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

Behavioral Counseling to Promote a Healthy Diet and Physical Activity for Cardiovascular Disease Prevention in Adults With Cardiovascular Risk Factors: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Cardiovascular disease is the leading cause of death in the US, and poor diet and lack of physical activity are major factors contributing to cardiovascular morbidity and mortality.

OBJECTIVE

To review the benefits and harms of behavioral counseling interventions to improve diet and physical activity in adults with cardiovascular risk factors.

DATA SOURCES

MEDLINE, PubMed, PsycINFO, and the Cochrane Central Register of Controlled Trials through September 2019; literature surveillance through July 24, 2020.

STUDY SELECTION

English-language randomized clinical trials (RCTs) of behavioral counseling interventions to help people with elevated blood pressure or lipid levels improve their diet and increase physical activity.

DATA EXTRACTION AND SYNTHESIS

Data were extracted from studies by one reviewer and checked by a second. Random-effects meta-analysis and qualitative synthesis were used.

MAIN OUTCOMES AND MEASURES

Cardiovascular events, mortality, subjective well-being, cardiovascular risk factors, diet and physical activity measures (eg, minutes of physical activity, meeting physical activity recommendations), and harms. Interventions were categorized according to estimated contact time as low (≤30 minutes), medium (31-360 minutes), and high (>360 minutes).

RESULTS

Ninety-four RCTs were included (N = 52 174). Behavioral counseling interventions involved a median of 6 contact hours and 12 sessions over the course of 12 months and varied in format and dietary recommendations; only 5% addressed physical activity alone. Interventions were associated with a lower risk of cardiovascular events (pooled relative risk, 0.80 [95% CI, 0.73-0.87]; 9 RCTs [n = 12 551]; I2 = 0%). Event rates were variable; in the largest trial (Prevención con Dieta Mediterránea [PREDIMED]), 3.6% in the intervention groups experienced a cardiovascular event, compared with 4.4% in the control group. Behavioral counseling interventions were associated with small, statistically significant reductions in continuous measures of blood pressure, low-density lipoprotein cholesterol levels, fasting glucose levels, and adiposity at 12 to 24 months' follow-up. Measurement of diet and physical activity was heterogeneous, and evidence suggested small improvements in diet consistent with the intervention recommendation targets but mixed findings and a more limited evidence base for physical activity. Adverse events were rare, with generally no group differences in serious adverse events, any adverse events, hospitalizations, musculoskeletal injuries, or withdrawals due to adverse events.

CONCLUSIONS AND RELEVANCE

Medium- and high-contact multisession behavioral counseling interventions to improve diet and increase physical activity for people with elevated blood pressure and lipid levels were effective in reducing cardiovascular events, blood pressure, low-density lipoproteins, and adiposity-related outcomes, with little to no risk of serious harm.

Recruitment Strategies and Costs Associated With Enrolling People With Insomnia and High Blood Pressure Into an Online Behavioral Sleep Intervention: A Single-Site Pilot Study

BACKGROUND

Recruitment in clinical research is a common challenge and source of study failure. The reporting of recruitment methods and costs in hypertension trials is limited especially for smaller, single-site trials, online intervention trials, and trials using newer online recruitment strategies.

OBJECTIVE

The aims of this study are to describe and examine the feasibility of newer online-e-mail recruitment strategies and traditional recruitment strategies used to enroll participants with insomnia and high blood pressure into an online behavioral sleep intervention study (Sleeping for Heart Health).

METHODS

The 16 online-e-mail-based and traditional recruitment strategies used are described. Recruitment strategy feasibility was examined by study interest and enrollee yields, conversion rates, and costs (direct, remuneration, labor, and cost per enrollee).

RESULTS

From August 2014 to October 2015, 183 people were screened and 58 (31.7%) enrolled in the study (51.1 ± 12.9 years, 63.8% female, 72.4% African American, 136 ± 12/88 ± 7 mm Hg, 87.9% self-reported hypertension, 67.2% self-reported antihypertensive medication use). The recruitment strategies yielding the highest enrollees were the university hospital phone waiting message system (25.4%), Craigslist (22.4%), and flyers (20.3%) at a per enrollee cost of $42.84, $98.90, and $128.27, respectively. The university hospital phone waiting message system (55.6%) and flyers (54.5%) had the highest interested participant to enrolled participant conversion rate of all recruitment strategies.

CONCLUSION

Approximately 70% of all enrolled participants were recruited from the university hospital phone waiting message system, Craigslist, or flyers. Given the recruitment challenges that most researchers face, we encourage the documenting, assessing, and reporting of detailed recruitment strategies and associated recruitment costs so that other researchers may benefit.

The Recruitment Experience of a Randomized Clinical Trial to Aid Young Adult Smokers to Stop Smoking without Weight Gain with Interactive Technology

Multiple recruitment strategies are often needed to recruit an adequate number of participants, especially hard to reach groups. Technology-based recruitment methods hold promise as a more robust form of reaching and enrolling historically hard to reach young adults. The TARGIT study is a randomized two-arm clinical trial in young adults using interactive technology testing an efficacious proactive telephone Quitline versus the Quitline plus a behavioral weight management intervention focusing on smoking cessation and weight change. All randomized participants in the TARGIT study were required to be a young adult smoker (18–35 years), who reported smoking at least 10 cigarettes per day, had a BMI < 40 kg/m^2, and were willing to stop smoking and not gain weight. Traditional recruitment methods were compared to technology-based strategies using standard descriptive statistics based on counts and proportions to describe the recruitment process from initial pre-screening (PS) to randomization into TARGIT. Participants at PS were majority Black (59.80%), female (52.66%), normal or over weight (combined 62.42%), 29.5 years old, and smoked 18.4 cigarettes per day. There were differences in men and women with respect to reasons for ineligibility during PS (p < 0.001; ignoring gender specific pregnancy-related ineligibility). TARGIT experienced a disproportionate loss of minorities during recruitment as well as a prolonged recruitment period due to either study ineligibility or not completing screening activities. Recruitment into longer term behavioral change intervention trials can be challenging and multiple methods are often required to recruit hard to reach groups.

ClinicalTrials.gov Identifier NCT01199185

The NHLBI funded TARGIT as part of a U01 Cooperative Agreement and as such the study design was approved. They did not have input into the data collection, analysis, or the interpretation of the data or in the writing of this report.

Reduced dietary salt for the prevention of cardiovascular disease

BACKGROUND

This is an update of a Cochrane review that was first published in 2011 of the effects of reducing dietary salt intake, through advice to reduce salt intake or low-sodium salt substitution, on mortality and cardiovascular events.

OBJECTIVES

1. To assess the long-term effects of advice and salt substitution, aimed at reducing dietary salt, on mortality and cardiovascular morbidity.2. To investigate whether a reduction in blood pressure is an explanatory factor in the effect of such dietary interventions on mortality and cardiovascular outcomes.

SEARCH METHODS

We updated the searches of CENTRAL (2013, Issue 4), MEDLINE (OVID, 1946 to April week 3 2013), EMBASE (OVID, 1947 to 30 April 2013) and CINAHL (EBSCO, inception to 1 April 2013) and last ran these on 1 May 2013. We also checked the references of included studies and reviews. We applied no language restrictions.

SELECTION CRITERIA

Trials fulfilled the following criteria: (1) randomised, with follow-up of at least six months, (2) the intervention was reduced dietary salt (through advice to reduce salt intake or low-sodium salt substitution), (3) participants were adults and (4) mortality or cardiovascular morbidity data were available. Two review authors independently assessed whether studies met these criteria.

