Cross-border mobility in the Meuse-Rhine Euroregion: impact of COVID-19 border restrictions on everyday activities and visiting social network members.

Introduction: Cross-border mobility (CBM) to visit social network members or for everyday activities is an important part of daily life for citizens in border regions, including the Meuse-Rhine Euroregion (EMR: neighboring regions from the Netherlands, Belgium, and Germany). We assessed changes in CBM during the COVID-19 pandemic and how participants experienced border restrictions. Methods: Impact of COVID-19 on the EMR' is a longitudinal study using comparative cross-border data collection. In 2021, a random sample of the EMR-population was invited for participation in online surveys to assess current and pre-pandemic CBM. Changes in CBM, experience of border restrictions, and associated factors were analyzed using multinomial and multivariable logistic regression analysis. Results: Pre-pandemic, 82% of all 3,543 participants reported any CBM: 31% for social contacts and 79% for everyday activities. Among these, 26% decreased social CBM and 35% decreased CBM for everyday activities by autumn 2021. Negative experience of border restrictions was reported by 45% of participants with pre-pandemic CBM, and was higher (p < 0.05) in Dutch participants (compared to Belgian; aOR= 1.4), cross-border [work] commuters (aOR= 2.2), participants with cross-border social networks of friends, family or acquaintances (aOR= 1.3), and those finding the measures 'limit group size' (aOR= 1.5) and 'minimalize travel' (aOR= 2.0) difficult to adhere to and finding 'minimalize travel' (aOR= 1.6) useless. Discussion: CBM for social contacts and everyday activities was substantial in EMR-citizens, but decreased during the pandemic. Border restrictions were valued as negative by a considerable portion of EMR-citizens, especially when having family or friends across the border. When designing future pandemic control strategies, policy makers should account for the negative impact of CBM restrictions on their citizens.

Impact of post-COVID-19 condition on health status and activities of daily living: the PRIME post-COVID study.

OBJECTIVE: To assess health and activities of daily living (ADL) in SARS-CoV-2-positive adults with and without post-COVID-19 condition (PCC) and compare this with negative tested individuals. Furthermore, different PCC case definitions were compared with SARS-CoV-2-negative individuals. METHODS: All adults tested PCR positive for SARS-CoV-2 at the Public Health Service South Limburg (Netherlands) between June 2020 and November 2021 (n=41 780) and matched PCR negative individuals (2:1, on age, sex, year-quarter test, municipality; n=19 875) were invited by email. Health (five-level EuroQol five-dimension (EQ5D) index and EuroQol visual analogue scale (EQVAS)) and ADL impairment were assessed. PCC classification was done using the WHO case definition and five other common definitions. RESULTS: In total, 8409 individuals (6381 SARS-CoV-2 positive; 53±15 years; 57% female; 9 (7-11) months since test) were included. 39.4% of positives had PCC by the WHO case definition (EQVAS: 71±20; EQ5D index: 0.800±0.191; ADL impairment: 30 (10-70)%) and perceived worse health and more ADL impairment than negatives, that is, difference of -8.50 points (95% CI -9.71 to -7.29; p<0.001) for EQVAS, which decreased by 1.49 points (95% CI 0.86 to 2.12; p<0.001) in individuals with PCC for each comorbidity present, and differences of -0.065 points (95% CI -0.074 to -0.056; p<0.001) for EQ5D index, and +16.72% (95% CI 15.01 to 18.43; p<0.001) for ADL impairment. Health and ADL impairment were similar in negatives and positives without PCC. Replacing the WHO case definition with other PCC definitions yielded comparable results. CONCLUSIONS: Individuals with PCC have substantially worse health and more ADL impairment than negative controls, irrespective of the case definition. Authorities should inform the public about the associated burden of PCC and enable adequate support.

The association between SARS-CoV-2 seroprevalence and cross-border mobility for visiting family or friends among Dutch residents of a Euregional province.

