"Rescue" of Nonparticipants in Colorectal Cancer Screening: A Randomized Controlled Trial of Three Noninvasive Test Options.

Few studies have directly targeted nonparticipants in colorectal cancer screening to identify effective engagement strategies. We undertook a randomized controlled trial that targeted nonparticipants in a previous trial of average-risk subjects which compared participation rates for mailed invitations offering a fecal test, a blood test or a choice of either. Nonparticipants (n = 899) were randomized to be offered a kit containing a fecal immunochemical test (FIT), directions on how to arrange a blood DNA test, or the option of doing either. Screening participation was assessed 12 weeks after the offer. To assess the cognitive and attitudinal variables related to participation and invitee choice, invitees were surveyed after 12 weeks, and associations were investigated using multinomial logistic regression. Participation rates were similar between groups (P = 0.88): 12.0% for FIT (35/292), 13.3% for the blood test (39/293), and 13.4% for choice (39/290). Within the choice group, participation was significantly higher with FIT (9.7%, 28/290) compared with the blood test (3.8%, 11/290, P = 0.005). The only variable significantly associated with participation was socioeconomic status when offered FIT, and age when offered choice but there was none when offered the blood test. Survey respondents indicated that convenience, time-saving, comfort, and familiarity were major influences on participation. There was no clear advantage between a fecal test, blood test, or choice of test although, when given a choice, the fecal test was preferred. Differences in variables associated with participation according to invitation strategy warrant consideration when deciding upon an invitation strategy for screening nonparticipants. PREVENTION RELEVANCE: This trial of screening for those at average risk for colorectal cancer targeted past fecal-test nonparticipants and compared participation rates for mailed invitations offering a fecal test, blood test, or choice of either. Although there was no clear advantage between strategies, factors associated with participation differed between each strategy.

Characteristics Associated With Consent and Reasons for Declining in a Randomized Trial in Pregnancy.

OBJECTIVE: To evaluate the maternal characteristics associated with consent to a randomized trial of labor induction in pregnancy. METHODS: This is a secondary analysis of low-risk nulliparous women randomized to induction of labor at 39 weeks or expectant management. During the trial, the Data and Safety Monitoring Committee requested additional fields on the screening log, which already included race and ethnicity: maternal age, type of insurance, and the reason for declining consent if declined. RESULTS: From August 2016 (start of additional data collection) to August 2017, 1,965 (28%) of the 7,112 eligible women consented to the trial. Consent was more likely for Black women (41%, adjusted odds ratio [aOR] 1.47, 95% CI 1.24-1.74), and less likely for Asian women (15%, aOR 0.64, 95% CI 0.48-0.84), compared with White women (24%). Women without private insurance were more likely to consent (38%, aOR 1.55, 95% CI 1.34-1.79), compared with those with private insurance (22%). Younger women were also more likely to consent. Among eligible women who declined participation and provided a reason (68%), preference to be expectantly managed (85%) was most common, a response more common in Asian women (aOR 1.75, 95% CI 1.31-2.33) and less common in women without private insurance (aOR 0.60, 95% CI 0.51-0.70). Not wanting to participate in research was more common in Asian women (aOR 2.41, 95% CI 1.44-4.03). Declining consent because family or friends objected was more common in Asian women (aOR 2.51, 95% CI 1.27-4.95) and women without private insurance (aOR 1.68, 95% CI 1.10-2.59). CONCLUSION: Frequency of consent and reasons for declining consent were associated with age, type of insurance, and race and ethnicity. These findings should be considered when developing recruitment strategies that promote diverse participant representation. CLINICAL TRIAL REGISTRATION: ClinialTrials.gov, NCT01990612.

Cost and efficacy comparison of prenatal recall and reflex DNA screening for trisomy 21, 18 and 13.

