can influence priorities for treatment. This study aimed to identify the ADHD management options caregivers most prefer and to determine if preferences differ by time since initial ADHD diagnosis.

METHODS

Primary caregivers (n = 184) of a child aged 4-14 years old in care for ADHD were recruited from January 2013 through March 2015 from community-based pediatric and mental health clinics and family support organizations across the state of Maryland. Participants completed a survey that included child/family demographics, child clinical treatment, and a Best-Worst Scaling (BWS) experiment to elicit ADHD management preferences. The BWS comprised 18 ADHD management profiles showing seven treatment attributes, where the best and worst attribute levels were selected from each profile. A conditional logit model using effect-coded variables was used to estimate preference weights stratified by time since ADHD diagnosis.

RESULTS

Participants were primarily the mother (84%) and had a college or postgraduate education (76%) with 75% of the children on stimulant medications. One-on-one caregiver behavior training, medication use seven days a week, therapy in a clinic, and an individualized education program were most preferred for managing ADHD. Aside from caregiver training and monthly out-of-pocket costs, caregivers of children diagnosed with ADHD for less than two years prioritized medication use lower than other care management attributes and caregivers of children diagnosed with ADHD for two or more years preferred school accommodations, medication, and provider specialty.

CONCLUSIONS

Preferences for ADHD treatment differ based on the duration of the child's ADHD. Acknowledging that preferences change over the course of care could facilitate patient/family-centered care planning across a range of resources and a multidisciplinary team of professionals.

Education and patient preferences for treating type 2 diabetes: a stratified discrete-choice experiment

PURPOSE

Diabetes is a chronic condition that is more prevalent among people with lower educational attainment. This study assessed the treatment preferences of patients with type 2 diabetes by educational attainment.

METHODS

Patients with type 2 diabetes were recruited from a national online panel in the US. Treatment preferences were assessed using a discrete-choice experiment. Participants completed 16 choice tasks in which they compared pairs of treatment profiles composed of six attributes: A1c decrease, stable blood glucose, low blood glucose, nausea, treatment burden, and out-of-pocket cost. Choice models and willingness-to-pay (WTP) estimates were estimated using a conditional logit model and were stratified by educational status.

RESULTS

A total of 231 participants with a high school diploma or less education, 156 participants with some college education, and 165 participants with a college degree or more completed the survey. Participants with a college degree or more education were willing to pay more for A1c decreases ($58.84, standard error [SE]: 10.6) than participants who had completed some college ($28.47, SE: 5.53) or high school or less ($17.56, SE: 3.55) (p≤0.01). People with a college education were willing to pay more than people with high school or less to avoid nausea, low blood glucose events during the day/night, or two pills per day.

CONCLUSION

WTP for aspects of diabetes medication differed for people with a college education or more and a high school education or less. Advanced statistical methods might overcome limitations of stratification and advance understanding of preference heterogeneity for use in patient-centered benefit-risk assessments and personalized care approaches.

Using Best-Worst Scaling to Investigate Preferences in Health Care

INTRODUCTION

Best-worst scaling (BWS) is becoming increasingly popular to elicit preferences in health care. However, little is known about current practice and trends in the use of BWS in health care. This study aimed to identify, review and critically appraise BWS in health care, and to identify trends over time in key aspects of BWS.

METHODS

A systematic review was conducted, using Medline (via Pubmed) and EMBASE to identify all English-language BWS studies published up until April 2016. Using a predefined extraction form, two reviewers independently selected articles and critically appraised the study quality, using the Purpose, Respondents, Explanation, Findings, Significance (PREFS) checklist. Trends over time periods (≤2010, 2011, 2012, 2013, 2014 and 2015) were assessed further.

RESULTS

A total of 62 BWS studies were identified, of which 26 were BWS object case studies, 29 were BWS profile case studies and seven were BWS multi-profile case studies. About two thirds of the studies were performed in the last 2 years. Decreasing sample sizes and decreasing numbers of factors in BWS object case studies, as well as use of less complicated analytical methods, were observed in recent studies. The quality of the BWS studies was generally acceptable according to the PREFS checklist, except that most studies did not indicate whether the responders were similar to the non-responders.