BACKGROUND: Border measures were implemented in many countries as infection prevention measures to interrupt between-country COVID-19 transmission. Border closings impact border region residents, as their professional and social lives are often intertwined across national borders. We studied whether crossing borders to visit family/friends in neighbouring countries (cross-border mobility) was associated with SARS-CoV-2 seroprevalence in Dutch Euregional residents. METHODS: SARS-CoV-2 serostatus (negative/positive) was assessed (pre-vaccination) using laboratory testing to determine previous infection. Visiting Belgian or German family/friends in February-March 2020 was questioned. The association between cross-border mobility and seroprevalence was tested using logistic regression analysis, adjusted for previously identified exposure factors. RESULTS: In 9,996 participants, 36.8 % (n = 3,677) reported cross-border family/friends. Of these, one-third (n = 1,306) visited their cross-border family/friends in February-March 2020. Multivariable analyses revealed no positive association between cross-border mobility and seropositivity, for both participants living in a border municipality (ORfamily/friends not visited=0.90 [95 % CI:0.78-1.04], ORfamily/friends visited=0.88 [95 % CI:0.73-1.05]), and for participants not living in a border municipality (ORfamily/friends not visited=0.91 [95 % CI:0.72-1.16], ORfamily/friends visited=0.62 [95 % CI:0.41-0.94]). CONCLUSIONS: This study provided no evidence of cross-border mobility as an important exposure factor for SARS-CoV-2. The results of our unique real-world study suggest that cross-border mobility did not substantially contribute to cross-border SARS-CoV-2 transmission in the Netherlands.

The role of social network structure and function in moderate and severe social and emotional loneliness: The Dutch SaNAE study in older adults.

Background: Loneliness is a serious public health problem. This became even more visible during the COVID-19 pandemic. Yet, the key social network aspects contributing to loneliness remain unknown. Here, we evaluated social network structure and function and associations with (moderate/severe) social and emotional loneliness in older adults. Methods: This cross-sectional study includes online questionnaire data (SaNAE cohort, August-November 2020), in independently living Dutch adults aged 40 years and older. For the separate outcomes of social and emotional loneliness, associations with structural social network aspects (e.g., network diversity - having various types of relationships, and density - network members who know each other), and functional social network aspects (informational, emotional, and practical social support) were assessed and risk estimates were adjusted for age, educational level, level or urbanization, comorbidities, and network size. Multivariable logistic regression analyses were stratified by sex. Results: Of 3396 participants (55 % men; mean age 65 years), 18 % were socially lonely which was associated with a less diverse and less dense network, living alone, feeling less connected to friends, not having a club membership, and fewer emotional supporters (men only) or informational supporters (women only). 28 % were emotionally lonely, which was associated with being socially lonely, and more exclusively online (versus in-person) contacts (men only), and fewer emotional supporters (women only). Conclusion: Network structure and function beyond the mere number of contacts is key in loneliness. Public health strategies to prevent loneliness in older adults should be sex-tailored and promote network diversity and density, club membership, informational and emotional support, and in-person contact.

Prevalence of Long-term Symptoms Varies When Using Different Post-COVID-19 Definitions in Positively and Negatively Tested Adults: The PRIME Post-COVID Study.

Background: Long-term symptoms after a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (ie, post-coronavirus disease 2019 [COVID-19] condition or long COVID) constitute a substantial public health problem. Yet, the prevalence remains currently unclear as different case definitions are used, and negatively tested controls are lacking. We aimed to estimate post-COVID-19 condition prevalence using 6 definitions. Methods: The Prevalence, Risk factors, and Impact Evaluation (PRIME) post-COVID-19 condition study is a population-based sample of COVID-19-tested adults. In 2021, 61 655 adults were invited to complete an online questionnaire, including 44 symptoms plus a severity score (0-10) per symptom. Prevalence was calculated in both positively and negatively tested adults, stratified by time since their COVID-19 test (3-5, 6-11, or ≥12 months ago). Results: In positive individuals (n = 7405, 75.6%), the prevalence of long-term symptoms was between 26.9% and 64.1% using the 6 definitions, while in negative individuals (n = 2392, 24.4%), the prevalence varied between 11.4% and 32.5%. The prevalence of long-term symptoms potentially attributable to COVID-19 ranged from 17.9% to 26.3%. Conclusions: There is a (substantial) variation in prevalence estimates when using different post-COVID-19 condition definitions, as is current practice; there is limited overlap between definitions, indicating that the essential post-COVID-19 condition criteria are still unclear. Including negatives is important to determine long-term symptoms attributable to COVID-19. Trial registration: ClinicalTrials.gov Identifier: NCT05128695.

