How to Establish and Follow up a Large Prospective Cohort Study in the 21st Century--Lessons from UK COSMOS

Creation of a pandemic memory by tracing COVID-19 infections and immunity in Luxembourg (CON-VINCE)

BACKGROUND

During the COVID-19 pandemic swift implementation of research cohorts was key. While many studies focused exclusively on infected individuals, population based cohorts are essential for the follow-up of SARS-CoV-2 impact on public health. Here we present the CON-VINCE cohort, estimate the point and period prevalence of the SARS-CoV-2 infection, reflect on the spread within the Luxembourgish population, examine immune responses to SARS-CoV-2 infection and vaccination, and ascertain the impact of the pandemic on population psychological wellbeing at a nationwide level.

METHODS

A representative sample of the adult Luxembourgish population was enrolled. The cohort was followed-up for twelve months. SARS-CoV-2 RT-qPCR and serology were conducted at each sampling visit. The surveys included detailed epidemiological, clinical, socio-economic, and psychological data.

RESULTS

One thousand eight hundred sixty-five individuals were followed over seven visits (April 2020-June 2021) with the final weighted period prevalence of SARS-CoV-2 infection of 15%. The participants had similar risks of being infected regardless of their gender, age, employment status and education level. Vaccination increased the chances of IgG-S positivity in infected individuals. Depression, anxiety, loneliness and stress levels increased at a point of study when there were strict containment measures, returning to baseline afterwards.

CONCLUSION

The data collected in CON-VINCE study allowed obtaining insights into the infection spread in Luxembourg, immunity build-up and the impact of the pandemic on psychological wellbeing of the population. Moreover, the study holds great translational potential, as samples stored at the biobank, together with self-reported questionnaire information, can be exploited in further research.

TRIAL REGISTRATION

Trial registration number: NCT04379297, 10 April 2020.

Novel recruitment approaches and operational results for a statewide population Cohort for cancer research: The Healthy Oregon Project

Background

Cancer health research relies on large-scale cohorts to derive generalizable results for different populations. While traditional epidemiological cohorts often use costly random sampling or self-motivated, preselected groups, a shift toward health system-based cohorts has emerged. However, such cohorts depend on participants remaining within a single system. Recent consumer engagement models using smartphone-based communication, driving projects, and social media have begun to upend these paradigms.

Methods

We initiated the Healthy Oregon Project (HOP) to support basic and clinical cancer research. HOP study employs a novel, cost-effective remote recruitment approach to effectively establish a large-scale cohort for population-based studies. The recruitment leverages the unique email account, the HOP website, and social media platforms to direct smartphone users to the study app, which facilitates saliva sample collection and survey administration. Monthly newsletters further facilitate engagement and outreach to broader communities.

Results

By the end of 2022, the HOP has enrolled approximately 35,000 participants aged 18-100 years (median = 44.2 years), comprising more than 1% of the Oregon adult population. Among those who have app access, ∼87% provided consent to genetic screening. The HOP monthly email newsletters have an average open rate of 38%. Efforts continue to be made to improve survey response rates.

Conclusion

This study underscores the efficacy of remote recruitment approaches in establishing large-scale cohorts for population-based cancer studies. The implementation of the study facilitates the collection of extensive survey and biological data into a repository that can be broadly shared and supports collaborative clinical and translational research.

Lifetime exposure to unemployment and prior working conditions are associated with retiree's health: A retrospective study in a large population-based French cohort

It is unclear whether unemployment exposure, as well as working conditions, can have sustained effects on the health of retirees who are no longer exposed. The aim of the present study is to investigate this issue in 29,281 French retirees from the CONSTANCES cohort in whom the prevalence of suboptimal self-rated health, disability for routine tasks, cardiovascular diseases and cancers is assessed according to lifetime exposure to unemployment and prior working conditions. The analyses are performed retrospectively using multivariable logistic regression models with adjustment for potential confounders such as sex, birth year, parental histories of cardiovascular disease and cancer, social position, retirement age and duration. High lifetime exposure to unemployment is associated with an increased prevalence of suboptimal self-rated health (adjusted odds ratio (95% CI), 1.39 (1.23-1.57)), disability for routine tasks (1.41 (1.26-1.57)) and several cardiovascular diseases including stroke (1.66 (1.19-2.31)), myocardial infarction (1.65 (1.18-2.31)) and peripheral arterial disease (2.38 (1.46-3.90)). Bad prior working conditions are associated with an increased prevalence of disability for routine tasks (1.17 (1.04-1.33)) and cancers (1.27 (1.04-1.54)), notably prostate cancer (1.60 (1.01-2.64)). These findings suggest that unemployment and working conditions have long-term health effects that may cumulate over lifetime, emphasizing that risk evaluation and preventive strategies in retirees, as in workers, should take into account the life-course of individuals in addition to traditional risk factors.

Generalization of finetuned transformer language models to new clinical contexts

Objective

We have previously developed a natural language processing pipeline using clinical notes written by epilepsy specialists to extract seizure freedom, seizure frequency text, and date of last seizure text for patients with epilepsy. It is important to understand how our methods generalize to new care contexts.

Materials and methods

We evaluated our pipeline on unseen notes from nonepilepsy-specialist neurologists and non-neurologists without any additional algorithm training. We tested the pipeline out-of-institution using epilepsy specialist notes from an outside medical center with only minor preprocessing adaptations. We examined reasons for discrepancies in performance in new contexts by measuring physical and semantic similarities between documents.

Results

Our ability to classify patient seizure freedom decreased by at least 0.12 agreement when moving from epilepsy specialists to nonspecialists or other institutions. On notes from our institution, textual overlap between the extracted outcomes and the gold standard annotations attained from manual chart review decreased by at least 0.11 F1 when an answer existed but did not change when no answer existed; here our models generalized on notes from the outside institution, losing at most 0.02 agreement. We analyzed textual differences and found that syntactic and semantic differences in both clinically relevant sentences and surrounding contexts significantly influenced model performance.

Discussion and conclusion

Model generalization performance decreased on notes from nonspecialists; out-of-institution generalization on epilepsy specialist notes required small changes to preprocessing but was especially good for seizure frequency text and date of last seizure text, opening opportunities for multicenter collaborations using these outcomes.

Distinct cardiovascular and cancer burdens associated with social position, work environment and unemployment: a cross-sectional and retrospective study in a large population-based French cohort

OBJECTIVES

Distinguish the respective effects of social position, work environment and unemployment on cardiovascular and cancer risks.

DESIGN

A cross-sectional and retrospective observational study.

SETTING

A population-based French cohort (CONSTANCES).

PARTICIPANTS

130 197 adults enrolled between 2012 and 2021 without missing values.

PRIMARY OUTCOME MEASURES

The associations of social position, work environment and unemployment exposure with the prevalence of cardiovascular events and cancers simultaneously tested using logistic regression models adjusting for common risk factors.

RESULTS

While social position, work environment and unemployment exposure are strongly inter-related with each other, they are not linked to the same cardiovascular and cancer outcomes. Low social position and long unemployment duration are significantly associated with an increased prevalence of angina pectoris, myocardial infarction and peripheral arterial disease (OR=1.22 to 1.90, p<0.04 to p<0.0001) but not of stroke. In contrast, a bad work environment is associated with an increased prevalence of stroke (OR=1.29, p<0.01) but not of angina pectoris, myocardial infarction and peripheral arterial disease. Low social position is associated with an increased prevalence of cervical and lung cancers (OR=1.73 and 1.95, p<0.002 and p<0.03) and a decreased prevalence of skin cancer (OR=0.70, p<0.0001) while a bad work environment is associated with an increased prevalence of breast, skin, prostate and colon cancers (OR=1.31 to 2.91, p<0.0002 to p<0.0001). Unemployment exposure is not associated with the prevalence of any type of cancers.

CONCLUSIONS

Social position, work environment and unemployment are associated with distinct cardiovascular and cancerous diseases that could add up during lifetime, they should therefore be considered all together in any preventive strategy.

Cardiovascular burden and unemployment: A retrospective study in a large population-based French cohort

The specific effect of unemployment on cardiovascular health relatively to the effects of social position and work environment is still unclear. To clarify this effect, the associations between current or past unemployment and the prevalence of common cardiovascular risk factor and events were tested using multiple logistic regression models with adjustment for both social position and prior work environment. The analyses were performed in a population-based French cohort (CONSTANCES) that included 131,186 adults enrolled between 2012 and 2021. Participants who were unemployed at inclusion (n = 8278) were overexposed to non-moderate alcohol consumption, smoking, leisure-time physical inactivity and depression (odds ratios (ORs) from 1.19 to 1.58) whereas those who have been unemployed at least once in the past (n = 19,015) were additionally overexposed not only to the previous risk factors but also to obesity, diabetes and sleep disorders (ORs from 1.10 to 1.35). These latter were also more exposed to non-fatal myocardial infarction and peripheral arterial disease (ORs of 1.44 and 1.47 respectively), overexposures that persisted after further adjustment for cardiovascular risk factors (ORs of 1.36 and 1.33). The overexposures to risk factors and cardiovascular events were both dependent on the duration of past unemployment. They were equally observed in participants with low social position or bad work environment. These results suggest that unemployment increases cardiovascular risk independently from social position and work environment with a cumulative effect over time. The effect of unemployment could add up to those of low social position and bad work environment during lifetime to further increase cardiovascular risk. They also suggest that long-term unemployment increases the prevalence of cardiovascular events through pathways including but not limited to overexposure to common risk factors.

