Daytime and nighttime smartphone use: A study of associations between multidimensional smartphone behaviours and sleep among 24,856 Danish adults.

The around-the-clock smartphone use and its relation to disturbed sleep is a public health concern. The present study aimed to quantify the effects of different dimensions of smartphone behaviours (frequency of daytime use, problematic use, use before sleep and use during the sleep period) on disturbed sleep (sleep quality and sleep quantity) and to disentangle their inter-relationship in a large population-based sample of 24,856 Danish adults aged ≥16 years. Data come from the SmartSleep Experiment, which is a web-based survey carried out using a citizen science approach. Tested items were used to evaluate smartphone use and disturbed sleep was evaluated with the Karolinska Sleep Questionnaire (KSQ). Linear and multinomial logistic regression was employed to evaluate the relationship between smartphone use and disturbed sleep. While several of the smartphone measures were associated with disturbed sleep when assessed individually, smartphone use during the sleep period was the only dimension consistently associated with disturbed sleep when assessed independently of other smartphone behaviours. Weekly smartphone use during the sleep period versus no use was associated on average with a 0.96 point higher score (95% confidence interval [CI] 0.90-1.02) on the 5-point KSQ scale, and a higher risk of both short (odds ratio [OR] 1.32, 95% CI 1.08-1.62) and long (OR 1.94, 95% CI 1.63-2.32) sleep duration. Smartphone use during the sleep period is the factor strongest associated to disturbed sleep relative to other dimensions of smartphone use. Recommendations around smartphone use during the sleep period are warranted in order to protect the fundamentally important biological and mental processes of sleep.

Smartphone interactions and mental well-being in young adults: A longitudinal study based on objective high-resolution smartphone data.

Aims: To investigate the effects of objectively measured smartphone interactions on indicators of mental well-being among men and women in a population of young adults. Methods: A total of 816 young adults (mean±SD age 21.6±2.6 years; 77% men) from the Copenhagen Network Study were followed with objective recordings of smartphone interactions from calls, texts and social media. Participants self-reported on loneliness, depressive symptoms and disturbed sleep at baseline and in a four-month (interquartile range 75-163 days) follow-up survey. Multiple linear regression was used to analyse the association between smartphone interactions and mental well-being separately for men and women. Results: A higher number of smartphone interactions was associated with lower levels of loneliness at baseline and the same pattern appeared for depressive symptoms, although this was less pronounced. A high level of smartphone interaction was associated with lower levels of disturbed sleep for men, but not for women. In follow-up analyses, a high versus low level of smartphone interaction was associated with an increase in loneliness and depressive symptoms over time for women, but not for men. Conclusions: Smartphone interactions are related to better mental well-being, which may be attributed to the beneficial effects of an underlying social network. Over time, accommodating a large network via smartphone communication might, however, have negative effects on mental well-being for women.

'Standing together - at a distance': Documenting changes in mental-health indicators in Denmark during the COVID-19 pandemic.

Aims: There is a need to document the mental-health effects of the COVID-19 pandemic and its associated societal lockdowns. We initiated a large mixed-methods data collection, focusing on crisis-specific worries and mental-health indicators during the lockdown in Denmark. Methods: The study incorporated five data sources, including quantitative surveys and qualitative interviews. The surveys included a time series of cross-sectional online questionnaires starting on 20 March 2020, in which 300 (3×100) Danish residents were drawn every three days from three population groups: the general population (N=1046), families with children (N=1032) and older people (N=1059). These data were analysed by trend analysis. Semi-structured interviews were conducted with 32 people aged 24-83 throughout Denmark to provide context to the survey results and to gain insight into people's experiences of the lockdown. Results: Absolute level of worries, quality of life and social isolation were relatively stable across all population groups during the lockdown, although there was a slight deterioration in older people's overall mental health. Many respondents were worried about their loved ones' health (74-76%) and the potential long-term economic consequences of the pandemic (61-66%). The qualitative interviews documented significant variation in people's experiences, suggesting that the lockdown's effect on everyday life had not been altogether negative. Conclusions: People in Denmark seem to have managed the lockdown without alarming changes in their mental health. However, it is important to continue investigating the effects of the pandemic and various public-health measures on mental health over time and across national contexts.

Self-reported and tracked nighttime smartphone use and their association with overweight and cardiometabolic risk markers.