Social networks and health behaviors during the COVID-19 pandemic: a qualitative study among older adults in the Netherlands.

Aim: Social networks, all social relationships that people have, may influence people's health behavior and well-being, which was evaluated in this qualitative study in older adults. Furthermore, we evaluated people's needs for strengthening social networks. Subject and methods: For this qualitative study, semi-structured interviews were conducted between May and July 2021 among 24 adults aged 60 years and older. Results: Respondents provided information on social network structure (number and types of relations) and function (social support). They received informational support from friends, emotional support from their partner/spouse, and all types of support (including practical support) from family. Respondents stated that their health behavior was mainly influenced by a partner/spouse. Family and friends were mostly for socializing. To strengthen networks, in-person bilateral or small group interactions were preferred. Conclusion: Family and friends were important social supporters and positively influenced health behaviors. This study emphasizes the importance of social networks in health promotion.

Differences in non-positive intention to accept the COVID-19 booster vaccine between three countries in the cross-border region Meuse-Rhine Euroregion: The Netherlands, Belgium, and Germany.

COVID-19 booster vaccination has shown to add to the protection against infection with SARS-CoV2 and subsequent severe disease. This longitudinal cross-border study aimed to identify factors associated with COVID-19 booster vaccine intentions in an initially vaccinated adult population living in the Meuse-Rhine Euroregion (EMR; including the Netherlands, Belgium, and Germany) and differences between countries. Data collection took place in autumn of 2021 and consisted of online questionnaires sent to a random sample of the population based on governmental registries. Data from 3,319 fully and partially vaccinated adults were used to examine determinants of non-positive intention for a booster vaccination (i.e., uncertain or do not want), using multivariable logistic regression analyses weighted by age group, sex, and country. Compared to German residents, Dutch residents (OR = 2.4) and Belgian residents (OR = 1.4) were more likely to be uncertain or not want to receive a booster vaccine in September-October 2021. Factors independently associated with non-positive intention were female sex (OR = 1.6), absence of comorbidities (OR = 1.3), time since last vaccination less than 3 months ago for those fully vaccinated (OR = 1.6), being partially vaccinated (OR = 3.6), a negative experience with communication of COVID-19 measures (OR = 2.2), and regarding measures as ineffective (OR = 1.1). Results indicate that booster vaccine intentions differ between countries in the cross border Meuse-Rhine Euroregion. Non-positive intention for the booster vaccine is prevalent in all three countries of the EMR, but to a different extent, as shown in this study. Cross-border collaboration and sharing information and knowledge about vaccination strategies could play a role in limiting the impact of COVID-19.

High proportions of post-exertional malaise and orthostatic intolerance in people living with post-COVID-19 condition: the PRIME post-COVID study.

Background: Exercise-based treatments can worsen/exacerbate symptoms in people who were SARS-CoV-2 positive and living with post-COVID-19 condition (PL-PCC) and who have post-exertional malaise (PEM) or orthostatic intolerance (OI). Nevertheless, PEM and OI are not routinely assessed by clinicians. We estimated PEM and OI proportions in PL-PCC, as well as in people not living with PCC (PnL-PCC) and negatives (i.e., never reported a SARS-CoV-2 positive test), and identified associated factors. Methods: Participants from the Prevalence, Risk factors, and Impact Evaluation (PRIME) post-COVID-19 condition study were included. PEM and OI were assessed using validated questionnaires. PCC was defined as feeling unrecovered after SARS-CoV-2 infection. Multivariable regression analyses to study PEM and OI were stratified for sex. Results: Data from 3,783 participants were analyzed. In PL-PCC, the proportion of PEM was 48.1% and 41.2%, and the proportion of OI was 29.3% and 27.9% in women and men, respectively. Proportions were higher in PL-PCC than negatives, for PEM in women OR=4.38 [95%CI:3.01-6.38]; in men OR = 4.78 [95%CI:3.13-7.29]; for OI in women 3.06 [95%CI:1.97-4.76]; in men 2.71 [95%CI:1.75-4.21]. Associated factors were age ≤ 60 years, ≥1 comorbidities, and living alone. Conclusion: High proportions of PEM and OI are observed in PL-PCC. Standard screening for PEM and OI is recommended in PL-PCC to promote appropriate therapies.

