Study Participation Rate Research Articles

Do participation rates change when active consent procedures replace passive consent.

Researchers face considerable ambiguity and controversy regarding the issue of informed consent. Decisions about consent procedures can affect study participation rates and prevalence estimates among specific populations. Changing from passive to active parental consent procedures was examined in a case study with an anonymous survey of sixth- through eighth-grade students' substance use. Four types of procedures for obtaining parental consent were examined. Results suggest that certain types of consent procedures can yield high levels of participation. This study also demonstrates that low participation rates with some active consent procedures can cause biases in sample characteristics and outcome data.

Smoking behavior and alcohol drinking in students in a rural area of East Germany

The present investigation ("Torgau Study") provides epidemiological information on a target population which in the past has hardly been in the focus of health promotion activities: the subgroup of children and adolescents of rural regions in Eastern Germany. A total survey was conducted that encompassed all classes from grade 6 to 10 of all schools in the district of Torgau (Saxony). Together, 5,925 students in the age range 12 to 16 years participated in this study (participation rate: 81.3%). The results provide a differentiated picture of their smoking behavior and alcohol use broken down by gender, school-type and grade. With respect to smoking the data show that the prevalence of regular smokers (i.e., daily smokers) in grade 10 is 41% in the Mittelschule (the school-type with a stronger vocational orientation) and 29% in the Gymnasium (the school-type with a university-preparatory curriculum). 51.9% of all students report that at least one parent smokes. There is a highly significant association between smoking status of the parents and smoking status of their children. The analysis of reasons for smoking highlight the stepwise transition into nicotine dependency from a psychological perspective. Most of the adolescents (about 80%) know about the dangers of passive smoking. However, with increasing age this knowledge loses its subjective relevance because dissonance-reducing strategies are applied ("doesn't matter"-attitude). Among girls, even in grade 10, there are almost no daily alcohol consumers (less than 1%); among boys in grade 10 the rate of daily alcohol users is about 8%. The rate of those 10th graders who consume alcoholic beverages at least once a week is however 30.6% (girls: 18.7%; boys: 44.2%). The longer the alcohol experience the more specific become the social and emotional motives for drinking. Altogether, the results suggest that efforts to prevent substance misuse in the rural regions of Eastern Germany are as necessary as in other regions. But the time has come that innovative approaches of drug prevention that are implemented and evaluated mostly in the bigger cities should also be started in the rural regions (not only of Eastern Germany), and should be adapted to the specific conditions there.

Evaluation of buccal cell collection protocols for genetic susceptibility studies

Buccal cells are increasingly used as a source of quality DNA to improve participation rates in molecular studies. Here, three buccal cell collection protocols were compared to determine factors affecting the yield of cells, total DNA per sample, and DNA yield per cell. In addition, kinetic quantitative polymerase chain reaction (PCR) (TaqMan™) was used to quantify human DNA available for PCR. The method of collection used influenced the overall DNA yield per sample. The collection buffer used influenced the number of cells but not the overall DNA yield per sample. Repeated freezing and thawing did not affect overall DNA yield per sample, DNA yield per cell, or the total number of cells collected. Mouthwashes had the highest DNA yield per sample (20.8 μg) compared with cytobrush samples (1.9 μg from three cytobrushes) and tongue depressors (0.8 μg from three tongue depressors). However, mouthwash samples may contain significant non-human DNA and other contaminants that could interfere with some molecular studies. Spectrometry grossly overestimated the total DNA recovered from mouthwash samples compared with fluorometry or quantitative PCR.

Predictors of Concomitant Cervical Intraepithelial Neoplasia in Women with Newly Diagnosed Atypical Squamous Cells of Undetermined Significance

The percentage of women with atypical squamous cells of undetermined significance (ASCUS) with concomitant cervical intraepithelial neoplasia (CIN) is relatively high, varying between 18% and 30%, depending on the series. The objective of this study was to identify factors other than cervical human papillomavirus (HPV) infection that would help to identify women with newly diagnosed ASCUS and in need of referral to colposcopy. A total of 360 eligible women in whom ASCUS was diagnosed and who were referred to the colposcopy clinic of Saint-Sacrement Hospital in Quebec City were included in this study (participation rate, 92%). Eligible women were those aged between 18 and 50 years, with newly diagnosed ASCUS, with no history of cervical biopsies or treatment, and not pregnant at the time of their visit. During their gynecological visit, a cell sample was collected for HPV testing, and colposcopically directed biopsies of lesions were obtained. HPVs were detected using the Digene hybrid capture test. Logistical regression was used to estimate odds ratios (ORs) for concomitant CIN and their 95% confidence intervals (CIs). All ORs were adjusted for cervical HPV infection and other risk factors. Cervical HPV infection was the factor most strongly related to concomitant CIN (OR = 4.0; 95% CI = 2.2-7.3). After taking into account the presence of cervical HPV infection, two variables were significantly associated with concomitant CIN. Compared to older women, those aged 35 or younger had a higher risk of concomitant CIN (OR - 2.3; 95% CI - 1.3-4.2). Current smoking was positively associated with concomitant CIN (OR - 2.7; 95% CI - 1.4-5.1), while there was no association between past smoking and concomitant CIN. Having had more than four sexual partners in the last 5 years was associated with an OR of 2.1; however, this association did not reach statistical significance. Cervical HPV infection, younger age, and current smoking were independent determinants of both CIN1 and CIN2 and 3. Age and smoking status are independent predictors of concomitant CIN in women with newly diagnosed ASCUS. When HPV testing is not available, clinicians could preferentially refer younger women and those who smoke to colposcopy, as they represent a population with ASCUS at high risk of concomitant CIN.

