Revisiting the continuum of resistance model in the digital age: a comparison of early and delayed respondents to the Norwegian counties public health survey

Background The continuum of resistance model’s premise is that delayed respondents to a survey are more similar to non-respondents than early respondents are. For decades, survey researchers have applied this model in attempts to evaluate and adjust for non-response bias. Despite a recent resurgence in the model’s popularity, its value has only been assessed in one large online population health survey. Methods Respondents to the Norwegian Counties Public Health Survey in Hordaland, Norway, were divided into three groups: those who responded within 7 days of the initial email/SMS invitation (wave 1, n = 6950); those who responded after 8 to 14 days and 1 reminder (wave 2, n = 4950); and those who responded after 15 or more days and 2 reminders (wave 3, n = 4045). Logistic regression analyses were used to compare respondents’ age, sex and educational level between waves, as well as the prevalence of poor general health, life dissatisfaction, mental distress, chronic health problems, weekly alcohol consumption, monthly binge drinking, daily smoking, physical activity, low social support and receipt of a disability pension. Results The overall response to the survey was 41.5%. Respondents in wave 1 were more likely to be older, female and more highly educated than those in waves 2 and 3. However, there were no substantial differences between waves for any health outcomes, with a maximal prevalence difference of 2.6% for weekly alcohol consumption (wave 1: 21.3%, wave 3: 18.7%). Conclusions There appeared to be a mild continuum of resistance for demographic variables. However, this was not reflected in health and related outcomes, which were uniformly similar across waves. The continuum of resistance model is unlikely to be useful to adjust for nonresponse bias in large online surveys of population health.publishedVersio

Assessing the cumulative effect of long-term training load on the risk of injury in team sports

Objectives: Determine how to assess the cumulative effect of training load on the risk of injury or health problems in team sports. Methods: First, we performed a simulation based on a Norwegian Premier League male football dataset (n players=36). Training load was sampled from daily session rating of perceived exertion (sRPE). Different scenarios of the effect of sRPE on injury risk and the effect of relative sRPE on injury risk were simulated. These scenarios assumed that the probability of injury was the result of training load exposures over the previous 4 weeks. We compared seven different methods of modelling training load in their ability to model the simulated relationship. We then used the most accurate method, the distributed lag non-linear model (DLNM), to analyse data from Norwegian youth elite handball players (no. of players=205, no. of health problems=471) to illustrate how assessing the cumulative effect of training load can be done in practice. Results: DLNM was the only method that accurately modelled the simulated relationships between training load and injury risk. In the handball example, DLNM could show the cumulative effect of training load and how much training load affected health problem risk depending on the distance in time since the training load exposure. Conclusion: DLNM can be used to assess the cumulative effect of training load on injury risk.publishedVersio

A new statistical approach to training load and injury risk: separating the acute from the chronic load

The relationship between recent (acute) training load relative to long-term (chronic) training load may be associated with sports injury risk. We explored the potential for modelling acute and chronic loads separately to address current statistical methodology limitations. We also determined whether there was any evidence of an interaction in the association between acute and chronic training loads and injury risk in football. A men’s Qatar Stars League football cohort (1 465 players, 1 977 injuries), where training load was defined as the number of minutes of activity, and a Norwegian elite U-19 football cohort (81 players, 60 injuries), where training load was defined as the session rating of perceived exertion (sRPE). Mixed logistic regression was run with training load on the current day (acute load) and cumulative past training load estimated by distributed lag non-linear models (chronic load) as independent variables. Injury was the outcome. An interaction between acute and chronic training load was modelled. In both football populations, we observed that the risk of injury on the current day for different values of acute training load was highest for players with low chronic load, followed by high and then medium chronic load. The slopes varied substantially between different levels of chronic training load, indicating an interaction. Modelling acute and chronic loads separately in regression models is a suitable statistical approach for analysing the association between relative training load and injury risk in injury prevention research. Sports scientists should also consider the potential for interactions between acute and chronic load.publishedVersio

Changes in life expectancy and disease burden in Norway, 1990–2019: an analysis of the Global Burden of Disease Study 2019

