Background
Hispanic women are projected to have the highest birthrates for any minority group in the United States by the year 2009[
1] and by 2030, are expected to be the largest minority group in the United States[
2]. Despite the increase in population growth, substantial health disparities exist between Hispanic and non-Hispanic whites. Hispanic women have two to four times the risk of developing gestational diabetes mellitus (GDM) compared with non-Hispanic white women[
3]. Important disparities also exist between the heterogeneous Latina subgroups. Hispanic women of Puerto Rican descent have an elevated risk of low birth weight and poor neonatal health outcomes as compared to other Hispanic groups [
4‐
7]. Despite the increasing size of this population and the observed health disparities, relatively few health prevention studies on maternal and fetal disorders have included Hispanic women.
In 1994, the National Institutes of Health required recruitment plans for the inclusion of women and minorities in clinical research or scientific justification for their exclusion[
8,
9]. However, studies have found that conducting longitudinal studies involving Hispanics is challenging[
10]. Hispanics in the United States are more likely than non-Hispanic whites to have low income and educational levels, factors which have been associated with nonparticipation in health research[
11]. Lower levels of literacy and health literacy among Hispanics and a higher proportion of Spanish-only speaking households in a community have also been associated with reduced rates of participation[
12]. In addition to such individual level factors, system-wide reasons cited for low participation among Hispanics include ineffective communication and informed consent procedures by research staff; lack of, or poor quality, incentives; cumbersome protocols; and failure to provide accessible sites for participation[
13].
The majority of prior research has focused on traditional methods of community-based recruitment such as use of public databases, mass media advertising, or community health screening[
13]. However, special challenges are encountered when recruitment targets a physician practice-based population. To our knowledge, no published studies have examined recruitment strategies for Hispanic pregnant women in a practice-based setting. Cost-effective culturally appropriate recruitment strategies that increase participation among Hispanic prenatal care patients are needed.
Proyecto Buena Salud is an ongoing prospective cohort study among pregnant women of Puerto Rican and Dominican descent with the major goal of evaluating modifiable determinants of GDM. This report describes the strategies that were developed to recruit Hispanic prenatal care patients from this practice-based setting, rates of recruitment over the first time, and characteristics of the study population. Recruitment into the study began in January 2006 and the results from the first 32 months are presented. This information should be valuable in planning studies and developing strategies to enhance recruitment in Hispanic pregnant populations.
Discussion
Strategies used to recruit pregnant Hispanic women of varying educational and socioeconomic status into a longitudinal cohort study, Proyecto Buena Salud, were described. Findings add to the sparse collection of strategies to include Hispanic women in research on areas of maternal/fetal health disparities. Several techniques were implemented to promote recruitment from this clinical setting. These included 1) use of bilingual recruiters, 2) a flexible recruitment process, 3) training recruiters to be culturally sensitive, 4) use of culturally tailored materials, 5) prescreening of participants, 6) compensating participants, 7) seeking cooperation from the clinic staff, and 8) continuously monitoring recruitment goals. Like other investigators,[
13,
23] we utilized multiple different but complementary strategies. In addition, pregnancy is a finite time interval during which women may be more motivated to learn about the impact of their behaviors on their own health as well as that of their future offspring[
23].
The overall recruitment goal of Proyecto Buena Salud was to enroll approximately 39 to 40 women per month, for a total of 1269 pregnant Hispanic women over the first 32 months of the study. Our observed recruitment rates were lower at 27 women per month, for a total of 851 women over the first 32 months of the study. The inability to meet projected recruitment goals was due, in part, to higher than anticipated refusal rates which were 48% of eligible women as opposed to a projected refusal rate of 6%. Prior data on participation rates in pregnancy cohorts is sparse. However, Savitz et al. reported recruiting 57% of eligible pregnant women into the Pregnancy, Infection, and Nutrition (PIN) Study[
24]. We observed slightly lower, but comparable, recruitment rates of 52.4% of eligible women. Although similar in design to Proyecto Buena Salud, the PIN study was conducted among predominantly non-Hispanic white and African-American women and also required a blood sample.
