Nonresponse research--an underdeveloped field in epidemiology

The Use of Machine Translation for Outreach and Health Communication in Epidemiology and Public Health: Scoping Review

BACKGROUND

Culturally and linguistically diverse groups are often underrepresented in population-based research and surveillance efforts, leading to biased study results and limited generalizability. These groups, often termed "hard-to-reach," commonly encounter language barriers in the public health (PH) outreach material and information campaigns, reducing their involvement with the information. As a result, these groups are challenged by 2 effects: the medical and health knowledge is less tailored to their needs, and at the same time, it is less accessible for to them. Modern machine translation (MT) tools might offer a cost-effective solution to PH material language accessibility problems.

OBJECTIVE

This scoping review aims to systematically investigate current use cases of MT specific to the fields of PH and epidemiology, with a particular interest in its use for population-based recruitment methods.

METHODS

PubMed, PubMed Central, Scopus, ACM Digital Library, and IEEE Xplore were searched to identify articles reporting on the use of MT in PH and epidemiological research for this PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews)-compliant scoping review. Information on communication scenarios, study designs and the principal findings of each article were mapped according to a settings approach, the World Health Organization monitoring and evaluation framework and the service readiness level framework, respectively.

RESULTS

Of the 7186 articles identified, 46 (0.64%) were included in this review, with the earliest study dating from 2009. Most of the studies (17/46, 37%) discussed the application of MT to existing PH materials, limited to one-way communication between PH officials and addressed audiences. No specific article investigated the use of MT for recruiting linguistically diverse participants to population-based studies. Regarding study designs, nearly three-quarters (34/46, 74%) of the articles provided technical assessments of MT from 1 language (mainly English) to a few others (eg, Spanish, Chinese, or French). Only a few (12/46, 26%) explored end-user attitudes (mainly of PH employees), whereas none examined the legal or ethical implications of using MT. The experiments primarily involved PH experts with language proficiencies. Overall, more than half (38/70, 54% statements) of the summarizing results presented mixed and inconclusive views on the technical readiness of MT for PH information.

CONCLUSIONS

Using MT in epidemiology and PH can enhance outreach to linguistically diverse populations. The translation quality of current commercial MT solutions (eg, Google Translate and DeepL Translator) is sufficient if postediting is a mandatory step in the translation workflow. Postediting of legally or ethically sensitive material requires staff with adequate content knowledge in addition to sufficient language skills. Unsupervised MT is generally not recommended. Research on whether machine-translated texts are received differently by addressees is lacking, as well as research on MT in communication scenarios that warrant a response from the addressees.

Prolonged grief disorder prevalence in adults 65 years and over: a systematic review

BACKGROUND

Prolonged grief disorder (PGD) is a recently recognised mental health disorder with an estimated prevalence of 10% in the bereaved adult population. This review aims to appraise and summarise evidence relating to PGD in older adults (≥65 years), a growing population group, most likely to experience bereavement and often assumed to cope well.

METHOD

Literature from Medline, PsycINFO, CINAHL, Cochrane Library and Web of Science was searched. Epidemiological and non-epidemiological studies including data on frequency of PGD in older adults bereaved by mainly natural causes were included and a descriptive analysis undertaken.

RESULTS

From 2059 records, three epidemiological and six non-epidemiological studies were included. Most studies had good internal but not external validity. Conditional prevalence for PGD ranged between 3.2% and 48.8%. Heterogeneity in sample characteristics and study methodology contributed to this variability resulting in a descriptive analysis. The prevalence rate of 9.1% by Kersting et al was the best available estimate for PGD in older adults for western countries. The small number of epidemiological studies and the use of varying PGD-constructs which did not match International Classification of Diseases 11th Revision and Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria were the main limiting factors.

CONCLUSION

This first review on PGD prevalence in older adults suggests that, despite studies' methodological short comings, a similar proportion of older adults experience PGD as the general bereaved adult population (1:10). With older adults forming the largest subgroup among the bereaved, health and social care systems need to adapt their provision of care to address the specific needs of older adults.

Verified Parental Cardiovascular Events for Young and Middle-Aged Ischaemic Stroke Patients and Controls

Introduction. Nonmodifiable cardiovascular risk factors, like age and sex, are easily quantifiable. Due to immense technical progress in diagnostics and medical data storage, the aim of this study was to quantify, verify, and to compare parental cardiovascular events (CVE) as an additional nonmodifiable risk factor for young and middle-aged ischaemic stroke patients and controls. Methods. Information about parental CVE was first obtained by standardized questionnaires answered by 385 acute ischaemic stroke patients (15-60 years of age) and 260 controls. After consent to contact living and include deceased parents, patients and controls provided necessary personal identification of their parents. Thereafter, CVE were verified by standardized questionnaires answered by parents or medical records in case of deceased parents. Results. One hundred-and-nine (14.2%) of 770 patient parents vs. 128 (24.6%) of 520 control parents were not available for verification. Active participation was obtained for 229 (73.9%) of 310 patient parents vs.113 (58.2%) of 194 control parents. Medical record verification was obtained for 192 (54.7%) of 351 deceased patient parents, vs.103 (52.0%) of 198 deceased control parents. This study showed highest death rates of fathers (65.3% patient fathers and 57.6% control fathers) and highest numbers of CVE, especially myocardial infarction among patient fathers of patients aged 50-60 years. Discussion and Conclusion. Obtaining verified parental CVE as a nonmodifiable risk factor is still challenging, despite widely available digital medical information. To attain more accurate information on parental CVE, we recommend active involvement of family members in addition to medical record verification, especially for patients aged <50 years. Trial Registration. This trial is registered with NCT01597453

Educating physicians on strong opioids by descriptive versus simulated-experience formats: a randomized controlled trial

BACKGROUND

Long-term prescriptions of strong opioids for chronic noncancer pain-which are not supported by scientific evidence-suggest miscalibrated risk perceptions among those who prescribe, dispense, and take opioids. Because risk perceptions and behaviors can differ depending on whether people learn about risks through description or experience, we investigated the effects of descriptive versus simulated-experience educative formats on physicians' risk perceptions of strong opioids and their prescription behavior for managing chronic noncancer pain.

METHODS

Three hundred general practitioners and 300 pain specialists in Germany-enrolled separately in two independent exploratory randomized controlled online trials-were randomly assigned to either a descriptive format (fact box) or a simulated-experience format (interactive simulation).

PRIMARY ENDPOINTS

Objective risk perception (numerical estimates of opioids' benefits and harms), actual prescriptions of seven therapy options for managing chronic pain.

SECONDARY ENDPOINT

Implementation of intended prescriptions of seven therapy options for managing chronic pain.

RESULTS

Both formats improved the proportion of correct numerical estimates of strong opioids' benefits and harms immediately after intervention, with no notable differences between formats. Compared to description, simulated experience led to significantly lower reported actual prescription rates for strong and/or weak opioids, and was more effective at increasing prescription rates for non-drug-based therapies (e.g., means of opioid reduction) from baseline to follow-up for both general practitioners and pain specialists. Simulated experience also resulted in a higher implementation of intended behavior for some drug-based and non-drug-based therapies.

CONCLUSIONS

The two formats, which recruit different cognitive processes, may serve different risk-communication goals: If the goal is to improve exact risk perception, descriptive and simulated-experience formats are likely to be equally suitable. If, however, the goal is to boost less risky prescription habits, simulated experience may be the better choice.

TRIAL REGISTRATION

DRKS00020358 (German Clinical Trials Register, first registration: 07/01/2020).

Predictors of non-response to successive waves of surveys in the Japan Environment and Children's Study during the 3-year postpartum period: a longitudinal cohort study

OBJECTIVES

We examined changes in factors related to non-response to successive waves of the nationwide birth cohort study, the Japan Environment and Children's Study (JECS), during the first 3 years after childbirth.

DESIGN

Longitudinal cohort study.

SETTING

As the baseline survey, mothers completed self-administered questionnaires distributed by hand during pregnancy or 1 month after delivery. The self-administered questionnaires that we used in this study were then distributed by mail every 6 months until the children were 3 years old, for a total of six times.

PARTICIPANTS

Of 103 060 mothers who consented to participate in the JECS during pregnancy, 88 489 mothers were included in the study after excluding those with multiple births, miscarriages or stillbirths and those who withdrew from the study within 3 years after providing informed consent.