DATA COLLECTION AND ANALYSIS

A single author extracted data and assessed study validity, and a second author checked this. We contacted trial authors where possible to obtain missing information. We extracted events and calculated risk ratios (RRs) and 95% confidence intervals (CIs).

MAIN RESULTS

Eight studies met the inclusion criteria: three in normotensives (n = 3518) and five in hypertensives or mixed populations of normo- and hypertensives (n = 3766). End of trial follow-up ranged from six to 36 months and the longest observational follow-up (after trial end) was 12.7 years.The risk ratios (RR) for all-cause mortality in normotensives were imprecise and showed no evidence of reduction (end of trial RR 0.67, 95% confidence interval (CI) 0.40 to 1.12, 60 deaths; longest follow-up RR 0.90, 95% CI 0.58 to 1.40, 79 deaths n=3518) or in hypertensives (end of trial RR 1.00, 95% CI 0.86 to 1.15, 565 deaths; longest follow-up RR 0.99, 95% CI 0.87 to 1.14, 674 deaths n=3085). There was weak evidence of benefit for cardiovascular mortality (hypertensives: end of trial RR 0.67, 95% CI 0.45 to 1.01, 106 events n=2656) and for cardiovascular events (hypertensives: end of trial RR 0.76, 95% CI 0.57 to 1.01, 194 events, four studies, n = 3397; normotensives: at longest follow-up RR 0.71, 95% CI 0.42 to 1.20, 200 events; hypertensives: RR 0.77, 95% CI 0.57 to 1.02, 192 events; pooled analysis of six trials RR 0.77, 95% CI 0.63 to 0.95, n = 5912). These findings were driven by one trial among retirement home residents that reduced salt intake in the kitchens of the homes, thereby not requiring individual behaviour change.Advice to reduce salt showed small reductions in systolic blood pressure (mean difference (MD) -1.15 mmHg, 95% CI -2.32 to 0.02 n=2079) and diastolic blood pressure (MD -0.80 mmHg, 95% CI -1.37 to -0.23 n=2079) in normotensives and greater reductions in systolic blood pressure in hypertensives (MD -4.14 mmHg, 95% CI -5.84 to -2.43 n=675), but no difference in diastolic blood pressure (MD -3.74 mmHg, 95% CI -8.41 to 0.93 n=675).Overall many of the trials failed to report sufficient detail to assess their potential risk of bias. Health-related quality of life was assessed in one trial in normotensives, which reported significant improvements in well-being but no data were presented.

AUTHORS' CONCLUSIONS

Despite collating more event data than previous systematic reviews of randomised controlled trials, there is insufficient power to confirm clinically important effects of dietary advice and salt substitution on cardiovascular mortality in normotensive or hypertensive populations. Our estimates of the clinical benefits from advice to reduce dietary salt are imprecise, but are larger than would be predicted from the small blood pressure reductions achieved. Further well-powered studies would be needed to obtain more precise estimates. Our findings do not support individual dietary advice as a means of restricting salt intake. It is possible that alternative strategies that do not require individual behaviour change may be effective and merit further trials.

The effects of weight loss and salt reduction on visit-to-visit blood pressure variability: results from a multicenter randomized controlled trial

OBJECTIVES

As evidence suggests visit-to-visit variability (VVV) of blood pressure (BP) is associated with cardiovascular events and mortality, there is increasing interest in identifying interventions that reduce VVV of BP. We investigated the effects of weight loss and sodium reduction, alone or in combination, on VVV of BP in participants enrolled in phase II of the Trials of Hypertension Prevention.

METHODS

BP readings were taken at 6-month intervals for 36 months in 1820 participants with high-normal DBP who were randomized to weight loss, sodium reduction, combination (weight loss and sodium reduction), or usual care groups. VVV of BP was defined as the SD of BP across six follow-up visits.

RESULTS

VVV of SBP was not significantly different between participants randomized to the weight loss (7.2 ± 3.1  mmHg), sodium reduction (7.1 ± 3.0  mmHg), or combined (6.9 ± 2.9  mmHg) intervention groups vs. the usual care group (6.9 ± 2.9  mmHg). In a fully adjusted model, no difference (0.0 ± 0.2  mmHg) in VVV of SBP was present between individuals who successfully maintained their weight loss vs. individuals who did not lose weight during follow-up (P = 0.93). Also, those who maintained a reduced sodium intake throughout follow-up did not have lower VVV of SBP compared to those who did not reduce their sodium intake (0.1 ± 0.3  mmHg; P = 0.77). Results were similar for VVV of DBP.

CONCLUSIONS

These findings suggest that weight loss and sodium reduction may not be effective interventions for lowering VVV of BP in individuals with high-normal DBP.

Differences in weight loss and health outcomes among African Americans and whites in multicentre trials

The efficacy of behavioural lifestyle interventions (BLI) for weight loss and prevention and treatment of diabetes and hypertension is well established but may vary among racial/ethnic subgroups. This report reviews literature from 1990 to 2012 to determine if outcomes were similar among African Americans (AA) and whites participating in multicentre BLIs funded by the National Institutes of Health. We identified seven relevant trials that reported subgroup analyses for AA. On average, AA lost less weight at 6 months (AA: -1.6 to -7.5 kg; whites: -3.8 to -8.2 kg), but also had less or similar weight regain compared with whites. There were no reported differences between races in diabetes incidence. Three analyses reported no differences in blood pressure; however, a fourth reported that AA women were the only group that did not experience a significant change in blood pressure. Despite increased attention to cultural relevance, race-specific differences in weight loss persist in trials spanning 20 years; however, risk factor modification was similar across race/ethnic groups. Additional research is needed to understand the mechanisms of risk factor modification, and potential for weight change to promote even greater risk factor modification for AA than has been observed to date.

Overcoming recruitment challenges in palliative care clinical trials

PURPOSE

Palliative care is increasingly viewed as a necessary component of cancer care, especially for patients with advanced disease. Rigorous clinical trials are thus needed to build the palliative care evidence base, but clinical research-especially participant recruitment-is difficult. Major barriers include (1) patient factors, (2) "gatekeeping," and (3) ethical concerns. Here we discuss an approach to overcoming these barriers, using the Palliative Care Trial (PCT) as a case study.

PATIENTS AND METHODS

The PCT was a 2 × 2 × 2 factorial randomized controlled trial (RCT) of different service delivery models to improve pain control in the palliative setting. It used a recruitment protocol that fused evidence-based strategies with principles of "social marketing," an approach involving the systematic application of marketing techniques. Main components included (1) an inclusive triage algorithm, (2) information booklets targeting particular stakeholders, (3) a specialized recruitment nurse, and (4) standardization of wording across all study communications.

RESULTS

From an eligible pool of 607 patients, the PCT enrolled 461 patients over 26 months. Twenty percent of patients referred to the palliative care service were enrolled (76% of those eligible after screening). Several common barriers were minimized; among those who declined participation, family disinterest was uncommon (5%), as was the perception of burden imposed (4%).

CONCLUSION

Challenges to clinical trial recruitment in palliative care are significant but not insurmountable. A carefully crafted recruitment and retention protocol can be effective. Our experience with designing and deploying a social-marketing-based protocol shows the benefits of such an approach.

Reduced dietary salt for the prevention of cardiovascular disease: a meta-analysis of randomized controlled trials (Cochrane review)

BACKGROUND

Although meta-analyses of randomized controlled trials (RCTs) of salt reduction report a reduction in the level of blood pressure (BP), the effect of reduced dietary salt on cardiovascular disease (CVD) events remains unclear.

METHODS

We searched for RCTs with follow-up of at least 6 months that compared dietary salt reduction (restricted salt dietary intervention or advice to reduce salt intake) to control/no intervention in adults, and reported mortality or CVD morbidity data. Outcomes were pooled at end of trial or longest follow-up point.