A qualitative study examining newly diagnosed breast cancer patients' experiences of participating in the Alberta Moving Beyond Breast Cancer (AMBER) prospective cohort study

BACKGROUND

Decisions to participate in cancer trials are associated with uncertainty, distress, wanting to help find a cure, the hope for benefit, and altruism. There is a gap in the literature regarding research examining participation in prospective cohort studies. The aim of this study was to examine the experiences of newly diagnosed women with breast cancer participating in the AMBER Study to identify potential strategies to support patients' recruitment, retention, and motivation.

METHODS

Newly diagnosed breast cancer patients were recruited from the Alberta Moving Beyond Breast Cancer (AMBER) cohort study. Data were collected using semi-structured conversational interviews with 21 participants from February to May 2020. Transcripts were imported into NVivo software for management, organization, and coding. Inductive content analysis was undertaken.

RESULTS

Five main concepts associated with recruitment, retention, and motivation to participate were identified. These main concepts included: (1) personal interest in exercise and nutrition; (2) investment in individual results; (3) personal and professional interest in research; (4) burden of assessments; (5) importance of research staff.

CONCLUSIONS

Breast cancer survivors participating in this prospective cohort study had numerous reasons for participating and these reasons could be considered in future studies to enhance participant recruitment and retention. Improving recruitment and retention in prospective cancer cohort studies could result in more valid and generalizable study findings that could improve the care of cancer survivors.

Prevalence and trends of common mental disorders from 2007-2009 to 2019-2022: results from the Netherlands Mental Health Survey and Incidence Studies (NEMESIS), including comparison of prevalence rates before vs. during the COVID-19 pandemic

Up-to-date information on the prevalence and trends of common mental disorders is relevant to health care policy and planning, owing to the high burden associated with these disorders. In the first wave of the third Netherlands Mental Health Survey and Incidence Study (NEMESIS-3), a nationally representative sample was interviewed face-to-face from November 2019 to March 2022 (6,194 subjects; 1,576 interviewed before and 4,618 during the COVID-19 pandemic; age range: 18-75 years). A slightly modified version of the Composite International Diagnostic Interview 3.0 was used to assess DSM-IV and DSM-5 diagnoses. Trends in 12-month prevalence rates of DSM-IV mental disorders were examined by comparing these rates between NEMESIS-3 and NEMESIS-2 (6,646 subjects; age range: 18-64 years; interviewed from November 2007 to July 2009). Lifetime DSM-5 prevalence estimates in NEMESIS-3 were 28.6% for anxiety disorders, 27.6% for mood disorders, 16.7% for substance use disorders, and 3.6% for attention-deficit/hyperactivity disorder. Over the last 12 months, prevalence rates were 15.2%, 9.8%, 7.1%, and 3.2%, respectively. No differences in 12-month prevalence rates before vs. during the COVID-19 pandemic were found (26.7% pre-pandemic vs. 25.7% during the pandemic), even after controlling for differences in socio-demographic characteristics of the respondents interviewed in these two periods. This was the case for all four disorder categories. From 2007-2009 to 2019-2022, the 12-month prevalence rate of any DSM-IV disorder significantly increased from 17.4% to 26.1%. A stronger increase in prevalence was found for students, younger adults (18-34 years) and city dwellers. These data suggest that the prevalence of mental disorders has increased in the past decade, but this is not explained by the COVID-19 pandemic. The already high mental disorder risk of young adults has particularly further increased in recent years.

Evaluating novel methods of outcome assessment following cardiac arrest

INTRODUCTION

We compared novel methods of long-term follow-up after resuscitation from cardiac arrest to a query of the National Death Index (NDI). We hypothesized use of the electronic health record (EHR), and internet-based sources would have high sensitivity for identifying decedents identified by the NDI.

METHODS

We performed a retrospective study including patients treated after cardiac arrest at a single academic center from 2010 to 2018. We evaluated two novel methods to ascertain long-term survival and modified Rankin Scale (mRS): 1) a structured chart review of our health system's EHR; and 2) an internet-based search of: a) local newspapers, b) Ancestry.com, c) Facebook, d) Twitter, e) Instagram, and f) Google. If a patient was not reported deceased by any source, we considered them to be alive. We compared results of these novel methods to the NDI to calculate sensitivity. We queried the NDI for 200 in-hospital decedents to evaluate sensitivity against a true criterion standard.

RESULTS

We included 1,097 patients, 897 (82%) alive at discharge and 200 known decedents (18%). NDI identified 197/200 (99%) of known decedents. The EHR and local newspapers had highest sensitivity compared to the NDI (87% and 86% sensitivity, respectively). Online sources identified 10 likely decedents not identified by the NDI. Functional status estimated from EHR, and internet sources at follow up agreed in 38% of alive patients.

CONCLUSIONS

Novel methods of outcome assessment are an alternative to NDI for determining patients' vital status. These methods are less reliable for estimating functional status.

Follow-up of infants with colic into childhood: Do they develop behavioural problems?

AIM

To assess whether infants with colic (IC) demonstrate persisting developmental dysregulation into childhood, manifested as behavioural problems, and to determine if these behavioural problems are associated with parenting factors.

METHODS

Preschool children with a history of IC at the age of 0-3 months, as defined by the Wessel criteria, were invited to participate in an observational follow-up study, in which their caregivers completed the Child Behaviour Checklist (CBCL). Raw scores and clinical-range scores on the internalising, externalising and total behavioural problems scales were compared with a Dutch normative sample using independent t-tests and Chi-square tests. For the clinical-range scores, multivariable logistic regressions (odds ratios [99% confidence interval, CI]) were used to adjust for confounders and to identify variables associated with behavioural problems.

RESULTS

Two hundred and fifty-eight children with a history of IC (median age 5.1 (interquartile range, IQR 4.6-5.5) years, 51.9% boys) were included. The cases had a significantly higher adjusted risk (adjusted odds ratios (aORs) [99% CI]) of scoring in the clinical range of the emotionally reactive, internalising and total problems scale (2.96 [1.24-7.06]; 2.50 [1.35-4.62]; 2.98 [1.46-6.07], respectively). Internalising (P < 0.001), externalising (P < 0.001) and total (P < 0.001) behavioural problems in children with a history of IC were associated with higher parenting stress scores.

CONCLUSIONS

Children with a history of IC demonstrated significantly more internalising behavioural problems at preschool age compared to the norm sample. Specific advice and support need to be available for parents to understand and regulate the behaviour of their child, from infancy to childhood.

Atypical working hours are associated with tobacco, cannabis and alcohol use: longitudinal analyses from the CONSTANCES cohort

BACKGROUND

This study examined prospective associations between atypical working hours with subsequent tobacco, cannabis and alcohol use as well as sugar and fat consumption.

METHODS

In the French population-based CONSTANCES cohort, 47,288 men and 53,324 women currently employed included between 2012 and 2017 were annually followed for tobacco and cannabis use. Among them, 35,647 men and 39,767 women included between 2012 and 2016 were also followed for alcohol and sugar and fat consumption. Three indicators of atypical working hours were self-reported at baseline: working at night, weekend work and non-fixed working hours. Generalized linear models computed odds of substance use and sugar and fat consumption at follow-up according to atypical working hours at baseline while adjusting for sociodemographic factors, depression and baseline substance use when appropriate.

RESULTS

Working at night was associated with decreased smoking cessation and increased relapse in women [odds ratios (ORs) of 0.81 and 1.25], increased cannabis use in men [ORs from 1.46 to 1.54] and increased alcohol use [ORs from 1.12 to 1.14] in both men and women. Weekend work was associated with decreased smoking cessation in women [ORs from 0.89 to 0.90] and increased alcohol use in both men and women [ORs from 1.09 to 1.14]. Non-fixed hours were associated with decreased smoking cessation in women and increased relapse in men [ORs of 0.89 and 1.13] and increased alcohol use in both men and women [ORs from 1.12 to 1.19]. Overall, atypical working hours were associated with decreased sugar and fat consumption.

CONCLUSIONS

The potential role of atypical working hours on substance use should be considered by public health policy makers and clinicians in information and prevention strategies.

China rheumatoid arthritis registry of patients with Chinese medicine (CERTAIN): Rationale, design, and baseline characteristics of the first 11,764 enrollees

BACKGROUND

Chinese medicine (CM) has become a popular interventional treatment for rheumatoid arthritis (RA). However, limited knowledge about general characteristics and long-term clinical outcomes hampers the development of CM for RA.

PURPOSE

The main objectives of the China Rheumatoid Arthritis Registry of Patients with Chinese Medicine (CERTAIN) were to describe the population of RA patients receiving CM treatment in multiple centers in China using different variables and compare these findings with internationally reported data.

STUDY DESIGN

The CERTAIN is a prospective, multicenter, observational disease registry.

METHODS

Adult RA patients who fulfilled the 2010 American College of Rheumatology/ European League Against Rheumatism classification criteria for RA and received CM treatment were recruited into the CERTAIN by rheumatologists from 145 hospitals across 30 provinces in China. Data on demographics, disease characteristics, comorbidities, treatments, and adverse events, with a 2-year follow-up, were collected and documented using a predefined protocol.

RESULTS

In the 2 years since the study began in September 2019, 11,764 patients have been enrolled (enrolment is ongoing), and 13.10% of participants have completed the 6-month follow-up. We present the baseline characteristics of the first 11,764 enrollees.