OBJECTIVE: To compare costs and efficacy of reflex and recall prenatal DNA screening for trisomy 21, 18 and 13 (affected pregnancies). In both methods women have Combined test markers measured. With recall screening, women with a high Combined test risk are recalled for counselling and offered a DNA blood test or invasive diagnostic testing. With reflex screening, a DNA analysis is automatically performed on plasma collected when blood was collected for measurement of the Combined test markers. METHODS: Published data were used to estimate, for each method, using various unit costs and risk cut-offs, the cost per woman screened, cost per affected pregnancy diagnosed, and for a given number of women screened, numbers of affected pregnancies diagnosed, unaffected pregnancies with positive results, and women with unaffected pregnancies having invasive diagnostic testing. RESULTS: Cost per woman screened is lower with reflex v recall screening: £37 v £38, and £11,043 v £11,178 per affected pregnancy diagnosed (DNA £250, Combined test markers risk cut-off 1 in 150). Reflex screening results in similar numbers of affected pregnancies diagnosed, with 100-fold fewer false-positives and 20-fold fewer women with unaffected pregnancies having invasive diagnostic testing. CONCLUSIONS: Reflex DNA screening is less expensive, more cost-effective, and safer than recall screening.

[Parents avoiding child vaccination in the neonatal period - an analysis of attitudes].

OBJECTIVE: Parents' avoidance of vaccination is a growing phenomenon and leads to the deterioration of the epidemiological situation regarding diseases included in active prevention programs. The aim of the study was to analyze the attitudes of parents who avoid vaccination in newborns. PATIENTS AND METHODS: Material and methods: The study included parents who refused to perform vaccination in theirnewborn. A survey analyzing the attitudes of parents avoiding vaccination in newborns was performed in a tertiary referral hospital in the years 2015-2017. We gathered information concerning their demographic data, comprising the reasons for their decision, information sources and the implementation of vaccination in a child after six months.. RESULTS: Results: We observed an increase in the number of parents avoiding vaccination in the years 2015-2017 (1.58%, 2.54%, 2.83% respectively). The parents were mature (age 31.5-34.5 years), usually with university education (93%). 63% had more than one child. In large families, 67% of the parents had vaccinated their older children. The lack of honest medical information from the personnel, negative opinions from the Internet and other parents were the reasons for avoiding vaccination. CONCLUSION: Conclusions: The insufficient activity of the medical personnel and the strong influence of anti-vaxxers' opinions, which is easily accessible on social media, are the reasons for the nonoptimal implementation of the vaccination program. It is necessary to spread honest knowledge about the epidemiological threats concerning vaccine-preventable diseases and develop a skillful way of distributing it through all the possible ways of communication.

Predictors of activity involvement in dementia care homes: a cross-sectional study.

BACKGROUND: Despite the finding that involvement in activities is one of the most important needs of residents with dementia living in care homes, care facilities struggle to fulfill this need. Over the years, various factors are suggested which may contribute to or disable activity provision in dementia care homes. These include limited financial resources, task oriented staff and disease-related characteristics of residents. This study aims to further clarify which of these factors predict higher activity involvement. METHODS: Data were derived from the second measurement (2011) of the Living Arrangements for people with Dementia study. One thousand two hundred eighteen people residing in 139 dementia care homes were involved. Forty predictors of higher involvement were studied. Multilevel backward regression analyses were performed. RESULTS: The most important predictors of higher involvement were: absence of agitation, less ADL dependency, and a higher cognitive status of the residents, higher staff educational level, lower experienced job demands by care staff and a smaller number of residents living in the dementia care wards of a facility. More social supervisor support as perceived by staff was found to predict less activity involvement. CONCLUSIONS: To increase the activity involvement of care home residents with dementia it seems vital to: 1) reduce staff's experienced job demands; 2) elevate their overall educational level; 3) train staff to provide suitable activities, taking account of the behavior and preserved capabilities of residents; and 4) foster transition towards small-scale care. In order to achieve these aims, care organizations might need to evaluate the use of their financial means.