CONCLUSION

Use of BWS object case and BWS profile case has drastically increased in health care, especially in the last 2 years. In contrast with previous discrete-choice experiment reviews, there is increasing use of less sophisticated analytical methods.

Review of the evidence: prevalence of medical conditions in the United States population with serious mental illness

OBJECTIVE

Persons with serious mental illness (SMI) have high rates of premature mortality from preventable medical conditions, but this group is underrepresented in epidemiologic surveys and we lack national estimates of the prevalence of conditions such as obesity and diabetes in this group. We performed a comprehensive review to synthesize estimates of the prevalence of 15 medical conditions among the population with SMI.

METHOD

We reviewed studies published in the peer-reviewed literature from January 2000 to August 2012. Studies were included if they assessed prevalence in a sample of 100 or more United States (US) adults with schizophrenia or bipolar disorder.

RESULTS

A total of 57 studies were included in the review. For most medical conditions, the prevalence estimates varied considerably. For example, estimates of obesity prevalence ranged from 26% to 55%. This variation appeared to be due to differences in measurement (e.g., self-report versus clinical measures) and underlying differences in study populations. Few studies assessed prevalence in representative, community samples of persons with SMI.

CONCLUSIONS

In many studies, the prevalence of medical conditions among the population with SMI was higher than among the overall US population. Screening for and monitoring of these conditions should be common practice in clinical settings serving persons with SMI.

Selective expansion of merocytic dendritic cells and CD8DCs confers anti-tumour effect of Fms-like tyrosine kinase 3-ligand treatment in vivo

Vaccination with autologous cancer cells aims to enhance adaptive immune responses to tumour-associated antigens. The incorporation of Fms-like tyrosine kinase 3-ligand (FLT3L) treatment to the vaccination scheme has been shown previously to increase the immunogenicity of cancer vaccines, thereby enhancing their therapeutic potential. While evidence has been provided that FLT3L confers its effect through the increase of absolute dendritic cell (DC) numbers, it is currently unknown which DC populations are responsive to FLT3L and which effect FLT3L treatment has on DC functions. Here we show that the beneficial effects of FLT3L treatment resulted predominantly from a marked increase of two specific DC populations, the CD8 DCs and the recently identified merocytic DC (mcDC). These two DC populations (cross)-present cell-associated antigens to T cells in a natural killer (NK)-independent fashion. FLT3L treatment augmented the absolute numbers of these DCs, but did not change their activation status nor their capacity to prime antigen-specific T cells. While both DC populations effectively primed CD8(+) T cell responses to cell-associated antigens, only mcDC were capable to prime CD4(+) T cells to cell-associated antigens. Consequentially, the transfer of tumour vaccine-pulsed mcDC, but not of CD8 DCs, protected mice from subsequent tumour challenge in a vaccination model and resulted in eradication of established tumours in a therapeutic approach. These results show that the beneficial effect of FLT3L is associated with the induction of mcDC and suggests that selective targeting to mcDC or instilling mcDC 'characteristics' into conventional DC populations could significantly enhance the efficacy of tumour vaccines.

Cross-priming is under control of the relB gene

Cross-priming is an important mechanism of intercell transfer of antigenic material leading to the specific activation of cytotoxic T lymphocytes. Dendritic cells (DCs) are considered the central antigen-presenting cell in cross-priming. Here we decided to probe the role of the relB gene, a regulator of DC differentiation, in the in vivo cross-priming of a model tumour antigen, TAP(-/-) murine embryo cells (MEC), expressing human adenovirus type 5 early region 1. To this end, we used relB(-/-) mutant mice to generate bone marrow (BM) chimeras as these possess few residual DC but are capable of initiating CD4+ and CD8+ T-cell responses in vivo. Our results show that relB(-/-) BM chimeras are unable to cross-prime CD8+ T cells, suggesting that the relB gene regulates cross-priming.