PRIMARY AND SECONDARY OUTCOME MEASURES

Data were collected at the baseline survey on participants' socioeconomic status, medical history, health status, health-related behaviours and their children's health conditions and living situations. The strength of the impact of related factors and the prediction of response status were examined and compared using binominal logistic regression analysis.

RESULTS

For all six follow-up questionnaire surveys, higher maternal age was strongly associated with providing a response. Factors that were strongly associated with mothers not providing a response were smoking after childbirth and having more children. The concordance rate of response status based on the presented model was about 70%, suggesting that the response status for the first 3 years after birth can be predicted from the information collected in the baseline survey.

CONCLUSION

By identifying predictors of non-response from information obtained in baseline surveys, researchers may be able to reduce non-response to successive survey waves by issuing reminders, reviewing data collection methods and providing appropriate financial and/or non-financial incentives.

Demographic differences in willingness to share electronic health records in the All of Us Research Program

OBJECTIVE

Participant willingness to share electronic health record (EHR) information is central to success of the National Institutes of Health All of Us Research Program (AoURP). We describe the demographic characteristics of participants who decline access to their EHR data.

MATERIALS AND METHODS

We included participants enrolling in AoURP between June 6, 2017 and December 31, 2019 through the Trans-American Consortium for the Health Care Systems Research Network (TACH). TACH is a consortium of health care systems spanning 6 states, and an AoURP research partner.

RESULTS

We analyzed data for 25 852 participants (89.3% of those enrolled). Mean age = 52.0 years (SD 16.8), with 66.5% White, 18.7% Black/African American, 7.7% Hispanic, 32.5% female, and 76% with >a high school diploma. Overall, 2.3% of participants declined to share access to their EHR data (range across TACH sites = 1.3% to 3.5%). Younger age, female sex, and education >high school were significantly associated with decline to share EHR data, odds ratio (95% confidence interval) = 1.26 (1.19-1.33), 1.74 (1.42-2.14), and 2.44 (1.86-3.21), respectively. Results were similar when several sensitivity analyses were performed.

DISCUSSION

AoURP seeks a dataset reflecting our nation's diversity in all aspects of participation. Those under-represented in biomedical research may be reluctant to share access to their EHR data.

CONCLUSION

In our data, race and ethnicity were not independently related to participant decision to decline access to their EHR information. Results suggest that the value of the AoURP dataset is unlikely to be constrained by the size or the racial/ethnic composition of this subgroup.

The role of simulated-experience and descriptive formats on perceiving risks of strong opioids: A randomized controlled trial with chronic noncancer pain patients

OBJECTIVES

Opioid prescription rates worldwide suggest miscalibrated risk perceptions among those who prescribe, dispense, and take opioids. Findings from cognitive science show that risk perceptions can differ systematically depending on whether people learn about risks by description or experience. We investigated the effects of descriptive and simulated experience risk formats on patients' risk perceptions and behavior regarding long-term strong opioid use.

METHODS

300 German patients with chronic noncancer pain were randomly assigned in an exploratory randomized controlled trial to either a descriptive format (fact box) or a simulated experience format (interactive simulation). Primary endpoints were subjective and objective risk perceptions and intended intake behavior.

RESULTS

Both formats significantly improved patients' objective risk perception; patients who saw the fact box estimated some outcomes more accurately (p = .031). Formats were equally effective in improving patients' subjective risk perception in terms of opioids' harms; however, patients receiving the simulation showed a greater reduction and termination of their opioid intake (p = .030) and a higher uptake of alternative therapies.

CONCLUSIONS

Descriptive and simulated experience risk formats improve risk perceptions and behavior regarding potent but highly risky drugs.

PRACTICE IMPLICATIONS

To eliminate risky behavior, simulated experience formats may be superior to descriptive formats.

Use of register- and survey-based measures of anxiety in a population-based Danish cohort

OBJECTIVE

We explored the comparability of anxiety measures from register- and survey-based data including analyses of prevalence and associations with selected psychiatric and somatic diseases.

METHODS

We measured anxiety using Danish registers (hospital diagnosis and anxiolytic drug prescriptions), self-reports, symptom checklist (SCL) scores, and a clinical interview in 7493 adults with mean age 52 (SD 13.3) years who participated in a health survey between 2012 and 2015. We estimated the prevalence of anxiety, agreement between different measures and performed quantitative bias analysis.

RESULTS

The lifetime prevalence of hospital diagnosed anxiety, anxiolytic drug prescriptions, and self-reported anxiety were 4.4%, 6.2%, and 5.1%, respectively, after adjusting for selective participation. The agreement between the different anxiety measures was low. Thus, 25% with an anxiety diagnosis and 20% with anxiolytic drug prescriptions also had a high SCL score. Anxiolytic drugs were the only measure significantly associated with higher odds of heart disease. Hospital diagnosis and self-reported anxiety were associated with depression with odds ratio (OR) above 15, whereas anxiolytic drug prescriptions were less strongly associated (OR = 2.2(95% confidence interval: 1.26-3.91)). The risk estimates attenuated considerably when correcting for measurement error, whereas the ORs became slightly higher when the selective participation in the survey was accounted for.

CONCLUSION

Anxiety diagnosed in hospitals and self-reported anxiety showed low level of agreement but provide comparable results regarding frequency measures and associations with disease outcomes.

Educating Pharmacists on the Risks of Strong Opioids With Descriptive and Simulated Experience Risk Formats: A Randomized Controlled Trial

Objectives. High opioid prescription rates in the United States and Europe suggest miscalibrated risk perceptions among those who prescribe, dispense, and take opioids. Findings from cognitive decision science suggest that risk perceptions and behaviors can differ depending on whether people learn about risks by experience or description. This study investigated effects of a descriptive versus an experience-based risk education format on pharmacists’ risk perceptions and counseling behavior in the long-term administration of strong opioids to patients with chronic noncancer pain. Methods. In an exploratory, randomized controlled online trial, 300 German pharmacists were randomly assigned to either a descriptive format (fact box) or a simulated experience format (interactive simulation). Primary Outcome Measures. 1) Objective risk perception, 2) subjective risk perception, and 3) intended and 4) actual counseling behavior. Results. Both risk formats significantly improved pharmacists’ objective risk perception, but pharmacists exposed to the fact box estimated the benefit-harm ratio more accurately than those exposed to the simulation. Both formats proved equally effective in adjusting pharmacists’ subjective risk perception toward a better recognition of opioids’ harms; however, pharmacists receiving the simulation showed a greater change in their actual counseling behavior and higher consistency between their intended and actual counseling than pharmacists receiving the fact box. Conclusion. The simulated experience format was less effective than the descriptive format in improving pharmacists’ objective risk perception, equally effective in motivating pharmacists to counsel patients on less risky treatment alternatives and more effective in changing the reported actual counseling behavior. Implications. These exploratory findings provide important insights into the relevance of the description-experience gap for drug safety and raise questions for future research regarding the specific mechanisms at work.

Seroprevalence of SARS-CoV-2 antibodies in Saint Petersburg, Russia: a population-based study

Properly conducted serological survey can help determine infection disease true spread. This study aims to estimate the seroprevalence of SARS-CoV-2 antibodies in Saint Petersburg, Russia accounting for non-response bias. A sample of adults was recruited with random digit dialling, interviewed and invited for anti-SARS-CoV-2 antibodies. The seroprevalence was corrected with the aid of the bivariate probit model that jointly estimated individual propensity to agree to participate in the survey and seropositivity. 66,250 individuals were contacted, 6,440 adults agreed to be interviewed and blood samples were obtained from 1,038 participants between May 27 and June 26, 2020. Naïve seroprevalence corrected for test characteristics was 9.0% (7.2-10.8) by CMIA and 10.5% (8.6-12.4) by ELISA. Correction for non-response decreased estimates to 7.4% (5.7-9.2) and 9.1% (7.2-10.9) for CMIA and ELISA, respectively. The most pronounced decrease in bias-corrected seroprevalence was attributed to the history of any illnesses in the past 3 months and COVID-19 testing. Seroconversion was negatively associated with smoking status, self-reported history of allergies and changes in hand-washing habits. These results suggest that even low estimates of seroprevalence can be an overestimation. Serosurvey design should attempt to identify characteristics that are associated both with participation and seropositivity.

Factors predicting missing instruments in three cancer randomized clinical trials

PURPOSE

Missing patient-reported outcome (PRO) data can seriously threaten the validity of randomized clinical trials (RCTs). Identifying which factors predict missing instruments may help researchers develop strategies to prevent it from happening. This study examined the association of factors with time to the first missing instrument after randomization in three cooperative group RCTs.

