***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Objectives : To determine the effects of risk and payment on  subjects ’ willingness to participate  , and to examine how payment influences subjects ’ potential behaviours and risk evaluations . Methods : A 3 ( level of risk ) × 3 ( level of monetary payment ) , between subjects , completely r and omised factorial design was used . Students enrolled at one of five US pharmacy schools read a recruitment notice and informed consent form for a hypothetical study , and completed a question naire . Risk level was manipulated using recruitment notices and informed consent documents from hypothetical biomedical research projects . Payment levels were determined using the payment models evaluated by Dickert and Grady as a guide . Five dependent variables were assessed in the question naire : willingness to participate , willingness to participate with no payment , propensity to neglect to tell about restricted activities , propensity to neglect to tell about negative effects , and risk rating . Results : Monetary payment had positive effects on respondents ’ willingness to participate in research , regardless of the level of risk . However , higher monetary payments did not appear to blind respondents to the risks of a study . Payment had some influence on respondents ’ potential behaviours regarding concealing information about restricted activities . However , payment did not appear to have a significant effect on respondents ’ propensity to neglect to tell research ers about negative effects . Conclusions : Monetary payments appear to do what they are intended to do : make subjects more willing to participate in research . Concerns about payments blinding subjects to risks could not be substantiated in the present study . However , the findings do raise other concerns — notably the potential for payments to diminish the integrity of a study ’s findings . Future research is critical to make sound decisions about the payment of research subjects OBJECTIVE A feasibility study for a trial of strategies for the prevention of atherosclerosis in patients with systemic lupus erythematosus ( SLE ) was stopped because of inadequate recruitment . There is little underst and ing of the factors influencing patients ' decisions about participation in prevention trials . Our goal was to determine factors that patients with SLE consider in deciding about participating in prevention trials , to uncover concerns about SLE trials , and to investigate how study design and purpose affect participation decisions . METHODS We conducted focus groups with trial participants ( n = 13 ) , trial non participants ( n = 8) , and a group of patients with diabetes ( n = 9 ) . We conducted telephone interviews with SLE patients who refused participation in the trial and the focus groups ( n = 10 ) . A trained facilitator elicited factors influencing participation decisions . Transcripts were coded and grouped into themes using grounded theory . RESULTS Demographic characteristics of the groups were similar . Seven factors emerged as important in decision making : current health status , study design , physician involvement , personal benefit , altruism , time , and incentives . These factors were considered by individuals who elected to participate and those who did not , but weighed differently . Among the trial participants , good health status , encouragement from one 's physician , and desires to learn and to contribute stimulated participation . Reasons for nonparticipation included current health status , medication and r and omization concerns , and personal factors . CONCLUSION We observed that similar factors were weighed differently by participants and non participants . Our results suggest that strategies such as health education , enlistment of personal physicians , and limitation of time requirements may enhance recruitment of patients with SLE into clinical prevention trials One of the most influential factors in science and medicine has been the development of placebo-controlled clinical trials . However , recruitment of patients for clinical trials is sometimes a major problem in clinical research . Successful patient recruitment may be enhanced with a clear underst and ing of the motivating factors that determine a patient 's decision to enter a study . We have developed the Patients ' Expectations , Attitudes and Knowledge ( PEAK ) Program consisting of question naires design ed to study the factors motivating patients to enter a clinical trial , as well as capturing the experiences of research participants . A total of 247 female patients with dyspepsia ( mean age : 43.9 ; range : 18.0 - 78.0 years ) who entered either of two prospect i ve double-blind , r and omized , placebo-controlled multicenter trials in the USA completed PEAK Entry question naires during the first study visit . Based on their responses , the top