Pre-Survey Text Messages (SMS) Improve Participation Rate in an Australian Mobile Telephone Survey: An Experimental Study.

Mobile telephone numbers are increasingly being included in household surveys samples. As approach letters cannot be sent because many do not have address details, alternatives approaches have been considered. This study assesses the effectiveness of sending a short message service (SMS) to a random sample of mobile telephone numbers to increase response rates. A simple random sample of 9000 Australian mobile telephone numbers: 4500 were randomly assigned to be sent a pre-notification SMS, and the remaining 4500 did not have a SMS sent. Adults aged 18 years and over, and currently in paid employment, were eligible to participate. American Association for Public Opinion Research formulas were used to calculated response cooperation and refusal rates. Response and cooperation rate were higher for the SMS groups (12.4% and 28.6% respectively) than the group with no SMS (7.7% and 16.0%). Refusal rates were lower for the SMS group (27.3%) than the group with no SMS (35.9%). When asked, 85.8% of the pre-notification group indicated they remembered receiving a SMS about the study. Sending a pre-notification SMS is effective in improving participation in population-based surveys. Response rates were increased by 60% and cooperation rates by 79%.

Why parents refuse newborn hearing screening and default on follow-up rescreening--a South African perspective.

OBJECTIVES: This study describes screen refusal and follow-up default characteristics together with caregiver reasons for screen refusal and follow-up default in two South African universal newborn hearing screening programs. METHODS: A retrospective record review of universal newborn hearing screening conducted at two hospitals (Hospital A n = 954 infants; Hospital B n = 2135) over a 31-33 month period. Otoacoustic emission screening was conducted with rescreen recommended within six weeks for a uni- or bilateral refer. Program efficacy was described according to coverage, referral and follow-up rates. A prospective telephonic interview with caregivers who declined the initial screen (n = 25) and who defaulted on follow-up (n = 25) constituted the next study component. Caregivers were randomly selected from the screening programs for a survey related to reasons for newborn hearing screening refusal and follow-up default. RESULTS: Screening coverage (89.3% Hospital A; 57.4% Hospital B), initial referral rates (11.6% Hospital A; 21.2% Hospital B) and follow-up return rates (56.1% Hospital A; 35.8% Hospital B) differed significantly between hospitals and were below benchmarks. The most frequent reasons for screen refusal were related to costs (72%), caregiver knowledge of newborn hearing screening (64%) and health care professional knowledge and team collaboration (16%). Almost all caregivers (96%) indicated that if costs had been included in the birthing package or covered by medical insurance they would have agreed to newborn hearing screening. Reasons for follow-up default were most commonly related to caregiver knowledge of newborn hearing screening (32%) and costs (28%). One in four caregivers (24%) defaulted on follow-up because they forgot to bring their infant for a rescreen. Only half of caregivers (48%) who defaulted on follow-up reported being aware of initial screen results while 60% reported being aware of the recommended follow-up rescreen. CONCLUSION: Caregivers most commonly refused screening due to associated costs and mostly defaulted on follow-up due to an apparent lack of knowledge regarding initial screen outcome and recommendations made for follow-up. Including NHS as a mandated birthing service is essential if coverage is to be increased, while reducing follow-up defaults requires proactive reminders and improved communication with caregivers.

Is participation contagious? Evidence from a household vector control campaign in urban Peru.

OBJECTIVES: High rates of household participation are critical to the success of door-to-door vector control campaigns. We used the Health Belief Model to assess determinants of participation, including neighbour participation as a cue to action, in a Chagas disease vector control campaign in Peru. METHODS: We evaluated clustering of participation among neighbours; estimated participation as a function of household infestation status, neighbourhood type and number of participating neighbours; and described the reported reasons for refusal to participate in a district of 2911 households. RESULTS: We observed significant clustering of participation along city blocks (p<0.0001). Participation was significantly higher for households in new versus established neighbourhoods, for infested households, and for households with more participating neighbours. The effect of neighbour participation was greater in new neighbourhoods. CONCLUSIONS: Results support a 'contagion' model of participation, highlighting the possibility that one or two participating households can tip a block towards full participation. Future campaigns can leverage these findings by making participation more visible, by addressing stigma associated with spraying, and by employing group incentives to spray.