Changes in structure and function of social networks of independently living middle-aged and older adults in diverse sociodemographic subgroups during the COVID-19 pandemic: a longitudinal study.

BACKGROUND: Social networks, i.e., all social relationships that people have, contribute to well-being and health. Governmental measures against COVID-19 were explicitly aimed to decrease physical social contact. We evaluated ego-centric social network structure and function, and changes therein, among various sociodemographic subgroups before and during the COVID-19 pandemic. METHODS: Independently living Dutch adults aged 40 years and older participating in the SaNAE longitudinal cohort study filled in online questionnaires in 2019 and 2020. Changes in network size (network structure) and social supporters (network function) were assessed. Associations with risk for changes (versus stable) were assessed for sociodemographic subgroups (sex, age, educational level, and urbanization level) using multivariable regression analyses, adjusted for confounders. RESULTS: Of 3,344 respondents 55% were men with a mean age of 65 years (age range 41-95 in 2020). In all assessed sociodemographic subgroups, decreases were observed in mean network size (total population: 11.4 to 9.8), the number of emotional supporters (7.2 to 6.1), and practical supporters (2.2 to 1.8), and an increase in the number of informational supporters (4.1 to 4.7). In all subgroups, the networks changed to being more family oriented. Some individuals increased their network size or number of supporters; they were more often women, higher-educated, or living in rural areas. CONCLUSION: The COVID-19 pandemic impacted social networks of people aged 40 years and older, as they increased informational support and reduced the number of their social relationships, mainly in terms of emotional and practical supporters. Notably, some individuals did not show such unfavorable trends and managed to reorganize their networks to attribute social support roles more centrally.

Sex and age differences in the proportion of experienced symptoms by SARS-CoV-2 serostatus in a community-based cross-sectional study.

We examined the possible sex and age differences in the proportion of experienced Coronavirus Disease 2019 (COVID-19) symptoms in unaware (previously) infected adults, and their uninfected counterparts, estimated by serostatus prior to vaccination, at the end of 2020 (Wuhan strain). A cross-sectional community-based study using a convenience sample of 10 001 adult inhabitants of a southern Dutch province, heavily affected by COVID-19, was conducted. Participants donated a blood sample to indicate past infection by serostatus (positive/negative). Experienced symptoms were assessed by questionnaire, before the availability of the serological test result. Only participants without confirmed SARS-CoV-2 infection were included (n = 9715, age range 18-90 years). The seroprevalence was comparable between men (17.3%) and women (18.0%), and participants aged 18-60 years (17.3%) and aged 60 years and older (18.6%). We showed sex and age differences in the proportion experienced symptoms by serostatus in a large cohort of both unaware (untested) seropositive compared with seronegative reference participants. Irritability only differed by serostatus in men (independent of age), while stomach ache, nausea and dizziness only differed by serostatus in women aged 60 years and older. Besides, the proportion of experiencing pain when breathing and headache differed by serostatus in men aged 18-60 years only. Our study highlights the importance of taking possible sex and age differences into account with respect to acute and long-term COVID-19 outcomes. Identifying symptom profiles for sex and age subgroups can contribute to timely identification of infection, gaining importance once governments currently move away from mass testing again.

Exposure factors associated with SARS-CoV-2 seroprevalence during the first eight months of the COVID-19 pandemic in the Netherlands: A cross-sectional study.