The efficacy of immunotherapy in an experimental murine model of allergic asthma is related to the strength and site of T cell activation during immunotherapy

In the present study, the relation between the efficacy of immunotherapy, and the strength and site of T cell activation during immunotherapy was evaluated. We used a model of allergic asthma in which OVA-sensitized and OVA-challenged mice display increased airway hyperresponsiveness, airway inflammation, and Th2 cytokine production by OVA-specific T cells. In this model, different immunotherapy strategies, including different routes of administration, or treatment with entire OVA or the immunodominant T cell epitope OVA(323-339), or treatment with a peptide analogue of OVA(323-339) with altered T cell activation capacity were studied. To gain more insight in how immunotherapy affects allergen-specific T cells, the site of Ag-specific T cell activation and the magnitude of the T cell response induced during different immunotherapy strategies were determined using an adoptive transfer model. Our data suggest that amelioration of airway hyperresponsiveness and inflammation is associated with the induction of a strong, synchronized, and systemic T cell response, resulting in a decreased OVA-specific Th2 response. In contrast, deterioration of the disease after immunotherapy is associated with the induction of a weak nonsynchronized T cell response, resulting in the enhancement of the OVA-specific Th2 response after challenge.

Modulation of Th2 responses by peptide analogues in a murine model of allergic asthma: amelioration or deterioration of the disease process depends on the Th1 or Th2 skewing characteristics of the therapeutic peptide

Allergen-specific CD4+ Th2 cells play an important role in the immunological processes of allergic asthma. Previously we have shown that, by using the immunodominant epitope OVA323-339, peptide immunotherapy in a murine model of OVA induced allergic asthma, stimulated OVA-specific Th2 cells, and deteriorated airway hyperresponsiveness and eosinophilia. In the present study, we defined four modulatory peptide analogues of OVA323-339 with comparable MHC class II binding affinity. These peptide analogues were used for immunotherapy by s.c. injection in OVA-sensitized mice before OVA challenge. Compared with vehicle-treated mice, treatment with the Th2-skewing wild-type peptide and a Th2-skewing partial agonistic peptide (335N-A) dramatically increased airway eosinophilia upon OVA challenge. In contrast, treatment with a Th1-skewing peptide analogue (336E-A) resulted in a significant decrease in airway eosinophilia and OVA-specific IL-4 and IL-5 production. Our data show for the first time that a Th1-skewing peptide analogue of a dominant allergen epitope can modulate allergen-specific Th2 effector cells in an allergic response in vivo. Furthermore, these data suggest that the use of Th1-skewing peptides instead of wild-type peptide may improve peptide immunotherapy and may contribute to the development of a successful and safe immunotherapy for allergic patients.

Opposite effects of immunotherapy with ovalbumin and the immunodominant T-cell epitope on airway eosinophilia and hyperresponsiveness in a murine model of allergic asthma

In the present study, we investigated immunotherapy using an entire protein or an immunodominant epitope in a murine model of allergic asthma. Immunotherapy was performed in ovalbumin (OVA)-sensitized mice before OVA challenge. Mice were treated subcutaneously with OVA, the immunodominant epitope OVA323-339, or vehicle. In vehicle-treated animals, repeated OVA challenge induced increased serum levels of OVA-specific immunoglobulin (Ig)G1, IgE, airway eosinophilia, and hyperresponsiveness, compared with saline-challenged animals. In addition, interleukin (IL)-4 and IL-5 production upon OVA restimulation of lung-draining lymph node cells in vitro were significantly increased in OVA-challenged animals. Immunotherapy using OVA significantly reduced airway eosinophilia and hyperresponsiveness. This finding was accompanied by significantly reduced OVA-specific IL-4 and IL-5 production. Further, OVA immunotherapy induced increased serum levels of OVA-specific IgG1, whereas OVA-specific IgG2a and IgE levels were not affected. In contrast to OVA immunotherapy, immunotherapy with OVA323-339 aggravated airway eosinophilia and hyperresponsiveness. OVA-specific IgG1, IgG2a, and IgE serum levels, and in vitro IL-4 and IL-5 production, were not affected. Thus, immunotherapy with protein resulted in beneficial effects on airway eosinophilia and hyperresponsiveness, which coincided with a local reduced T-helper 2 (Th2) response. In contrast, peptide immunotherapy aggravated airway hyperresponsiveness and eosinophilia, indicating a local enhanced Th2 response.