Prevention of childhood obesity: recruiting strategies via local paediatricians and study protocol for a telephone-based counselling programme.

AIM: Prevention research has to elucidate how families with overweight children can be convinced to participate in obesity intervention trials. Here we describe the detailed recruitment process for a telephone-based obesity prevention programme for families with overweight children and present participation rates, the study design and a socio-demographic description of participating families. METHODS: Overweight (BMI > 90th percentile) children and adolescents 4-17 years of age were screened via the German paediatrician network CrescNet. The prevention programme (multiple computer aided telephone counselling interviews) was suggested to eligible families via local paediatricians. Participating families were compared anthropometrically and socio-demographically to the entire screening population and to micro-census data, a representative national survey. RESULTS: The screening process assessed 4005 candidates for eligibility. Paediatricians reported having suggested programme participation to 3387 candidates (referred to as 100%). 427 candidates (12.6%) returned a written consent for programme participation. 303 candidates (9.0%) started the intervention. The study population (n = 303) included more obese (45.6% vs. 33.2%; p < 0.001) and fewer overweight participants (40.4% vs. 55.2%; p < 0.001) than the entire screening population. Compared to the micro-census, families with adolescents (8.2% vs. 16.9%; p < 0.001) and single parents (16.0% vs. 23.3%; p < 0.005) were underrepresented in the study population, whereas families living in rural areas were overrepresented (58.7% vs. 50.2%; p < 0.005). CONCLUSIONS: Although 84.6% of the paediatricians forwarded the suggestion for programme participation to eligible families, participation rates for this low-threshold; telephone-based obesity intervention remained very low. "Hard-to-engage groups" for effective obesity prevention seem to include single parents, as well as parents of adolescents.

Demographic and health factors associated with enrollment in posttrial studies: the Women's Health Initiative Hormone Therapy Trials.

BACKGROUND: After clinical trials end, continued follow-up of the assembled cohort often is desirable for additional research. Factors influencing participants' decisions to consent to additional follow-up and how these shape posttrial cohorts have not been broadly studied. PURPOSE: We examined how two re-enrollment campaigns and the passage of time altered features of the posttrial cohorts compared with the original Women's Health Initiative (WHI) Hormone Therapy clinical trials. METHODS: We examined associations that markers of sociodemography, health, lifestyle, and on-trial experiences had with re-enrollment and contrasted the characteristics of successive posttrial cohorts with those of the original enrollees. RESULTS: The posttrial enrollment campaigns re-enrolled 81.1% and 82.5% of available women, respectively. Women who re-enrolled tended to have better health characteristics than those not re-enrolled. Compared to women of comparable age in the original cohort, women retained for the second posttrial follow-up less often had a history of cardiovascular disease (odds ratio (OR) = 0.36), hypertension (OR = 0.57), diabetes (OR = 0.59), or measured cognitive deficit (OR = 0.40). These women more often had graduated from high school (OR = 1.72) and had participated in other WHI trials (OR = 1.76). LIMITATIONS: We have examined experience with creating follow-up cohorts from participants in a single study. Thus, our findings may not apply to other cohorts and protocols. CONCLUSIONS: Posttrial enrollment in follow-up studies can be successful; however, the characteristics of the resulting cohort may differ substantially from the originally assembled group of trial participants. Collection during the original trial of potential predictors of differential re-enrollment may strengthen interpretation of findings.

Improving response rate and quality of survey data with a scratch lottery ticket incentive.