BACKGROUND: The availability of valid Severe Acute Respiratory Syndrome Coronvirus-2 (SARS-CoV-2) serological tests overcome the problem of underestimated cumulative Coronavirus Disease 2019 (COVID-19) cases during the first months of the pandemic in The Netherlands. The possibility to reliably determine the number of truly infected persons, enabled us to study initial drivers for exposure risk in the absence of routine testing. Numerous activities or circumstances can accelerate virus spread, here defined as exposure factors. Hence, we aimed to evaluate a wide variety of demographic, behavioural and social exposure factors associated with seropositivity during the first eight months of the pandemic in Limburg, The Netherlands. METHODS: SARS-CoV-2 point-seroprevalence was determined cross-sectionally to indicate previous infection in a convenience sample of minimal 10,000 inhabitants of the study province. All adult (18+ years) inhabitants of the study province were eligible to register themselves for participation. Once the initial 10,000 registrations were reached, a reserve list was kept to ensure sufficient participants. Possible exposure factors were mapped by means of an extensive questionnaire. Associated exposure factors were determined using univariable and multivariable logistic regression models. RESULTS: Seropositivity was established in 19.5% (n = 1,948) of the 10,001 participants (on average 49 years old (SD = 15; range 18-90 years), majority women (n = 5,829; 58.3%). Exposure factors associated with seropositivity included current education, working in healthcare and not working from home, and being a member of three or four associations or clubs. Specifically for February-March 2020, visiting an après-ski bar during winter sports in Austria, travelling to Spain, celebrating carnival, and participating in a singing activity or ball sport were associated with seropositivity. CONCLUSIONS: Our results confirm that relevant COVID-19 exposure factors generally reflected circumstances where social distancing was impossible, and the number and duration of contacts was high, in particular for indoor activities.

Design and recruitment of a large-scale cohort study on prevalence, risk factors and impact evaluation of post-COVID-19 condition and its wider long-term social, mental, and physical health impact: The PRIME post-COVID study.

Background: Persistent symptoms, described as long COVID or post-COVID-19 condition, pose a potential public health problem. Here, the design and recruitment of the PRIME post-COVID study is described. PRIME post-COVID is a large-scale population-based observational study that aims to improve understanding of the occurrence, risk factors, social, physical, mental, emotional, and socioeconomic impact of post-COVID-19 condition. Methods: An observational open cohort study was set up, with retrospective and prospective assessments on various health-conditions and health-factors (medical, demographic, social, and behavioral) based on a public health COVID-19 test and by self-report (using online questionnaires in Dutch language). Invited for participation were, as recorded in a public health registry, adults (18 years and older) who were tested for COVID-19 and had a valid Polymerase Chain Reaction (PCR) positive or negative test result, and email address. In November 2021, 61,655 individuals were invited by email to participate, these included all eligible adults who tested PCR positive between 1 June 2020 and 1 November 2021, and a sample of adults who tested negative (2:1), comparable in distribution of age, sex, municipality of residence and year-quarter of testing. New recruitment periods are planned as well. Participants are followed over time by regular follow-up measurements. Data are analyzed using the appropriate data-analyses methods. Discussion: The PRIME post-COVID study will provide insights into various health-related aspects of post-COVID-19 condition in the context of various stages of the COVID-19 pandemic. Results will inform practical guidance for society, clinical and public health practice for the prevention and care for long-term impact of COVID-19. Trial registration ClinicalTrialsgov identifier: NCT05128695.

Association between social network characteristics and prevalent and incident depression: The Maastricht Study.