Nighttime smartphone use is associated with sleep problems, which in turn have a bidirectional association with overweight. We aim to investigate whether nighttime smartphone use and sleep are related to overweight and metabolic dysfunction in adult populations. We used data from three population samples (aged 16-89) from the SmartSleep Study, which included survey data (N = 29,838), high-resolution tracking data (N = 3446), follow-up data (N = 1768), and cardiometabolic risk markers (N = 242). Frequent self-reported nighttime smartphone use was associated with 51% higher odds (95% CI: 1.32; 1.70) of overweight compared with no use. Tracked nighttime smartphone use was also associated with overweight. Similar results were found for obesity as an outcome. No consistent associations were found between nighttime smartphone use and cardiometabolic risk markers in a small subsample of healthy young women. Poor sleep quality (vs. good sleep quality) was associated with overweight (OR = 1.19, 85% CI: 1.10; 1.28). Overall, frequent nighttime smartphone use was consistently associated with overweight and a higher BMI across diverse population samples. The bidirectional interplay between nighttime smartphone use, sleep, and overweight may create a vicious circle of metabolic dysfunction over time. Therefore, nighttime smartphone use may be a potential target point for public health interventions to reduce overweight at the population level.

Burden of Medication Overuse in Migraine: A Cross-sectional, Population-Based Study in Five European Countries Using the 2020 National Health and Wellness Survey (NHWS).

INTRODUCTION: Overuse of medication to treat migraine attacks can lead to development of a new type of headache or significant worsening of pre-existing headache, known as medication overuse headache. However, data concerning the burden of medication overuse (MO) in migraine are limited. This study aimed to assess the humanistic burden of MO in individuals with migraine from five European countries. METHODS: Data are from the 2020 National Health and Wellness Survey-a cross-sectional, population-based survey conducted in France, Germany, Italy, Spain, and the UK. Data were included from adults (≥ 18 years) with a self-reported diagnosis of migraine and at least one migraine attack and one headache in the past 30 days. MO was defined as (i) use of simple analgesics/over-the-counter medications on ≥ 15 days/month; or (ii) use of migraine medication, including combination analgesics, on ≥ 10 days/month. Humanistic burden of MO was assessed using the 12-Item Short-Form Health Survey (SF-12v2), EuroQol 5-Dimensions 5-Levels (EQ-5D), Short-Form 6-Dimensions (SF-6D), and Migraine Disability Assessment (MIDAS). The association of MO with humanistic burden was evaluated using generalized linear models adjusted for potential confounders in the full migraine population and in subgroups defined by headache frequency (monthly headache days [MHDs] 1-3, 4-7, 8-14, or ≥ 15). RESULTS: Among individuals with migraine, humanistic burden (SF-12v2, SF-6D, EQ-5D, and MIDAS) was higher in individuals who reported MO (n = 431) versus no MO (n = 3554), even after adjustment for confounding variables (p < 0.001 for all measures). MIDAS and EQ-5D scores were higher in individuals with MO than without, at all levels of headache frequency. For SF-12v2 and SF-6D, differences between groups with/without MO were seen only at lower levels of headache frequency (MHD 1-3 and 4-7). CONCLUSION: Among people with migraine, those who report MO face a greater humanistic burden than those without MO, irrespective of headache frequency.

Night-time smartphone use, sleep duration, sleep quality, and menstrual disturbances in young adult women: A population-based study with high-resolution tracking data.

Study Objectives: To explore the relationship among night-time smartphone use, sleep duration, sleep quality, and menstrual disturbances in young adult women. Methods: Women aged 18-40 years were included in the SmartSleep Study in which they objectively tracked their smartphone use via the SmartSleep app between self-reported sleep onset and offset times (n = 764) and responded to a survey (n = 1068), which included background characteristics, sleep duration, sleep quality (Karolinska Sleep Questionnaire), and menstrual characteristics (International Federation of Gynecology and Obstetrics' definitions). Results: The median tracking time was four nights (interquartile range: 2-8). Higher frequency (p = .05) and longer duration (p = .02) of night-time smartphone use were associated with long sleep duration (≥9 h), but not with poor sleep quality or short sleep duration (<7 h). Short sleep duration was associated with menstrual disturbances (OR = 1.84, 95% confidence interval [CI] = 1.09 to 3.04) and irregular menstruation (OR = 2.17, 95% CI = 1.08 to 4.10), and poor sleep quality was associated with menstrual disturbances (OR = 1.43, 95% CI = 1.19 to 1.71), irregular menstruation (OR = 1.34, 95% CI = 1.04 to 1.72), prolonged bleedings (OR = 2.50, 95% CI = 1.44 to 4.43) and short-cycle duration (OR = 1.40, 95% CI = 1.06 to 1.84). Neither duration nor frequency of night-time smartphone use was associated with menstrual disturbances. Conclusions: Night-time smartphone use was associated with longer sleep duration, but not with menstrual disturbances in adult women. Short sleep duration and sleep quality were associated with menstrual disturbances. Further investigation of the effects of night-time smartphone use on sleep and female reproductive function in large prospective studies is needed.