METHODS

We performed descriptive analyses and Cox proportional hazards regressions for three RCTs selected from the Canadian Cancer Trials Group: MA17 (breast cancer), PR7 (prostate cancer), and LY12 (non-Hodgkin's lymphoma). The outcome was the time from randomization to the first missing instrument. Variables for 15 factors were used as covariates based on availability and previously-reported putative associations with missing PRO data.

RESULTS

Nine percent of 1352 subjects on MA17, 37% of 923 subjects on PR7, and 59% of 477 subjects on LY12 had a missing instrument. Twenty-five percent of subjects on MA17 had first missing instrument within 4.6 years. The median time to first missing instrument was: not observed for MA17, 7.3 years for PR7, 0.12 years for LY12. Cox regression revealed statistically significant independent associations with outcome for only five factors: baseline age (PR7) and level of well-being (LY12), and centre level of activity (LY12), presence of post-graduate residency training program (MA17, PR7), and centre geographic location (PR7, LY12).

CONCLUSION

Many factors reported to have association with missing instruments do not seem to predict time to the first missing instrument after randomization in RCTs. Context is important in understanding the few that may.

Selection bias in general practice research: analysis in a cohort of pregnant Danish women

OBJECTIVE

The aim of the present study was to examine selection in a general practice-based pregnancy cohort.

DESIGN

Survey linked to administrative register data.

SETTING AND SUBJECTS

In spring 2015, GPs were recruited from two Danish regions. They were asked to invite all pregnant women in their practice who had their first prenatal care visit before 15 August 2016 to participate in the survey.

OUTCOME MEASURES

The characteristics of GPs and the pregnant women were compared at each step in the recruitment process - the GP's invitation, their agreement to participate, actual GP participation, and the women's participation - with an uncertainty coefficient to quantify the step where the largest selection occurs.

RESULTS

Significant differences were found between participating and non-participating practices with regards to practice characteristics such as the number of patients registered with the practice, the age and sex of doctors, and the type of practice. Despite these differences, the characteristics of the eligible patients differed little between participating and non-participating practices. In participating practices significant differences were, however, observed between recruited and non-recruited patients.

CONCLUSION

The skewed selection of patients was mainly caused by a high number of non-participants within practices that actively took part in the study. We recommend that a focus on the sampling within participating practices be the most important factor in representative sampling of patient populations in general practice. Key points Selection among general practitioners (GPs) is often unavoidable in practice-based studies, and we found significant differences between participating and non-participating practices. These include practice characteristics such as the number of GPs, the number of patients registered with the GP practice, as well as the sex and age of the GPs. •Despite this, only small differences in the characteristics of the eligible patients were observed between participating and non-participating practices. •In participating practices, however, significant differences were observed between recruited and non-recruited patients. •Comprehensive sampling within participating practices may be the best way to generate representative samples of patients.

Experiencing the risk of overutilising opioids among patients with chronic non-cancer pain in ambulatory care (ERONA): the protocol of an exploratory, randomised controlled trial

INTRODUCTION

The US opioid crisis and increasing prescription rates in Europe suggest inappropriate risk perceptions and behaviours of people who prescribe, take or advise on opioids: physicians, patients and pharmacists. Findings from cognitive and decision science in areas other than drug safety suggest that people's risk perception and behaviour can differ depending on whether they learnt about a risk through personal experience or description. Experiencing the risk of overutilising opioids among patients with chronic non-cancer pain in ambulatory care (ERONA) is the first-ever conducted trial that aims at investigating the effects of these two modes of learning on individuals' risk perception and behaviour in the long-term administration of WHO-III opioids in chronic non-cancer pain.

METHODS AND ANALYSIS

ERONA-an exploratory, randomised controlled online survey intervention trial with two parallel arms-will examine the opioid-associated risk perception and behaviour of four groups involved in the long-term administration of WHO-III opioids: (1) family physicians, (2) physicians specialised in pain therapy, (3) patients with chronic (≥3 months) non-cancer pain and (4) pharmacists who regularly dispense narcotic substances. Participants will be randomly assigned to one of two online risk education interventions, description based or experiencebased. Both interventions will present the best medical evidence available. Participants will be queried at baseline and after intervention on their risk perception of opioids' benefit-harm ratio, their medical risk literacy and their current/intended risk behaviour (in terms of prescribing, taking or counselling, depending on study group). A follow-up will occur after 9 months, when participants will be queried on their actual risk behaviour. The study was developed by the authors and will be conducted by the market research institution IPSOS Health.

ETHICS AND DISSEMINATION

The study was approved by the Institutional Review Board of the Max Planck Institute for Human Development. Results will be disseminated through peer-reviewed journals, conference presentations and social media.

TRIAL REGISTRATION NUMBER

DRKS00020358.

Participants who were difficult to recruit at baseline are less likely to complete a follow-up questionnaire - results from the German National Cohort

Background

With declining response proportions in population-based research the importance of evaluating the effectiveness of measures aimed at improving response increases. We investigated whether an additional flyer with information about the study influences participation in a follow-up questionnaire and the time participants take to send back filled questionnaire.

Methods

In a trial embedded within the German National Cohort we compared responses to invitations for a follow-up questionnaire either including a flyer with information about the cohort study or not including it. Outcomes of interest were participation in the follow-up (yes vs. no) and time to response (in days). We analyzed paradata from baseline recruitment to account for differences in recruitment history between participants.

Results

Adding a flyer to invitations did neither influence the likelihood of participation in the follow-up (OR 0.94, 95% CI: 0.80, 1.11), nor the time it took participants to return completed questionnaires (β̂ = 1.71, 95% CI: − 1.01, 4.44). Subjects who, at baseline, needed to be reminded before eventually participating in examinations and subjects who scheduled three or more appointments until eventually completing baseline examinations were less likely to complete the follow-up questionnaire and, if they did, took more time to complete questionnaires.

Conclusions

Evaluating the effectiveness of measures aimed at increasing response can help to improve the allocation of usually limited resources. Characteristics of baseline recruitment can influence response to follow-up studies and therefore information about recruitment history (i.e., paradata) might prove useful to tailor follow-up recruitments to those who were difficult to recruit during baseline. To this end, however, it is necessary to routinely and meticulously collect paradata during recruitment.

Factors of non-responsive or lost-to-follow-up Japanese mothers during the first year post partum following the Japan Environment and Children's Study: a longitudinal cohort study

OBJECTIVES

We examined the factors related to lost-to-follow-up of a birth cohort study during the first year after delivery.

DESIGN

Longitudinal cohort study.

SETTING

Questionnaires were provided by mail. Mothers answered the questionnaires about the children twice: at 6 months and 1 year.

PARTICIPANTS

Of 103 062 pregnancies who consented to participate in the Japan Environment and Children's Study (JECS), 93 417 mothers were included in the study after excluding those with multiple births, miscarriages or stillbirths and those who withdrew from the study within 1 year after providing informed consent.

PRIMARY AND SECONDARY OUTCOME MEASURES

Participants' socioeconomic status, medical history, health status, health-related behaviours, their children's health conditions and living situations were collected by self-administered questionnaires during pregnancy or 1 month after delivery as the baseline survey. In addition, two self-administered questionnaires were distributed 6 months and 1 year after delivery. Using the response status of the two questionnaires after delivery, participants' follow-up status was divided into four groups. The related factors were examined using logistic regression analysis.

RESULTS

Factors positively correlated with lost-to-follow-up to the questionnaires were postpartum physical conditions, psychological distress during pregnancy, the child's health status at birth, the child's primary caregiver and the number of siblings of the child. Partners' active participation in JECS was associated with a lower lost-to-follow-up rate to the two questionnaires, whereas inactive participation was positively associated with a higher lost-to-follow-up rate.

CONCLUSION

The response rate to the questionnaires seems to be related to the interest and understanding of participants' partners. In addition, the response rates are related to participants' physical conditions and living conditions. To decrease lost-to-follow-up rates in consecutive questionnaire surveys within a cohort study, it may be important for investigators to recognise that participants and their motivation in research can be influenced by perceptions they may have regarding the objectives of the research.

Job type and other socio-demographic factors associated with participation in a national, cross-sectional study of Danish employees

OBJECTIVES

Participation in population-based surveys and epidemiological studies has been declining over the years in many countries. The aim of this study was to examine the association between job type and participation in the work environment and health in Denmark survey with/without taking into account other socio-demographic factors.