Predictors of Concomitant Cervical Intraepithelial Neoplasia in Women with Newly Diagnosed Atypical Squamous Cells of Undetermined Significance

Objective The percentage of women with atypical squamous cells of undetermined significance (ASCUS) with concomitant cervical intraepithelial neoplasia (CIN) is relatively high, varying between 18% and 30%, depending on the series. The objective of this study was to identify factors other than cervical human papillomavirus (HPV) infection that would help to identify women with newly diagnosed ASCUS and in need of referral to colposcopy. Materials and Methods A total of 360 eligible women in whom ASCUS was diagnosed and who were referred to the colposcopy clinic of Saint-Sacrement Hospital in Quebec City were included in this study (participation rate, 92%). Eligible women were those aged between 18 and 50 years, with newly diagnosed ASCUS, with no history of cervical biopsies or treatment, and not pregnant at the time of their visit. During their gynecological visit, a cell sample was collected for HPV testing, and colposcopically directed biopsies of lesions were obtained. HPVs were detected using the Digene hybrid capture test. Logistical regression was used to estimate odds ratios (ORs) for concomitant CIN and their 95% confidence intervals (CIs). All ORs were adjusted for cervical HPV infection and other risk factors. Results Cervical HPV infection was the factor most strongly related to concomitant CIN (OR = 4.0; 95% CI = 2.2–7.3). After taking into account the presence of cervical HPV infection, two variables were significantly associated with concomitant CIN. Compared to older women, those aged 35 or younger had a higher risk of concomitant CIN (OR - 2.3; 95% CI - 1.3–4.2). Current smoking was positively associated with concomitant CIN (OR - 2.7; 95% CI - 1.4–5.1), while there was no association between past smoking and concomitant CIN. Having had more than four sexual partners in the last 5 years was associated with an OR of 2.1; however, this association did not reach statistical significance. Cervical HPV infection, younger age, and current smoking were independent determinants of both CIN1 and CIN2 and 3. Conclusion Age and smoking status are independent predictors of concomitant CIN in women with newly diagnosed ASCUS. When HPV testing is not available, clinicians could preferentially refer younger women and those who smoke to colposcopy, as they represent a population with ASCUS at high risk of concomitant CIN.

Participation Rates in a Case-Control Study:: The Impact of Age, Race, and Race of Interviewer

PURPOSE: Despite concerns about declining participation rates in epidemiologic studies in recent years, relatively few papers have discussed obstacles to recruiting study participants or strategies for optimizing response rates. This report describes factors associated with nonparticipation in a population-based, case-control study of breast cancer and discusses ways to overcome barriers to participation. METHODS: Contact and cooperation rates were calculated for participants in the Carolina Breast Cancer Study (CBCS), stratified by case status, age, race, and race of interviewer. Demographic and breast cancer risk factor characteristics of partial and full responders also were compared. RESULTS: Contact rates and cooperation rates varied by case/control status and demographic characteristics. Contact rates were lower among controls, younger women, and black women. Cooperation rates were lower among controls, older women, and black cases. Cooperation rates were higher among both black and nonblack women when participants and interviewers were concordant on race. CONCLUSIONS: Obstacles to recruitment seem to differ among race and age subgroups, suggesting that recruitment strategies may need to be tailored to potential participants based upon demographic characteristics. Strategies have been implemented to improve response rates in this and other epidemiologic studies; however, additional research and innovation in this area are needed.

