Recruitment in the hypertension detection and follow-up program

Recruitment strategies for a lung cancer chemoprevention trial involving ex-smokers

The ability to recruit qualified subjects who are willing to adhere to the study protocol in clinical trials is an essential component of translational research. Such tasks can be particularly challenging for chemoprevention studies when the targeted study population is healthy, at risk individuals who do not have signs or symptoms of the disease, and the study participation involves complex scheduling and invasive procedures such as bronchoscopy. In this report, we describe the recruitment process and evaluated the effectiveness of various recruitment strategies utilized in our National Cancer Institute sponsored lung cancer chemoprevention study with celecoxib. Heavy ex-smokers were recruited into the study through various methods such as radio advertisements, print media, mass mailings, flyers, internet postings and others. The number of inquiries, on-site screenees and randomization generated by each method determined the efficacy of that recruitment strategy. We prescreened 4470 individuals, invited 323 people for on-site screening and randomized 137 subjects. Radio advertisements (ads) generated the most inquiries (71.1%), followed by internet posting (11.8%), print media (6.0%), posted and racked flyers (4.4%), mass mailings (2.7%) and other strategies such as referrals from friends or family members or health care providers (2.3%). Radio ads, although costly, yielded the most subjects for on-site screening and randomization. Moreover, among the various types of radio stations, news radio stations were by far the most successful. Our results suggest that advertising on news radio is a highly effective recruitment method for successful accrual of ex-smokers into lung cancer chemoprevention trials.

Recruitment of African Americans with chronic renal insufficiency into a multicenter clinical trial: the african american study of kidney disease and hypertension

In patients with hypertensive nephrosclerosis, the African American Study of Kidney Disease and Hypertension (AASK) demonstrated the superiority of angiotensin-converting enzyme inhibitor therapy in blunting progression of renal disease compared with a b blocker and a dihydropyridine calcium channel blocker. In addition, the study found that a blood pressure treatment strategy that resulted in an achieved blood pressure of 128/78 mm Hg (low blood pressure goal) was no more effective in slowing the progression of renal disease than a strategy that resulted in a blood pressure of 141/85 mm Hg (usual blood pressure goal). AASK, which enrolled only African Americans with mild to moderate chronic renal insufficiency, also provided an opportunity to evaluate recruitment methods in minority populations. Eighty-three percent of patients were recruited through screening in clinical practice. To randomize 635 patients, 558,295 charts were reviewed (approximately 879 charts per randomized patient). More than half of the randomized patients (n=635 or 58%) were found by chart review. Sixty percent of women with creatinine levels considered within the normal range had at least mild chronic renal insufficiency. Screening in clinical practice was the most effective strategy to recruit participants with mild to moderate chronic renal insufficiency and hypertension into the clinical trial. This technique may also be an effective approach in trials of other essentially asymptomatic conditions.

A conceptual model for the recruitment of diverse women into research studies

Researchers' understanding of recruitment and retention of study subjects is in its infancy. To address the dearth of information on the underrepresentation of diverse populations of women in research studies relating to health issues, the University of California, San Francisco (UCSF) National Center of Excellence in Women's Health completed a comprehensive examination of issues related to recruitment. By synthesizing data from literature reviews, focus groups, surveys, one-on-one interviews, and direct experience recruiting diverse populations of women for research, a conceptual model was developed. This model outlines the interplay of three factors found to be relevant to the recruitment of diverse populations of women into research studies: awareness, acceptance, and access. Practical examples of cost-effective recruitment strategies to be considered for implementation to increase the presence of awareness, acceptability, and access are included in this report.

Recruitment for controlled clinical trials: literature summary and annotated bibliography

This article is a literature summary and annotated bibliography of research on recruitment for controlled clinical trials published through 1995. It extends and revises a similar review published in this journal a decade ago. The current commentary focuses on intervening developments in recruitment, including diverse populations, HIV trials, primary prevention trials, recruitment strategies, overall planning and management, patient and physician attitudes, adherence, generalizability, and cost. Profound barriers may exist in the recruitment of diverse populations, involving language, cultural factors, beliefs about medical research, and the appropriateness of available protocols. Extensive literature exists on patient and physician barriers to participation. Trials in HIV-infected or AIDs-diagnosed individuals introduce special considerations, including issues of confidentiality, parallel track design, and populations difficult to define and track. Recruitment strategies such as patient registries, occupational screening, direct mail, and the media are now prominent in the literature. Successful planning and management of an overall recruitment plan include piloting strategies, monitoring recruitment by data tracking systems, and hiring quality staff. Generalizability of study results is influenced by the characteristics of participants and by their adherence to study protocol. With increasingly limited funding to conduct clinical trials, efforts to quantify and reduce recruitment costs are being made. While over 4000 titles were identified, primarily by MEDLINE literature search, the articles summarized emphasize data-supported and -confirmed conclusions, and broad coverage of disease areas. We annotate here 91 outstanding articles useful for formulation of overall recruitment approaches in clinical trials.