DESIGN

Cross-sectional survey using questionnaire data on working environment and registry data on job type, industry and socio-economic variables.

SETTING

The work environment and health study.

PARTICIPANTS

A total of 50 806 employees (15 767 in a stratified workplace sample; 35 039 in a random sample) working at least 35 hours/month and earning at least 3000 Danish Krones.

OUTCOME MEASURES

The outcome was participation (yes/no) and logistic regression was used to estimate the OR for participation with 95% CI.

RESULTS

In the random sample, women were more likely to participate than men, and married/non-married couples were more likely to participate than persons living alone or more families living together. Participation increased with higher age, higher annual personal income, higher education and Danish origin, and there were marked differences in participation between job types and geographical regions. For armed forces, craft and related trade workers, and skilled agricultural, forestry and fishery workers, the association between job type and participation was strongly attenuated after adjustment for sex and age. Additional adjustment for annual income, education, cohabitation, country of origin and geographical region generally attenuated the association between job type and participation. Similar results were found in the stratified workplace sample.

CONCLUSION

In this population of Danish employees, participation varied across types of jobs. Some but not all the variation between job types was explained by other socio-demographic factors. Future studies using questionnaires may consider targeting efforts to (sub-)populations, defined by job type and other factors, where response probability is particularly important.

Study invitations with envelopes made from recycled paper do not increase likelihood of active responses or study participation in the German National Cohort

OBJECTIVE

We conducted a trial embedded within the German National Cohort comparing the responses to study invitations sent in recycled envelopes of grey color vs. envelopes of white color. We analyzed paradata for reactions to the invitation letters by potential subjects, the duration between mailing date of the invitation and active responses, and study participation.

RESULTS

Grey envelopes only slightly increased the chance of active responses (OR 1.16, 95% CI 0.83, 1.62) to the invitation letter. Potential study subjects with German nationality (OR 3.75, 95% CI 2.07, 7.66) and age groups above 50 years (50-59: OR 1.78, 95% CI 1.19, 2.69; 60-69: OR 2.25, 95% CI 1.48, 3.43) were more likely to actively respond to the invitation letter. The duration between mailing date of the invitation and active response was not associated with envelope color, sex, nationality, or age. Our trial replicates previous observations that the color of the envelope of a study invitation does not influence the likelihood of an active response or study participation.

Evaluating selection bias in a population-based cohort study with low baseline participation: the LIFE-Adult-Study

Background

Participation in epidemiologic studies is steadily declining, which may result in selection bias. It is therefore an ongoing challenge to clarify the determinants of participation to judge possible selection effects and to derive measures to minimise that bias. We evaluated the potential for selection bias in a recent population-based cohort study with low baseline participation and investigated reasons for nonparticipation.

Methods

LIFE-Adult is a cohort study in the general population of the city of Leipzig (Germany) designed to gain insights into the distribution and development of civilisation diseases. Nine thousand one hundred forty-five participants aged 40–79 years were randomly sampled in 2011–2014. We compared LIFE-Adult participants with both the Leipzig population and nonparticipants using official statistics and short questionnaire data. We applied descriptive statistics and logistic regression analysis to evaluate the determinants of study participation.

Results

Thirty-one percent of the invited persons participated in the LIFE-Adult baseline examination. Study participants were less often elderly women and more often married, highly educated, employed, and current nonsmokers compared to both the Leipzig population and nonparticipants. They further reported better health than nonparticipants. The observed differences were considerable in education and health variables. They were generally stronger in men than in women. For example, in male study participants aged 50–69, the frequency of high education was 1.5 times that of the general population, and the frequency of myocardial infarction was half that of nonparticipants. Lack of time and interest, as well as health problems were the main reasons for nonparticipation.

Conclusions

Our investigation suggests that the low baseline participation in LIFE-Adult is associated with the typical selection of study participants with higher social status and healthier lifestyle, and additionally less disease. Notably, education and health status seem to be crucial selection factors. Consequently, frequencies of major health conditions in the general population will likely be underestimated. A differential selection related to sex might also distort effect estimates. The extent of the assessment, the interest in the research topic, and health problems of potential participants should in future be considered in LIFE-Adult and in similar studies to raise participation and to minimise selection bias.

Electronic supplementary material

The online version of this article (10.1186/s12874-019-0779-8) contains supplementary material, which is available to authorized users.

Analysis of non-respondent pregnant women who were registered in the Japan Environment and Children's Study: a longitudinal cohort study

OBJECTIVES

Non-response to questionnaires in a longitudinal study reduces the effective sample size and introduces bias. We identified the characteristics of non-respondent pregnant women, and compared them with respondents in the Japan Environment and Children's Study (JECS) during the gestational period.

DESIGN

This was a questionnaire-based, longitudinal cohort study.

SETTING

Questionnaires were provided by research coordinators to mothers at prenatal examinations (at obstetrics clinics) or by mail. Mothers were measured twice: during the first trimester and during the second/third trimester.

PARTICIPANTS

Data were collected from the 10 129 participating mothers of the 10 288 children surveyed in the 2011 baseline JECS. We excluded responses from mothers who had a miscarriage or stillbirth; therefore, we analysed data from 9649 participants.

PRIMARY AND SECONDARY OUTCOME MEASURES

Data concerning demographics, medical history, health characteristics, health-related behaviour and environmental exposure were collected via self-administered questionnaires. The response status of participants' partners and contact with their obstetrician were also examined. Multivariate logistic regression analysis was used to examine factors related to non-response.

RESULTS

Response was associated with living with one's mother-in-law (ORs: 0.47, 95% CIs: 0.24 to 0.85), positive participation of participants' partner (OR: 0.25, 95% CI: 0.17 to 0.35) and multiple visits to the obstetrician (OR: 0.02, 95% CI: 0.02 to 0.03). Participants who had a medical history of allergic rhinitis, had body pain or drank alcohol had higher odds of responding (ORs: 0.68, 0.96 and 0.36, 95% CIs: 0.48 to 0.95 and 0.95 to 0.98 and 0.16 to 0.72, respectively); those exposed to secondary smoke had lower odds of responding (OR: 1.59, 95% CI: 1.12 to 2.23).

CONCLUSIONS

The non-response rate decreased when participants reported health-related behaviour or characteristics. Obtaining the understanding of people around each participant might help increase response rates.

Cross-sectional International Multicenter Study on Quality of Life and Reasons for Abandonment of Upper Limb Prostheses

Background:

This multicenter study aimed to examine the reasons for prosthesis rejection and assess the quality of life (QOL) among patients with upper limb deficiency.

Methods:

Three rehabilitation centers in Japan and 1 academic medical center in the United States participated. Patients between the age of 12 and 75 years with unilateral or bilateral upper limb absence from the level of wrist to shoulder disarticulation were included. Two questionnaires were used, an original questionnaire on prosthesis use and the EQ-5D, which were completed by both the participant and a live-in proxy.

Results:

Of the 367 patients with upper limb loss invited, 174 patients participated in this study. Eighty percent of the study population were male patients. The most common amputation level was transradial. Trauma was the most common cause of limb loss. The prosthesis rejection rate was 9% (n = 16). The most common reason for abandonment was a lack of prosthesis functionality. Ten of 16 prosthesis nonusers (63%) and 59 prosthesis users (38%) were unemployed or students. The mean EQ-5D utility score was significantly higher in prosthesis users than in nonusers (0.762 versus 0.628, P < 0.01). Live-in proxies significantly overestimated QOL in male patients (0.77 versus 0.807, P=0.01).

Conclusions:

The current prosthesis rejection rate is low. QOL was significantly higher in prosthesis users than in nonusers. More prosthesis users were employed compared with nonusers. Care should be taken not to overestimate the QOL of male patients with upper limb loss as their proxies often did.

Factors associated with unwillingness to seek professional help for depression: a web-based survey

Objective

Depression is a prevalent disorder that has a substantial impact on not only individuals but also society as a whole. Despite many effective depression interventions, delay in initial treatment contact is problematic. The Internet is a possible tool for low-cost dissemination of appropriate information and awareness raising about depressive disorders among the general public. This study aimed to identify factors associated with unwillingness to seek professional help for depression in Internet users.