A recruitment challenge unique to clinical settings is cancelled appointments. Among the potential participants that were not approached in the clinic, 55.0% did not show for their scheduled prenatal care appointment or had rescheduled. The fact that these appointments were not study-related suggests that the traditional approach of asking potential participants to make separate (non medical) trips to the clinic would not be feasible for this population. Our study population was predominantly young and unmarried. This is consistent with prior studies which suggest that approximately 40% of Hispanic young girls, especially in low income families, drop out of school by eighth grade, are frequently in partnered relationships, and begin childbearing early[
25]. Low attendance to prenatal visits may therefore be due to personal and child sickness, domestic tasks, unanticipated employment opportunities, and partner restrictions.
It is also possible that the projected recruitment goals of Proyecto Buena Salud were overly ambitious. A recent review of participation rates in epidemiologic surveys,[
20] found that participation rates have been declining during the past 30 years with even steeper declines in recent years. For example, national epidemiologic surveys conducted among the general population such as the 2005 Behavioral Risk Factor Surveillance Survey and Multi-Ethnic Study of Atherosclerosis, initiated in 2000, observed recruitment rates of 51.1% and 59.8%, respectively[
20].
Our strategies to recruit Hispanic pregnant participants had several strengths. The clinical staff understanding of the study design and sense of involvement helped maintain the integrity of the research effort. The use of dedicated research staff from similar cultural backgrounds who were trained to be culturally sensitive established the legitimacy of the study and allayed potential fear about the use of information collected. Prior research has shown that the race, ethnicity, and sex of a recruiter can affect a respondent's level of cooperation[
12]. The use of bilingual recruiters as well as Spanish versions of study materials helped to address linguistic isolation.
By focusing on patients from physician practices who had regularly scheduled prenatal care visits, research demands on participants' time, effort, and travel were minimized. In addition, by collecting selected data from the medical records after delivery, participant burden was reduced. The option to complete the enrollment process in one of multiple ways, by telephone or at a subsequent prenatal care visit, was also viewed as removing critical barriers to enrollment.
It has been suggested that monetary incentives may have a greater impact on the decisions of minority, low education, and low income individuals to participate in research studies. However, other research suggests that monetary incentives encourage participation among respondents with higher education and income who have a greater demand to be compensated for their time[
20]. Our study provided women with a combination of gifts for the baby as well as retail gift certificates; recruiters indicated that this was a critical factor in women's decision to participate.
Our strategies to recruit participants had several limitations. This study found, as have others,[
24] that ensuring that each eligible patient was approached by the recruiter was difficult given staffing constraints and the competing, higher priority need for the medical exam. Recruiters often missed potential participants because they were busy with other participants. This is due, in part, to the clustered scheduling of new prenatal care patients at certain times of the day. In contrast, increasing the number of recruiters led to overstaffing for the remainder of the day. Having regular clinic staff perform recruiting was considered, but ruled out, because the protocol was too complex. In addition, the logistical challenges that occur in a busy clinic pose challenges to clinic staff that are already overburdened. At times, over the course of recruitment, clinic staff considered the presence of recruiters an intrusion which may have also impacted recruitment rates in unmeasurable ways.
Women who were located in the clinic and approached for recruitment may differ in substantive ways from women who were not located. Due to HIPAA privacy regulations, information could not be collected on women who refused to participate or were not eligible or missed. However, comparisons between our sample and Hispanic women from the greater Springfield/Massachusetts area, the source population from which this cohort arose, were conducted. While mail surveys of women after delivery[
26] have found that women who choose to participate in health research studies are healthier overall than those who choose not to participate, cohort studies of pregnant women have not found this to be true[
24]. Similarly, this study found no substantial differences in the socio-demographics and risk profiles between enrolled women and women in the greater area indicating that the current sample is largely representative. However, it is important to note that findings based on the contacted population may not be generalizable to this larger population.
Lastly, a variety of recruitment strategies were used which likely had a synergistic impact on recruitment. Due to their implementation at overlapping times, it cannot be determined to what degree each recruitment technique would succeed individually. Due to the prospective cohort study design used in the current study, it was not possible to determine whether this intensive recruitment strategy would be more effective than a less intensive strategy. A randomized trial would be required to test the impact of these recruitment strategies on recruitment rates. In addition, qualitative research exploring why some strategies were effective, while other strategies were less effective, would also informative.
Competing interests
The authors declare that they have no competing interests.
Authors' contributions
LCT conceived of the study, and participated in its design and coordination and drafted the manuscript. RF and GM participated in the design and coordination of the study. RF and VH performed the statistical analysis. All authors read and approved the final manuscript.