RESULTS

Seven studies were identified: three in normotensives, two in hypertensives, one in a mixed population of normo- and hypertensives and one in heart failure. Salt reduction was associated with reductions in urinary salt excretion of between 27 and 39 mmol/24 h and reductions in systolic BP between 1 and 4 mm Hg. Relative risks (RRs) for all-cause mortality in normotensives (longest follow-up-RR: 0.90, 95% confidence interval (CI): 0.58-1.40, 79 deaths) and hypertensives (longest follow-up RR 0.96, 0.83-1.11, 565 deaths) showed no strong evidence of any effect of salt reduction CVD morbidity in people with normal BP (longest follow-up: RR 0.71, 0.42-1.20, 200 events) and raised BP at baseline (end of trial: RR 0.84, 0.57-1.23, 93 events) also showed no strong evidence of benefit. Salt restriction increased the risk of all-cause mortality in those with heart failure (end of trial RR 2.59, 1.04-6.44, 21 deaths).We found no information on participant's health-related quality of life.

CONCLUSIONS

Despite collating more event data than previous systematic reviews of RCTs (665 deaths in some 6,250 participants) there is still insufficient power to exclude clinically important effects of reduced dietary salt on mortality or CVD morbidity. Our estimates of benefits from dietary salt restriction are consistent with the predicted small effects on clinical events attributable to the small BP reduction achieved.

Reduced dietary salt for the prevention of cardiovascular disease

BACKGROUND

An earlier Cochrane review of dietary advice identified insufficient evidence to assess effects of reduced salt intake on mortality or cardiovascular events.

OBJECTIVES

1. To assess the long term effects of interventions aimed at reducing dietary salt on mortality and cardiovascular morbidity.2. To investigate whether blood pressure reduction is an explanatory factor in any effect of such dietary interventions on mortality and cardiovascular outcomes.

SEARCH STRATEGY

The Cochrane Library (CENTRAL, Health Technology Assessment (HTA) and Database of Abstracts of Reviews of Effect (DARE)), MEDLINE, EMBASE, CINAHL and PsycInfo were searched through to October 2008. References of included studies and reviews were also checked. No language restrictions were applied.

SELECTION CRITERIA

Trials fulfilled the following criteria: (1) randomised with follow up of at least six-months, (2) intervention was reduced dietary salt (restricted salt dietary intervention or advice to reduce salt intake), (3) adults, (4) mortality or cardiovascular morbidity data was available. Two reviewers independently assessed whether studies met these criteria.

DATA COLLECTION AND ANALYSIS

Data extraction and study validity were compiled by a single reviewer, and checked by a second. Authors were contacted where possible to obtain missing information. Events were extracted and relative risks (RRs) and 95% CIs calculated.

MAIN RESULTS

Seven studies (including 6,489 participants) met the inclusion criteria - three in normotensives (n=3518), two in hypertensives (n=758), one in a mixed population of normo- and hypertensives (n=1981) and one in heart failure (n=232) with end of trial follow-up of seven to 36 months and longest observational follow up (after trial end) to 12.7 yrs. Relative risks for all cause mortality in normotensives (end of trial RR 0.67, 95% CI: 0.40 to 1.12, 60 deaths; longest follow up RR 0.90, 95% CI: 0.58 to 1.40, 79 deaths) and hypertensives (end of trial RR 0.97, 95% CI: 0.83 to 1.13, 513 deaths; longest follow up RR 0.96, 95% CI; 0.83 to 1.11, 565 deaths) showed no strong evidence of any effect of salt reduction. Cardiovascular morbidity in people with normal blood pressure (longest follow-up RR 0.71, 95% CI: 0.42 to 1.20, 200 events) or raised blood pressure at baseline (end of trial RR 0.84, 95% CI: 0.57 to 1.23, 93 events) also showed no strong evidence of benefit. Salt restriction increased the risk of all-cause death in those with congestive heart failure (end of trial relative risk: 2.59, 95% 1.04 to 6.44, 21 deaths). We found no information on participants health-related quality of life.

AUTHORS' CONCLUSIONS

Despite collating more event data than previous systematic reviews of randomised controlled trials (665 deaths in some 6,250 participants), there is still insufficient power to exclude clinically important effects of reduced dietary salt on mortality or cardiovascular morbidity in normotensive or hypertensive populations. Further RCT evidence is needed to confirm whether restriction of sodium is harmful for people with heart failure. Our estimates of benefits from dietary salt restriction are consistent with the predicted small effects on clinical events attributable to the small blood pressure reduction achieved.

Low patient enrollment sites in multicenter randomized clinical trials of cerebrovascular diseases: associated factors and impact on trial outcomes

Wide variability in patient enrollment among participating sites is a common phenomenon in multicenter trials. We examined stroke trial-related factors associated with the proportion of sites with low patient enrollment and the effect of these low-enrollment sites on trial outcome. We identified efficacy clinical trials enrolling patients with cerebrovascular diseases between 1980 and 2008 using an electronic database. The trials included in our analyses were multicenter randomized controlled trials (RCTs) comparing efficacy endpoints between two or more treatment groups and having >5 sites. Sites enrolling <10 patients or <2% of total trial patients were defined as low- enrollment sites. Trials were classified into tertiles based on the proportion of low-enrollment sites. Factors associated with trials that could be ascertained through a systematic review of published data were identified and examined. The association between low enrollment and a conclusive trial designation (defined by the ability to reject the primary null hypothesis either at or before target enrollment or demonstrate equivalence/noninferiority with adequate statistical power, depending on the initial design) was assessed using a multivariate logistic regression model. We identified 51 trials that met the inclusion criteria and provided information regarding patients enrolled per center. A total of 3059 participating centers enrolled a total of 53,742 trial participants; 78% of the participating sites enrolled <2% of trial participants. Trials enrolling acute stroke patients (within 24 hours of symptom onset) or those evaluating endovascular/surgical intervention had a higher proportion of low-enrollment sites (<10 patients per site). Studies with a higher proportion of low-enrollment sites were more likely to target acute stroke patients and less likely to randomize ≥1000 patients, use general efficacy endpoints, and stratify by site. There was no association between the studies with a higher proportion of low-enrollment sites and designation as a conclusive trial. A better understanding of factors associated with low-enrollment sites in clinical trials and the impact on a trial's ability to demonstrate conclusive outcomes may lead to strategies to make trial enrollments more efficient and cost-effective.

Innovative Proven Clinical-Research Strategies for Participant Recruitment and Retention

The ability to successfully recruit and retain research participants is an important precursor to conducting a successful clinical trial. With respect to participant recruitment, we discuss potential strategies used in well-known and successful research studies to reach out to the targeted populations, including public education on the importance of clinical trials and the use of new media in reaching out to a wider population. The measures used by research studies to engage their participants and their healthcare providers to optimise participant retention are also examined. We conclude by discussing how these strategies may be adapted for use in Singapore.

Strategies and cost of recruitment of middle-aged and older unmarried women in a cancer screening study

OBJECTIVES

We compared strategies and costs associated with recruiting unmarried middle-aged and older women who partner with women (WPW) and women who partner with men (WPM) into an observational study about experiences with cancer screening.

METHODS

We used targeted and respondent-driven sampling methods to recruit potential participants. Comparable recruitment strategies were used for WPW and WPM.