Results

This web-based cross-sectional study surveyed 595 participants who scored over the cutoff point for depression on a self-rated mental-health questionnaire for depression, had never been assessed or treated by a mental health professional, and were experiencing depressive symptoms for at least 6 months. Among the 595 participants, 329 (55.3%) reported they were unwilling to seek professional help for depression. Regression analysis indicated that unwillingness to seek professional help for depression was associated with male sex and financial issues as a depression trigger, and that willingness to seek professional help was associated with problems with interpersonal relationships. The Internet warrants further complementary investigation to elucidate factors associated with unwillingness to seek professional help for depression.

A systematic review and development of a classification framework for factors associated with missing patient-reported outcome data

BACKGROUND/AIMS

Missing patient-reported outcome data can lead to biased results, to loss of power to detect between-treatment differences, and to research waste. Awareness of factors may help researchers reduce missing patient-reported outcome data through study design and trial processes. The aim was to construct a Classification Framework of factors associated with missing patient-reported outcome data in the context of comparative studies. The first step in this process was informed by a systematic review.

METHODS

Two databases (MEDLINE and CINAHL) were searched from inception to March 2015 for English articles. Inclusion criteria were (a) relevant to patient-reported outcomes, (b) discussed missing data or compliance in prospective medical studies, and (c) examined predictors or causes of missing data, including reasons identified in actual trial datasets and reported on cover sheets. Two reviewers independently screened titles and abstracts. Discrepancies were discussed with the research team prior to finalizing the list of eligible papers. In completing the systematic review, four particular challenges to synthesizing the extracted information were identified. To address these challenges, operational principles were established by consensus to guide the development of the Classification Framework.

RESULTS

A total of 6027 records were screened. In all, 100 papers were eligible and included in the review. Of these, 57% focused on cancer, 23% did not specify disease, and 20% reported for patients with a variety of non-cancer conditions. In total, 40% of the papers offered a descriptive analysis of possible factors associated with missing data, but some papers used other methods. In total, 663 excerpts of text (units), each describing a factor associated with missing patient-reported outcome data, were extracted verbatim. Redundant units were identified and sequestered. Similar units were grouped, and an iterative process of consensus among the investigators was used to reduce these units to a list of factors that met the guiding principles. The list was organized on a framework, using an iterative consensus-based process. The resultant Classification Framework is a summary of the factors associated with missing patient-reported outcome data described in the literature. It consists of 5 components (instrument, participant, centre, staff, and study) and 46 categories, each with one or more sub-categories or examples.

CONCLUSION

A systematic review of the literature revealed 46 unique categories of factors associated with missing patient-reported outcome data, organized into 5 main component groups. The Classification Framework may assist researchers to improve the design of new randomized clinical trials and to implement procedures to reduce missing patient-reported outcome data. Further research using the Classification Framework to inform quantitative analyses of missing patient-reported outcome data in existing clinical trials and to inform qualitative inquiry of research staff is planned.

Establishment of a cohort for deep phenotyping of the immune response to influenza vaccination among elderly individuals recruited from the general population

Elderly individuals have the highest burden of disease from influenza infection but also the lowest immune response to influenza vaccination. A better understanding of the host response to influenza vaccination in the elderly is therefore urgently needed. We conducted a biphasic prospective, population-based study from Dec. 2014 to May 2015 (pilot study) and Sept. 2015 to May 2016 (main study). Individuals 65-80 y of age were randomly selected from the residents' registration office in Hannover, Germany, for the pilot (n = 34) and main study (n = 200). The pilot study tested recruitment for study arms featuring 2, 4, or 5 visits/blood draws. The 5-visit (day 0, 1/3, 7, 21, 70 with respect to vaccination) study arm was selected for the main study. Both studies featured vaccination with Fluad™ (Novartis, Italy), a detailed medical history, a physical exam, recording of adverse events, completion of a questionnaire on common infections and an end-of-study questionnaire, and blood samples. Response rates in the pilot and main studies were 3.7% and 4.0%, respectively. Willingness to participate did not differ among the study arms (Fisher's exact test, p = 0.44). In both studies, there were no losses to follow-up. Compliance with study visits, blood sampling and completion of the questionnaires was very high (100%, >97%, 100%, respectively), as were participants' acceptance of and satisfaction with both phases of the study. The low response rates indicate the need for optimized recruitment strategies if the study population is to be representative of the general population. Nonetheless, the complex prospective study design proved to be highly feasible.

A two-phase sampling survey for nonresponse and its paradata to correct nonresponse bias in a health surveillance survey

BACKGROUND

The decline in participation rates in surveys, including epidemiological surveillance surveys, has become a real concern since it may increase nonresponse bias. The aim of this study is to estimate the contribution of a complementary survey among a subsample of nonrespondents, and the additional contribution of paradata in correcting for nonresponse bias in an occupational health surveillance survey.

METHODS

In 2010, 10,000 workers were randomly selected and sent a postal questionnaire. Sociodemographic data were available for the whole sample. After data collection of the questionnaires, a complementary survey among a random subsample of 500 nonrespondents was performed using a questionnaire administered by an interviewer. Paradata were collected for the complete subsample of the complementary survey. Nonresponse bias in the initial sample and in the combined samples were assessed using variables from administrative databases available for the whole sample, not subject to differential measurement errors. Corrected prevalences by reweighting technique were estimated by first using the initial survey alone and then the initial and complementary surveys combined, under several assumptions regarding the missing data process. Results were compared by computing relative errors.

RESULTS

The response rates of the initial and complementary surveys were 23.6% and 62.6%, respectively. For the initial and the combined surveys, the relative errors decreased after correction for nonresponse on sociodemographic variables. For the combined surveys without paradata, relative errors decreased compared with the initial survey. The contribution of the paradata was weak.

CONCLUSION

When a complex descriptive survey has a low response rate, a short complementary survey among nonrespondents with a protocol which aims to maximize the response rates, is useful. The contribution of sociodemographic variables in correcting for nonresponse bias is important whereas the additional contribution of paradata in correcting for nonresponse bias is questionable.

Unit Nonresponse in a Population-Based Study of Prostate Cancer

Low unit response rates can increase bias and compromise study validity. Response rates have continued to fall over the past decade despite all efforts to increase participation. Many factors have been linked to reduced response, yet relatively few studies have employed multivariate approaches to identify characteristics that differentiate respondents from nonrespondents since it is hard to collect information on the latter. We aimed to assess factors contributing to enrollment of prostate cancer (PCa) patients. We combined data from the North Carolina-Louisiana (LA) PCa Project's LA cohort, with additional sources such as US census tract and LA tumor registry data. We included specific analyses focusing on blacks, a group often identified as hard to enroll in health-related research. The ability to study the effect of Hurricane Katrina, which occurred amidst enrollment, as a potential determinant of nonresponse makes our study unique. Older age (≥ 70) for blacks (OR 0.65) and study phase with respect to Hurricane Katrina for both races (OR 0.59 for blacks, OR 0.48 for whites) were significant predictors of participation with lower odds. Neighborhood poverty for whites (OR 1.53) also was a significant predictor of participation, but with higher odds. Among blacks, residence in Orleans parish was associated with lower odds of participation (OR 0.33) before Katrina. The opposite occurred in whites, with lower odds (OR 0.43) after Katrina. Our results overall underscore the importance of tailoring enrollment approaches to specific target population characteristics to confront the challenges posed by nonresponse. Our results also show that recruitment-related factors may change when outside forces bring major alterations to a population's environment and demographics.

Boys and Road Rage: Driving-Related Violence and Aggression in Western Australia

This article reports on the results of a population survey of 1208 West Australian drivers designed to measure the prevalence of drivingrelated violence and aggression as well as perceptions of these behaviours. A clear distinction is made between driving-related violence (restricted to criminal acts of violence, threats of violence and vehicle damage) and other aggressive driving behaviours. Although the majority of survey respondents had experienced some form of aggressive driving behaviour, only 13% reported ever being a victim of driving-related violence. However, 17% of respondents believed they were likely, or very likely, to be a victim of driving-related violence within the coming year. More than two thirds of respondents thought their likelihood of being a victim of driving-related violence had increased over the past 10 years. Both aggressive driving behaviours and driving-related violence were typically perpetrated by young males against other males. The article concludes with a discussion of the masculinist characteristics of road rage and what this implies for the prevention of this crime.

Selection bias in follow-up interviews with individuals attending the emergency department for occupational injuries

OBJECTIVE

To examine whether supplementary interview participation was comparable for occupationally injured patients attending two hospital emergency departments and to investigate the magnitude of selection bias in relation to sex, age, severity, job tasks and industry risk level.