BACKGROUND: The quality of data collected in survey research is usually indicated by the response rate; the representativeness of the sample, and; the rate of completed questions (item-response). In attempting to improve a generally declining response rate in surveys considerable efforts are being made through follow-up mailings and various types of incentives. This study examines effects of including a scratch lottery ticket in the invitation letter to a survey. METHOD: Questionnaires concerning oral health were mailed to a random sample of 2,400 adults. A systematically selected half of the sample (1,200 adults) received a questionnaire including a scratch lottery ticket. One reminder without the incentive was sent. RESULTS: The incentive increased the response rate and improved representativeness by reaching more respondents with lower education. Furthermore, it reduced item nonresponse. The initial incentive had no effect on the propensity to respond after the reminder. CONCLUSION: When attempting to improve survey data, three issues become important: response rate, representativeness, and item-response. This study shows that including a scratch lottery ticket in the invitation letter performs well on all the three.

A game dynamic model for vaccine skeptics and vaccine believers: measles as an example.

Widespread avoidance of Measles-Mumps-Rubella vaccination (MMR), with a consequent increase in the incidence of major measles outbreaks, demonstrates that the effectiveness of vaccination programs can be thwarted by the public misperceptions of vaccine risk. By coupling game theory and epidemic models, we examine vaccination choice among populations stratified into two behavioral groups: vaccine skeptics and vaccine believers. The two behavioral groups are assumed to be heterogeneous with respect to their perceptions of vaccine and infection risks. We demonstrate that the pursuit of self-interest among vaccine skeptics often leads to vaccination levels that are suboptimal for a population, even if complete coverage is achieved among vaccine believers. The demand for measles vaccine across populations driven by individual self-interest was found to be more sensitive to the proportion of vaccine skeptics than to the extent to which vaccine skeptics misperceive the risk of vaccine. Furthermore, as the number of vaccine skeptics increases, the probability of infection among vaccine skeptics increases initially, but it decreases once the vaccine skeptics begin receiving the vaccination, if both behavioral groups are vaccinated according to individual self-interest. Our results show that the discrepancy between the coverages of measles vaccine that are driven by self-interest and those driven by population interest becomes larger when the cost of vaccination increases. This research illustrates the importance of public education on vaccine safety and infection risk in order to maintain vaccination levels that are sufficient to maintain herd immunity.

The effect of health, socio-economic position, and mode of data collection on non-response in health interview surveys.

AIMS: To investigate the relationship between potential explanatory factors (socio-economic factors and health) and non-response in two general population health interview surveys (face-to-face and telephone), and to compare the effects of the two interview modes on non-response patterns. METHODS: Data derives from The Danish Health Interview Survey 2000 (face-to-face interview) and The Funen County Health Survey 2000/2001 (telephone interview). Data on all invited individuals were obtained from administrative registers and linked to survey data at individual level. Multiple logistic regression analyses were used to examine associations between potential explanatory factors and non-response. RESULTS: The overall response rate was higher in the face-to-face interview survey (74.5%) than in the telephone survey (69.2%). Refusal was the most common reason for non-response and the same factors were generally associated with non-response in both modes of interview. The non-response rate was high among persons with low socio-economic position. No significant associations between health and non-response were found. CONCLUSIONS: Health status does not play a systematic role for non-response rates in health interview surveys, but the non-response rate is higher in lower socio-economic groups. Analyses of non-response should be performed to understand the implications of survey findings.

Active parent consent for health surveys with urban middle school students: processes and outcomes.