Regular physical activity and changes in risk factors for coronary heart disease: a nine months prospective study

This study reports the non-acute effects of a long-term training programme of increasing intensity on some cardiovascular risk factors and the interrelation between these risk factors. Twenty sedentary men and 14 sedentary women were trained 3 to 4 times a week for nine months. After 36 weeks all individuals ran a half marathon run. The Wmax, weight, body mass index, systolic and diastolic blood pressure were recorded. The concentrations of fibrinogen, tissue plasminogen activator, plasminogen activator inhibitor, triacylglycerols, total cholesterol, LDL cholesterol, HDL cholesterol and lipoprotein(a) were measured. The training programme induced a median increase in Wmax of 12% in the male group (from 226 to 251.5 Watt) and of 18% in the female group (from 160 to 188.5 Watt). These increases inn Wmax did not correlate with any other property under investigation in this study. Blood pressure was not altered, but body weight and body mass index were significantly decreased in the male group (from 74.6 to 72.2 kg and from 23.1 to 22.0 kg/m2, respectively) at the end of the training programme and decreased non-significantly in the female group (from 63.0 to 60.7 kg and from 21.6 to 21.5 kg/m2, respectively). In the male group total cholesterol, low density lipoprotein cholesterol and triacylglycerols decreased significantly under the influence of the training sessions. Furthermore, in both groups, a great decrease in plasma plasminogen activator inhibitor concentrations was noticed: in men from 22.5.10(3) AU/l to 4.5.10(3) AU/l and in women from 18.7 x 10(3) AU/l to 5.1 x 10(3) AU/l. However, the changes in the lipid and fibrinolytic quantities were not correlated with each other. Initial total cholesterol, LDL cholesterol and triacylglycerol levels correlated significantly with systolic blood pressure, while diastolic pressure was correlated to tissue plasminogen activator. Since tissue plasminogen activator also was significantly related to triacylglycerols, a trias existed between primary risk factors like blood pressure, lipid levels and fibrinolysis. In contrast, the changes in these properties under the influence of physical training were not interrelated. Median serum lipoprotein(a) concentrations were significantly increased in both men and women five days before the half marathon run: from 32 mg/l to 39 mg/l in men, and from 65 mg/l to 125.5 mg/l in women. Concomitantly, median fibrinogen concentrations were significantly elevated in men (from 2.32 g/l to 3.10 g/l) and non-significantly in women (from 2.62 g/l to 2.93 g/l), although no correlation existed between the changes in these properties. In conclusion, the nine months exercise programme increased the aerobic fitness in both men and women as indicated by the Wmax increase. This improvement coincided but was not correlated with beneficial changes in several anthropometric, lipid and fibrinolytic properties. Improvement in the risk factors under investigation was more pronounced in men than in women. The changes in lipid and haemostasis properties did not correlate with each other. The increases in lipoprotein(a) and fibrinogen concentrations, both atherogenic indices, could actually present a normal physiological response to the physical strain of exercise training of increasing workload.

Long-term physical exercise and lipoprotein(a) levels in a previously sedentary male and female population

We investigated the effect of long-term physical exercise on serum lipoprotein(a) levels. 21 sedentary men and 15 sedentary women were trained three to four times a week with increasing intensity during 9 months. After 24 weeks all subjects ran a 15 km race and after 36 weeks a half marathon run (21 km). Blood samples were drawn before the training programme, 5 days before both races and 5 days after the half marathon run. Median (interquartile range) pre-training values in the male group were 32 (11-63) mg/L and in the female group 65 (23-199) mg/L. After 24 weeks of training, serum lipoprotein(a) concentrations had risen significantly in both male and female groups. Moreover, after 36 weeks of training, in preparation for the half marathon competition, median serum lipoprotein(a) rose almost twofold in both groups and was still elevated 5 days later. This study demonstrates that an exercise programme which includes running of increasing distances significantly increases serum lipoprotein(a) concentration.