RESULTS

During 25 months (June 1, 2003, through June 30, 2005), 773 women were screened for study eligibility; 630 were enrolled (213 WPW, 417 WPM). Average staff time spent for recruitment was 100 min per participant. There were no differences by partner gender in average recruitment time (WPW, 90 min; WPM, 100 min). Print media was the most efficient recruitment mode (time per participant: 10 min for WPW, 15 min for WPM). Recruitment costs differed by partner gender ($140 for WPW, $110 for WPM). Costs associated with print media were $10 per WPW and $20 per WPM. Recruitment through community events had higher costs ($490 per WPW, $275 per WPM) but yielded more women with less education and lower incomes, who identified as a racial or ethnic minority, and self-reported a disability. Compared with WPM, WPW had more education and higher incomes, but were less likely to identify as a racial minority and self-report a disability.

CONCLUSIONS

There was a trade-off between cost and sample diversity for the different recruitment methods. The per-person costs were lowest for print media, but recruitment through community events ensured a more diverse representation of unmarried heterosexual and sexual minority women.

Relaxation therapies for the management of primary hypertension in adults

BACKGROUND

Lifestyle interventions are often recommended as initial treatment for mild hypertension, but the efficacy of relaxation therapies is unclear.

OBJECTIVES

To evaluate the effects of relaxation therapies on cardiovascular outcomes and blood pressure in people with elevated blood pressure.

SEARCH STRATEGY

We searched the Cochrane Library, MEDLINE, EMBASE, Science Citation Index, ISI Proceedings, ClinicalTrials.gov, Current Controlled Trials and reference lists of systematic reviews, meta-analyses and randomised controlled trials (RCTs) included in the review.

INCLUSION CRITERIA

RCTs of a parallel design comparing relaxation therapies with no active treatment, or sham therapy; follow-up >/=8 weeks; participants over 18 years, with raised systolic blood pressure (SBP) >/=140 mmHg or diastolic blood pressure (DBP) >/=85 mmHg); SBP and DBP reported at end of follow-up.

EXCLUSION CRITERIA

participants were pregnant; participants received antihypertensive medication which changed during the trial.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed trial quality. Disagreements were resolved by discussion or a third reviewer. Random effects meta-analyses and sensitivity analyses were conducted.

MAIN RESULTS

29 RCTs, with eight weeks to five years follow-up, met our inclusion criteria; four were excluded from the primary meta-analysis because of inadequate outcome data. The remaining 25 trials assessed 1,198 participants, but adequate randomisation was confirmed in only seven trials and concealment of allocation in only one. Only one trial reported deaths, heart attacks and strokes (one of each). Meta-analysis indicated that relaxation resulted in small, statistically significant reductions in SBP (mean difference: -5.5 mmHg, 95% CI: -8.2 to -2.8, I2 =72%) and DBP (mean difference: -3.5 mmHg, 95% CI: -5.3 to -1.6, I2 =75%) compared to control. The substantial heterogeneity between trials was not explained by duration of follow-up, type of control, type of relaxation therapy or baseline blood pressure. The nine trials that reported blinding of outcome assessors found a non-significant net reduction in blood pressure (SBP mean difference: -3.2 mmHg, 95% CI: -7.7 to 1.4, I(2) =69%) associated with relaxation. The 15 trials comparing relaxation with sham therapy likewise found a non-significant reduction in blood pressure (SBP mean difference: -3.5 mmHg, 95% CI: -7.1 to 0.2, I(2) =63%).

AUTHORS' CONCLUSIONS

In view of the poor quality of included trials and unexplained variation between trials, the evidence in favour of causal association between relaxation and blood pressure reduction is weak. Some of the apparent benefit of relaxation was probably due to aspects of treatment unrelated to relaxation.

A systematic review of reasons for nonentry of eligible patients into surgical randomized controlled trials

BACKGROUND

The low recruitment rates into surgical randomized controlled trials (RCTs) threaten the validity of their findings. We reviewed the reasons for nonentry of eligible patients into surgical RCTs that would form the basis for future prospective research.

METHODS

A systematic review of the English language literature for studies reporting reasons for nonentry of eligible patients into surgical RCTs and of recommendations made to improve the low recruitment rates.

RESULTS

We reviewed 401 articles, including 94 articles presenting the results of 62 studies: 23 reports of recruitment into real surgical RCTs, 11 surveys of patients regarding hypothetical surgical RCTs, 10 surveys of clinicians and 18 literature reviews. The most frequently reported patient-related reasons for nonentry into surgical RCTs were preference for one form of treatment, dislike of the idea of randomization, and the potential for increased demands. Distrust of clinicians caused by a struggle to understand, explicit refusal of a no-treatment (placebo) arm, and the mere inability to make a decision were frequently reported in studies of real RCTs and patient surveys, but were not emphasized in surveys of clinicians and review articles. Difficulties with informed consent, the complexity of study protocols, and the clinicians' loss of motivation attributable to lack of recognition were the most commonly reported clinician-related reasons.

CONCLUSIONS

There seems to be a discrepancy between real reasons for nonentry of eligible patients into surgical RCTS and those perceived by the clinicians, which require further prospective research. A summary and discussion of main recommendations sighted in the literature is presented.

Potassium supplementation for the management of primary hypertension in adults

BACKGROUND

Epidemiological evidence on the effects of potassium on blood pressure is inconsistent.

OBJECTIVES

To evaluate the effects of potassium supplementation on health outcomes and blood pressure in people with elevated blood pressure.

SEARCH STRATEGY

We searched the Cochrane Library, MEDLINE, EMBASE, Science Citation Index, ISI Proceedings, ClinicalTrials.gov, Current Controlled Trials, CAB abstracts, and reference lists of systematic reviews, meta-analyses and randomised controlled trials (RCTs) included in the review.

SELECTION CRITERIA

Inclusion criteria were: 1) RCTs of a parallel or crossover design comparing oral potassium supplements with placebo, no treatment, or usual care; 2) treatment and follow-up >=8 weeks; 3) participants over 18 years, with raised systolic blood pressure (SBP) >=140 mmHg or diastolic blood pressure (DBP) >=85 mmHg); 4) SBP and DBP reported at end of follow-up. We excluded trials where: participants were pregnant; received antihypertensive medication which changed during the study; or potassium supplementation was combined with other interventions.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed trial quality. Disagreements were resolved by discussion or a third reviewer. Random effects meta-analyses and sensitivity analyses were conducted.

MAIN RESULTS

Six RCT's (n=483), with eight to 16 weeks follow-up, met our inclusion criteria. Meta-analysis of five trials (n=425) with adequate data indicated that potassium supplementation compared to control resulted in a large but statistically non-significant reductions in SBP (mean difference: -11.2, 95% CI: -25.2 to 2.7) and DBP (mean difference: -5.0, 95% CI: -12.5 to 2.4). The substantial heterogeneity between trials was not explained by potassium dose, quality of trials or baseline blood pressure. Excluding one trial in an African population with very high baseline blood pressure resulted in smaller overall reductions in blood pressure (SBP mean difference: -3.9, 95% CI: -8.6 to 0.8; DBP mean difference: -1.5, 95% CI: -6.2 to 3.1). Further sensitivity analysis restricted to two high quality trials (n=138) also found non-significant reductions in blood pressure (SBP mean difference: -7.1, 95% CI: -19.9 to 5.7; DBP mean difference: -5.5, 95% CI: -14.5 to 3.5).

AUTHORS' CONCLUSIONS

This systematic review found no statistically significant effect of potassium supplementation on blood pressure. Because of the small number of participants in the two high quality trials, the short duration of follow-up, and the unexplained heterogeneity between trials, the evidence about the effect of potassium supplementation on blood pressure is not conclusive. Further high quality RCTs of longer duration are required to clarify whether potassium supplementation can reduce blood pressure and improve health outcomes.