BACKGROUND: To achieve high participation rates and a representative sample, active parent consent procedures require a significant investment of study resources. The purpose of this article is to describe processes and outcomes of utilizing active parent consent procedures with sixth-grade students from urban, ethnically diverse, economically disadvantaged K-8 public schools involved in an evaluation of a middle school service-learning program. METHODS: As part of the evaluation of the Lead Peace-Plus service-learning program, active parent consent was obtained for participation in school-based health surveys conducted with sixth graders in 3 schools. To achieve acceptable rates of parent permission, we employed multiple procedures including regular communication with school staff, incentives for involved schools and teachers, a multipronged approach for reaching parents, and direct encouragement of students to return forms through repeated classroom visits, individual and classroom incentives. We used Fisher's exact tests to compare selected characteristics among students whose parents weren't reached, those whose parents refused, and those whose parents consented to survey participation. RESULTS: We achieved a parent response rate of 94.6% among sixth-grade students. No significant differences in student gender, race/ethnicity, school, or free/reduced lunch status were identified across parent consent status groups. Rates of absenteeism were significantly higher (p = .03) among students whose parents weren't reached compared to other groups. CONCLUSIONS: Employing a multifaceted active parent consent campaign can result in high rates of parental response with limited sampling bias among an urban, ethnically diverse and economically disadvantaged group of middle school students.

Assessing non-response bias in pediatric palliative care research.

National experts have recognized a need for increased research in pediatric palliative care. However, when conducting research it is important to use rigorous methods, report significant and non-significant findings, and include information on responders and non-responders. Most studies do not present information on non-responders, yet this is critical as the results many not be generalizable if there are inherent differences between the two groups. Using survey data from parents whose children with life-limiting illnesses were enrolled in Florida's publicly funded pediatric palliative care program called Partners in Care: Together for Kids; this study investigates whether non-response bias exists, and if so, what characteristics are associated with non-response. Bivariate and multivariate analyses were conducted to determine whether individual characteristics differed between responders and non-responders. Throughout our analyses, we conducted the analyses using different ways in which 'non-response' can be defined. Our results suggest that regardless of how non-response is defined, Black, non-Hispanic parents were less likely to participate than White non-Hispanic parents. However, we also found that of the Black, non-Hispanic parents who did not participate, their primary reason for doing so was that they had non-working or disconnected phone numbers. Only 3% of the Black, non-Hispanic parents who did not participate flatly refused. Information from this study can be used to design interventions aimed at increasing minority participation in pediatric palliative care research.

Reasons for non-participation in a parental program concerning underage drinking: a mixed-method study.

BACKGROUND: Alcohol consumption among adolescents is a serious public health concern. Research has shown that prevention programs targeting parents can help prevent underage drinking. The problem is that parental participation in these kinds of interventions is generally low. Therefore, the aim of the present study is to examine non-participation in a parental support program aiming to prevent underage alcohol drinking. The Health Belief Model has been used as a tool for the analysis. METHODS: To understand non-participation in a parental program a quasi-experimental mixed-method design was used. The participants in the study were invited to participate in a parental program targeting parents with children in school years 7-9. A questionnaire was sent home to the parents before the program started. Two follow-up surveys were also carried out. The inclusion criteria for the study were that the parents had answered the questionnaire in school year 7 and either of the questionnaires in the two subsequent school years (n = 455). Multinomial logistic regression analysis was used to examine reasons for non-participation. The final follow-up questionnaire included an opened-ended question about reasons for non-participation. A qualitative content analysis was carried out and the two largest categories were included in the third model of the multinomial logistic regression analysis. RESULTS: Educational level was the most important socio-demographic factor for predicting non-participation. Parents with a lower level of education were less likely to participate than those who were more educated. Factors associated with adolescents and alcohol did not seem to be of significant importance. Instead, program-related factors predicted non-participation, e.g. parents who did not perceive any need for the intervention and who did not attend the information meeting were more likely to be non-participants. Practical issues, like time demands, also seemed to be important. CONCLUSION: To design a parental program that attracts parents independently of educational level seems to be an important challenge for the future as well as program marketing. This is something that must be considered when implementing prevention programs.

Social contact networks and disease eradicability under voluntary vaccination.