METHODS

Workers aged 18-70 years who contacted the two emergency departments for an acute occupational injury in 2013 were eligible and given a short questionnaire. Following written consent, a semi-structured interview concerning health and transient risk factors was conducted by telephone. The two departments were compared for study recruitment by age and sex. Respondents and non-respondents to the interview were compared for age, sex, injury severity, job tasks and industry risk level.

RESULTS

Of 4002 patients attending the two hospitals, 1693 (42%) participated in the interview. One hospital had a markedly higher response rate to the questionnaire, but the proportions of participation in the interview were similar in the two hospitals. Patients aged <30 years were over-represented among non-respondents whereas sex, injury severity, job task and industry risk level were not significantly different between respondents and non-respondents.

CONCLUSIONS

Despite a relatively low interview participation rate among injured individuals attending the emergency department, selection bias was limited. This indicates that results regarding injury risk patterns may be more widely generalisable when examining the causality of occupational injuries. However, the study also showed that young injured workers were less likely to participate in follow-up interviews, which is an important factor when interpreting age-related risk of injury.

Relationship between respiratory and food allergy and evaluation of preventive measures

Food allergy and respiratory allergy are two frequently associated diseases and with an increasing prevalence. Several reports show the presence of respiratory symptoms in patients with food allergy, while certain foods may be related to the development or exacerbation of allergic rhinitis and asthma. The present update focuses on this relationship, revealing a pathogenic and clinical association between food and respiratory allergy. This association is even more intense when the food hypersensitivity is persistent or starts in the early years of life. Food allergy usually precedes respiratory allergy and may be a risk factor for allergic rhinitis and asthma, becoming a relevant clinical marker for severe atopic asthma. Furthermore, the presence of co-existing asthma may enhance life-threatening symptoms occurring during a food allergic reaction. Recommendations for dietary restrictions during pregnancy and breastfeeding to prevent the development of respiratory allergy are controversial and not supported by consistent scientific data. Current recommendations from medical societies propose exclusive breastfeeding during the first four months of life, with the introduction of solid food in the fourth to the seventh month period of life. A delayed introduction of solid food after this period may increase the risk of developing subsequent allergic conditions. Further studies are encouraged to avoid unjustified recommendations involving useless dietary restrictions.

Is self-selection the main driver of positive interpretations of general health checks? The Inter99 randomized trial

OBJECTIVE

To investigate if the lower mortality among participants of a health check followed by lifestyle intervention of high risk persons is explained by self-selection.

METHODS

All persons residing in the study area (Copenhagen; Denmark) were randomized to intervention (n=11,629) or control group (n=47,987). Persons in the intervention group were invited for a health check and individual lifestyle counselling. At baseline, 52.5% participated. Differences between participants and control group in 10-year all-cause and disease specific mortality was assessed. In survival analyses we controlled for socio-demography and mental and physical health.

RESULTS

Mortality rates were highest among non-participants and lowest among participants in the intervention group, whereas mortality rates of controls were approximately the average of those of participants and non-participants. In adjusted analyses the difference in both all-cause mortality (HR 0.73, 95% CI 0.62-0.85) and disease specific mortality was diminished between participants and controls, and turning insignificant as regard cancer mortality. In total, 39% of the lower mortality among participants in the intervention group was explained by self-selection according to socio-demography and health.

CONCLUSION

A substantial part of the lower mortality among participants in a preventive health check can be explained by confounding. The remaining lower mortality is most probably due to residual confounding, as the lower mortality was seen both for lifestyle related and non-lifestyle related diseases.

Assessment of participation bias in cohort studies: systematic review and meta-regression analysis

Abstract The proportion of non-participation in cohort studies, if associated with both the exposure and the probability of occurrence of the event, can introduce bias in the estimates of interest. The aim of this study is to evaluate the impact of participation and its characteristics in longitudinal studies. A systematic review (MEDLINE, Scopus and Web of Science) for articles describing the proportion of participation in the baseline of cohort studies was performed. Among the 2,964 initially identified, 50 were selected. The average proportion of participation was 64.7%. Using a meta-regression model with mixed effects, only age, year of baseline contact and study region (borderline) were associated with participation. Considering the decrease in participation in recent years, and the cost of cohort studies, it is essential to gather information to assess the potential for non-participation, before committing resources. Finally, journals should require the presentation of this information in the papers.

Participation rates, response bias and response behaviours in the community survey of the Swiss Spinal Cord Injury Cohort Study (SwiSCI)

Background

Surveying persons with disabilities is challenging, as targeted subjects may experience specific barriers to survey participation. Here we report on participation rates and response behaviour in a community survey of people with spinal cord injury (SCI) in Switzerland. The cross-sectional survey was implemented as part of the Swiss Spinal Cord Injury Cohort Study (SwiSCI) and represents the largest population-based SCI survey in Europe including nearly 2000 persons. Design features to enhance participation rates included the division of the questionnaire volume over three successive modules; recurrent and mixed-mode reminding of non-responders; and mixed-mode options for response.

Methods

We describe participation rates of the SwiSCI community survey (absolute and cumulative cooperation, contact, response, and attrition rates) and report on response rates in relation to recruitment efforts. Potential non-response bias and the association between responders’ characteristics and response behaviour (response speed: reminding until participation; response mode: paper-pencil vs. online completion) were assessed using regression modelling.

Results

Over the successive modules, absolute response rates were 61.1, 80.6 and 87.3 % which resulted in cumulative response rates of 49.3 and 42.6 % for the second and third modules. Written reminders effectively increased response rates, with the first reminder showing the largest impact. Telephone reminders, partly with direct telephone interviewing, enhanced response rate to the first module, but were essentially redundant in subsequent modules. Non-response to the main module was related to current age, membership of Swiss Paraplegic Association (SPA) and time since injury, but not to gender, lesion level and preferred language of response. Response speed increased with household income, but was not associated to other sociodemographic factors, lesion characteristics or health indicators. We found significant associations between online completion and male gender, younger age, higher education, higher income, SPA membership, tetraplegia, longer time since injury, higher quality of life, and more participation restrictions.

Conclusion

In this sample with little non-response bias, recurrent and mixed-mode reminding and mixed-mode options for response were key features of optimizing survey design.

Alcohol consumption, drinking patterns, and cognitive function in older Eastern European adults

Objective:

To investigate associations of frequency, quantity, binge, and problem drinking with cognitive function in older Eastern European adults.

Methods:

The investigation included 14,575 participants, aged 47 to 78 years at cognitive assessment in 2006–2008 from Novosibirsk (Russia), Krakow (Poland), and 6 Czech towns participating in the HAPIEE (Health, Alcohol, and Psychosocial Factors in Eastern Europe) prospective cohort study. Average response rates were 59% at baseline (2002–2005) and 63% in 2006–2008. Alcohol consumption was assessed at baseline and in 2006–2008. Cognitive tests included immediate and delayed word recall, semantic fluency (animal naming), and letter cancellation. Associations between alcohol indices and cognitive scores were analyzed cross-sectionally (all measures from 2006 to 2008) and prospectively (alcohol and covariates from 2002 to 2005 and cognition from 2006 to 2008).

Results:

In cross-sectional analyses, nondrinkers had lower cognitive scores and female moderate drinkers had better cognitive performance than light drinkers. Heavy, binge, and problem drinking were not consistently associated with cognitive function. Few associations were replicated in prospective analyses. Participants who stopped drinking during follow-up had worse cognition than stable drinkers; in men, regression coefficients (95% confidence interval) ranged from −0.26 (−0.36, −0.16) for immediate recall to −0.14 (−0.24, −0.04) for fluency.

Conclusion:

Regular and episodic heavy drinking were not consistently associated with cognitive function. Worse cognition in participants who stopped drinking during follow-up suggests that inclusion of less healthy ex-drinkers may partly explain poorer cognition in nondrinkers.