Why are African Americans under-represented in medical research studies? Impediments to participation

OBJECTIVES

In accordance with the NIH Revitalization Act of 1993, the National Institutes of Health and the Alcohol, Drug and Mental Health Administration require grant applicants and cooperative agreement participants to include minorities in human subject research. In an environment characterized by diminishing research dollars, this mandate has increased the pressure on investigators to determine factors that impede minority participation and to develop strategies to overcome these impediments.

METHODS

An extensive review of the literature was conducted to identify the factors possibly responsible for the low participation levels of African Americans in medical research studies and to highlight areas for further research. The items examined included the historical relationship between African Americans and medical researchers and the attitudes, perceptions and beliefs of potential participants and researchers as they relate to the low representation of African Americans in medical research.

RESULTS

The factors identified as possible impediments to African American participation included distrust of the medical/scientific community, poor access to primary medical care, the failure of researchers to recruit African Americans actively, the alienation of minority health professionals, lack of knowledge about clinical trials, language and cultural barriers.

CONCLUSIONS

Well-designed, relevant, ethical research in conjunction with an appreciation of the many barriers to participation are paramount to increasing African American presence in clinical research.

Recruitment in the Trial of Nonpharmacologic Intervention in the Elderly (TONE)

OBJECTIVE

To compare the effectiveness of different approaches to participant enrollment in a behavior modification trial.

DESIGN

Concurrent, prospective evaluation performed in context of recruitment for a randomized, controlled trial.

SETTING

Four study centers located in Baltimore, Maryland, Memphis, Tennessee New Brunswick, New Jersey, and Winston-Salem, North Carolina.

PARTICIPANTS

Men and women aged 60 to 80 years who were being treated with a prescription medication for control of hypertension.

MAIN OUTCOME MEASURES

Visit counts and percent yields were assessed at each stage of the screening and randomization process. Logistic regression was used to contrast the randomization yields for different recruitment strategies and to explore the impact of sociodemographic characteristics and geographic location on recruitment yields.

RESULTS

The overall randomization yields from a prescreen contact and a first screening visit to enrollment in the trial were 11% and 31%, respectively. Randomization yields varied significantly by participant age, education, and marital status.

CONCLUSIONS

Our results demonstrate the feasibility of recruitment for trials of nonpharmacologic interventions in older people and suggest that mass mailing and mass media advertising campaigns provide an effective means of enrolling in such studies participants with a broad range of personal characteristics.

The Women's Health Trial Feasibility Study in Minority Populations: design and baseline descriptions

The Women's Health Trial: Feasibility Study in Minority Populations (WHT:FSMP), a randomized trial of 2208 women, was conducted to investigate three questions. First, can women from minority and low-socioeconomic-status populations be recruited in numbers sufficient to evaluate a dietary intervention designed to lower fat intake. Second, the efficacy of a low fat, increased fruit/vegetable/ grain product intervention for reducing fat consumption. Third, will participation in the intervention lower plasma cholesterol and estradiol levels relative to the controls. The baseline results showed that an adequate number of minority and low SES women could be recruited to test the study hypotheses. A diverse study population of postmenopausal women consuming a high fat diet was recruited: 28% of participants were Black, 16% were Hispanic, 11% had less than a high school level of education, and 15.5% had household incomes of < $15,000.

Recruitment for phase II of the Trials of Hypertension Prevention. Effective strategies and predictors of randomization. Trials of Hypertension Prevention (TOHP) Collaborative Research Group

Phase II of the Trials of Hypertension Prevention is a multicenter, randomized, controlled trial designed to determine the efficacy of weight loss and reduction of sodium intake for lowering blood pressure and incidence of hypertension among persons with high-normal levels of blood pressure. The 2 x 2 factorial study design includes weight loss alone, restricted sodium intake alone, the combination of weight loss and sodium restriction, and a control group. Nine clinical centers used a variety of recruitment strategies to enroll 2382 participants over 17 months, which exceeded the sample size goal of 2250. Among randomized participants, 21% were minorities and 34% were women. Overall, direct mail generated the most randomized participants (73%), followed by community screening (12%) and media advertisement (11%). Referrals from community health care providers yielded few participants. Prescreening improved overall efficiency and reduced costs. Participants who were more likely to drop out voluntarily during the three-visit screening regimen tended to be younger, single, male, smokers, and less educated.

Effect of recruitment strategy on types of subjects entered into a primary prevention clinical trial

Clinical trials typically recruit subjects through referrals or media promotion, with generalizability of the results often uncertain. As part of a primary prevention trial to evaluate strategies for increasing physical activity in sedentary men and women, two recruitment sources, a random-digit-dial telephone survey and a community media campaign, were used to identify subjects. Baseline characteristics of 357 randomized men and women aged 50 to 65 years were compared by recruitment source. Whereas there were few differences between recruitment sources for demographic variables, telephone survey recruitment was particularly successful in recruiting smokers and persons with other cardiovascular risk factors into the trial. Counter to expectations, subsequent exercise adherence rates did not differ by recruitment source. The results suggest that the survey method, while more expensive, may be particularly useful for locating higher-risk subjects who could especially benefit from increases in physical activity but who rarely are recruited through more traditional approaches.