Bill & Melinda Gates FoundationpublishedVersio

Overuse injuries in sport: development, validation and application of a new surveillance method

Introduction: Overuse injuries, defined as those without a specific, identifiable event responsible for their occurrence, may be a substantial problem in many sports. However, current surveillance methods in sports injury epidemiology studies, which rely heavily on time loss for injury definitions and severity measurement, may underestimate their true impact. This is because athletes often continue to participate in sport despite the existence of overuse injuries. The main aim of this dissertation was to develop a new method to record overuse injuries in sport, and to establish its validity by applying it in a number of different research settings

Prevalence and Burden of Health Problems in Male Elite Ice Hockey Players : A Prospective Study in the Norwegian Professional League

Background: As previous epidemiological studies in elite ice hockey have focused on acute time-loss injuries, little is known about the burden of overuse injuries and illnesses in ice hockey. Purpose: To report the prevalence and burden of all health problems in male professional ice hockey players in Norway during a single competitive season. Study Design: Descriptive epidemiological study. Methods: A total of 225 male ice hockey players in the GET League (the premier professional league) in Norway reported all health problems (acute injuries, overuse injuries, and illnesses) during the 2017-2018 competitive season. Players reported all injuries and illnesses for 31 weeks using the Oslo Sports Trauma Research Center Questionnaire on Health Problems. Results: At any given time, 40% (95% CI, 37%-43%) of players reported symptoms from an injury or illness, and 20% (95% CI, 19%-22%) experienced health problems with a substantial negative impact on training and performance. Acute injuries represented the greatest incidence, prevalence, and burden (defined as the cross-product of severity and incidence). The most burdensome acute injuries were to the head/face, shoulder/clavicle, knee, and ankle. The most burdensome overuse injuries were to the knee, lumbar spine, and hip/groin. Conclusion: This registration captured a greater burden from overuse injuries than traditional injury registration, but acute injuries did represent a major problem. These data provide guidance in the development of prevention programs for both acute and overuse injuries, which should focus on the lumbar spine, hip/groin, and knee.One or more of the authors declared the following potential conflict of interest or source of funding: Funding for this project was received from Stiftelsen Fondet til fremme av idrettsmedisin og idrettsfysioterapi i Norge. The Oslo Sports Trauma Research Center has been established at the Norwegian School of Sport Sciences through generous grants from the Royal Norwegian Ministry of Culture, the South-Eastern Norway Regional Health Authority, the International Olympic Committee, the Norwegian Olympic and Paralympic Committee and Confederation of Sports, and Norsk Tipping. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.publishedVersio

Mental Health in Elite Student Athletes: Exploring the Link Between Training Volume and Mental Health Problems in Norwegian College and University Students

Objectives: To examine mental health problems among elite athletes in a student population, compared to the general student population, and to explore the association between weekly hours of training across mental health indicators. Methods: Data are from a national study from 2018 of all college and university students in Norway. Participants indicated if they considered themselves to be an elite athlete, and how many hours per week they trained. Mental health problems were assessed using several well-validated questionnaires. Results: Among 50,054 students, 1.3% identified themselves as elite athletes. Both male and female elite athletes had generally better mental health across most health outcomes, reporting fewer mental health problems, less loneliness, higher satisfaction with life, more positive affect, and fewer alcohol problems. Elite athletes in team sports had slightly better mental health compared to athletes of individual sports. Increased hours of weekly exercise was associated with better mental health. However, there was generally little to be gained from increasing the amount of training from 7–10 hours/week to 14+ hours per week. Female athletes who trained 14 or more hours per week reported poorer mental health across most outcome measures. Conclusion: This study showed that both male and female elite athletes generally had better mental health across a range of health outcomes, when compared to the general student population. The study also found a positive dose-response relationship between weekly hours of training and mental health, but also a worsening of mental health for females at the extreme end of exercise continuum. The self-report nature of this student sample means that care should be taken when generalizing to other studies of elite athletes

Mental health in elite student athletes: Exploring the link between training volume and mental health problems in Norwegian college and university students