CONCLUSIONS

The CERTAIN is the first nationwide registry to document comprehensive data on CM treatment in patients with RA. The development of the CERTAIN resource is a significant step forward for Chinese RA patients, herbal medicine users, and research communities and will deepen our understanding of CM for RA.

REGISTRATION

The study was registered at ClinicalTrials.gov (NCT05219214).

Wi-Fi technology and human health impact: a brief review of current knowledge

An enormous increase in the application of wireless communication in recent decades has intensified research into consequent increase in human exposure to electromagnetic (EM) radiofrequency (RF) radiation fields and potential health effects, especially in school children and teenagers, and this paper gives a snap overview of current findings and recommendations of international expert bodies, with the emphasis on exposure from Wi-Fi technology indoor devices. Our analysis includes over 100 in vitro, animal, epidemiological, and exposure assessment studies (of which 37 in vivo and 30 covering Wi-Fi technologies). Only a small portion of published research papers refers to the “real” health impact of Wi-Fi technologies on children, because they are simply not available. Results from animal studies are rarely fully transferable to humans. As highly controlled laboratory exposure experiments do not reflect real physical interaction between RF radiation fields with biological tissue, dosimetry methods, protocols, and instrumentation need constant improvement. Several studies repeatedly confirmed thermal effect of RF field interaction with human tissue, but non-thermal effects remain dubious and unconfirmed.

Direct mail from primary care and targeted recruitment strategies achieved a representative uptake of prostate cancer screening

OBJECTIVES

Prostate cancer screening studies has previously not been able to reflect a diverse group of participants. We evaluated a range of recruitment strategies and their ability to recruit from the Black population and areas of deprivation.

STUDY DESIGN AND SETTINGS

IP1-PROSTAGRAM was a prospective, population-based, paired screening study of 408 participants conducted at seven UK primary care practices and two imaging centres. All participants underwent screening with a PSA test, MRI and transrectal ultrasound. A number of recruitment strategies were embedded including direct mail, media campaigns and a targeted recruitment strategy to increase participation among harder-to-reach groups.

RESULTS

1,316 expressions of interest in total were received (20^th September 2018 to 15th May 2019). The direct mail strategy generated 317 expressions of interest from 1707 invitation letters. 387 expressions of interest were received following the targeted strategy and 612 from media campaigns. The recruitment target was met 19 months ahead of schedule. Of 411 participants, ethnicity was White (38.0%), Black (32.4%), Asian (23.0%) and Other/Mixed (4.4%) ethnic groups. This higher recruitment of black men was driven by the targeted recruitment strategy. A comparison of recruitment methods showed marked differences between ethnicities recruited (p<0.001). The proportion of black participants recruited by direct mail (8%) was similar to the prevalence of black local population (9%) whereas targeted recruitment was 88% (115) and media recruitment 1.7% (1). The Index of Multiple Deprivation (IMD) distribution was similar to the local population with marginal higher recruitment from more deprived areas; proportion increasing from 26% to 40% from least to most deprived IMD quintiles (Quintiles 4/5 vs. 1/2). Direct mail recruited a close-to-normal distribution for deprivation with targeted recruitment trending towards recruiting from most deprived areas.

CONCLUSIONS

Direct mail and targeted strategies designed to engage a diverse population can achieve a representative uptake from black participants and those from a lower socioeconomic group.

Clustering of Small Territories Based on Axes of Inequality

Background: In the present paper, we conduct a study before creating an e-cohort for the design of the sample. This e-cohort had to enable the effective representation of the province of Girona to facilitate its study according to the axes of inequality. Methods: The territory under study is divided by municipalities, considering these different axes. The study consists of a comparison of 14 clustering algorithms, together with 3 data sets of municipal information to detect the grouping that was the most consistent. Prior to carrying out the clustering, a variable selection process was performed to discard those that were not useful. The comparison was carried out following two axes: results and graphical representation. Results: The intra-cluster results were also analyzed to observe the coherence of the grouping. Finally, we study the probability of belonging to a cluster, such as the one containing the county capital. Conclusions: This clustering can be the basis for working with a sample that is significant and representative of the territory.

OUP accepted manuscript

Objective

Materials and Methods

Results

Discussion and Conclusion

Recruiting Participants for Population Health Intervention Research: Effectiveness and Costs of Recruitment Methods for a Cohort Study

Background

Public health research studies often rely on population-based participation and draw on various recruitment methods to establish samples. Increasingly, researchers are turning to web-based recruitment tools. However, few studies detail traditional and web-based recruitment efforts in terms of costs and potential biases.

Objective

This study aims to report on and evaluate the cost-effectiveness, time effectiveness, and sociodemographic representation of diverse recruitment methods used to enroll participants in 3 cities of the Interventions, Research, and Action in Cities Team (INTERACT) study, a cohort study conducted in Canadian cities.

Methods

Over 2017 and 2018 in Vancouver, Saskatoon, and Montreal, the INTERACT study used the following recruitment methods: mailed letters, social media (including sponsored Facebook advertisements), news media, partner communications, snowball recruitment, in-person recruitment, and posters. Participation in the study involved answering web-based questionnaires (at minimum), activating a smartphone app to share sensor data, and wearing a device for mobility and physical activity monitoring. We describe sociodemographic characteristics by the recruitment method and analyze performance indicators, including cost, completion rate, and time effectiveness. Effectiveness included calculating cost per completer (ie, a participant who completed at least one questionnaire), the completion rate of a health questionnaire, and the delay between completion of eligibility and health questionnaires. Cost included producing materials (ie, printing costs), transmitting recruitment messages (ie, mailing list rental, postage, and sponsored Facebook posts charges), and staff time. In Montreal, the largest INTERACT sample, we modeled the number of daily recruits through generalized linear models accounting for the distributed lagged effects of recruitment campaigns.

Results

Overall, 1791 participants were recruited from 3 cities and completed at least one questionnaire: 318 in Vancouver, 315 in Saskatoon, and 1158 in Montreal. In all cities, most participants chose to participate fully (questionnaires, apps, and devices). The costs associated with a completed participant varied across recruitment methods and by city. Facebook advertisements generated the most recruits (n=687), at a cost of CAD $15.04 (US $11.57; including staff time) per completer. Mailed letters were the costliest, at CAD $108.30 (US $83.3) per completer but served to reach older participants. All methods resulted in a gender imbalance, with women participating more, specifically with social media. Partner newsletters resulted in the participation of younger adults and were cost-efficient (CAD $5.16 [US $3.97] per completer). A generalized linear model for daily Montreal recruitment identified 2-day lag effects on most recruitment methods, except for the snowball campaign (4 days), letters (15 days), and reminder cards (5 days).

Conclusions

This study presents comprehensive data on the costs, effectiveness, and bias of population recruitment in a cohort study in 3 Canadian cities. More comprehensive documentation and reporting of recruitment efforts across studies are needed to improve our capacity to conduct inclusive intervention research.

Effects of different invitation strategies on participation in a cohort study of Iranian public sector employees: a cluster randomized trial

Background

Identifying strategies to optimize participation in health studies is one of the major concerns for researchers. The purpose of this study was to evaluate the efficiency of different invitation strategies on participation rate in the Employees’ Health Cohort Study of Iran (EHCSIR).

Methods

Two cluster-randomized trials were carried out to assess the outcomes of different invitation strategies. In the first phase, 7 units with 1880 employees (3 hospitals, 3 health centers, and 1 office) were assigned to the three parallel modes of invitation: 1) invitation letter, 2) phone call and 3) Short Message Service (SMS). In the second phase, 6 hospitals with 1633 employees were allocated to two invitation methods: 1) invitation letter, 2) invitation letter plus EHCSIR project introduction video. All groups were followed up by phone calls. A logistic mixed-effects model was used to compare the effectiveness of the strategies. The cost-effectiveness of the interventions was also compared.

Results

In the first phase, the participation rates in the invitation letter, phone call, and SMS groups were 27.04% (182/673), 21.55% (131/608), and 22.54% (135/599), respectively. Using an invitation letter was significantly more successful than SMS (Adjusted Odds Ratio = 1.80, 95% CI =1.14 to 2.85). Average Cost-Effectiveness Ratios (ACER) were $1.37, $1.42, and $1.55 for the invitation letter, phone call, and SMS, respectively. In the second phase, adding a project introduction video to the invitation letter did not significantly influence the participation rate (Adjusted OR = 0.58, 95% CI =0.24 to 1.36). The ACER was $1.21 for the invitation letter only and $2.01 for the invitation letter plus the introduction video.

Conclusions

In comparison with the phone call and SMS, the invitation letter is the most effective invitation method for public sector employees to participate in a cohort study. Sending an introduction video did not significantly increase the participation rate compared to sending an invitation letter only.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-021-01405-8.

Recruitment of Low-wage Workers for a Time-Sensitive Natural Experiment to Evaluate a Minimum Wage Policy: Challenges and Lessons Learned

Natural experiments are often used for answering research questions in which randomization is implausible. Effective recruitment strategies are well documented for observational cohort studies and clinical trials, unlike recruitment methods for time-sensitive natural experiments. In this time-sensitive study of the impact of a minimum wage policy, we aimed to recruit 900 low-wage workers in Minneapolis, Minnesota and Raleigh, North Carolina. We present our recruitment strategies, challenges, and successes for participant screening and enrollment of a difficult-to-reach population.