Magnesium supplementation for the management of essential hypertension in adults

BACKGROUND

Epidemiological evidence on the effects of magnesium on blood pressure is inconsistent. Metabolic and experimental studies suggest that magnesium may have a role in the regulation of blood pressure.

OBJECTIVES

To evaluate the effects of magnesium supplementation as treatment for primary hypertension in adults.

SEARCH STRATEGY

We searched the Cochrane Library, MEDLINE, EMBASE, Science Citation Index, ISI Proceedings, ClinicalTrials.gov, Current Controlled Trials, CAB abstracts, and reference lists of systematic reviews, meta-analyses and randomised controlled trials (RCTs) included in the review.

SELECTION CRITERIA

Inclusion criteria were: 1) RCTs of a parallel or crossover design comparing oral magnesium supplementation with placebo, no treatment, or usual care; 2) treatment and follow-up >/=8 weeks; 3) participants over 18 years old, with raised systolic blood pressure (SBP) >/=140 mmHg or diastolic blood pressure (DBP) >/=85 mmHg; 4) SBP and DBP reported at end of follow-up. We excluded trials where: participants were pregnant; received antihypertensive medication which changed during the study; or magnesium supplementation was combined with other interventions.

DATA COLLECTION AND ANALYSIS

Two reviewers independently abstracted data and assessed trial quality. Disagreements were resolved by discussion or a third reviewer. Random effects meta-analyses and sensitivity analyses were conducted.

MAIN RESULTS

Twelve RCTs (n=545) with eight to 26 weeks follow-up met our inclusion criteria. The results of the individual trials were heterogeneous. Combining all trials, participants receiving magnesium supplements as compared to control did not significantly reduce SBP (mean difference: -1.3 mmHg, 95% CI: -4.0 to 1.5, I(2)=67%), but did statistically significantly reduce DBP (mean difference: -2.2 mmHg, 95% CI: -3.4 to -0.9, I(2)=47%). Sensitivity analyses excluding poor quality trials yielded similar results. Sub-group analyses and meta-regression indicated that heterogeneity between trials could not be explained by dose of magnesium, baseline blood pressure or the proportion of males among the participants.

AUTHORS' CONCLUSIONS

In view of the poor quality of included trials and the heterogeneity between trials, the evidence in favour of a causal association between magnesium supplementation and blood pressure reduction is weak and is probably due to bias. This is because poor quality studies generally tend to over-estimate the effects of treatment. Larger, longer duration and better quality double-blind placebo controlled trials are needed to assess the effect of magnesium supplementation on blood pressure and cardiovascular outcomes.

Calcium supplementation for the management of primary hypertension in adults

BACKGROUND

Metabolic studies suggest calcium may have a role in the regulation of blood pressure. Some epidemiological studies have reported that people with a higher intake of calcium tend to have lower blood pressure. Previous systematic reviews and meta-analyses have reached conflicting conclusions about whether oral calcium supplementation can reduce blood pressure.

OBJECTIVES

To evaluate the effects of oral calcium supplementation as a treatment for primary hypertension in adults.

SEARCH STRATEGY

We searched the Cochrane Library, MEDLINE, EMBASE, Science Citation Index, ISI Proceedings, ClinicalTrials.gov, Current Controlled Trials, CAB abstracts, and reference lists of systematic reviews, meta-analyses and randomised controlled trials (RCTs) included in the review.

SELECTION CRITERIA

Inclusion criteria were: 1) RCTs comparing oral calcium supplementation with placebo, no treatment, or usual care; 2) treatment and follow-up >/=8 weeks; 3) participants over 18 years old, with raised systolic blood pressure (SBP) >/=140 mmHg or diastolic blood pressure (DBP) >/=85 mmHg; 4) SBP and DBP reported at end of follow-up. We excluded trials where: participants were pregnant; received antihypertensive medication which changed during the study; or calcium supplementation was combined with other interventions.

DATA COLLECTION AND ANALYSIS

Two reviewers independently abstracted data and assessed trial quality. Disagreements were resolved by discussion or a third reviewer. Random effects meta-analyses and sensitivity analyses were conducted.

MAIN RESULTS

We included 13 RCTs (n=485), with between eight and 15 weeks follow-up. The results of the individual trials were heterogeneous. Combining all trials, participants receiving calcium supplementation as compared to control had a statistically significant reduction in SBP (mean difference: -2.5 mmHg, 95% CI: -4.5 to -0.6, I(2 )= 42%), but not DBP (mean difference: -0.8 mmHg, 95% CI: -2.1 to 0.4, I(2) = 48%). Sub-group analyses indicated that heterogeneity between trials could not be explained by dose of calcium or baseline blood pressure. Heterogeneity was reduced when poor quality trials were excluded. The one trial reporting adequate concealment of allocation and the one trial reporting adequate blinding yielded results consistent with the primary meta-analysis.

AUTHORS' CONCLUSIONS

In view of the poor quality of included trials and the heterogeneity between trials, the evidence in favour of causal association between calcium supplementation and blood pressure reduction is weak and is probably due to bias. This is because poor quality studies generally tend to over-estimate the effects of treatment. Larger, longer duration and better quality double-blind placebo controlled trials are needed to assess the effect of calcium supplementation on blood pressure and cardiovascular outcomes.

Considerations in recruiting underscreened women to focus groups on screening for cervical cancer

This article describes recruitment activities and costs from two independently conducted studies that used similar, systematic approaches to recruiting two subgroups of underscreened women, Black women and Mexican women. The studies varied in number of recruiters, venues of recruitment, and region of the country. The ratio of women approached to women who were underscreened was 4:1 for Black women and 10:1 for Mexican women. Hysterectomy was a predominant reason for ineligibility among Black women but not Mexican women. In both studies, personal networks were the most productive method of identifying women. Flyers and organized community venues were least productive. The cost incurred for identifying a woman who was eligible for a focus group was 145 dollars for Black women and 59 dollars for Mexican women. Those planning research or program activities that include recruiting underscreened women either to focus groups or health services could benefit from this information.

When free condoms and spermicide are not enough: barriers and solutions to participant recruitment to community-based trials

While randomised controlled trials remain the accepted 'gold standard' in medical research, participant recruitment is often problematic, particularly with primary care trials or those requiring healthy volunteers. Such difficulties can jeopardise the trial, leading to early abandonment, reduced statistical power or timetable and budget overruns. Substantial changes in recruitment plans may reduce the generalisability of the research. In order to overcome some of the more common recruitment difficulties, it is important that researchers share their recruitment strategy successes and failures. We report our experience of recruiting healthy volunteers to a condom trial, based within primary care and community populations. This was an RCT of the effect that using an additional spermicidal lubricant has on condom failure. We originally aimed to recruit entirely from Family Planning Clinics, but eventually required a wide variety of strategies. Targeted mailings, newspaper coverage and electronic 'posters' were among the most successful we used to bolster clinic recruitment. Concerned at our slow recruitment rates, we conducted a questionnaire survey investigating the reasons for participation and non-participation in the research completed by 101 trial participants, 112 decliners and 90 controls (total 303). The most important reasons given for taking part included 'considering the research to be important' (85%), 'wanting to help the researchers' (70%), 'having time to help' (62%) and 'getting free condoms and lubricant' (56%). The most popular reasons for declining were 'not wanting to use condoms' (38%), 'partner's unwillingness to take part' (29%), 'not wanting to alter usual contraceptive practice' (27%), 'not having time' (21%). Contrary to expectations, embarrassment and fears about confidentiality were relatively unimportant factors in this decision. In conclusion, the key to attaining recruitment targets was the core research team taking an active part, working closely with clinic staff and maintaining tight control of the process. Altruism remains a powerful motivation for participants, supported by incentives and procedural details to minimise personal inconvenience. Even for intimate research topics, these general factors outweigh specific issues.