three factors motivating patients to join the clinical trial were : interest in receiving investigational treatment with average score ( AS ) of 4.33 + /- 0.08 ( M + /- SEM ) on a 5-point scale , possibility of getting skilled professional care ( AS = 4.07 + /- 0.09 ) , and altruism expressed as an intention to help develop a new drug for the sake of other people ( AS = 3.89 + /- 0.09 ) . Age , ethnicity , and educational status significantly affected motivational factors of patients . These results indicate that recruitment can be enhanced by targeting these motivations in physician/patient communications , informed consent process and advertising for study participants OBJECTIVES Gender and ethnicity are factors affecting the incidence and severity of vascular disease as well as subsequent treatment outcomes . Although well studied in other fields , balanced enrollment of patients with relevant demographic characteristics in vascular surgery r and omized controlled trials ( RCTs ) is not well known . This study describes the reporting of gender and ethnicity data in vascular surgery RCTs and analyzes whether these studies adequately represent our diverse patient population . METHODS We conducted a retrospective review of United States-based RCTs from 1983 through 2007 for three broadly defined vascular procedures : aortic aneurysm repair ( AAR ) , carotid revascularization ( CR ) , and lower extremity revascularization ( LER ) . Included studies were examined for gender and ethnicity data , study parameters , funding source , and geographic region . The Nationwide Inpatient Sample ( NIS ) data base was analyzed to obtain group-specific procedure frequency as an estimate of procedure frequency in the general population . RESULTS We review ed 77 studies , and 52 met our inclusion criteria . Only 85 % reported gender , and 21 % reported ethnicity . Reporting of ethnicity was strongly associated with larger ( > 280 participants ) , multicenter , government-funded trials ( P < .001 for all ) . Women are disproportionately under-represented in RCTs for all procedure categories ( AAR , 9.0 % vs 21.5 % ; CR , 30.0 % vs 42.9 % ; LER , 22.4 % vs 41.3 % ) . Minorities are under-represented in AAR studies ( 6.0 % vs 10.7 % ) and CR studies ( 6.9 % vs 9.5 % ) but are over-represented in LER studies ( 26.0 % vs 21.8 % , P < .001 for all ) . CONCLUSIONS Minority ethnicity and female gender are under-reported and under-represented in vascular surgery RCTs , particularly in small , non-government-funded and single-center trials . The generalizability of some trial results may not be applicable to these population s. Greater effort to enroll a balanced study population in RCTs may yield more broadly applicable results The study objective was to assess willingness of men who have sex with men ( MSM ) enrollled in a vaccine preparedness study ( ' Projeto Rio ' ) to participate in phase III anti-HIV/AIDS vaccine trials . Overall , 57 % of Projeto Rio participants stated they would participate in a putative vaccine trial . MSM who reported commercial sex work were significantly ( p<0.05 ) more likely to engage in risky behaviours than others . In bivariate analysis , commercial sex workers ( CSWs ) were significantly ( p<0.05 ) more likely than non-commercial sex workers ( NCSWs ) to be willing to participate in vaccine trials ( 62.6 % versus 51.4 % ) . Among those willing , CSWs reported significantly more often ( p<0.05 ) ( 50.5 % ) than NCSWs ( 38.0 % ) that they would enroll to protect themselves from HIV . In multivariate analyses , variables associated with willingness to participate ( WTP ) were lower educational level , positive serology for syphilis , and ' engagement , under the influence of alcohol , in risky sexual practice s that would normally be avoided ' , but not commercial sex work . The potential enrollment in vaccine trials of MSM CWSs , as well as participants of low socio-economic status and high risk , seems thus to be possible Summary : Underst and ing why people join HIV vaccine efficacy trials is critical for trial recruitment and education efforts . We assessed participants ' motivations for joining the VaxGen VAX004 study  , a r and omized , double-blind , placebo-controlled , phase 3 multicenter trial . Of 5417 participants , 94 % were men who have sex with men ( MSM ) and 6 % were women at risk for heterosexual transmission of HIV . Most participants gave altruistic reasons for trial participation : 99 % reported having joined to help find an HIV vaccine , and 98 % reported having joined to help their community . Some gave more personal reasons : 56 % joined to reduce risk behavior  and 46 % joined to get protection from HIV . Additional reasons related to receiving services or compensation included to obtain information about HIV ( 75 % ) , to receive free HIV testing ( 34 % ) , and for financial reimbursement ( 14 % ) . Multivariate logistic