Participants Attrition in a Longitudinal Study: The Malaysian Cohort Study Experience

The attrition rate of longitudinal study participation remains a challenge. To date, the Malaysian Cohort (TMC) study follow-up rate was only 42.7%. This study objective is to identify the cause of attrition among TMC participants and the measures to curb it. A total of 19,343 TMC participants from Kuala Lumpur and Selangor that was due for follow-up were studied. The two most common attrition reasons are undergoing medical treatment at another government or private health center (7.0%) and loss of interest in participating in the TMC project (5.1%). Those who were inclined to drop out were mostly Chinese, aged 50 years and above, unemployed, and had comorbidities during the baseline recruitment. We have also contacted 2183 participants for the home recruitment follow-up, and about 10.9% agreed to join. Home recruitment slightly improved the overall follow-up rate from 42.7% to 43.5% during the three-month study period.

Older adults' motivations to participate or not in epidemiological research. Qualitative inquiry on a study into dementia in Switzerland

INTRODUCTION

High participation in epidemiological studies is crucial for both external and internal validity. Because response rates have declined in recent years, there is an increasing need to understand the drivers and the barriers to research participation. This study aims to uncover the motivations in favour and against participation of older adults to an epidemiological study on health and dementia.

METHODS

Twenty-two older adults, who already took part to the preliminary phase of an epidemiological study in Switzerland, agreed to participate to semi-structured, face-to- face interviews. An experienced researcher carried out all interviews in a quiet place of choice of the interviewee either at their domicile or the university, between November 2019 and January 2020. The interviews were audio and video taped, transcribed verbatim, and thematically analysed by two independent researchers.

RESULTS

We identified three main themes for the motivations in favour of participation (i.e. personal, related to the outcomes of research, and altruistic motivations), and we highlighted subthemes for each theme (e.g. personal motivations: curiosity; civic engagement; interest in the topic; trust in science; everyone counts; openness; play the game). Motivations against participation reflected the first two themes, while there was no counterpart for altruistic motivations.

CONCLUSIONS

Our thematic analysis revealed that older adults hold specular motivations in favour and against participation to research. Studying jointly motivations in favour and against provides information for recruitment strategies and to overcome barriers to participation, respectively. Participatory action research can inform the design and conduction of and should precede epidemiological studies in older adults, and can potentially contribute to attain high response rates.

Toward a Working Definition of eCohort Studies in Health Research: Narrative Literature Review

Background

The wide availability of internet-connected devices and new sensor technologies increasingly infuse longitudinal observational study designs and cohort studies. Simultaneously, the costly and time-consuming nature of traditional cohorts has given rise to alternative, technology-driven designs such as eCohorts, which remain inadequately described in the scientific literature.

Objective

The aim of this study was to outline and discuss what may constitute an eCohort, as well as to formulate a first working definition for health researchers based on a review of the relevant literature.

Methods

A two-staged review and synthesis process was performed comparing 10 traditional cohorts and 10 eCohorts across the six core steps in the life cycle of cohort designs.

Results

eCohorts are a novel type of technology-driven cohort study that are not physically linked to a clinical setting, follow more relaxed and not necessarily random sampling procedures, are primarily based on self-reported and digitally collected data, and systematically aim to leverage the internet and digitalization to achieve flexibility, interactivity, patient-centeredness, and scalability. This approach comes with some hurdles such as data quality, generalizability, and privacy concerns.

Conclusions

eCohorts have similarities to their traditional counterparts; however, they are sufficiently distinct to be treated as a separate type of cohort design. The novelty of eCohorts is associated with a range of strengths and weaknesses that require further exploration.

A digital health research platform for community engagement, recruitment, and retention of sexual and gender minority adults in a national longitudinal cohort study--The PRIDE Study

OBJECTIVE

Sexual and gender minority (SGM) people are underrepresented in research. We sought to create a digital research platform to engage, recruit, and retain SGM people in a national, longitudinal, dynamic, cohort study (The PRIDE Study) of SGM health.

MATERIALS AND METHODS

We partnered with design and development firms and engaged SGM community members to build a secure, cloud-based, containerized, microservices-based, feature-rich, research platform. We created PRIDEnet, a national network of individuals and organizations that actively engaged SGM communities in all stages of health research. The PRIDE Study participants were recruited via in-person outreach, communications to PRIDEnet constituents, social media advertising, and word-of-mouth. Participants completed surveys to report demographic as well as physical, mental, and social health data.

RESULTS

We built a secure digital research platform with engaging functionality that engaged SGM people and recruited and retained 13 731 diverse individuals in 2 years. A sizeable sample of 3813 gender minority people (32.8% of cohort) were recruited despite representing only approximately 0.6% of the population. Participants engaged with the platform and completed comprehensive annual surveys- including questions about sensitive and stigmatizing topics- to create a data resource and join a cohort for ongoing SGM health research.

DISCUSSION

With an appealing digital platform, recruitment and engagement in online-only longitudinal cohort studies are possible. Participant engagement with meaningful, bidirectional relationships creates stakeholders and enables study cocreation. Research about effective tactics to engage, recruit, and maintain active participation from all communities is needed.

CONCLUSION

This digital research platform successfully recruited and engaged diverse SGM participants in The PRIDE Study. A similar approach may be successful in partnership with other underrepresented and vulnerable populations.

Understanding participation in European cohort studies of preterm children: the views of parents, healthcare professionals and researchers

BACKGROUND

Retention of participants in cohort studies is a major challenge. A better understanding of all elements involved in participation and attrition phenomena in particular settings is needed to develop effective retention strategies. The study aimed to achieve an in-depth understanding of participant retention in longitudinal cohorts focusing on participants' and researcher's perspectives, across three diverse socio-geographic and cultural settings.

METHODS

This study used a triangulation of multi-situated methods to collect data on cohort studies of children born with less than 32 weeks of gestation in Denmark, Italy and Portugal. It included focus groups and individual semi-driven interviewing with involved key actors (i.e. parents, staff, healthcare professionals, researchers) and a collaborative visual methodology. A purposive sample of 48 key actors (n = 13 in Denmark; n = 13 in Italy; n = 22 in Portugal) was collected. A triangulation of phenomenological thematic analysis with discourse analysis was applied. Cross-contextual and context-specific situational elements involved in participation and attrition phenomena in these child cohorts were identified at various levels and stages.

RESULTS

Main findings included: situational challenges affecting potential and range of possibilities for implementation strategies (geopolitical environment, societal changes, research funding models); situational elements related to particular strategies acting as deterrents (postal questionnaires) and facilitators (multiple flexible strategies, reminders, regular interaction); main motivations to enrol and participate (altruism/solidarity and gratitude/sense of duty to reciprocate); main motivational deterrents to participate to follow-up waves (lack of bonding, insufficient feedback); entanglement of clinical and research follow-up as facilitator and deterrent.

CONCLUSIONS

The multi-situated approach used, addressing the interplay of the lived experience of individuals, was of most value to understand participation variability under different implemented strategies in-context. Cross-contextual and context-specific situational elements that have been influential factors towards participation and attrition in the cohorts were identified.

Methodological considerations in establishing and maintaining longitudinal health workforce studies: Lessons learned from the WiSDOM cohort in South Africa

BACKGROUND

Health workforce cohort studies are uncommon in low-and middle-income countries (LMICs), especially those in sub-Saharan Africa.

OBJECTIVE

Describe the methodology and lessons learned from establishing and maintaining the WiSDOM (Wits longitudinal Study to Determine the Operation of the labour Market among its health professional graduates) health professional cohort study in South Africa.

METHODS

WiSDOM is a prospective longitudinal cohort study that commenced in 2017. The cohort focuses on the eight professional groups of clinical associates, dentists, doctors, nurses, occupational therapists, oral hygienists, pharmacists and physiotherapists. Annual, electronic follow-up surveys have been conducted in 2018, 2019 and 2020 with informed consent. Key steps in establishing the WiSDOM cohort include consultation, communication and marketing, stakeholder feedback, resources and infrastructure. Retention strategies consist of an electronic database, detailed cohort contact information, cohort engagement, communication and feedback, short survey tools, and appropriate incentives.

RESULTS

We obtained an overall response rate of 89.5% at baseline in 2017, 79.6% in 2018, 68.3% in 2019 and 72.8% in 2020. The largest decline in response rates is for medical doctors: 66.0% response rate in 2018, 53.2% in 2019 and 58.2% in 2020. However, for each of the three follow-up surveys, we have obtained response rates in excess of 80% for clinical associates, dentists, nurses, oral hygienists, pharmacists and physiotherapists. Since baseline, the outright refusals have remained very low at 4.7%. The multiple logistic regression analysis showed that self-identified race was the only significant socio-demographic difference between medical doctor respondents and non-respondents. Black African doctors and Indian doctors were 2.0 and 2.6 times more likely respectively to respond than White doctors (p < 0.05).

CONCLUSION

Other LMICs can learn from WiSDOM's lessons of establishing and maintaining a health professional cohort that aims to generate new knowledge for health system transformation.

Association of Apelin Levels in Overweight-obese Children with Pubertal Development, but Not with Insulin Sensitivity: 6.5 Years Follow up Evaluation

BACKGROUND

Obesity in youth is associated with increased risk of metabolic disorders. Adipose tissue hormones are involved in body-weight regulation. Among these, apelin is recognized as an insulin-sensitizer adipokine. Data on apelin levels in obese children and its relation to insulin-sensitivity are limited.