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.

Mass mailing and telephone contact were effective in recruiting veterans into an antibiotic treatment randomized clinical trial

OBJECTIVE

Achieving enrollment goals of randomized clinical trials (RCT) within budgets depends on the timely recruitment of sufficient numbers of participants. We report a comparison of recruitment methods and yields of previously deployed veterans into a large RCT.

STUDY DESIGN AND SETTING

A retrospective survey concerning recruitment was administered to staff at 28 sites participating in the VA Cooperative Study #475, "Antibiotic Treatment of Gulf War Veterans' Illnesses" (GWVI).

RESULTS

Twenty-one sites reported identifying 31,407 Gulf War Veterans (GWV). Of these, 13.7% were successfully contacted, 3.5% were enrolled, and 1.2% were randomized. Mass mailings and direct telephone calls to GWV identified from a GWV database accounted for 78% of the GWV contacted. The other 22% were contacted by using referrals from medical staff, veterans' groups, media advertisements, and other methods. Data collected prospectively at the Albany Stratton VAMC were similar to data collected retrospectively from other sites.

CONCLUSION

These findings demonstrate that in previously deployed GWV with GWVI, 1.2% could be randomized. Although the use of all recruitment methods combined achieved the study recruitment goal, these data demonstrate that mass mailing and direct telephone contacts were effective recruitment methods.

Advice to reduce dietary salt for prevention of cardiovascular disease

BACKGROUND

Restricting sodium intake in elevated blood pressure over short periods of time reduces blood pressure. Long term effects (on mortality, morbidity or blood pressure) of advice to reduce salt in patients with elevated or normal blood pressure are unclear.

OBJECTIVES

To assess in adults the long term effects (mortality, cardiovascular events, blood pressure, quality of life, weight, urinary sodium excretion, other nutrients and use of anti-hypertensive medications) of advice to restrict dietary sodium using all relevant randomised controlled trials.

SEARCH STRATEGY

The Cochrane Library, MEDLINE, EMBASE, bibliographies of included studies and related systematic reviews were searched for unconfounded randomised trials in healthy adults aiming to reduce sodium intake over at least 6 months. Attempts were made to trace unpublished or missed studies and authors of all included trials were contacted. There were no language restrictions.

SELECTION CRITERIA

Inclusion decisions were independently duplicated and based on the following criteria: 1) randomisation was adequate; 2) there was a usual or control diet group; 3) the intervention aimed to reduce sodium intake; 4) the intervention was not multifactorial; 5) the participants were not children, acutely ill, pregnant or institutionalised; 6) follow-up was at least 26 weeks; 7) data on any of the outcomes of interest were available.

DATA COLLECTION AND ANALYSIS

Decisions on validity and data extraction were made independently by two reviewers, disagreements were resolved by discussion or if necessary by a third reviewer. Random effects meta-analysis, sub-grouping, sensitivity analysis and meta-regression were performed.

MAIN RESULTS

Three trials in normotensives (n=2326), five in untreated hypertensives (n=387) and three in treated hypertensives (n=801) were included, with follow up from six months to seven years. The large, high quality (and therefore most informative) studies used intensive behavioural interventions. Deaths and cardiovascular events were inconsistently defined and reported; only 17 deaths equally distributed between intervention and control groups occurred. Systolic and diastolic blood pressures were reduced at 13 to 60 months in those given low sodium advice as compared with controls (systolic by 1.1 mm Hg, 95% CI 1.8 to 0.4, diastolic by 0.6 mm hg, 95% CI 1.5 to -0.3), as was urinary 24 hour sodium excretion (by 35.5 mmol/ 24 hours, 95% CI 47.2 to 23.9). Degree of reduction in sodium intake and change in blood pressure were not related. People on anti-hypertensive medications were able to stop their medication more often on a reduced sodium diet as compared with controls, while maintaining similar blood pressure control.

REVIEWER'S CONCLUSIONS

Intensive interventions, unsuited to primary care or population prevention programmes, provide only minimal reductions in blood pressure during long-term trials. Further evaluations to assess effects on morbidity and mortality outcomes are needed for populations as a whole and for patients with elevated blood pressure. Evidence from a large and small trial showed that a low sodium diet helps in maintenance of lower blood pressure following withdrawal of antihypertensives. If this is confirmed, with no increase in cardiovascular events, then targeting of comprehensive dietary and behavioural programmes in patients with elevated blood pressure requiring drug treatment would be justified.

Reduced dietary salt for prevention of cardiovascular disease

BACKGROUND

Restricting sodium intake in elevated blood pressure over short periods of time reduces blood pressure. Long term effects (on mortality, morbidity or blood pressure) of advice to reduce salt in patients with elevated or normal blood pressure are unclear.

OBJECTIVES

To assess in adults the long term effects (mortality, cardiovascular events, blood pressure, quality of life, weight, urinary sodium excretion, other nutrients and use of anti-hypertensive medications) of advice to restrict dietary sodium using all relevant randomised controlled trials.

SEARCH STRATEGY

The Cochrane Library, MEDLINE, EMBASE, bibliographies of included studies and related systematic reviews were searched for unconfounded randomised trials in healthy adults aiming to reduce sodium intake over at least 6 months. Attempts were made to trace unpublished or missed studies and authors of all included trials were contacted. There were no language restrictions.

SELECTION CRITERIA

Inclusion decisions were independently duplicated and based on the following criteria: 1) randomisation was adequate; 2) there was a usual or control diet group; 3) the intervention aimed to reduce sodium intake; 4) the intervention was not multifactorial; 5) the participants were not children, acutely ill, pregnant or institutionalised; 6) follow-up was at least 26 weeks; 7) data on any of the outcomes of interest were available.

DATA COLLECTION AND ANALYSIS

Decisions on validity and data extraction were made independently by two reviewers, disagreements were resolved by discussion or if necessary by a third reviewer. Random effects meta-analysis, sub-grouping, sensitivity analysis and meta-regression were performed.

MAIN RESULTS

Three trials in normotensives (n=2326), five in untreated hypertensives (n=387) and three in treated hypertensives (n=801) were included, with follow up from six months to seven years. The large, high quality (and therefore most informative) studies used intensive behavioural interventions. Deaths and cardiovascular events were inconsistently defined and reported; only 17 deaths equally distributed between intervention and control groups occurred. Systolic and diastolic blood pressures were reduced at 13 to 60 months in those given low sodium advice as compared with controls (systolic by 1.1 mm Hg, 95% CI 1.8 to 0.4, diastolic by 0.6 mm hg, 95% CI 1.5 to -0.3), as was urinary 24 hour sodium excretion (by 35.5 mmol/ 24 hours, 95% CI 47.2 to 23.9). Degree of reduction in sodium intake and change in blood pressure were not related. People on anti-hypertensive medications were able to stop their medication more often on a reduced sodium diet as compared with controls, while maintaining similar blood pressure control.

REVIEWER'S CONCLUSIONS

Intensive interventions, unsuited to primary care or population prevention programmes, provide only minimal reductions in blood pressure during long-term trials. Further evaluations to assess effects on morbidity and mortality outcomes are needed for populations as a whole and for patients with elevated blood pressure. Evidence from a large and small trial showed that a low sodium diet helps in maintenance of lower blood pressure following withdrawal of antihypertensives. If this is confirmed, with no increase in cardiovascular events, then targeting of comprehensive dietary and behavioural programmes in patients with elevated blood pressure requiring drug treatment would be justified.