[The first KiGGS follow-up (KiGGS Wave 1): study conduct, sample design, and response]

The "German Health Interview and Examination Survey for Children and Adolescents" (KiGGS) is part of the health monitoring system of the Robert Koch Institute (RKI). Following the KiGGS baseline study (2003 - 06), which comprised interviews and physical examinations of 0- to 17-year-old participants, KiGGS Wave 1 (2009 - 2012) was carried out as a telephone-based survey. In addition to providing longitudinal data, a second essential aim of KiGGS is to regularly provide population-based cross-sectional data on the health situation of children and adolescents aged 0-17 years living in Germany. Therefore, the study population of KiGGS Wave 1 consists of re-invited participants from the baseline study (KiGGS cohort), supplemented by newly invited children aged 0-6 years. The newly invited participants were randomly chosen from local population registries in the 167 baseline sample points. This method was chosen to supplement the sample with younger age groups. This article focuses on the age groups from 0 to 17 years, which are relevant for prevalence estimations among children and adolescents. In total 12,368 children and adolescents took part; among them 4,455 newly invited and 7,913 re-invited participants (response 38.8 and 72.9%, respectively). A comparison of the net sample with the resident German population (0-17 years) regarding particular population characteristics and an analysis of the relationship between the re-participation rate and certain characteristics collected in the baseline study (7-17 years) suggest a mostly unbiased sample. To account for certain aspects of the population and nonresponse, cross-sectional and trend analyses were partially corrected by weighting factors.

Household and occupational exposure to pesticides and risk of breast cancer

The association between breast cancer in women and the use of household or occupational pesticides was examined in a population-based case-control study. This study was conducted in Western Australia in 2009-2011 and included 1,789 controls and 1,205 cases. Information on household pesticide exposure was collected from questionnaires. For occupational pesticide exposure, job-specific modules (JSMs) were used. To evaluate potential recall bias, we stratified the analysis by belief about whether pesticides contribute to breast cancer. Unconditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Women's exposures to pesticides in households and workplaces were not related to increased risk of breast cancer (OR = 1.10; CI: 0.86-1.37) and (OR = 0.77; CI: 0.45-1.32), respectively. The prevalence of occupational exposure to pesticides among women in our study was low. In the stratified analyses, the odd ratios associated with household pesticide use were similar among participants who believed pesticides increased breast cancer risk and those who did not. The results of our study did not show associations between breast cancer and household or occupational exposure to pesticides.

Specific impairment of functional connectivity between language regions in former early preterms

Very preterm (PT) birth (≤32 weeks of gestation) carries a high risk for an adverse neurodevelopmental outcome. In recent years, the importance of neurocognitive deficits in the language domain has been increasingly recognized, which can be well-characterized using neuropsychological testing and noninvasive imaging approaches. We compared former early PT born children and adolescents (PT, n = 29, 20M) and typically developing children (TD, n = 19, 7M), using conventional fMRI group analyses as well as functional connectivity analyses. We found only small regions with significantly different group activation (PT > TD) but significantly stronger connectivity between superior temporal lobe (STL) language regions in TD participants. There were also significant differences in local and global network efficiency (TD > PT). Surprisingly, there was a stronger connectivity of STL regions with non-STL regions both intrahemispherically and interhemispherically in PT participants, suggesting the coexistence of reduced and increased connectivity in the language network of former PTs. Very similar results were obtained when using task-based versus resting state functional connectivity approaches. Finally, lateralization of functional connectivity correlated with verbal comprehension abilities, suggesting that a more bilateral language comprehension representation is associated with better performance. Our results underline the importance of interhemispheric crosstalk for language comprehension.

What influences the decision to participate in colorectal cancer screening with faecal occult blood testing and sigmoidoscopy?

INTRODUCTION

Uptake is an important determinant of the effectiveness of population-based screening. Uptake of colorectal cancer (CRC) screening generally remains sub-optimal.

AIM

To determine factors influencing the decision whether to participate or not among individuals invited for faecal occult blood test (FOBT) or flexible sigmoidoscopy (FS) screening.

METHODS

A questionnaire was sent to a stratified random sample of individuals aged 50-74, previously invited for a randomised CRC screening trial offering FOBT or FS, and a reference group from the same population not previously invited (screening naïve group). The questionnaire assessed reasons for (non)-participation, individuals' characteristics associated with participation, knowledge, attitudes and level of informed choice.

RESULTS

The response rate was 75% (n=341/452) for CRC screening participants, 21% (n=676/3212) for non-participants and 38% (n=192/500) for screening-naïve individuals. The main reasons for FOBT and FS participation were acquiring certainty about CRC presence and possible early CRC detection. Anticipated regret and positive attitudes towards CRC screening were strong predictors of actual participation and intention to participate in a next round. The main reason for non-participation in FOBT screening was lack of abdominal complaints. Non-participation in FS screening was additionally influenced by worries about burden. Eighty-one percent of participants and 12% of non-participants made an informed choice on participation.

CONCLUSION

Only 12% of non-participants made an informed choice not to participate. These results imply that governments and/or organizations offering screening should focus on adequately informing and educating target populations about the harms and benefits of CRC screening. This may impact uptake of CRC screening.

The sixth survey of the Tromso Study (Tromso 6) in 2007-08: collaborative research in the interface between clinical medicine and epidemiology: study objectives, design, data collection procedures, and attendance in a multipurpose population-based health survey

AIMS

To provide a synopsis of the sixth survey of the Tromsø Study, Tromsø 6, objectives and new target areas, study design, follow-up studies, data collection, attendance, and participant characteristics.

METHODS

The Tromsø Study, initiated in 1974, is an epidemiological, prospective study of health conditions and chronic diseases, and a resource for the surveillance of disease risk factors. The purpose of Tromsø 6 (2007-08) was to collect novel and repeated measurements of exposure data and to assess levels of disease risk factors. Tromsø 6 included a main study that comprised two screening visits and several follow-up studies. Main study data collection: First visit (n=12,984): questionnaires, interviews, measurements of height, weight, hip and waist circumference, heart rate, blood pressure, forearm bone density, grip strength, pain sensitivity measurements, and blood and hair samples and nose and throat swab cultures. Second visit (n=7307): sampling of biological specimens (blood, urine, nose and throat swab cultures) and clinical examinations (12-lead electrocardiography, cognitive tests, visual acuity test, retinal photography, carotid ultrasound, spirometry, dual-energy X-ray absorptiometry, and echocardiography.

RESULTS

A total of 12,984 participants aged 30-87 years were examined. The attendance rate was 66%, lower than in previous Tromsø Study surveys. The attendance was lowest in the youngest and oldest, those invited for the first time, and lower in men than women.

CONCLUSIONS

The completion of the survey with this comprehensive data collection went satisfactorily. The decreasing attendance rate calls for new recruitment strategies and optimisation of the study organisation to facilitate attendance.

Bias in clinical epidemiological study designs

Systematic error, or bias, is error that occurs in each measurement made and which has a direction, i.e., the measured value is always either greater or smaller than the true value. The presence of systematic error directly affects the internal validity of the study, and indirectly affects the external validity of the results obtained. In general, such error can be classified as selection bias, classification bias or confounding bias. It is essential to deal with possible bias in the research design phase, since only confounding bias can be controlled in the phase corresponding to analysis of the results.

Socioeconomic status and children's mental health: results from the Bergen Child Study

PURPOSE

It is generally accepted that mental health problems are unequally distributed across population strata defined by socioeconomic status (SES), with more problems for those with lower SES. However, studies of this association in children and adolescents are often restricted by the use of global measures of mental health problems and aggregation of SES-indicators. We aim to further elucidate the relationship between childhood mental health problems and SES by including more detailed information about mental health and individual SES-indicators.

METHODS

The participants (N = 5,781, age 11-13) were part of the Bergen Child Study (BCS). Mental health was assessed using the teacher, parent and self-report versions of the Strengths and Difficulties Questionnaire (SDQ), including an impact section, used to measure symptom dimensions and probability of psychiatric disorders. Parent reports of family economy and parental education were used as SES measures.

RESULTS

For each SES indicator we confirmed an inverse relationship across all the symptom dimensions. Poor family economy consistently predicted mental health problems, while parental education level predicted externalizing disorders stronger than internalizing disorders.

CONCLUSION

In this Norwegian sample of children, family economy was a significant predictor of mental health problems as measured across a wide range of symptom dimensions and poor economy predicted a high probability of a psychiatric disorder. Longitudinal studies of the impact of low family income as well as other SES factors on externalizing and internalizing symptom dimensions and disorders are called for.

Determinants of non- response to a second assessment of lifestyle factors and body weight in the EPIC-PANACEA study

Background

This paper discusses whether baseline demographic, socio-economic, health variables, length of follow-up and method of contacting the participants predict non-response to the invitation for a second assessment of lifestyle factors and body weight in the European multi-center EPIC-PANACEA study.