OBJECTIVE

We aimed to evaluate apelin levels in relation to obesity and insulin sensitivity in a large cohort of overweight/obese children and adolescents. Furthermore, these youths were reevaluated after a median 6.5 years of follow-up, thus allowing assessing changes in apelin levels in relation to increasing age and weight changes.

METHODS

Clinical data in 909 children and adolescents were collected between 2007 and 2010. Two hundred and one were reexamined at a median 6.5 years of follow-up. All subjects at baseline and at follow-up underwent an OGTT. Apelin levels were measured on sera by ELISA method.

RESULTS

At baseline, lower apelin levels were associated with increasing age and puberty (Tanner ≥II 0.67 ± 0.96 ng/mL vs. Tanner I 0.89 ± 1.13 ng/mL, p < .002), but not with body-weight. At follow-up, apelin levels in the 201 subjects reexamined were significantly lower than at baseline (0.45 ± 0.77 ng/mL at follow-up, 0.68 ± 0.95 ng/mL baseline, p < .001), confirming the effects of age and puberty. Body-weight did not affect apelin levels. Multiple regression analysis confirmed that sex and puberty were associated with lower apelin levels, independently from age and insulin-sensitivity.

CONCLUSIONS

Apelin levels decrease significantly with pubertal development, whilst body-weight in children and adolescents did not determine changes in apelin. Reduced levels of apelin in children and adolescents may therefore represent a necessary response to maintain the "physiological" insulin resistance of puberty. Abbreviations: ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; G: glucose; BMI: Body mass index; DBP: Diastolic blood pressure; ELISA: enzyme-linked immunosorbent assay; HDL-C: High-density lipoprotein-cholesterol; HOMA-B: Homeostatic model assessment for beta-cell function; HOMA-IR: Homeostatic model assessment of insulin-resistance; INS: Insulin; ISI: insulin-sensitivity index; LDL-C: Low-density lipoprotein cholesterol; NW: normal weight; OB: obese; OGTT: oral glucose tolerance test; OW: overweight; SBP: Systolic blood pressure; TC: Total cholesterol; TGs: Triglycerides.

Pharmacist and patient perspectives on recruitment strategies for randomized controlled trials: a qualitative analysis

BACKGROUND

Although recruitment is a major challenge for most randomized controlled trials, few report on the difficulties of recruitment, or how it might be enhanced. The objective of our study was to qualitatively explore the experiences of both patients and pharmacists related to recruitment for ACCESS, a large trial involving low-income seniors, given that two of our most successful recruitment strategies were direct patient recruitment materials and use of community pharmacists.

METHODS

Using qualitative descriptive methods, we collected data from pharmacists and study participants. Pharmacists were asked about their impressions of the study, as well as challenges they faced and methods they used to recruit potential participants. Focus groups with trial participants centered on the patient recruitment materials. Interviews and focus groups were recorded, transcribed and analyzed using thematic analysis.

RESULTS

Pharmacists noted that their first impressions of the study were positive as they described being enticed to help the study team by the potential benefit of copayment elimination for their patients and the low time commitment. Pharmacists noted they were more likely to recruit if they were well informed on the study, as they could answer their patients' questions. Participants noted that their primary motivations for participating were the tangible benefits of free medications and the intrinsic value of participating in research.

CONCLUSIONS

We noted that recruitment through pharmacies was an effective method as most patients have trusting relationships with their pharmacist. To optimize recruitment through pharmacies, study procedures should be straightforward, and pharmacists need to be equipped with good knowledge of the study. When promoting a study to potential participants, messaging should ensure the individuals are aware of the tangible benefits of participation while still presenting a full overview of the trial.

TRIAL REGISTRATION

Trial Registration Number: NCT02579655 - initially registered Oct 19, 2015.

Intermediate-term clinical and radiographic outcomes with less invasive adult spinal deformity surgery: patients with a minimum follow-up of 4 years

BACKGROUND

Little information exists regarding longer-term outcomes with minimally invasive spine surgery (MISS), particularly regarding long-segment and deformity procedures. We aimed to evaluate intermediate-term outcomes of MISS for adult spinal deformity (ASD).

METHODS

This retrospective review of a prospectively collected multicenter database examined outcomes at 4 or more years following circumferential MIS (cMIS) or hybrid (HYB) surgery for ASD. A total of 53 patients at 8 academic centers satisfied the following inclusion criteria: age > 18 years and coronal Cobb > 20°, pelvic incidence-lumbar lordosis (PI-LL) > 10°, or sagittal vertical axis (SVA) > 5 cm.

RESULTS

Radiographic outcomes demonstrated improvements of PI-LL from 16.8° preoperatively to 10.8° and coronal Cobb angle from 38° preoperatively to 18.2° at 4 years. The incidence of complications over the follow-up period was 56.6%. A total of 21 (39.6%) patients underwent reoperation in the thoracolumbar spine, most commonly for adjacent level disease or proximal junctional kyphosis, which occurred in 11 (20.8%) patients. Mean Oswestry Disability Index (ODI) at baseline and years 1 through 4 were 49.9, 33.1, 30.2, 32.7, and 35.0, respectively. The percentage of patients meeting minimal clinically important difference (MCID) (defined as 12% or more from baseline) decreased over time, with leg pain reduction more durable than back pain reduction.

CONCLUSIONS

Intermediate-term clinical and radiographic improvement following MISS for ASD is sustained, but extent of improvement lessens over time. Outcome variability exists within a subset of patients not meeting MCID, which increases over time after year two. Loss of improvement over time was more notable in back than leg pain. However, average ODI improvement meets MCID at 4 years after MIS ASD surgery.

A cross-sectional survey examining motivation and beliefs to participating in a web-based prospective cohort study on nutrition and health among individuals with a low socioeconomic status

Background

Prospective cohort studies may support public health efforts in reducing health inequalities. However, individuals with a low socioeconomic status (SES) are generally underrepresented in health research. This study aimed to examine the intention and determinants of intention of individuals with a low SES towards participation in a Web-based prospective project on nutrition and health (NutriQuébec) in order to develop recruitment and retention strategies.

Methods

A cross-sectional survey based on the Theory of planned behaviour was conducted in the Province of Québec, Canada. Low SES individuals (high school or less and annual household income < $55,000 CAN) were recruited through a Web panel of a polling firm to assess intention, attitude, subjective norm and perceived behavioural control (PBC) towards participation in the NutriQuébec project. Linear regression and logistic regression analyses were conducted.

Results

Mean age of respondents (184 women, 141 men) was 57.6 y (SD = 13.6). Attitude (ß = 0.54, 95%CI: 0.41–0.68) and PBC (ß = 0.50, 95%CI: 0.37–0.63) were significantly associated with intention. Participants who agreed that participating in the study would contribute to an improvement in 1) collective health (odds ratio [OR] = 2.15, 95%CI: 1.27–3.64) and in 2) one’s lifestyle habits (OR = 1.70, 95%CI: 1.04–2.78) were more likely to express positive intention compared to participants who did not agree with these statements. Participants who agreed to participate in the study even 1) in the absence of a financial incentive (OR = 1.43, 95%CI: 1.04–1.99) and even 2) if the completion of questionnaires took up to two hours (OR = 1.78, 95%CI: 1.27–2.48) were also more likely to express high intention. Receiving a personalized brief health assessment (OR = 1.61, 95%CI: 1.13–2.30) and the use of simple questions in the questionnaires (OR = 1.54, 95%CI: 1.05–2.25) were facilitating factors associated with high intention. Participants believing that participation would be too time-consuming were less likely to have positive intention (OR = 0.57, 95%CI: 0.43–0.75).

Conclusions

The development of a positive attitude and a high PBC towards participation in the NutriQuébec project will be necessary to obtain representative data of low SES adults.

General concepts in biostatistics and clinical epidemiology: observational studies with cohort design

Cohort studies evaluate the relationship between exposure to a specific event or phenomenon and the occurrence of an associated out-come of interest (or lack thereof). This methodological design has been widely used in certain areas of medicine, such as the study of cardiovascular risk factors and the effects of ionizing radiation in humans. It is a useful study design, especially for research involving low-occurrence exposures, because it can be easily adapted to various contexts. This article, which provides an overview of observational cohort studies, is part of a methodology series on general concepts in biostatistics and clinical epidemiology developed by the Chair of Scientific Research Methodology at the University of Valparaísos School of Medicine in Chile. It describes historical, practical, and theoretical concepts related to cohort studies; essential elements in cohort study design, and variations and derivations of it; potential types and sources of bias in these types of observational/longitudinal studies, and various methods researchers can use to address/minimize them.

Beliefs Related to Participation in a Large Web-Based Prospective Survey on Diet and Health Among Individuals With a Low Socioeconomic Status: Qualitative Study

BACKGROUND

NutriQuébec is a Web-based prospective study on the relationship between diet and health as well as the impact of food-related health policies in the adult population of Québec, Canada. Recruitment and retention of individuals with a low socioeconomic status (SES) in such a study are known to be challenging, yet critical for achieving representativeness of the entire population.

OBJECTIVE

This study aimed to identify the behavioral, normative, and control beliefs of individuals with a low SES regarding participation in the NutriQuébec project and to identify their preferences regarding recruitment methods.

METHODS

A total of four focus groups were conducted in community centers located in low-income areas of Québec City, Canada. On the basis of the theory of planned behavior, participants' beliefs associated with attitude, subjective norm, and perceived behavioral control regarding hypothetical participation in the NutriQuébec project were identified. Focus groups were recorded, transcribed, and coded by two analysts.