Why do lean hypertensives have higher mortality rates than other hypertensives? Findings of the Hypertension Detection and Follow-up Program

Specific causes of death were analyzed for 10,908 participants in the Hypertension Detection and Follow-up Program, to explore possible explanations for the observed excess 8.3-year mortality from all causes in hypertensives with low body mass. Although the cardiovascular mortality rate among men in the lowest decile of body mass (body mass index 21.96 or less) was 50% higher than that of men in the median class (body mass index 26.4-28.8), death rate for noncardiovascular deaths was more than 2 1/2 times higher in men with lean versus median body mass. The pattern was similar among women. Among noncardiovascular causes, striking differences in mortality rates between lean hypertensives and those of average body mass were observed for cirrhotic death (relative risk of 12+ in men and 11+ in women), for nonmalignant respiratory disease in men (relative risk of 7+), for violent death (both sexes), and for malignant neoplasms in men. Prevalence of smoking was almost twice as high in the lowest compared with the median body mass group; among the lean, excess deaths, particularly noncardiovascular deaths, were concentrated among smokers. Thus, male smokers in the lowest decile of body mass constituted only 3% of the study population, but contributed 8% of all deaths, 11% of all noncardiovascular deaths, and 22% of all cirrhotic deaths. A larger proportion of deaths occurred early in follow-up in the lean versus other hypertensives, suggesting occult disease among the lean at baseline. There was no evidence that more severe or treatment-resistant hypertension was present in or could explain excess mortality among the hypertensives with low body mass. The inference from the findings is not that overweight is protective for hypertensives nor that excess risk is due to leanness per se. Rather, a reasonable hypothesis, particularly from findings on specific causes of death, is that excess mortality in lean hypertensives is due to deleterious lifestyles, particularly smoking and excess alcohol intake, contributing to both leanness and risk of death.

Comparison of recruitment strategies for a large-scale clinical trial in the elderly

Formal evaluation of recruitment strategies for clinical trials conducted in the community setting, rather than in hospitals, is limited despite recruitment rates and costs having significant implications for the planning of large trials. As part of the development of a large-scale primary prevention trial of low-dose aspirin in 15,000 elderly persons (aged 70 years and above) to be undertaken in a community setting, a pilot study involving 400 participants was carried out to evaluate different recruitment strategies. Three techniques were compared: recruiting from the electoral roll (by individual invitation using direct mail), local community approach (through retirement villages, local media, elderly community groups), and using general/family practice (identifying persons over 70 within a practice and direct mail invitation to participate). Screening of potential participants was carried out by a trained trial nurse with limited involvement only of medical practitioners. The target recruitment figure was achieved in 4 months using the equivalent of 1.5 full-time nurses. General practice was the most effective method utilized, with a yield of one participant recruited per six approached at an estimated cost of A$48.36 per recruited participant. This compares with yield rates of 1 per 29 (for the local community approach) and 1 per 17 for the electoral roll, and costs per participant of A$42.54 and A$59.37 respectively. Other less tangible benefits of general practice include the greater cooperation of primary care practitioners in patient follow-up and end-point ascertainment.

Using a population-based cancer registry for recruitment in a pilot cancer control study

Cancer control investigations in the United States rarely use population-based registries as a resource for recruitment. A placebo-controlled, double-blind, randomized toxicity trial of tamoxifen was conducted among postmenopausal women with node negative breast cancer. To achieve the accrual goal of 140 subjects in this single institution study, the Wisconsin Cancer Reporting System (WCRS), a population-based cancer registry, was used. Registry information from the last 9 years was used to identify 3,585 women who met the study criteria with respect to age, stage, and previous therapy. The vital status of identified women was confirmed using Wisconsin state death records. For identified cases, rosters were prepared and sent to the physician with a cover letter and study description. The physicians were asked to update the list and, if appropriate, to sign letters to potentially eligible and interested women. Thirty-eight percent of women receiving a letter and study information from their physicians contacted the study office about participation. Eighteen months from its initiation, 140 women were entered on study. This successful use of a population-based cancer registry illustrates an efficient recruitment method which could be modified for other cancer control/chemoprevention trials.

Recruitment in NHLBI population-based studies and randomized clinical trials: data analysis and survey results

Data on screening and recruitment from current and previous NHLBI population-based studies (PBSs) and randomized clinical trials (RCTs) were examined. In only two of the studies examined was the projected recruitment completed within the planned recruitment period. The shape of the graph of the relation between enrollment of participants and time varies by study. A single summary statistic for measuring the efficiency of recruitment in RCTs and PBSs is proposed and applied to the examined studies. In addition to providing summary data on recruitment for several studies, this article reports the survey results of a questionnaire sent to the coordinating centers of currently and previously funded National Heart, Lung, and Blood Institute and Veteran's Administration studies. The purpose was to ascertain the desirability of recommending that a generic core of information be collected on recruitment and screening in future studies. Most respondents believed that comparing data collected uniformly and prospectively might be helpful in designing further studies. The variables most respondents believed to be potentially useful are described.