Non-response bias in prospective studies of patients and health care professionals

Low participation and high attrition rates in research studies may produce socially and psychologically biased study samples which limit the generalizability of findings. Although this problem is often acknowledged, published studies sometimes fail to assess and report non-response bias and make few efforts to prevent it. Two examples, one involving patients and another involving health professionals, are reported to illustrate the problem. The first was a randomized controlled trial of presenting a prenatal screening test, with questionnaires given to participants on four occasions. The final sample differed in ethnic group and use of screening, being more likely to be white and to undergo the test. The second example was a randomized controlled trial of communication skills training of obstetricians and midwives. Those completing the study differed from the others in holding more positive attitudes towards training and having better communication skills. Potential solutions to the problem of non-response bias are addressed.

Bringing community involvement into a Cretan primary/hospital care center: an evaluation of population habits and attitudes toward health care.

In a small Cretan township hospital combining secondary and primary care, a questionnaire was distributed to a consecutive visitor sample. The questionnaire requested information on the participants' personal smoking and other life habits, perceptions and expectations of the delivery of the health care services, and attitudes toward their own doctors and others who provide various health services. Three hundred and one individuals of both sexes who were 15 years and older participated in the study (participation rate, more than 97%). An interesting and varied response was recorded, covering a wide range of perceptions, opinions, and attitudes not only toward the services, but also toward the staff. Although a high confidence in and appreciation of both the primary care and hospital sections appeared in the study results, these attitudes should not be allowed to deteriorate. Therefore, specific actions should be undertaken: constant upgrading of the existing organizational context, implementation of promotional and educational programs, and use of the questionnaire as an effective tool for periodically assessing the population's attitudes, experiences, and expectations.

Motivational Preconditions for Girls Gifted and Highly Gifted in Physics

During their socialisation process, many girls gifted in physics acquire a reality construction inconsistent with their objectively measurable competencies. In comparison to boys they rate their action and problem solving competencies unrealistically low, which results, for example, in extremely low participation rates in scientific and technical studies and professions. For this reason differences in motivation and self‐related cognitions become the focus of interest in explaining achievement differences. The present study was carried out prior to initial physics instruction. Students in the 7th grade of the German Gymnasium (243 girls and 282 boys) were divided according to their KFT 4‐13+ results into “average”, “gifted” or “highly gifted groups”. Prior to commencement of physics instruction, boys in general, as well as gifted male and female students, already possessed more knowledge of physics and more favourable motivation for the subject than girls or male and female students of average ability. In...

Participation rate in the Belgian population study on ambulatory blood pressure monitoring Reply

Participation rate in the Belgian population study on ambulatory blood pressure monitoring Reply

The quality of life of patients with newly diagnosed M1 prostate cancer: Experience with EORTC clinical trial 30853

This study was undertaken to evaluate the quality of life (QoL) of previously untreated patients with Ml prostate cancer before and during androgen-suppressive treatment. Assessment of QoL was included as an optimal component of EORTC protocol 30853, a phase III trial comparing LH-RH (luteinising hormone-releasing hormone) analogue combined with a non-steroidal anti-androgen versus orchiectomy in patients with M1 prostate cancer. At pretreatment and during the follow-up period, patients were asked to complete a questionnaire assessing their physical and psychosocial functioning, and their symptom levels. Physicians rated the patients' performance status, pain, urological symptoms and erectile function. Due to its optional nature, only a minority of the patients in the trial were recruited for the QoL investigation. 63 patients completed a pretreatment questionnaire, of whom 49 completed a second questionnaire at least once during the initial 15 month follow-up period. While statistically significant correlations were observed between patients' and physicians' ratings of physical functioning and pain, these were of only a moderate magnitude ( r = 0.43 and 0.30, respectively). No significant association was observed between physicians' and patients' ratings of micturation problems or of erectile function. Before treatment, fatigue, pain and decreased social role and sexual functioning were the problems most frequently reported by patients. With an average of approximately 1 year follow-up, statistically significant improvements were observed in patients' self-reported urological symptoms and metastatic pain. No significant changes were noted for the other QoL domains assessed. The results of this study confirm earlier findings that physicians' ratings may not reflect accurately the functional health and symptom experience of their patients. Patient-based QoL questionnaires offer the most direct means of evaluating the subjective morbidity associated with prostate cancer and its treatment. To increase participation and compliance rates in future studies, it is recommended that QoL assessment be made mandatory in those clinical trials in which QoL is considered to be an important study endpoint.

The Empirical Evidence of Foreign Language Study

This article examines national transcript samples that were set up at different times with different samples and different rules. College transcript samples covering the period 1972-86 show a flat participation rate in foreign language study but increases occurred among business majors and at nonselective institutions. Trends across five high school transcript samples (from 1969 to 1990), on the other hand, leave too much to speculation. Data from the 1991 National Household Education Survey are used to conclude that foreign language study in adulthood is largely a matter of personal interest, not economic interest, and that participation rates are very low. Data from the National Longitudinal Study of the High School Class of 1972 allow us to examine the long-term relationships between foreign language study and adult life. Findings indicate that those who studied foreign language in college were more likely to be working in human service occupations at age 32 or 33 than those who studied no foreign language and that, in terms of earnings and unemployment, the benefits of foreign language study are negligible.