Nighttime smartphone use and changes in mental health and wellbeing among young adults: a longitudinal study based on high-resolution tracking data.

Frequent nighttime smartphone use can disturb healthy sleep patterns and may adversely affect mental health and wellbeing. This study aims at investigating whether nighttime smartphone use increases the risk of poor mental health, i.e. loneliness, depressive symptoms, perceived stress, and low life satisfaction among young adults. High-dimensional tracking data from the Copenhagen Network Study was used to objectively measure nighttime smartphone activity. We recorded more than 250,000 smartphone activities during self-reported sleep periods among 815 young adults (university students, mean age: 21.6 years, males: 77%) over 16 weekdays period. Mental health was measured at baseline using validated measures, and again at follow-up four months later. Associations between nighttime smartphone use and mental health were evaluated at baseline and at follow-up using multiple linear regression adjusting for potential confounding. Nighttime smartphone use was associated with a slightly higher level of perceived stress and depressive symptoms at baseline. For example, participants having 1-3 nights with smartphone use (out of 16 observed nights) had on average a 0.25 higher score (95%CI:0.08;0.41) on the Perceived stress scale ranging from 0 to 10. These differences were small and could not be replicated at follow-up. Contrary to the prevailing hypothesis, nighttime smartphone use is not strongly related to poor mental health, potentially because smartphone use is also a social phenomenon with associated benefits for mental health.

Gender bias in specialty preferences among Danish medical students: a cross-sectional study.

INTRODUCTION: Female medical students tend to prefer person-oriented specialties characterized by close doctor-patient contact and aspects of care. Conversely, male medical students tend to seek towards specialties with elements of autonomy, technology and "action" . Furthermore, female doctors will outnumber male doctors in Denmark by 2017 and this may have implications for the availability of specialized doctors. MATERIAL AND METHODS: Data derives from a baseline questionnaire pertaining to a Danish follow-up study. A total of 561 first year medical students enrolled in 2006 and 2007 answered the questionnaire. Binary logistic regression analysis was used to calculate odds ratio estimates of the relationship between gender and specialty preference. Variables measuring self-image were included in the analysis as potential mediators. RESULTS: 47% female and 19% male students pursued personoriented specialties and 46% female and 68% male students pursued technique-oriented specialties. More female students pursued technique-oriented specialties than in 1992. Female students have 69% less probability of choosing a technique-oriented specialty than males. This association is mediated by lack of self-confidence. CONCLUSION: If specialty preferences are persistent during medical school, the results suggest that we will face more difficulties recruiting males to person-oriented specialties than females to technique-oriented specialties in the future. Furthermore, when addressing students' specialty preferences, we should consider both self confidence and gender. FUNDING: not relevant. TRIAL REGISTRATION: not relevant.

Female medical students are estimated to have a higher risk for developing eating disorders than male medical students.

INTRODUCTION: Studies show that university students are at risk for eating disorders. However, risk behaviour has not been studied among Danish medical students, nor have the gender differences in risk behaviour been described in a Danish context. MATERIAL AND METHODS: All first-year medical students (n = 979) received a questionnaire related to body perception, exercise habits, eating habits, height and weight in the fall of 2006 and 2007. The response rate was 57% (n = 561). The gender distribution of the study population was 71.8% females and 28.2% males and the average age was 21.5 years. RESULTS: More males (89.8%) than females (73.1%) were satisfied with their body and more females (34.8%) than males (10.9%) felt too fat. More females (42.7%) than males (19.9%) felt guilty when eating unhealthy food. 2.3% (all females) claimed to feel anxiety when they were about to eat. More males (48.4%) than females (28.6%) stated that they could not keep themselves from exercising. 13.5% of the underweight females (body mass index < 20 kg/m²) felt too fat, while none of the underweight males had this perception. In average, females and males displayed 2.8 and 2.1 risk behaviours, respectively. CONCLUSION: Female medical students have a drive for thinness and male medical students want to be muscular. More female than male students have a negative body perception. Female medical students are estimated to have a higher risk for developing eating disorders than male students. Future research in this area should address the causes of such behaviour.

The SmartSleep Experiment: Evaluation of changes in night-time smartphone behavior following a mass media citizen science campaign.