AIMS: Social network characteristics may provide a novel non-pharmaceutical target for the prevention of depression. We investigated the temporal association of a broad range of structural and functional social network characteristics with incident depressive symptoms over 5 years of follow-up. METHODS: We used data from The Maastricht Study, a population-based prospective cohort study (n=2,465, mean age 59.8±8.1 years, 49.1% women, 11,585 person-years of follow-up). Social network characteristics were assessed through a name generator questionnaire. Clinically relevant depressive symptoms (9-item Patient Health Questionnaire score≥10) were assessed at baseline and annually. We used multivariable logistic and Cox regression analyses, adjusted for sociodemographic, lifestyle and cardiovascular risk factors. RESULTS: In cross-sectional analyses less emotional support for discomfort and with important decisions, and less informational support were associated with prevalent depressive symptoms (OR[95%CI] 1.19 [1.01-1.40]; 1.22 [1.05-1.43], and 1.20 [1.04-1.39], respectively). Every fewer 10% of family members was associated with prevalent depressive symptoms (1.11 [1.01-1.23]). In longitudinal analyses, less emotional support on important decisions was also associated with higher risk of incident depressive symptoms (HR[95%CI] 1.13 [1.03-1.25]). In addition, every fewer 10% of the network that was a family member was associated with a higher hazard of incident depressive symptoms (1.07 [1.01-1.13]). CONCLUSIONS: This study shows that less emotional support and fewer family members in the network were associated with higher risk of both prevalent and incident depression. The importance of emotional support and the role that family plays should be considered in treatment and prevention of depression.

Social networks and infectious diseases prevention behavior: A cross-sectional study in people aged 40 years and older.

BACKGROUND: Social networks, i.e., our in-person and online social relations, are key to lifestyle behavior and health, via mechanisms of influence and support from our relations. We assessed associations between various social network aspects and practicing behavior to prevent respiratory infectious diseases. METHODS: We analyzed baseline-data (2019) from the SaNAE-cohort on social networks and health, collected by an online questionnaire in Dutch community-dwelling people aged 40-99 years. Outcome was the number of preventive behaviors in past two months [range 0-4]. Associations between network aspects were tested using ordinal regression analyses, adjusting for confounders. RESULTS: Of 5,128 participants (mean age 63; 54% male), 94% regularly washed hands with water and soap, 55% used only paper (not cloth) handkerchiefs/tissues; 19% touched their face as little as possible; 39% kept distance from people with respiratory infectious disease symptoms; median score of behaviors was 2. Mean network size was 11 (46% family; 27% friends); six network members were contacted exclusively in-person and two exclusively via phone/internet. Participants received informational, emotional, and practical support from four, six, and two network members, respectively. Independently associated with more preventive behaviors were: 'strong relationships', i.e., large share of friends and aspects related to so called 'weak relationships', a larger share of distant living network members, higher number of members with whom there was exclusively phone/internet contact, and more network members providing informational support. Club membership and a larger share of same-aged network members were inversely associated. CONCLUSION: Friends ('strong' relationships) may play an important role in the adoption of infection-preventive behaviors. So may 'weak relationships', e.g. geographically more distant network members, who may provide informational support as via non-physical modes of contact. Further steps are to explore employment of these types of relationships when designing infectious diseases control programs aiming to promote infection-preventive behavior in middle aged-and older individuals.

Spousal concordance in pathophysiological markers and risk factors for type 2 diabetes: a cross-sectional analysis of The Maastricht Study.

INTRODUCTION: We compared the degree of spousal concordance in a set of detailed pathophysiological markers and risk factors for type 2 diabetes to understand where in the causal cascade spousal similarities are most relevant. RESEARCH DESIGN AND METHODS: This is a cross-sectional analysis of couples who participated in The Maastricht Study (n=172). We used quantile regression models to assess spousal concordance in risk factors for type 2 diabetes, including four adiposity measures, two dimensions of physical activity, sedentary time and two diet indicators. We additionally assessed beta cell function and insulin sensitivity and glucose metabolism status with fasting and 2-hour plasma glucose and hemoglobin A1c. RESULTS: The strongest spousal concordance (beta estimates) was observed for the Dutch Healthy Diet Index (DHDI) in men. A one-unit increase in wives' DHDI was associated with a 0.53 (95% CI 0.22 to 0.67) unit difference in men's DHDI. In women, the strongest concordance was for the time spent in high-intensity physical activity (HPA); thus, a one-unit increase in husbands' time spent in HPA was associated with a 0.36 (95% CI 0.17 to 0.64) unit difference in women's time spent in HPA. The weakest spousal concordance was observed in beta cell function indices. CONCLUSIONS: Spousal concordance was strongest in behavioral risk factors. Concordance weakened when moving downstream in the causal cascade leading to type 2 diabetes. Public health prevention strategies to mitigate diabetes risk may benefit from targeting spousal similarities in health-related behaviors and diabetes risk factors to design innovative and potentially more effective couple-based interventions.

