Methods
Study design
This study employed a cross-sectional design. Data were collected using an online questionnaire to analyse sports injuries and assess mental health. The study follows the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines.
Setting and participants
Licensed competitive skaters from all figure skating clubs in the Swedish South-eastern Regional Figure Skating Federation (part of the Swedish Figure Skating Association, which had a population of 5000 competitive skaters in the 2018–2019 season) were invited (N=400, age 5–31 years) to complete an online questionnaire. Clubs sent an email about the study and a link to the questionnaire to all guardians of skaters younger than 15 years old and all skaters 15 years or older. Participants received four email reminders during the response time. A previous article based on the same population that analysed sports injuries10 includes a detailed presentation of the data collection procedures and a non-response analysis. The sample was found to be representative according to sex and birthyear. Skaters from the lowest competitive level (star competitions level) were under-represented, skaters from the intermediate competitive level (club competitions level) were overrepresented and the highest competitive level (A-level and elite level) was representatively sampled.
Ethics Statement
Ethical approval was obtained from the Regional Ethics Committee in Linkoping, Sweden (Dnr 2018/483-31). The study follows the WMA Declaration of Helsinki Ethical Principles for Medical Research Involving Human Subjects. Informed written consent was obtained from all skaters and guardians of skaters younger than 15 years. The skaters could at any time withdraw their participation without stating a cause.
Patient and public involvement statement
Former competitive figure skaters assisted with designing and testing the questionnaire. To test how younger skaters would perceive the questions, children not yet eligible for competition and their parents were also asked to test and evaluate the questionnaire during a pilot phase.
Data collection
Data were collected in April–July 2019 through an online questionnaire (Lynes™). Clubs also contributed aggregated data (sex, date of birth (year and month) and competitive level) on the total population of their licensed competitive skaters.
Participating skaters completed different questionnaires based on age (</≥12 years). Parents of children <12 years of age were expected to help interpret questions if their children asked for help but to otherwise not oversee their children when participating. The web questionnaire was designed based on questionnaires previously used with athletics populations15–18 and within the 2014 study Health Behaviours in School-aged Children by the Public Health Agency of Sweden, on behalf of the WHO.19 Full details of the questionnaire have been previously published.10 In brief, the questionnaire took approximately 20 min to complete and included questions on skater characteristics and skating level, physical and mental health, and injury status.
Outcome variables
Anxiety caseness (yes/no) was defined as a short-form Spielberger State-Trait Anxiety Inventory (short-STAI) score >12. Short-STAI is validated for adults20 and children aged 5–17 years.21 In the study in which short-STAI was developed, the authors converted short-STAI (6 questions scored 1–4; total score range 6–24) to a scale ranging from 20 to 80 for comparison with STAI-S (20 questions scored 1–4; total score range 20–80).20 In STAI-S, scores of 1–2 may indicate ‘no anxiety’, while scores of 3–4 may indicate ‘anxiety’. An STAI-S-cut-off score of >40 has been used in previous studies.22 23 This study used a corresponding cut-off score of >12 for short-STAI. By scoring >12, the responding athlete, on average, was less than moderately calm, relaxed and content and more than somewhat tense, upset and worried.
Depression caseness (yes/no) was defined as a WHO-5 score ≤40 for children between 9 and 12 years and ≤36 for adolescents between 13 and 16 years,24 and ≤50 for those ≥17 years.25 The depression caseness scores were calculated based on these age cut-offs for the WHO-5 instrument. The WHO-5 has been reported to be sensitive and specific when screening for depression.25 Each item is scored from zero (none of the time) to five (all of the time). In this study, the percentage score of the scale was used. The total index score ranges from the absence of well-being to the highest imaginable well-being.25
Explanatory variables
Age (continuous) was self-reported by the skater, who stated the year and month of birth.
A severe sports injury episode (yes/no) was defined as any injury or pain that had occurred in connection with training or competition in figure skating that resulted in >21 days of lost or altered participation in figure skating.26
An ongoing sports injury episode (yes/no) was defined as a current injury or pain that had occurred in connection with training or competition in figure skating, which prevented the skater from fully participating in training or competition.
The number of skipped main meals per week (continuous) was indicated by combining the skater’s responses on how often they ate breakfast, lunch and dinner on weekdays and weekends, respectively.
Body mass index (BMI) was calculated from self-reports of weight and height, and for respondents <18 years of age presented as International Obesity Task Force-BMI (IOTF-BMI). This measure assesses underweight and overweight BMI values adjusted for age.27
The Syndrome of Relative Energy Deficiency in Sport (RED-S syndrome) (yes/no) was indicated if a skater reported irregular menstruation or was underweight, according to IOTF-BMI.
Body image perception (underweight/normal/overweight) was indicated based on the respondent’s categorisation of themselves.
‘Figure skating load’ (low/high) was used to attribute high skating load to those competing at the elite level or national level and/or being at a double loop or higher skating level.
Mean weekly training hours (≤6 hours/7–12 hours/≥13 hours) were indicated through self-report.
A dichotomous variable for parental education level (high/low) was created based on the skater having at least one parent who had completed postsecondary education (yes/no) and was used as an indicator of socioeconomic status.28
Data analysis
All items related to skater characteristics, figure skating and determinants related to health status (physical and mental health) were presented descriptively using percentages for categorical variables and means and SD for continuous variables.
The low number of skaters reaching the cut-off level restricted the development of meaningful multiple models of determinants for depression caseness. Binary logistic regression analyses of determinants were therefore limited to anxiety caseness. Simple binary logistic regression analyses were initially used to identify explanatory factors associated with anxiety caseness. Then, a multivariable model was constructed by excluding the non-significant explanatory variables (p≥0.05) using backward elimination (Wald). Nagelkerke R2 was obtained for the multivariable model to estimate its accountability level. Associations with p<0.05 were considered to be statistically significant. All statistical tests were two sided. Three additional multivariable models were analysed as a sensitivity analysis, where significant variables were removed sequentially.
The analysis of factors associated with depression caseness was restricted to age and comorbidity with anxiety caseness. The skaters were classified into four groups based on their reported short-STAI and WHO-5 scores: (1) depression caseness and anxiety caseness, (2) depression caseness and no anxiety, (3) no depression and anxiety caseness and (4) neither depression nor anxiety caseness.
The age of participants in each group was compared with analysis of variance (ANOVA) with post-hoc Bonferroni correction.
All analyses were performed using The Statistical Package for the Social Sciences (SPSS) for Windows V.27.0.