The increasing 24-hour smartphone use is of public health concern. This study aims to evaluate whether a massive public focus on sleep and smartphone use generated through a large-scale citizen science project, the SmartSleep Experiment, influence participants' night-time smartphone behavior. A total of 8,894 Danish adults aged 16 and above participated in the SmartSleep Experiment, a web-based survey on smartphones and sleep behavior. The survey was carried out for one week in 2018, combined with an extensive national mass media campaign focusing on smartphone behaviors and sleep. A follow-up survey aimed at evaluating whether survey-participants had changed their night-time smartphone behavior was carried out two weeks after the campaign. A total of 15% of the participants who used their smartphone during sleep hours at baseline had changed their night-time smartphone behavior, and 83% of those indicated that they used their smartphone less at follow-up. The participants who had changed their smartphone behavior had primarily taken active precautions to avoid night-time smartphone use, e.g., activating silent mode (36%) or reduced their smartphone use before (50%) and during sleep hours (52%). The reduction in sleep problems (54%), recognition of poor smartphone behavior (48%), and the increased focus on night-time smartphone use (42%) were motivational factors for these behavior changes. Using citizen science and mass media appeared to be associated with changes in night-time smartphone behavior. Public health projects may benefit from combining citizen science with other interventional approaches.

High perceived stress and social interaction behaviour among young adults. A study based on objective measures of face-to-face and smartphone interactions.

Stress and mental health problems impede social functioning and may also complicate relationship formation with peers. The aim was to investigate whether high perceived stress among young adults is associated with social interaction behaviour both via face-to-face interaction and via smartphone interaction. The data was derived from the Copenhagen Network Study, where 535 first-year students (mean age 21.3, 77% male) self-reported on perceived stress at baseline and were subsequently followed for three months with continuous Bluetooth recordings of face-to-face interactions and smartphone interactions (calls and texts) measuring the network size, frequency, and duration of interactions. Logistic regression was used to assess associations between perceived stress (high/low) and social interactions adjusting for sex, age, and personality traits. Participants with high perceived stress were more likely to engage in a larger call and text network and have a higher call and text frequency compared to individuals with low perceived stress. We found a non-statistically significant tendency that participants with a high perceived stress level spend less time meeting face to face with peers. Stressed students engage in frequent smartphone interaction which may be explained by a social support seeking behaviour, or it may be that accommodating a large network via the smartphone is stress-inducing.

Overnight smartphone use: A new public health challenge? A novel study design based on high-resolution smartphone data.

BACKGROUND: Round-the-clock use of smartphones holds a potential for awakenings and/or shorter sleep duration, which may have adverse health consequences. We aim to describe overnight smartphone activity among young adults and to characterize those with smartphone interrupted sleep in terms of sleep impairment and mental and physical health indicators. METHODS: We use unique objective high-resolution information on timing of smartphone activity (based on >250,000 phone actions) continuously monitored over a four-week period among 815 young adults combined with indicators of mental and physical health. RESULTS: We find substantial overnight smartphone activity. More than 12% had smartphone activity in the middle of the night (3 to 5 hours after self-reported bedtime) and 41% had smartphone interrupted sleep on at least one weekday during a 4-week period. Those with frequent smartphone interrupted sleep had on average 48 minutes shorter self-reported sleep duration and higher body mass index, whereas there were no differences in physical or mental health symptoms. CONCLUSIONS: The substantial smartphone activity during bed hours among young adults may pose a public health challenge and especially the relation to overweight warrants close attention.

[Gender differences in the social relations of students]. / Kønsforskelle i studerendes sociale relationer.

INTRODUCTION: The aim of this study is to study gender differences in social network and social support among university students with a special view to social relations as a coping strategy for dealing with personal problems. MATERIAL AND METHODS: A total of 1,126 (48%) medical, psychology and liberal arts students who initiated their studies in 2006 or 2007 participated in the study. Data derives from a student register and a questionnaire on social network and social support. RESULTS: Approximately 85% of the students visit friends weekly, and about 40% spend time with their family weekly. Nearly half of the students have a partner. More female than male medical students have a partner when initiating their studies. More than 80% of the students have experienced mental health or social problems in the past, more female than male medical and liberal arts students. More than half of the male students handle their personal problems by themselves, whereas female students receive more social support. Significant gender differences in social support are mostly found among medical and liberal arts students. CONCLUSION: The results suggest that male and female students use different coping strategies when dealing with social and mental health problems, and gender differences in social relations seem to be most widespread among medical and liberal arts students - why and how should be investigated further.