RESULTS

Participants (16 men and 12 women) were aged between 28 and 72 years, and a majority of the participants had an annual household income of Can $19,999 or less. The main perceived advantages of participating in the NutriQuébec project were contributing to improved collective health and supporting research. The only disadvantage identified was the risk of having to fill out too many questionnaires. Participants could not, in general, identify persons from their entourage who would approve or disapprove their participation in the study. The main facilitators identified were obtaining a brief health assessment and the ability to complete questionnaires in a way that is not Web-based. The main barrier was the lack of internet access. The preferred means of recruitment were through social media, television, and community centers.

CONCLUSIONS

These results provide insightful information regarding the best methods and messages to use in order to recruit and retain individuals with a low SES in a population-based prospective study on lifestyle and health on the internet.

Feasibility of conducting an early pregnancy diet and lifestyle e-health intervention: the Pregnancy Lifestyle Activity Nutrition (PLAN) project

BACKGROUND

Childhood obesity is a global issue. Excessive weight gain in early pregnancy is independently associated with obesity in the next generation. Given the uptake of e-health, our primary aim was to pilot the feasibility of an e-health intervention, starting in the first trimester, to promote healthy lifestyle and prevent excess weight gain in early pregnancy. Methods: Women were recruited between 8 and 11 weeks gestation and randomised to the intervention or routine antenatal care. The intervention involved an e-health program providing diet, physical activity and well-being advice over 12 weeks.

RESULTS

Women (n = 57, 43.9% overweight/obese) were recruited at 9.38 ± 1.12 (control) and 9.06 ± 1.29 (intervention) weeks' gestation, mainly from obstetric private practices (81.2%). Retention was 73.7% for the 12-week intervention, 64.9% at birth and 55.8% at 3 months after birth.No difference in gestational weight gain or birth size was detected. Overall treatment effect showed a mean increase in score ranking the perceived confidence of dietary change (1.2 ± 0.46, p = 0.009) and score ranking readiness to exercise (1.21 ± 0.51, p = 0.016) over the intervention. At 3 months, infants weighed less in the intervention group (5405 versus 6193 g, p = 0.008) and had a lower ponderal index (25.5 ± 3.0 versus 28.8 ± 4.0 kg/m3) compared with the control group.

CONCLUSION AND DISCUSSION

A lifestyle intervention starting in the first-trimester pregnancy utilising e-health mode of delivery is feasible. Future studies need strategies to target recruitment of participants of lower socio-economic status and ensure maximal blinding. Larger trials (using technology and focused on early pregnancy) are needed to confirm if decreased infant adiposity is maintained.

A training and education program for genome medical research coordinators in the genome cohort study of the Tohoku Medical Megabank Organization

BACKGROUND

Genome cohort studies are used to analyze interactions between genetic and environmental factors, providing valuable information for personalized healthcare. Large-scale and long-term cohort studies require a number of specially trained personnel, of whom those involved in obtaining informed consent play a vital role, especially during the initial phase of such studies. The Japanese Society of Human Genetics (JSHG) previously established a certification system for genome medical research coordinators (GMRCs) responsible for obtaining written consent via face-to-face explanation. Meanwhile, in the Tohoku Medical Megabank Organization (ToMMo), GMRCs are expected to play important roles not only in obtaining informed consent and conducting various assessments, but also in communicating with participants throughout the long-term follow-up. Based on the JSHG program, we therefore developed a specific education and training program for ToMMo GMRCs consisting of 17 lectures, one practical training session on the informed consent procedure, and written and interview examinations. Re-education workshops aimed at self-improvement are also carried out following certification. In this study, we evaluated the education and training program in terms of overall understanding, usefulness, and satisfaction using an anonymous questionnaire.

METHODS

An anonymous questionnaire addressing each aspect of the education and training program (understanding, usefulness, and satisfaction) was distributed among 152 qualified ToMMo GMRCs. Responses were received from 94 participants (61.8%).

RESULTS

There was a significant association between the level of overall understanding of lectures and medical qualification (nurse or clinical laboratory technologist), but not with age or educational background. The level of understanding and overall usefulness were lower in sessions related to genetics and epidemiology than those dealing with ToMMo practices. In the re-education workshops, GMRCs showed a preference for and hoped to learn more about both background knowledge and research progress in the ToMMo.

CONCLUSIONS

The results of our questionnaire suggest that not all ToMMo GMRCs are able to understand everything during the initial education and training program, especially in terms of genomic medicine. Continuous re-education is therefore vital in improving knowledge, skills and motivation, and preparing GMRCs for a specialist role in community-based personalized healthcare.

Managing Achilles Pain (the MAP study) - A process evaluation of data collection methods

BACKGROUND

Process evaluations explore the way in which a study was conducted. The Managing Achilles Pain study (MAP study) had the primary aim of assessing the feasibility of the protocol for a future large longitudinal cohort study that would investigate the association and predictive relationship of self-efficacy, working alliance and expectations with outcome in the management of Achilles tendinopathy.

OBJECTIVES

This study aimed to evaluate the processes conducted in the MAP study by exploring the acceptability of the study procedures from the participants' and physiotherapists' perspectives.

DESIGN

A qualitative evaluation using semi-structured telephone interviews.

METHOD

All physiotherapists and participants who participated in the MAP study were invited. Data from physiotherapists (n = 6) and participants (n = 7) were transcribed and analysed using the Framework Approach.

FINDINGS

From the physiotherapists' perspective 4 themes were identified relating to obstacles; (1) access to participants; (2) recall; (3) visibility; (4) time, and 4 themes were identified relating to facilitating success; (1) training; (2) motivation; (3) incentives; (4) simplicity. From the participants' perspective 2 themes were identified relating to obstacles; (1) information from the physiotherapist; (2) follow up, 3 themes were identified relating to facilitating success; (1) motivation; (2) website; (3) questionnaire, and 1 theme relating to unintended consequences of participating in the study; positive experience.

CONCLUSIONS

Although clinicians are enthused to be involved in research, organisational factors impact levels of engagement. Key influences to optimising the potential success of a study include the publicising of the study; optimising verbal recruitment strategies; and clarity in communication.

Factors Influencing Web-Based Survey Response for a Longitudinal Cohort of Young Women Born Between 1989 and 1995

Background

With health research practices shifting toward rapid recruitment of samples through the use of online approaches, little is known about the impact of these recruitment methods on continued participation in cohort studies.

Objective

This study aimed to report on the retention of a cohort of young women who were recruited using an open recruitment strategy.

Methods

Women from the 1989-95 cohort of the Australian Longitudinal Study on Women’s Health, recruited in 2012 and 2013 were followed up annually via Web-based surveys in 2014, 2015, and 2016. Prevalence ratios for survey response were calculated using log-binomial models with generalized estimating equations including demographic, health-related, and recruitment method characteristics examined as explanatory factors.

Results

Of the 17,012 women who completed the baseline survey (Survey 1) in 2012 to 2013, approximately two-thirds completed Survey 2 (2014), and just over half completed Surveys 3 (2015) and 4 (2016). Women demonstrated transient patterns of responding with 38.21% (6501/17,012) of women completing all 4 surveys. Although retention of young women was associated with older age, higher education, higher self-rated health status, and low engagement with adverse health behaviors, the method of recruitment was a key determinant of study participation in the multivariate model. Although women were more likely to be recruited into the cohort via social media (eg, Facebook), retention over time was higher for women recruited through traditional media and referral approaches.

Conclusions

A balance must be obtained between achieving representativeness, achieving rapid cohort recruitment, and mitigating the pitfalls of attrition based on recruitment method in the new era of cohort studies, where traditional recruitment methods are no longer exclusively viable options.

Sample selection and reasons for non-participation in the PRedictors and Outcomes of incident FRACtures (PROFRAC) study

Background. Fragility fractures, associated with osteoporosis, are an escalating public health problem. We aim to describe sample selection, recruitment methods and reasons for non-participation in The PRedictors and Outcomes of incident FRACtures (PROFRAC) study. Design and Methods. Barwon Statistical Division residents aged 20+ years, with a radiologically-confirmed fracture between June 1^st 2012 and May 31^st 2013, were eligible. Individuals identified as fracture cases were invited by mail to complete a questionnaire. Reasons for non-participation were documented. Logistic regression techniques were used to determine odds ratios for participation and non-participation reasons. Results. A total of 1,458 of 2,155 (67.7%) adults with fracture (48.7% men) participated. Individuals were excluded due to inability to give informed consent, death, no knowledge of fracture, or inability to be contacted. The odds of participation decreased with age (OR 0.99, 95%CI 0.99-0.99, P=0.011) and increased among specific fracture groups [clavicle/scapula (OR 2.50, 1.30-4.68, P=0.006), forearm/humerus (OR 2.00, 1.22-3.27, P=0.006), wrist (OR 2.08, 1.31-3.32, P=0.002), hip (OR 2.12, 1.20-3.75, P=0.009), ankle (OR 1.85, 1.20-2.87, P=0.001), compared to face/skull fractures]. The odds of reporting disinterest, time constraints or personal reasons as the reason for non-participation decreased with age, whereas the odds of reporting frailty, language-related issues or illness as the reason for non-participation increased with of age [disinterest (OR 0.98, 0.97-0.98, P<0.001), time constraints (OR 0.97, 0.96-0.98, P<0.001), personal reasons (OR 0.98, 0.97-0.99, P=0.007), frailty (OR 1.12, 1.09-1.15, P<0.001), language-related issues (OR 1.02, 1.01-1.04, P<0.001), illness (OR 1.03, 1.02-1.05, P<0.001)]. Conclusions. Understanding drivers of research participation can inform study design to achieve optimal participation in health research.