Certain theories suggest that it should be difficult or impossible to eradicate a vaccine-preventable disease under voluntary vaccination: Herd immunity implies that the individual incentive to vaccinate disappears at high coverage levels. Historically, there have been examples of declining coverage for vaccines, such as MMR vaccine and whole-cell pertussis vaccine, that are consistent with this theory. On the other hand, smallpox was globally eradicated by 1980 despite voluntary vaccination policies in many jurisdictions. Previous modeling studies of the interplay between disease dynamics and individual vaccinating behavior have assumed that infection is transmitted in a homogeneously mixing population. By comparison, here we simulate transmission of a vaccine-preventable SEIR infection through a random, static contact network. Individuals choose whether to vaccinate based on infection risks from neighbors, and based on vaccine risks. When neighborhood size is small, rational vaccinating behavior results in rapid containment of the infection through voluntary ring vaccination. As neighborhood size increases (while the average force of infection is held constant), a threshold is reached beyond which the infection can break through partially vaccinated rings, percolating through the whole population and resulting in considerable epidemic final sizes and a large number vaccinated. The former outcome represents convergence between individually and socially optimal outcomes, whereas the latter represents their divergence, as observed in most models of individual vaccinating behavior that assume homogeneous mixing. Similar effects are observed in an extended model using smallpox-specific natural history and transmissibility assumptions. This work illustrates the significant qualitative differences between behavior-infection dynamics in discrete contact-structured populations versus continuous unstructured populations. This work also shows how disease eradicability in populations where voluntary vaccination is the primary control mechanism may depend partly on whether the disease is transmissible only to a few close social contacts or to a larger subset of the population.

Regional differences in attitudes that may affect health behavior and willingness to participate in research among Black Seventh-day Adventists.

OBJECTIVE: To identify the attitudes and perceptions of Black Seventh-day Adventists regarding health research and the healthcare system in two regions of the United States. DESIGN: Church members were selected from those who participated in the Adventist Health Study-2 (AHS-2) and those who chose not to participate. Participants were selected from two regions of the United States. SETTING: Participants were interviewed in their churches, in their homes, and in the research study office at Loma Linda University. Interviews were done in the Western and Southern regions of the United States. PARTICIPANTS: 384 Black Seventh-day Adventists, aged >30 years. MAIN OUTCOME MEASURES: Responses to the structured interviews from those in the Western region were compared to those in the Southern region. RESULTS: Those in the Southern region included more elderly subjects; they were more likely to own their home despite earning less; and were more likely to be married. Compared to the Western region participants, we found Southern participants to have greater participation in church activities, greater mistrust of the healthcare system and particular concerns about racial inequalities in care. In contrast, they also reported more positive experiences with their personal healthcare provider than Western participants. Southerners felt that they had greater control over their own health, perhaps in part due to a greater identification with the health teachings of the Adventist church. CONCLUSIONS: A number of clear differences were found between Black Adventist subjects living in either the Western or Southern regions of the United States. These factors should be considered carefully when planning the promotion for a research study.

Extended recruitment efforts minimize attrition but not necessarily bias.

OBJECTIVES: There has been a debate about the effect of extended recruitment efforts on attrition and bias. The aims of the present study are (1) to investigate the effectiveness of extensive multimode recruitment procedures; (2) to study their effect on attrition and bias; and (3) to determine the potential predictors of attrition. STUDY DESIGN AND SETTING: We used data from the longitudinal population-based study of health in Pomerania. RESULTS: Using multimode recruitment methods, we reached a follow-up response proportion of 83.6%. In-person contacts at home turned out to be an effective recruitment tool. Sociodemographic and health characteristics of late respondents and converted nonrespondents were most distinct from early respondents but not necessarily indicative of nonrespondents. Analyzing attrition bias, extended recruitment efforts produced an effect only for sociodemographic characteristics but not for health-related indicators. The strongest predictors for attrition from the regression model were late recruitment at baseline, unemployment, low educational level, female sex, and smoking habit. CONCLUSION: Extended recruitment efforts appeared justified in terms of response maximization. However, enhanced response proportions may not necessarily minimize bias. In our analysis, aiming for a high-response proportion in terms of health-related indicators had no effect, because late respondents did not differ from early respondents.