Objectives: To examine mental health problems among elite athletes in a student population, compared to the general student population, and to explore the association between weekly hours of training across mental health indicators. Methods: Data are from a national study from 2018 of all college and university students in Norway. Participants indicated if they considered themselves to be an elite athlete, and how many hours per week they trained. Mental health problems were assessed using several well-validated questionnaires. Results: Among 50,054 students, 1.3% identified themselves as elite athletes. Both male and female elite athletes had generally better mental health across most health outcomes, reporting fewer mental health problems, less loneliness, higher satisfaction with life, more positive affect, and fewer alcohol problems. Elite athletes in team sports had slightly better mental health compared to athletes of individual sports. Increased hours of weekly exercise was associated with better mental health. However, there was generally little to be gained from increasing the amount of training from 7–10 hours/week to 14+ hours per week. Female athletes who trained 14 or more hours per week reported poorer mental health across most outcome measures. Conclusion: This study showed that both male and female elite athletes generally had better mental health across a range of health outcomes, when compared to the general student population. The study also found a positive dose-response relationship between weekly hours of training and mental health, but also a worsening of mental health for females at the extreme end of exercise continuum. The self-report nature of this student sample means that care should be taken when generalizing to other studies of elite athletes

Overuse injuries in professional road cyclists

Background: Little epidemiological information exists on overuse injuries in elite road cyclists. Anecdotal reports indicate anterior knee pain and lower back pain may be common problems. Purpose: This study was conducted to register overuse injuries among professional road cyclists with special focus on anterior knee and lower back pain. Study Design: Descriptive epidemiology study. Methods: We attended training camps of 7 professional teams and interviewed 109 of 116 cyclists (94%) on overuse injuries they had experienced in the previous 12 months. Injuries that required attention from medical personnel or involved time loss from cycling were registered. Additional information on anterior knee pain and lower back pain was collected using specific questionnaires. Results: A total of 94 injuries were registered; 45% were in the lower back and 23% in the knee. Twenty-three time-loss injuries were registered—57% in the knee, 22% in the lower back, and 13% in the lower leg. Fifty-eight percent of all cyclists had experienced lower back pain in the previous 12 months, and 41% of all cyclists had sought medical attention for it. Thirty-six percent had experienced anterior knee pain and 19% had sought medical attention for it. Few cyclists had missed competitions because of pain in the lower back (6%) or anterior knee (9%). Conclusion: Lower back pain and anterior knee pain were the most prevalent overuse injuries, with knee injuries most likely to cause time loss and lower back pain causing the highest rates of functional impairment and medical attention. Clinical Relevance: Future efforts to prevent overuse injuries in competitive cyclists should focus on lower back pain and anterior knee pain

Mental Health in Elite Student Athletes: Exploring the Link Between Training Volume and Mental Health Problems in Norwegian College and University Students

Objectives: To examine mental health problems among elite athletes in a student population, compared to the general student population, and to explore the association between weekly hours of training across mental health indicators. Methods: Data are from a national study from 2018 of all college and university students in Norway. Participants indicated if they considered themselves to be an elite athlete, and how many hours per week they trained. Mental health problems were assessed using several well-validated questionnaires. Results: Among 50,054 students, 1.3% identified themselves as elite athletes. Both male and female elite athletes had generally better mental health across most health outcomes, reporting fewer mental health problems, less loneliness, higher satisfaction with life, more positive affect, and fewer alcohol problems. Elite athletes in team sports had slightly better mental health compared to athletes of individual sports. Increased hours of weekly exercise was associated with better mental health. However, there was generally little to be gained from increasing the amount of training from 7–10 hours/week to 14+ hours per week. Female athletes who trained 14 or more hours per week reported poorer mental health across most outcome measures. Conclusion: This study showed that both male and female elite athletes generally had better mental health across a range of health outcomes, when compared to the general student population. The study also found a positive dose-response relationship between weekly hours of training and mental health, but also a worsening of mental health for females at the extreme end of exercise continuum. The self-report nature of this student sample means that care should be taken when generalizing to other studies of elite athletes