Screening for Pregnancy Status in a Population-Based Sample: Characteristics Associated with Item Nonresponse

OBJECTIVES

Population-based recruitment of a cohort of women who are currently pregnant or who may become pregnant in a given timeframe presents challenges unique to identifying pregnancy status or the likelihood of future pregnancy. Little is known about the performance of individual eligibility items on pregnancy screeners although they are critical to participant recruitment. This paper examined the patterns and respondent characteristics of key pregnancy screener items used in a large national study.

METHODS

Cross-sectional analyses were conducted. Descriptive statistics and multivariable logistic regression models were used to examine nonresponse patterns to three questions (currently pregnant, trying to get pregnant and able to get pregnant). The questions were asked of 50,529 women in 17 locations across the US, as part of eligibility screening for the National Children's Study Vanguard Study household-based recruitment.

RESULTS

Most respondents were willing to provide information about current pregnancy, trying, and able to get pregnant: 99.3% of respondents answered all three questions and 97.4% provided meaningful answers. Nonresponse ranged from 0.3 to 2.5% for individual items. Multivariable logistic regression results identified small but statistically significant differences in nonresponse by respondent age, marital status, race/ethnicity-language, and household-based recruitment group.

CONCLUSIONS FOR PRACTICE

The high levels of response to pregnancy-related items are impressive considering that the eligibility questions were fairly sensitive, were administered at households, and were not part of a respondent-initiated encounter.

The protocol of a population-based prospective cohort study in southwest of Iran to analyze common non-communicable diseases: Shahrekord cohort study

Background

Prospective cohort studies are considered ideal choices to study multiple outcomes and risk factors for Non-communicable diseases (NCDs). Our aim is to set-up the protocol and analyze risk factors, incidence rates, prevalence, trends, and the models of environmental and genetic determinants of NCDs and their outcomes as well as interaction among such determinants.

Methods

Shahrekord cohort study (SCS) that is a population-based prospective, study on a cohort consisting of people aged 35-70 years started in November 2015 in Iran. The sample size of the original cohort is at least 10,000 people. Annual follow-ups (200,000 person-year) of the cohort were designed to be conducted up to 2036. Exposures (a detailed demographic, socioeconomic, general health, quality of life, physical activity, anthropometric indexes, stress, health literacy, social capital, nutrition and eating habits, lifestyle, occupational history, living place, blindness, deafness, electrocardiography, lung capacities, blood pressure, sleep, smoking and alcohol, contact to animals, physical examinations and medical history, dental health, used drugs and supplements, glucose and lipid profiles) were measured by relevant standard methods and questionnaires. Incidence of common NCDs (cardiovascular diseases, cancer, gastrointestinal, respiratory, renal, hepatic, accidents, injury and neurological diseases), trend of risk factors, hospitalization, disability, and death were considered the outcomes of the cohort. The definition of disease was determined based on the International Classification of Diseases 10th version (ICD-10). Routine hematologic and biochemical tests were conducted and an all-inclusive biobank (blood, hair, nail, and urine specimens) of the cohort was stored for future studies. All steps of data collection and examinations are directly monitored by the quality control team.

Discussion

The SCS is a unique study conducted in southwest of Iran that is a notable work given the climate conditions and ethnicity population (especially in Bakhtiari) of this region. By providing high quality the protocol and introduce it, the SCS can serve as a solid foundation for management and researchers in southwest of Iran. The SCS provides prerequisites for collaboration and regional, national, and international studies on NCDs. Data are available at the modeling in health research center, Shahrekord University of Medical Sciences, Shahrekord, Iran, for any collaboration.

Recruitment and Participation of Recreational Runners in a Large Epidemiological and Genetic Research Study: Retrospective Data Analysis

Background

With the increasing capacity for remote collection of both data and samples for medical research, a thorough assessment is needed to determine the association of population characteristics and recruitment methodologies with response rates.

Objective

The aim of this research was to assess population representativeness in a two-stage study of health and injury in recreational runners, which consisted of an epidemiological arm and genetic analysis.

Methods

The cost and success of various classical and internet-based methods were analyzed, and demographic representativeness was assessed for recruitment to the epidemiological survey, reported willingness to participate in the genetic arm of the study, actual participation, sample return, and approval for biobank storage.

Results

A total of 4965 valid responses were received, of which 1664 were deemed eligible for genetic analysis. Younger age showed a negative association with initial recruitment rate, expressed willingness to participate in genetic analysis, and actual participation. Additionally, female sex was associated with higher initial recruitment rates, and ethnic origin impacted willingness to participate in the genetic analysis (all P<.001).

Conclusions

The sharp decline in retention through the different stages of the study in young respondents suggests the necessity to develop specific recruitment and retention strategies when investigating a young, physically active population.

Cohort profile: LIFEWORK, a prospective cohort study on occupational and environmental risk factors and health in the Netherlands

PURPOSE

LIFEWORK is a large federated prospective cohort established in the Netherlands to quantify the health effects of occupational and environmental exposures. This cohort is also the Dutch contribution to the international Cohort Study of Mobile Phone Use and Health (COSMOS). In this paper, we describe the study design, ongoing data collection, baseline characteristics of participants and the repeatability of key questionnaire items.

PARTICIPANTS

88 466 participants were enrolled in three cohort studies in 2011-2012. Exposure information was collected by a harmonised core questionnaire, or modelled based on occupational and residential histories; domains include air pollution (eg, nitrogen dioxide (NO₂), particulate matter with diameter ≤2.5 µm (PM_2.5)), noise, electromagnetic fields (EMF), mobile phone use, shift work and occupational chemical exposures. Chronic and subacute health outcomes are assessed by self-report and through linkage with health registries.

FINDINGS TO DATE

Participants had a median age of 51 years at baseline (range 19-87), and the majority are female (90%), with nurses being over-represented. Median exposure levels of NO₂, PM_2.5, EMF from base stations and noise at the participants' home addresses at baseline were 22.9 µg/m³, 16.6 µg/m³, 0.003 mWm² and 53.1 dB, respectively. Twenty-two per cent of participants reported to have started using a mobile phone more than 10 years prior to baseline. Repeatability for self-reported exposures was moderate to high (weighted kappa range: 0.69-1) for a subset of participants (n=237) who completed the questionnaire twice.

FUTURE PLANS

We are actively and passively observing participants; we plan to administer a follow-up questionnaire every 4-5 years-the first follow-up will be completed in 2018-and linkage to cause-of-death and cancer registries occurs on a (bi)annual basis. This prospective cohort offers a unique, large and rich resource for research on contemporary occupational and environmental health risks and will contribute to the large international COSMOS study on mobile phone use and health.

An international prospective cohort study of mobile phone users and health (COSMOS): Factors affecting validity of self-reported mobile phone use

This study investigates validity of self-reported mobile phone use in a subset of 75 993 adults from the COSMOS cohort study. Agreement between self-reported and operator-derived mobile call frequency and duration for a 3-month period was assessed using Cohen's weighted Kappa (κ). Sensitivity and specificity of both self-reported high (≥10 calls/day or ≥4h/week) and low (≤6 calls/week or <30min/week) mobile phone use were calculated, as compared to operator data. For users of one mobile phone, agreement was fair for call frequency (κ=0.35, 95% CI: 0.35, 0.36) and moderate for call duration (κ=0.50, 95% CI: 0.49, 0.50). Self-reported low call frequency and duration demonstrated high sensitivity (87% and 76% respectively), but for high call frequency and duration sensitivity was lower (38% and 56% respectively), reflecting a tendency for greater underestimation than overestimation. Validity of self-reported mobile phone use was lower in women, younger age groups and those reporting symptoms during/shortly after using a mobile phone. This study highlights the ongoing value of using self-report data to measure mobile phone use. Furthermore, compared to continuous scale estimates used by previous studies, categorical response options used in COSMOS appear to improve validity considerably, most likely by preventing unrealistically high estimates from being reported.

Population characteristics of golden retriever lifetime study enrollees

BACKGROUND

Studying cancer and other diseases poses a problem due to their protracted and multifactorial nature. Prospective studies are useful to investigate chronic disease processes since collection of lifestyle information, exposure data and co-incident health issues are collected before the condition manifests. The Golden Retriever Lifetime Study is one of the first prospective studies following privately-owned dogs throughout life to investigate the incidence and risk factors for disease outcomes, especially cancer.Owners of golden retrievers in the contiguous United States volunteered their dogs in early life. Owners and veterinarians complete online questionnaires about health status and lifestyle; dogs undergo a physical examination and collection of biological samples annually. The data presented summarize the initial study visits and the corresponding questionnaires for 3044 dogs in the cohort.

RESULTS

The median age of dogs at enrollment was 14.0 months (interquartile range (IQR): 8-20 months). Approximately half of the population had undergone gonadectomy by their initial study visit. Medical conditions reported at enrollment consisted primarily of integumentary, gastrointestinal and urinary dysfunction. A large majority of the dogs have a record of having received preventive care (vaccines, parasiticides, flea and heartworm prevention) by the time of the initial study visit. Clinical pathology data were unremarkable.