Participation, retention, and associated factors of women in a prospective multicenter study on Chlamydia trachomatis infections (FemCure).

Prospective studies are key study designs when attempting to unravel health mechanisms that are widely applicable. Understanding the internal validity of a prospective study is essential to judge a study's quality. Moreover, insights in possible sampling bias and the external validity of a prospective study are useful to judge the applicability of a study's findings. We evaluated participation, retention, and associated factors of women in a multicenter prospective cohort (FemCure) to understand the study's validity.Chlamydia trachomatis (CT) infected adult women, negative for HIV, syphilis, and Neisseria gonorrhoeae were eligible to be preselected and included at three sexually transmitted infection (STI) clinics in the Netherlands (2016-2017). The planned follow-up for participants was 3 months, with two weekly rectal and vaginal CT self-sampling and online questionnaires administered at home and at the clinic. We calculated the proportions of preselected, included, and retained (completed follow-up) women. Associations with non-preselection, noninclusion, and non-retention (called attrition) were assessed (logistic and Cox regression).Among the 4,916 women, 1,763 (35.9%) were preselected, of whom 560 (31.8%) were included. The study population had diverse baseline characteristics: study site, migration background, high education, and no STI history were associated with non-preselection and noninclusion. Retention was 76.3% (n = 427). Attrition was 10.71/100 person/month (95% confidence interval 9.97, 12.69) and was associated with young age and low education. In an outpatient clinical setting, it proved feasible to include and retain women in an intensive prospective cohort. External validity was limited as the study population was not representative (sampling bias), but this did not affect the internal validity. Selective attrition, however (potential selection bias), should be accounted for when interpreting the study results.

Social networks in relation to self-reported symptomatic infections in individuals aged 40-75 - the Maastricht study.

BACKGROUND: Most infections are spread through social networks (detrimental effect). However, social networks may also lower infection acquisition (beneficial effect). This study aimed to examine associations between social network parameters and prevalence of self-reported upper and lower respiratory, gastrointestinal and urinary tract infections in a population aged 40-75. METHODS: In this population-based cross-sectional cohort study (N = 3004, mean age 60.0 ± 8.2 years, 49% women), infections within the past two months were assessed by self-administered questionnaires. Social network parameters were assessed using a name generator questionnaire. To examine the associated beneficial and detrimental network parameters, univariable and multivariable logistic regression was used. RESULTS: Participants reported an average of 10 people (alters) with whom they had 231 contacts per half year. Prevalences were 31.1% for upper respiratory, 11.5% for lower respiratory, 12.5% for gastrointestinal, and 5.7% for urinary tract infections. Larger network size, and a higher percentage of alters that were friends or acquaintances were associated with higher odds of upper respiratory, lower respiratory and/or gastrointestinal infections (detrimental). A higher total number of contacts, higher percentages of alters of the same age, and higher percentages of family members/acquaintances were associated with lower odds of upper respiratory, lower respiratory and/or gastrointestinal infections (beneficial). CONCLUSION: We identified both detrimental and beneficial associations of social network parameters with the prevalence of infections. Our findings can be used to complement mathematical models on infection spread, as well as to optimize current infectious disease control.

Social Network Characteristics Are Associated With Type 2 Diabetes Complications: The Maastricht Study.