Cross-sectional Epidemiologic Study for Assessing Cancer Risks at the Population Level

A cross-sectional study on associations between lifestyle factors and cancer risks was conducted in five areas of Japan. The study design and participation rate were described in the part I. In this paper, we showed the baseline data of lifestyle and health-related items with special reference to geographic difference. Medical history of peptic ulcer, family history of stomach cancer and any cancer, smoking and drinking habits, anthropometric features such as height, weight and body mass index, and biochemical parameters such as HDL cholesterol, uric acid, and abnormal GOT were significantly different among men by study areas. Urinary excretion level of sodium, potassium, calcium and magnesium, and nutritional intake level of energy, fat and carbohydrate also revealed the significant differences. The wives of male participants also showed the similar geographical difference. Correlation analysis was conducted between age-adjusted mortality rates of selected cancer sites and prevalence or average values of lifestyle and health-related factors. Significant associations were found between esophageal cancer and consumption of alcohol and cigarette, and stomach cancer and both medical histories of peptic ulcer and salt excretion in 24-h urine. J Epidemiol, 1992; 2 : 83-89.

Cross-sectional Epidemiologic Study for Assessing Cancer Risks at the Population Level

A cross-sectional study on associations between lifestyle factors and cancer risks was conducted in five areas of Japan. The study design and participation rate were described in the part I. In this paper, we showed the baseline data of lifestyle and health-related items with special reference to geographic difference. Medical history of peptic ulcer, family history of stomach cancer and any cancer, smoking and drinking habits, anthropometric features such as height, weight and body mass index, and biochemical parameters such as HDL cholesterol, uric acid, and abnormal GOT were significantly different among men by study areas. Urinary excretion level of sodium, potassium, calcium and magnesium, and nutritional intake level of energy, fat and carbohydrate also revealed the significant differences. The wives of male participants also showed the similar geographical difference. Correlation analysis was conducted between age-adjusted mortality rates of selected cancer sites and prevalence or average values of lifestyle and health-related factors. Significant associations were found between esophageal cancer and consumption of alcohol and cigarette, and stomach cancer and both medical histories of peptic ulcer and salt excretion in 24-h urine. J Epidemiol, 1992; 2 : 83-89.

The population study of women in Gothenburg 1980-81--the third phase of a longitudinal study. Comparison between participants and non-participants.

A representative population sample comprising 1,462 women was studied in Gothenburg, Sweden in 1968-69, and a third follow-up study was carried out in 1980-81. The participation rates in the baseline study and during the follow-up studies were high. In 1980-81 women in two new age strata, aged 26 and 38, were added. Women who had moved to or from Gothenburg during the study period were not found to differ from those who were living in Gothenburg during the total study period, while there were a few differences of statistical significance between refusers and participants in 1980-81. The mortality among initial refusers was about doubled compared to that of those who participated in the baseline study.

Using administrative data for longitudinal research: Comparisons with primary data collection

This paper discusses the advantages and disadvantages of using administrative data for longitudinal research, focusing on loss to follow-up. Comparisons between research relying on primary data collection and that using data bases are made. After development of a suitable framework, follow-up in several well-known projects based on primary data collection (the Seven Countries project on coronary heart disease, the Massachusetts research on long-term care and the Pittsburgh clinical trial of tonsillectomy) is compared with follow-up using the Health Services Commission data base in Manitoba, Canada. Overall follow-up in the Manitoba research compares favorably with participation and follow-up rates in other studies based on primary data collection. Initial nonresponse and nonlocation are major problems with studies using primary data; failure to locate earlier respondents in subsequent waves results in a wide range of overall response rates. Data bases do not require researchers to contact individuals and hence follow-up is simplified. Eight year follow-up rates in the Manitoba data base are almost always over 80% and often over 90%. Because records can be flexibly summarized for each individual over time, data bases facilitate certain types of longitudinal studies which would be difficult, if not impossible, to perform using other methodologies. If the desired data are available and recorded with acceptable accuracy, administrative data banks hold considerable promise for the health care researcher.

"A Status Group Dynamics Approach to Predicting Participation Rates in Regional Recreation Demand Studies": Reply

"A Status Group Dynamics Approach to Predicting Participation Rates in Regional Recreation Demand Studies": Reply

A Status Group Dynamics Approach to Predicting Participation Rates in Regional Recreation Demand Studies

A Status Group Dynamics Approach to Predicting Participation Rates in Regional Recreation Demand Studies