regression analysis showed that female participants were significantly more motivated than male participants to join the trial for protection and to receive services or compensation ( all P < 0.05 ) . Participants with 13 or more sex partners in the 6 months before enrollment were more likely than those with fewer sex partners to report having joined the trial for protection but less likely to have joined to reduce risk behavior ( both P < 0.05 ) . Because many participants reported personal protection from HIV as their reason for joining , vaccine trial risk-reduction counseling should continue to emphasize the placebo-controlled trial design and unknown efficacy of the test product , particularly for women and persons with large numbers of sex partners . Because a significant minority of participants reported joining to receive HIV information , HIV testing , and financial reimbursement , a need is indicated for provision of HIV prevention services outside research trials and for monitoring to ensure that participants are not motivated to join trials for financial gain BACKGROUND Paying patients to participate in clinical trials is ethically controversial . However , there has been no empirical documentation regarding whether payment represents an undue or unjust inducement . METHODS To evaluate these questions , we described hypothetical placebo-controlled trials of a new antihypertensive drug to 126 patients with mild-to-moderate hypertension recruited from hypertension and general medicine clinics at a university hospital . Using a 3 x 3 , within-subjects design , we altered a risk to participation ( either adverse effect rate or rate of r and omization to placebo ) and the payment participants would receive ( $ 100 , $ 1000 , and $ 2000 ) and asked patients to indicate their  willingness  to participate ( WTP ) in each trial using a 6-point scale . RESULTS Clustered ordinal logistic regression models revealed that patients ' WTP decreased with higher risk of adverse effects ( P<.001 ) , higher risk of being assigned to placebo ( P = .02 ) , and lower payment level ( P<.001 ) . There were no significant interactions between payment level and either risk variable , suggesting that increasing payments do not alter peoples ' perceptions of risk . There was a trend toward a positive interaction between income and the influence of payment on WTP ( P = .09 ) , suggesting that payment more strongly influences WTP  among wealthier people . Wealthier patients were more likely to state that payment was important in their participation decision ( 37 % vs 20 % , P = .05 ) . CONCLUSION Although higher payment motivates research participation , we found no evidence that commonly used payment levels represent undue or unjust inducements Injection drug users ( IDUs ) represent an important risk group for HIV infection . We assessed correlates of IDUs '  willingness to participate ( WTP ) in HIV vaccine trials , and examined temporal changes in WTP . Participants were enrolled in ALIVE , a prospect i ve study of HIV among IDUs in Baltimore ; semi-annual visits include interviews and HIV serology . Question naires regarding WTP were administered in 1993–1994 and again in 2001–2002 . Logistic regression was conducted to identify correlates of WTP . Wave 1 of the survey included 440 participants ; Wave 2 included 582 participants ( 189 participated in both waves ) .  WTP increased modestly over time ( 83.4 vs. 86.3 % ; p = 0.16 ) . Monetary incentives were the strongest predictor of WTP ( adjOR = 2.73 ; 95 % CI : 1.72–4.35 ) . High expectations of HIV treatment effectiveness did not predict WTP . In this cohort , WTP remained strong and modestly increased over the study period . These results should be considered in the planning of sampling and retention strategies for future vaccine trials Objective : To evaluate the representation of minority groups in r and omized control trials ( RCTs ) , and the frequency with which this information is reported . Study Design : Review ers collected data on the racial/ethnic composition of study sample s from all RCTs published in six leading medical journals in 1999 . Results : Of the 280 RCTs , most ( 204 , 71.3 % ) provided no information on the race/ethnicity of participants . Of the 89 U.S.-based RCTs , 50 ( 56.1 % ) reported their minority distribution . Relative to other trials , those funded by the National Institute of Health ( NIH ) ( n = 52 ) were more likely to report race/ethnicity data ( 55. 
    Output:
    
Our main findings are 1 ) the major motivation for Brazilian patients to participate in clinical trials is altruism , 2 ) monetary reimbursement is the least important factor motivating Brazilian patients , 3 ) the major barrier for Brazilian patients to not participate in clinical trials is the fear of side effects , and 4 ) Brazilian patients are more likely willing to participate in clinical trials than Indians .