OBJECTIVE: The relation between clinical complications and social network characteristics in type 2 diabetes mellitus (T2DM) has hardly been studied. Therefore, we examined the associations of social network characteristics with macro- and microvascular complications in T2DM and investigated whether these associations were independent of glycemic control, quality of life, and well-known cardiovascular risk factors. RESEARCH DESIGN AND METHODS: Participants with T2DM originated from the Maastricht Study, a population-based cohort study (n = 797, mean age 62.7 ± 7.6 years, 31% female). Social network characteristics were assessed through a name generator questionnaire. Diabetes status was determined by an oral glucose tolerance test. Macro- and microvascular complications were defined as a history of cardiovascular disease and the presence of impaired vibratory sense and/or retinopathy and/or albuminuria, respectively. We assessed cross-sectional associations of social network characteristics with macro- and microvascular complications by use of logistic regression adjusted for age, HbA1c, quality of life, and cardiovascular risk factors, stratified for sex. RESULTS: A smaller network size, higher percentages of family members, and lower percentages of friends were independently associated with macrovascular complications in both men and women. A smaller network size and less informational support were independently associated with microvascular complications in women, but not in men. CONCLUSIONS: This study shows that social network characteristics were associated with macro- and microvascular complications. Health care professionals should be aware of the association of the social network with T2DM outcomes. In the development of strategies to reduce the burden of disease, social network characteristics should be taken into account.

Subgroups Among Smokers in Preparation: A Cluster Analysis Using the I-Change Model.

BACKGROUND: Investigating potential sub-stages of change could provide important information that could be used to improve the tailoring of smoking cessation interventions to individual smokers' profiles. Smokers in the preparation stage may be most interesting, as they are most likely to participate in smoking cessation interventions. OBJECTIVE: To examine whether Dutch adult smokers in the preparation stage of change, i.e. motivated to quit smoking within one month, can be organized into subgroups. METHODS: Data from 753 smokers who participated in an effectiveness trial of a web-based, computer-tailored smoking cessation programme were subjected to secondary analysis. Cluster analyses were based on respondents' baseline responses to items on pros and cons of quitting and quitting self-efficacy. Chi-squared tests and ANOVA were used to compare the baseline characteristics of the resulting clusters. Logistic and multinomial regression were used for longitudinal comparisons of clusters with respect to smoking abstinence and stage transition at six-week and six-month follow-ups. RESULTS: Four clusters were identified; Classic, Unprepared, Progressing and Disengaged Preparers. Cross-sectional and longitudinal analyses validated these clusters: they differed with respect to the clustering variables, gender, cigarette dependence and educational level. Disengaged Preparers were less likely than Progressing Preparers to report smoking abstinence at six months (OR = 0.28; p < .05). CONCLUSIONS: These results suggest that smoking cessation interventions tailored to the preparation stage of change, i.e. the set of cognitions usually present in preparers, are only appropriate for the subgroup we defined as Classic Preparers. The other clusters might need different interventions as they display different cognition sets.

Socially isolated individuals are more prone to have newly diagnosed and prevalent type 2 diabetes mellitus - the Maastricht study.

BACKGROUND: Social isolation is associated with type 2 diabetes (T2DM), but it is unclear which elements play a crucial role in this association. Therefore, we assessed the associations of a broad range of structural and functional social network characteristics with normal glucose metabolism, pre-diabetes, newly diagnosed T2DM and previously diagnosed T2DM. METHODS: Participants originated from The Maastricht Study, a population-based cohort study (n = 2861, mean age 60.0 ± 8.2 years, 49% female, 28.8% T2DM (oversampled)). Social network characteristics were assessed through a name generator questionnaire. Diabetes status was determined by an oral glucose tolerance test. We used multinomial regression analyses to investigate the associations between social network characteristics and diabetes status, stratified by sex. RESULTS: More socially isolated individuals (smaller social network size) more frequently had newly diagnosed and previously diagnosed T2DM, while this association was not observed with pre-diabetes. In women, proximity and the type of relationship was associated with newly diagnosed and previously diagnosed T2DM. A lack of social participation was associated with pre-diabetes as well as with previously diagnosed T2DM in women, and with previously diagnosed T2DM in men. Living alone was associated with higher odds of previously diagnosed T2DM in men, but not in women. Less emotional support related to important decisions, less practical support related to jobs, and less practical support for sickness were associated with newly diagnosed and previously diagnosed T2DM in men and women, but not in pre-diabetes. CONCLUSION: This study shows that several aspects of structural and functional characteristics of the social network were associated with newly and previously diagnosed T2DM, partially different for men and women. These results may provide useful targets for T2DM prevention efforts.