Methods

Over 500.000 participants from several centers in ten European countries recruited between 1992 and 2000 were contacted 2–11 years later to update data on lifestyle and body weight. Length of follow-up as well as the method of approaching differed between the collaborating study centers. Non-responders were compared with responders using multivariate logistic regression analyses.

Results

Overall response for the second assessment was high (81.6%). Compared to postal surveys, centers where the participants completed the questionnaire by phone attained a higher response. Response was also high in centers with a short follow-up period. Non-response was higher in participants who were male (odds ratio 1.09 (confidence interval 1.07; 1.11), aged under 40 years (1.96 (1.90; 2.02), living alone (1.40 (1.37; 1.43), less educated (1.35 (1.12; 1.19), of poorer health (1.33 (1.27; 1.39), reporting an unhealthy lifestyle and who had either a low (<18.5 kg/m2, 1.16 (1.09; 1.23)) or a high BMI (>25, 1.08 (1.06; 1.10); especially ≥30 kg/m2, 1.26 (1.23; 1.29)).

Conclusions

Cohort studies may enhance cohort maintenance by paying particular attention to the subgroups that are most unlikely to respond and by an active recruitment strategy using telephone interviews.

The HUNT study: participation is associated with survival and depends on socioeconomic status, diseases and symptoms

Background

Population based studies are important for prevalence, incidence and association studies, but their external validity might be threatened by decreasing participation rates. The 50 807 participants in the third survey of the HUNT Study (HUNT3, 2006-08), represented 54% of the invited, necessitating a nonparticipation study.

Methods

Questionnaire data from HUNT3 were compared with data collected from several sources: a short questionnaire to nonparticipants, anonymous data on specific diagnoses and prescribed medication extracted from randomly selected general practices, registry data from Statistics Norway on socioeconomic factors and mortality, and from the Norwegian Prescription Database on drug consumption.

Results

Participation rates for HUNT3 depended on age, sex and type of symptoms and diseases, but only small changes were found in the overall prevalence estimates when including data from 6922 nonparticipants. Among nonparticipants, the prevalences of cardiovascular diseases, diabetes mellitus and psychiatric disorders were higher both in nonparticipant data and data extracted from general practice, compared to that reported by participants, whilst the opposite pattern was found, at least among persons younger than 80 years, for urine incontinence, musculoskeletal pain and headache. Registry data showed that the nonparticipants had lower socioeconomic status and a higher mortality than participants.

Conclusion

Nonparticipants had lower socioeconomic status, higher mortality and showed higher prevalences of several chronic diseases, whilst opposite patterns were found for common problems like musculoskeletal pain, urine incontinence and headache. The impact on associations should be analyzed for each diagnosis, and data making such analyses possible are provided in the present paper.

A country not divided: A comparison of public punitiveness and confidence in sentencing across Australia

Changes to sentencing legislation are often introduced or justified on the basis of satisfying public opinion. If sentencing policy is a reflection of public opinion we should see a concordance between different sentencing policies and public opinion. This paper provides a comparison between Australian States and Territories in terms of two key measures of public attitude concerning sentencing: confidence in sentencing and punitiveness. These results are based on acomprehensive telephone survey ( N = 6005) of Australian adults which utilized a stratified random sample of households from the Electronic White Pages. It was found that there were only minor differences in the key measures of public attitude despite the notable differences between the States and Territories of Australia with respect to sentencing policy. Differences in public attitudes across jurisdictions were small, accounting for less than 2 per cent of variation in confidence in sentencing and punitive attitudes scores. In addition, despite the predicted moderately negative association between confidence in sentencing and punitiveness, neither of these variables was related in any systematic way to jurisdictional differences in imprisonment rates. The major implication of these findings is that the wide differences in sentencing practice and policy between jurisdictions in Australia are not linked to differences in public attitudes, supporting Beckett's (1997) argument that sentencing policy is better understood as a function of political initiative rather than a direct articulation of public attitude.

Comparison of early-, late-, and non-participants in a school-based asthma management program for urban high school students

Background

To assess bias and generalizability of results in randomized controlled trials (RCT), investigators compare participants to non-participants or early- to late-participants. Comparisons can also inform the recruitment approach, especially when working with challenging populations, such as urban adolescents. In this paper, we describe characteristics by participant status of urban teens eligible to participate in a RCT of a school-based, web-based asthma management program.

Methods

The denominator for this analysis was all students found to be eligible to participate in the RCT. Data were analyzed for participants and non-participants of the RCT, as well as for students that enrolled during the initially scheduled recruitment period (early-participants) and persons that delayed enrollment until the following fall when recruitment was re-opened to increase sample size (late-participants). Full Time Equivalents (FTEs) of staff associated with recruitment were estimated.

Results

Of 1668 teens eligible for the RCT, 386 enrolled early, and 36 enrolled late, leaving 1246 non-participants. Participants were younger (p < 0.01), more likely to be diagnosed, use asthma medication, and have moderate-to-severe disease than non-participants, odds ratios (95% Confidence Intervals) = 2.1(1.7-2.8), 1.7(1.3-2.1), 1.4(1.0-1.8), respectively. ORs were elevated for the association of late-participation with Medicaid enrollment, 1.9(0.7-5.1) and extrinsic motivation to enroll, 1.7(0.6-5.0). Late-participation was inversely related to study compliance for teens and caregivers, ORs ranging from 0.1 to 0.3 (all p-values < 0.01). Early- and late-participants required 0.45 FTEs/100 and 3.3 FTEs/100, respectively.

Conclusions

Recruitment messages attracted youth with moderate-to-severe asthma, but extending enrollment was costly, resulting in potentially less motivated, and certainly less compliant, participants. Investigators must balance internal versus external validity in the decision to extend recruitment. Gains in sample size and external validity may be offset by the cost of additional staff time and the threat to internal validity caused by lower participant follow-up.

Trial Registration

ClinicalTrials.gov: NCT00201058

Non-response bias in a surveillance program for asbestos-related lung cancer

OBJECTIVES

In a cohort study non-response might lead to a biased selection of cohort members and may affect the validity and reliability of the study outcome. To detect the possible effects of a non-response bias on study results, we evaluated the reasons for non-participation and the differences of respondents and non-respondents in a health surveillance program for power industry workers, formerly exposed to asbestos.

METHODS

A cohort of former power plant workers was formed to participate in an early detection program for lung cancer. We evaluated the results of 1,019 individuals (mean age 66 yr), of which 839 took part in at least one examination, 180 refused to participate or did not respond. To obtain the reasons for non-response, we interviewed the cohort members by telephone or we requested them by mail to complete and return a brief questionnaire. Further sources of information were the communal registration offices and local health offices.

RESULTS

The main reasons for non-participation were refusal (35%), illness (23.3%), death (16.7%) and difficulties with traveling (13.3%). It was impossible to make contact with or obtain an explanation from 11.7%. In a logistic regression model we demonstrated that advanced age and a long travel distance from the study center negatively affected the participation rate (p<0.001). There was no difference between respondents and non-respondents regarding prevalence (p=0.559) and incidence of lung cancer (p=0.882).

CONCLUSION

We concluded that in our cohort non-participation did not cause a selection bias in terms of lung cancer rates.

Does problem behaviour affect attrition from a cohort study on adolescent mental health?

BACKGROUND

Most surveys are plagued by significant numbers of non-respondents. In psychiatric epidemiology, differences in levels of psychopathology are often assumed between respondents and non-respondents. However, studies on attrition are rare, especially in child and adolescent populations. The present study sought to estimate the association of depression, anti-social behaviour with attrition from a cohort study among adolescents.

METHODS

The adolescent mental health cohort study (AMHC) is a prospective follow-up study on prevalence and determinants of mental health problems and risk behaviour among Finnish adolescents at two study sites. Subjects of the final baseline sample (n = 3278) were reached for a 2-year follow-up. Differences in data collecting methods between the study sites yielded different response rates (78% vs. 51%). Chi-square statistics and logistic regression models were computed to estimate the effect of two types of problem behaviour on attrition.

RESULTS

Depression at baseline was associated with higher probability of attrition at follow-up. School performance was a stronger predictor of attrition than problem behaviour. The models predicted non-response in the study site with mainly school-based surveys but not in the study site with mainly postal surveys.

CONCLUSION

Internalizing problem behaviour may be underrepresented in adolescent mental health surveys. School performance is strongly associated with attrition. Hence, special attention should be paid to designing questionnaires targeting adolescents.