The Diabetes Prevention Program: recruitment methods and results

The Diabetes Prevention Program (DPP) is a multicenter randomized controlled trial designed to test whether diet and exercise or medication can prevent or delay the onset of type 2 diabetes in persons with impaired glucose tolerance, who are at increased risk of the disease. This paper describes DPP recruitment methods, strategies, performance, and costs. The DPP developed an organizational structure for comprehensive management and continuous monitoring of recruitment efforts. The DPP utilized a variety of recruitment strategies, alone or in combination, and a stepped informed consent procedure leading to randomization. Studywide and clinic-specific recruitment data were monitored, analyzed, and used to modify recruitment approaches. DPP recruitment was completed slightly ahead of schedule, meeting goals for the proportion of women enrolled and nearly meeting goals for the proportion of racial/ethnic minorities. Clinics varied widely in the recruitment strategies they used, and these strategies also varied by participant age, gender, and race/ethnicity. Staff time devoted to recruitment averaged 86.8 hours per week per clinic, with the majority of effort by staff specifically assigned to recruitment. The number of staff hours required to recruit a participant varied by recruitment strategy. Recruitment cost (excluding staff cost) was about 1075 US dollars per randomized participant. The DPP experience offers lessons for those planning similar efforts: (1) a method for ongoing assessment and revision of recruitment strategies is valuable; (2) a range of recruitment strategies may be useful; (3) the most effective methods for recruiting potential subjects may vary according to the gender, age, and race/ethnicity of those individuals; (4) recruitment strategies vary in the amount of staff time required to randomize a participant; and (5) a stepped screening may make it easier to identify and recruit volunteers who understand the requirements of the study.

Church rosters: is this a viable mechanism for effectively recruiting African Americans for a community-based survey?

OBJECTIVES

The purpose of this report is to describe the process, results, and implications in the phone recruitment of African Americans through church rosters for a survey of diet-and blood pressure-related awareness and hypertension prevalence.

DESIGN

The survey was conducted using a non-probability sample of churches and a random selection of participants from church rosters. Recruitment strategies included frequent contact with pastors and church representatives, presentations, standard and tailored recruitment approaches, and bi-annual progress reports. Church representatives provided the rosters and assisted in arranging interviews, which were conducted at church or the participants' homes.

RESULTS

Of 742 randomly selected, 315 (42.4%) were ineligible because of an unavailable or unreachable number, a move, discontinued church membership, death, or other reasons. Of the 344 eligible, 45.8% participated, 30.2% refused, 4.4% agreed to participate but did not, and 19.6% were incompletes (called less than three times before recruitment was terminated). Among participants, 70.4% were female, 58.2% had completed college, and the age range was 19-91 years. The survey's sample size goal of 196 was met.

CONCLUSIONS

In this study population, over 45% who were eligible participated. Rapport established with church representatives and congregations was critical to the sampling process. Using church rosters can be a low-cost, effective recruitment tool. However, key factors to consider when recruiting African Americans in this manner include: trust, study eligibility criteria, roster accuracy, and time, and generalizability.

Participant recruitment in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)

The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) is a practice-based, randomized, multicenter clinical trial in 42,419 high-risk hypertensive patients aged 55 years and older; 10,356 of these patients are also in a lipid-lowering trial component. The purpose of the antihypertensive component is to determine whether the occurrence of fatal coronary heart disease and/or nonfatal myocardial infarction differs between patients randomized to diuretic (chlorthalidone) and those randomized to either calcium antagonist (amlodipine), angiotensin-converting enzyme inhibitor (lisinopril), or alpha-adrenergic blocker (doxazosin) therapy. (The doxazosin arm has been discontinued.) The purpose of the lipid-lowering component is to determine whether lowering low-density lipoprotein cholesterol with a 3-hydroxymethyl-glutaryl coenzyme A reductase inhibitor (pravastatin) in moderately hypercholesterolemic patients will reduce all-cause mortality compared to a control group receiving "usual care." ALLHAT recruited patients from a variety of practice settings from February 1994 through January 1998. Sites were paid for randomizations and are paid for completed follow-up visits and documented study events. Communication and monitoring were facilitated by nine regional coordinator teams. It was recognized from the outset that patient recruitment would be a very large task because of the number of participants (> 40,000) needed, the ambitious nature of the goal for recruitment of African-Americans (> 55%), and the knowledge that many investigators had limited experience recruiting participants for clinical trials. Multiple adjustments in the initial ALLHAT overall recruitment plan facilitated achievement of sample size goals for both components of the trial. The experience obtained from this large trial should be valuable for the planning and implementation of successful recruitment in future trials.

Recruitment strategies in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial: the first six years

The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial has a total enrollment goal of almost 150,000 participants. These participants are being recruited at ten screening centers across the United States. All screening centers tested recruitment methodologies during a 1-year pilot phase. The main phase of recruitment was planned to take place over a 3-year period. The majority of participants are being recruited during the main phase of the study. Each of the screening centers tailors recruitment to its individual catchment area. Recruitment strategies in the PLCO trial are described. As the trial began, several protocol changes were made to help to increase enrollment. The National Cancer Institute (NCI) initiated recruitment efforts at the national level. The individual screening centers describe some of the specific recruitment experiences encountered. As the study progressed, the NCI implemented special initiatives to increase the enrollment of minority participants.

Challenges faced in recruiting patients from primary care practices into a physical activity intervention trial. Activity Counseling Trial Research Group

BACKGROUND

Special challenges are encountered when clinical trial recruitment targets a physician practice-based population, as opposed to recruiting from the community. Since most published information about recruitment has focused on the latter group, summation of successful primary-care-based recruitment strategies could prove useful for future trials recruiting from this population.

METHODS

The Activity Counseling Trial (ACT) is a multicenter, randomized clinical trial that evaluated approaches to primary care-based interventions to increase physical activity in sedentary adults 35-75 years of age. Fifty-four clinicians from eight practices recruited 874 participants from three U.S. sites. Recruitment challenges that related, in great part, to the primary care setting included: (1) focusing on patients from ACT physician practices who had regularly scheduled or intend-to-schedule appointments within the next year; (2) placing trial staff in the clinical offices for recruitment purposes; and (3) placing trial interventionists in the physicians' offices. Other challenges were related to recruitment of minorities and men.

RESULTS

Patient mailing yielded 43.4% of all randomized participants, followed by office-based questionnaires (32.5%) and direct telephone contact (21.6%). Based on a retrospective cost-effective analysis (indirect costs excluded), the self-administered office-based questionnaire was the least costly strategy for one site ($14/randomized participant), followed by patient mailing at another site ($58). The direct telephone contact method utilized at one site serving primarily a minority population yielded a per randomized participant cost of $80.

CONCLUSIONS

Recruitment of clinical trial participants from practice-based populations requires modification of the strategies used to recruit from the community. Multiple strategies should be employed, followed closely for their respective yields, and adapted as needed.

Recruitment and baseline characteristics of participants in the Dietary Approaches to Stop Hypertension trial. DASH Collaborative Research Group

Dietary Approaches to Stop Hypertension (DASH) was a randomized, multicenter feeding study designed to assess the effects of modifying dietary patterns on blood pressure. Among the most challenging aspects of conducting the DASH trial was the recruitment of participants at the 4 clinical centers. As part of the recruitment drive, 347,500 brochures were mailed, 250,500 coupons were distributed in coupon packs, 114 advertisements were published in newspapers or bulletins, 140 radio and 74 television advertisements were broadcast, and 68 screening events and presentations were conducted. These efforts yielded a total of 459 enrolled participants, ahead of schedule. The most common source of participants was mass mailing of individual brochures (n = 194, 42.3%), followed by word-of-mouth (n = 82, 17.8%), and then other types of mass mailing (n = 44, 9.6%). Recruitment of minority participants followed a similar pattern. Among the 3,192 persons attending the first in-person screening visit, the major reason for nonenrollment was low blood pressure (56%) rather than a diet-related factor. The study population was demographically heterogeneous (49% women, 60% African American, 48% married, and 77% employed full-time). On average, the diet of participants before the DASH feeding study was more similar to the trial control diet than to the combination diet, which reduced blood pressure more effectively. In summary, recruitment of a heterogeneous study population that includes a substantial number of minority participants is a feasible undertaking. However, the effort is considerable and requires a major commitment of resources.