Effects of long-term exercise of moderate intensity on anthropometric values and serum lipids and lipoproteins

The influence of endurance training on serum lipids and lipoproteins was investigated in 20 sedentary males and 14 sedentary females. The total group was trained 3 to 4 times a week for 9 months. After 24 weeks all subjects ran a 15 km-race and after 36 weeks a half-marathon (21 km) race. Anthropometric values were determined before and after the training programme. Blood samples were drawn before the start of the training programme and, in order to avoid the measurement of acute effects, 5 days before both races. In the male group, median body weight and body mass were significantly decreased (p < 0.01) after nine months of training, while in the female group body weight and body mass index remained essentially unchanged. Percentage body fat, measured by skinfold thickness was significantly decreased in both groups at the end of the training programme. During the training period, median serum total cholesterol, low density lipid cholesterol and triacylglycerol concentrations decreased significantly (p < 0.01) in the male group, while in the female population the median serum lipid- and lipoprotein concentrations did not differ from pre-training values. The changes in serum lipids or lipoproteins did not correlate significantly with changes in body weight, body mass index or percentage body fat. Stepwise multiple regression showed that these changes were mostly dependent on initial concentrations in serum. Finally, no significant increase in median high density lipid cholesterol was observed in either the male or female group.(ABSTRACT TRUNCATED AT 250 WORDS)

Body mass, body composition and sleeping metabolic rate before, during and after endurance training

Metabolic rate, more specifically resting metabolic rate (RMR) or sleeping metabolic rate (SMR), of an adult subject is usually expressed as a function of the fat-free mass (FFM). Chronic exercise is thought to increase FFM and thus to increase RMR and SMR. We determined body mass (BM), body composition, and SMR before, during, and after an endurance training programme without interfering with energy intake. The subjects were 11 women and 12 men, aged 37 (SD 3) years and body mass index 22.3 (SD 1.5) kg.m-2. The endurance training prepared subjects to run a half marathon competition after 44 weeks. The SMR was measured overnight in a respiration chamber. Body composition was measured by hydrostatic weighing. Measurements were performed at 0, 8, 20, 40, and 90 weeks after the start of the training. The BM had decreased from a mean value of 66.6 (SD 6.9) to 65.6 (SD 6.7) kg (P < 0.01), fat mass (FM) had decreased from 17.1 (SD 3.9) to 13.5 (SD 3.6) kg (P < 0.001), and FFM had increased from 49.5 (SD 7.3) to 52.2 (SD 7.6) kg (P < 0.001) at 40 weeks. Mean SMR before and after 40 weeks training was 6.5 (SD 0.7) and 6.2 (SD 0.6) MJ.day-1 (P < 0.05). The decrease in SMR was related to the decrease in BM (r = 0.62, P = 0.001). At 90 weeks, when most subjects had not trained for nearly a year, BM and SMR were not significantly different from the initial value while FM and FFM had not changed since week 40 of training.(ABSTRACT TRUNCATED AT 250 WORDS)

Prolonged physical conditioning and blood platelet release markers: a longitudinal study

To study the long-term non-acute effect of endurance physical exercise on blood platelet activation, 20 sedentary males and 14 sedentary females were trained 3 to 4 times a week for 9 months. After 24 weeks all subjects ran a 15-km race; and after 36 weeks a half-marathon (21 km) race. Blood samples were drawn before the training programme and 5 days after both races. Median (interquartile range) platelet factor 4 and beta-thromboglobulin pretraining values for the total group were 9 (5-35) and 69 (40-495) IU/ml, respectively. During the course of the training programme, plasma platelet factor 4 concentrations rose steadily and significantly in both the male and female group (p < 0.05), together with a non-significant rise in plasma beta-thromboglobulin. At the end of the training procedure, 5 days after the half-marathon run, median (interquartile range) plasma factor 4 and beta-thromboglobulin concentrations for the total group were 150 (62-198) and 156 (84-288) IU/ml, respectively. No difference existed in median platelet factor 4 and beta-thromboglobulin concentrations of the male and female population before or during the training programme. In summary, the results of this study demonstrate that prolonged physical conditioning of increasing intensity is mainly associated with an elevation of the platelet protein platelet factor 4.

Circulating soluble tumor necrosis factor receptors, interleukin-2 receptors, tumor necrosis factor alpha, and interleukin-6 levels in rheumatoid arthritis. Longitudinal evaluation during methotrexate and azathioprine therapy

OBJECTIVE

To assess whether circulating concentrations of soluble tumor necrosis factor receptors (sTNFR; p55 and p75), soluble interleukin-2 receptors (sIL-2R), tumor necrosis factor alpha (TNF alpha), and interleukin-6 (IL-6) reflect clinical response and whether changes are dependent on the drug used in rheumatoid arthritis (RA) patients taking methotrexate (MTX) or azathioprine (AZA).