CONCLUSIONS

This study represents one of the first lifetime observational investigations in veterinary medicine. The population characteristics reported here indicate a healthy cohort of golden retrievers cared for by owners committed to their dogs' health. Data acquired over the study period will provide valuable information about genetic, dietary and environmental risk factors associated with disease in golden retrievers and a framework for future prospective studies in veterinary medicine.

Galectin-3 and risk of ischaemic stroke: Reasons for Geographic and Racial Differences in Stroke cohort

BACKGROUND AND PURPOSE

Galectin-3 is a biomarker of atherosclerotic and cardiovascular disease, and may be a useful marker for ischaemic stroke risk.

METHODS

The Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort enrolled and examined 30 239 US participants between 2003 and 2007 (41% black, 59% white and 55% in the southeastern stroke belt). Baseline galectin-3 was measured in 526 subjects with incident ischaemic stroke over 5.4 years and in a cohort random sample (CRS) of 947 participants. Cox proportional hazards models were used to calculate hazard ratios (HRs) of ischaemic stroke by quartiles of galectin-3.

RESULTS

In the CRS, galectin-3 was significantly higher with older age, black race, female sex, body mass index, hypertension, diabetes mellitus and kidney disease, and also in those who developed incident stroke. Participants with galectin-3 levels in the fourth versus first quartile had a 2.3-fold increased stroke risk [95% confidence interval (CI) 1.6, 3.4] in an unadjusted model. An interaction with age was found (P = 0.06), and therefore age-stratified analyses were performed. Amongst those younger than age 64, baseline galectin-3 in the second-fourth quartiles was associated with increased stroke risk (HR 3.0, 95% CI 1.6, 5.5) compared to the first quartile in an age-, race- and sex-adjusted model. The HR was 2.0 (95% CI 1.0, 4.0) with multivariable adjustment. There was no association amongst older participants.

CONCLUSIONS

Galectin-3 was associated with incident ischaemic stroke in younger but not older individuals. Confirmation of this finding, and elucidation of its implications for stroke pathophysiology and prevention, is needed.

Collagen Augmentation Improves the Quality of Cartilage Repair After Microfracture in Patients Undergoing High Tibial Osteotomy: A Randomized Controlled Trial

BACKGROUND

The quality of cartilage repair after marrow stimulation is unpredictable. To overcome the shortcomings of the microfracture technique, various augmentation techniques have been developed. However, their efficacies remain unclear.

HYPOTHESIS

The quality of cartilage repair and clinical outcomes would be superior in patients undergoing high tibial osteotomy (HTO) with microfracture and collagen augmentation compared to those undergoing HTO with microfracture alone without collagen augmentation for the treatment of medial compartment osteoarthritis (OA) of the knee.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

Twenty-eight patients undergoing HTO were randomized into 2 groups: microfracture alone (group 1, n = 14) or microfracture with collagen augmentation (group 2, n = 14). At 1 year postoperatively, second-look arthroscopic surgery and biopsy of repaired cartilage were performed at the time of HTO plate removal. Biopsy specimens were graded using the International Cartilage Repair Society Visual Assessment Scale II (ICRS II). In addition, imaging outcomes in terms of the magnetic resonance observation of cartilage repair tissue (MOCART) score were assessed based on magnetic resonance imaging (MRI). Finally, clinical outcomes in terms of the visual analog scale (VAS) for pain score, Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC) score, and Tegner activity scale score were evaluated.

RESULTS

The mean ICRS II score in group 2 was significantly higher than that in group 1 (1053.2 vs 885.4, respectively; P = .002). Group 2 showed greater improvement in tissue morphology, cell morphology, surface architecture, middle/deep zone assessment, and overall assessment compared with group 1 ( P < .050 for all comparisons). Imaging outcomes based on the MOCART score were superior in group 2 compared to those in group 1 on MRI at 1 year postoperatively (64.6 vs 45.4, respectively; P = .001). The degree of defect repair was better in group 2 than in group 1 ( P = .040). Clinical outcomes in terms of the VAS for pain score, KOOS, IKDC score, and Tegner activity scale score were improved in both groups without between-group differences ( P > .100 for all comparisons).

CONCLUSION

The quality of cartilage repair after microfracture with collagen augmentation was superior to that after microfracture alone in patients undergoing HTO. Clinical results after 1 year did not reflect this difference in tissue repair. Therefore, a longer follow-up of the cohort is needed to answer this question.

Explaining ethnic disparities in lung function among young adults: A pilot investigation

Background

Ethnic disparities in lung function have been linked mainly to anthropometric factors but have not been fully explained. We conducted a cross-sectional pilot study to investigate how best to study ethnic differences in lung function in young adults and evaluate whether these could be explained by birth weight and socio-economic factors.

Methods

We recruited 112 university students of White and South Asian British ethnicity, measured post-bronchodilator lung function, obtained information on respiratory symptoms and socio-economic factors through questionnaires, and acquired birth weight through data linkage. We regressed lung function against ethnicity and candidate predictors defined a priori using linear regression, and used penalised regression to examine a wider range of factors. We reviewed the implications of our findings for the feasibility of a larger study.

Results

There was a similar parental socio-economic environment and no difference in birth weight between the two ethnic groups, but the ethnic difference in FVC adjusted for sex, age, height, demi-span, father’s occupation, birth weight, maternal educational attainment and maternal upbringing was 0.81L (95%CI: -1.01 to -0.54L). Difference in body proportions did not explain the ethnic differences although parental immigration was an important predictor of FVC independent of ethnic group. Participants were comfortable with study procedures and we were able to link birth weight data to clinical measurements.

Conclusion

Studies of ethnic disparities in lung function among young adults are feasible. Future studies should recruit a socially more diverse sample and investigate the role of markers of acculturation in explaining such differences.

Challenges and opportunities in establishing a collaborative multisite observational study of chronic diseases and lifestyle factors among adults in Puerto Rico

Background

Prevalence of chronic diseases and unhealthy lifestyle behaviors among the adult population of Puerto Rico (PR) is high; however, few epidemiological studies have been conducted to address these. We aimed to document the methods and operation of establishing a multisite cross-sectional study of chronic diseases and risk factors in PR, in partnership with academic, community, clinical, and research institutions.

Methods

The Puerto Rico Assessment of Diet, Lifestyle and Diseases (PRADLAD) documented lifestyle and health characteristics of adults living in PR, with the goal of informing future epidemiological and intervention projects, as well as public health, policy, and clinical efforts to help improve the population’s health. The study was conducted in three primary care clinics in the San Juan, PR metropolitan area. Eligible volunteers were 30–75y, living in PR for at least 10 months of the previous year, and able to answer interviewer-administered questionnaires without assistance. Questions were recorded electronically by trained interviewers, and included socio-demographic characteristics, lifestyle behaviors, self-reported medically-diagnosed diseases, and psychosocial factors. Waist and hip circumferences were measured following standardized protocols. A subset of participants answered a validated food frequency questionnaire, a legumes questionnaire, and had medical record data abstracted. Process and outcome evaluation indicators were assessed.

Results

The study screened 403 participants in 5 months. Of these, 396 (98%) were eligible and 380 (94%) had reliable and complete information. A subset of 242 participants had valid dietary data, and 236 had medical record data. The mean time to complete an interview was 1.5 h. Participants were generally cooperative and research collaborators were fully engaged. Having multiple sites helped enhance recruitment and sociodemographic representation. Diagnosed conditions were prevalent across sites. Challenges in data monitoring, interviewer training, and scheduling were identified and corrected, and should be addressed in future studies.

Conclusions

Epidemiological studies in PR can be successfully implemented in partnership with multiple institutions. Effective recruitment and implementation requires concerted planning and continued involvement from partners, frequent quality control, brief interviews, reasonable incentives, and thorough training/re-training of culturally-sensitive interviewers. Further studies are feasible and needed to help address highly prevalent chronic conditions in PR.

Design, methods and demographics from phase I of Alberta's Tomorrow Project cohort: a prospective cohort profile

BACKGROUND

Prospective cohorts have the potential to support multifactorial, health-related research, particularly if they are drawn from the general population, incorporate active and passive follow-up and permission is obtained to allow access by researchers to data repositories. This paper describes Phase I of the Alberta's Tomorrow Project cohort, a broad-based research platform designed to support investigations into factors that influence cancer and chronic disease risk.

METHODS

Adults aged 35-69 years living in Alberta, Canada, with no previous cancer diagnosis other than nonmelanoma skin cancer were recruited to the project by telephone-based random digit dialling. Participants were enrolled if they returned a Health and Lifestyle Questionnaire. Past year diet and physical activity questionnaires were mailed 3 months after enrolment. Consent was sought for active follow-up and linkage with administrative databases. Depending on enrolment date, participants were invited to complete up to 2 follow-up questionnaires (2004 and 2008).

RESULTS

Between 2001 and 2009, 31 072 (39% men) participants (mean age 50.2 [± 9.2] yr) were enrolled and 99% consented to linkage with administrative databases. Participants reported a wide range of educational attainment and household income. Compared with provincial surveillance data from the Canadian Community Health Survey, Alberta's Tomorrow Project participants had higher body mass index, lower prevalence of smoking and similar distribution of chronic health conditions. Follow-up questionnaires were completed by 83% and 72% of participants in 2004 and 2008, respectively. Robust quality control measures resulted in low frequencies of missing data.

INTERPRETATION

Alberta's Tomorrow Project provides a robust platform, based on a prospective cohort design, to support research into risk factors for cancer and chronic disease.