Pre-enrollment diets of Dietary Approaches to Stop Hypertension trial participants. DASH Collaborative Research Group

A large body of evidence suggests that several nutrients are related to blood pressure. Less is known about the eating patterns of special populations, such as those at risk for hypertension, or how demographic factors affect the diets of these populations. This article characterizes the usual diets of participants before they enrolled in the Dietary Approaches to Stop Hypertension (DASH) trial. During screening for DASH, 380 participants completed the National Cancer Institute food frequency questionnaire. Nutrient and food group intake, the Keys score (a measure of a diet's atherogenicity), and the Diet Quality Index were estimated from the food frequency questionnaire. The effects of age, sex, race, baseline weight, and education on these dietary factors were assessed among DASH participants and compared with similar data from the Third National Health and Nutrition Examination Survey and other published reports. Among DASH participants, African-Americans reported lower intakes of dairy products (P < .001), calcium (P < .001), and magnesium (P < .05) than did whites. Older women reported greater intakes of calcium, magnesium, and potassium (all P < .05) and less fat (P < .05) than did younger women. Older men consumed fewer servings of fruits (P < .03), less vitamin C (P < .05), and had a higher Keys score (P < .05) than did younger men. Heavier (body mass index > or = 25) participants reported lower intakes of protein and potassium, but higher fat and energy intakes (all P < .05). Taken together, these data show that younger, overweight African-American women have the least healthful diets, because they consume more atherogenic foods and fewer of the nutrients related to decreased blood pressure. Overall Diet Quality Index scores did not differ between African-American and white participants. Despite differences in dietary assessment methods between the population samples of DASH and the Third National Health and Nutrition Examination Survey, within each population sample patterns of micronutrient intake were similar between African-American and white participants.

Challenges in palliative care research; recruitment, attrition and compliance: experience from a randomized controlled trial

Randomized controlled trials (RCTs) in palliative cancer care often experience methodological problems. In this paper we discuss issues of major concern, including recruitment, patient attrition and compliance, arising from an RCT that compared comprehensive palliative care to conventional care. The main criteria for trial entry were incurable malignant disease and a survival expectancy of between 2 and 9 months. Patients' health-related quality of life (HRQL), self-assessed by multi-item questionnaires, was a defined endpoint. The planned number of patients was successfully recruited, although the patients were referred late in the course of their disease so that follow-up tended to be short. Compliance in completing HRQL questionnaires was good up to 1 month before the patient's death; but in the final weeks it was found to drop substantially. Based on our experience, recommendations are given for those planning similar research. Procedures for improving patient recruitment are suggested, stressing the need for local data management, repeated information to referral sources, extensive screening for potentially eligible patients and simple referral routines. Precise inclusion criteria, including prognostic factors other than physicians' estimates of life expectancy, should be used to ensure a sufficient follow-up period. For HRQL assessment, multi-item questionnaires can achieve excellent compliance up to 1 month before patients' death, but in order to evaluate the very final weeks of life we recommend the use of simpler methods.

Mass mailing and staff experience in a total recruitment program for a clinical trial: the SHEP experience. Systolic Hypertension in the Elderly Program. Cooperative Research Group

The Systolic Hypertension in the Elderly Program (SHEP) staff contacted 447,921 screenees, of whom 11,919 (2.7%) were originally eligible and 4,736 (1.1%) maintained eligibility and were randomized. The total number of participants enrolled at the 16 clinical centers ranged from 133 to 559. The low yield of screenees to randomizations resulted from the study design, not from low levels of agreement to participate, and required the employment of a variety of recruitment strategies in a prudent overall plan. SHEP was one of the first clinical trials to use mass mailing as a primary strategy of recruitment. The study used mailing lists from seven generic sources. More than 3.4 million letters of invitation were mailed; they yielded an overall response rate of 4.3%. Motor vehicle and voter registration lists provided the greatest numbers of names. Mailings to members of health maintenance organizations (HMOs) and registrants of the Health Care Finance Administration (HCFA) provided the greatest response rates. Considerable variability in response rates existed among clinical centers using generically similar mailing lists. Generally, the number of hours spent on recruitment showed a positive, but not statistically significant, association with randomization yields. The recruitment yield was statistically significantly higher in clinics with experienced recruitment coordinators than in clinics with inexperienced ones (p = 0.0008). From these findings we conclude that mass mailing is an important strategy in an overall recruitment program, that the involvement of experienced recruitment staff is important, and that although the total time spent by staff on recruitment may also improve results, it matters less than the staff's level of recruiting experience.

Recruitment strategies in the women's health trial: feasibility study in minority populations. WHT:FSMP Investigators Group. Women's Health Trial:Feasibility Study in Minority Populations

The Women's Health Trial:Feasibility Study in Minority Populations (WHT:FSMP) examined the feasibility of recruiting postmenopausal women from a broad range of racial and socioeconomic backgrounds into a primary prevention trial requiring marked reductions in dietary fat. Postmenopausal women aged 50-79 yr who had no history of cardiovascular disease or cancer and who consumed 36% or more total energy from fat qualified to participate. We randomized the women into dietary intervention (60%) or control (40%) groups; we aimed to randomize 750 women in 18 months in each of the three clinical centers. All centers achieved goals for randomization based on ethnicity, and two centers exceeded overall recruitment goals. The greatest source of randomized participants was mass mailing, followed by items in the media, referrals, and community outreach. Recruitment yields were generally similar for the ethnic groups but lower for less-educated participants. The experience of WHT:FSMP indicates that postmenopausal women from the African-American, Hispanic, and non-Hispanic white communities can be recruited into dietary intervention studies for the prevention of disease.

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.

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.

Baseline characteristics of participants in phase II of the Trials of Hypertension Prevention (TOHP II). Trials of Hypertension Prevention (TOHP) Collaborative Research Group

Phase II of the Trials of Hypertension Prevention (TOHP II) is a multicenter, controlled clinical trial designed to test whether weight loss, a reduced sodium intake, or a combination of weight loss and a reduced sodium intake will lower blood pressure (BP) and prevent the occurrence of hypertension. The study population consists of middle-aged, moderately overweight individuals with a diastolic BP between 83 and 89 mm Hg. Of the 2382 randomized participants, 816 (34%) are female and 494 (21%) are from a racial or ethnic minority background. At baseline, mean dietary intakes of sodium, based on measurements of 24-hour urinary excretion, were 199 mmol/d in men and 154 mmol/d in women. The average body mass index was 30.9 kg/m2. Across the four randomized groups, there was no substantial imbalance in the distribution of baseline variables; however, the mean age in the four groups was slightly but significantly different (range: 43.2 to 44.2 years, P = 0.02). A comparison of baseline characteristics of TOHP II participants with those of participants in three other primary prevention trials reveals a high level of mean dietary sodium intake in each study. Data reported in this article indicate that any subsequent differences in BP among the randomized groups are unlikely to result from maldistribution of known confounding variables at baseline. Finally, because of the high prevalence of overweight and excessive sodium intake in the United States, results from TOHP II should be broadly applicable to the general population.