METHODS

These cytokines and soluble receptors were assessed in 20 control subjects and serially for up to 48 weeks in 61 RA patients, by bioassay (IL-6) and immunoassays (sTNFR, sIL-2R, TNF alpha, and IL-6).

RESULTS

Concentrations of p55 and p75, sIL-2R, and TNF alpha (but not IL-6) were significantly higher in RA patients than in controls. Significant decreases in sIL-2R and p55 concentrations were associated with clinical improvement and were observed in patients treated with MTX, but not AZA. Both treatments induced decreases in IL-6 concentrations, but circulating AZA (or its metabolites) appears to interfere with the measurement of IL-6 bioactivity. TNF alpha and p75 levels did not show significant changes.

CONCLUSION

Measurement of circulating sIL-2R, p55, and IL-6 may be useful in the evaluation of RA disease activity and response to therapy. Interference by circulating levels of drugs must be ruled out when bioassays are used to evaluate cytokine levels.

Long-term effect of physical activity on energy balance and body composition

We studied the effect of an increase in physical activity on energy balance and body composition without interfering with energy intake (EI). Sixteen women and sixteen men, aged 28-41 years, body mass index 19.4-26.4 kg/m2, not participating in any sport before the start of the experiment, prepared to run a half-marathon competition after 44 weeks. Measurements of body composition, EI and energy expenditure (EE) were performed before (0 weeks), and 8, 20, and 40 weeks after the start of training. Body composition was measured with hydrodensitometry and isotope dilution, and EI with a 7 d dietary record. EE was measured overnight in a respiration chamber (sleeping metabolic rate (SMR)) and in a number of subjects over 2-week intervals with doubly-labelled water (average daily metabolic rate (ADMR)). ADMR showed an average increase of 30% in both sexes from the start of training onwards while SMR tended to decrease. EI showed a tendency to drop from week 20 to week 40 in the men and a tendency to increase from week 20 to week 40 in the women. Body mass (BM) did not change in both sexes until the observation at 40 weeks when the median value of the change in men was -1.0 kg (P < 0.01; Wilcoxon signed-rank) while the corresponding change of -0.9 kg in the women was not statistically significant. Body composition changes were most pronounced in men as well. Based on changes in BM, body volume and total body water, men lost 3.8 kg fat mass (FM) (P < 0.001; Wilcoxon signed-rank) and gained 1.6 kg protein mass (P < 0.01; Wilcoxon signed-rank) while the corresponding changes in women were 2.0 kg (P < 0.05; Wilcoxon signed-rank) and 1.2 kg (P < 0.05; Wilcoxon signed-rank). In men the loss of FM was positively correlated with the initial percentage body fat (Pearson r 0.92, P < 0.001). In conclusion, body fat can be reduced by physical activity although women tend to compensate for the increased EE with an increased EI, resulting in a smaller effect on BM and FM compared with men.

Removal of interleukin-1 beta and tumor necrosis factor from human plasma by in vitro dialysis with polyacrylonitrile membranes

We studied the suitability of in vitro dialysis with polyacrylonitrile (PAN) membranes to remove small amounts of interleukin-1 beta (IL-1 beta) and tumor necrosis factor (TNF) from plasma to be used as diluent for the standards in radioimmunoassays (RIA). Incubation of PAN membrane fragments with radiolabeled IL-1 beta or TNF yielded a significant binding of both cytokines to the membrane (percentage of membrane-bound cytokine after incubation in saline or plasma was 14-17% and 23-46%, respectively). Dialysis of plasma (containing radiolabeled cytokine) against plasma (initially devoid of cytokine) resulted in a binding percentage of IL-1 beta and TNF to the PAN membranes of 44 and 28%, respectively. When plasma was dialyzed against saline the percentage of membrane-bound IL-1 beta and TNF was 63 and 37%, respectively. After dialysis of plasma against either plasma or saline the percentage IL-1 beta recovered from the dialysate was approximately 16% in contrast with 1-2% TNF. The results confirm the capacity of in vitro dialysis with PAN membranes to remove IL-1 beta and to a lesser extent TNF from plasma. Removal is most marked in the first minutes of dialysis (suggesting saturation of the membrane) and less effective for TNF due to its low diffusion across the membrane.