Research Articles (Sport, Exercise Medicine & Lifestyle Institute (SEMLI))

Permanent URI for this collectionhttp://hdl.handle.net/2263/5227

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Epidemiology of ranger injuries among members of the Game Rangers Association of Africa : service-related risk and the call for targeted prevention strategies
Viljoen, Carel Thomas; Van Mechelen, Willem; Sykes, Leanne M.; Clark, James Robert; De Bruin, Louise; Mushonga, Tafadzwa; Janse van Rensburg, Dina Christina (Elsevier, 2026-09)
OBJECTIVES : To determine the epidemiology of ranger injuries, risk factors for injury, and health support needs among members of the Game Rangers Association of Africa (GRAA). METHODS : We employed a retrospective cross-sectional design to collect data online using a questionnaire developed specifically for this study. We used convenience sampling to include 120 rangers aged 18 years or older who were actively working in Africa. RESULTS : Our findings showed a career injury prevalence of 52 % and period prevalence (past 12 months) of 33 %. The lower limb was the most frequently injured anatomical region (38 %), followed by the upper limb (31 %) and trunk (19 %), specifically affecting the hand (19 %), ankle (14 %), and foot (13 %). The most common injury types included skin lacerations (29 %), followed by muscle injuries (23 %), and fractures (10 %). Working for more than 15 years as a ranger is associated with an increased risk for career injury (OR=2.63) compared to working for 10 years or less. Injuries resulted in a median of 7 days (IQR=0–20 days) lost from work, with most injuries requiring either emergency medical care (31 %) or consultation with a medical doctor (26 %). Rangers need better equipment, cardiovascular fitness training programs, safety training, and mental health support. CONCLUSION : One in every two rangers associated with the GRAA sustains an injury across their careers, with a third of rangers reporting being injured in the past 12 months. Working more than 15 years as a ranger was associated with an increased risk for career injury. Our findings should be used in conjunction with sound clinical reasoning to aid in the development of future injury prevention strategies for rangers working in Africa.
From evidence to action : a global call to advance sleep health in sport
Grandner, Michael A.; Athey, Amy; Bender, Amy; Charest, Jonathan; Halson, Shona L.; Janse van Rensburg, Dina Christina; Lastella, Michele; Nedelec, Mathieu; Sargent, Charli; Vitale, Jacopo; Brager, Allison (BMJ Publishing Group, 2026)
Awareness of sleep health in sport has increased substantially over the past decade, yet many high-performance environments continue to operate in ways that are fundamentally misaligned with healthy sleep and circadian biology. This editorial presents evidence-based sleep health practices to better address the culture, structure and operational demands of competitive sport.
Mapping mental health problems in elite female athletes—a scoping review. Emphasising limited research in Africa and South America
Naidoo, Dhavina; Chantler, Jessica; Gouttebarge, Vincent; Janse van Rensburg, Dina Christina; MacMillan, Candice (Elsevier, 2026)
BACKGROUND : Mental health symptoms and disorders are growing concerns among elite athletes facing unique psychological stressors from high-performance competition. While prevalence has been studied in male athletes and regions like Europe and Australia, significant gaps exist regarding elite female athletes from underrepresented regions, including Africa. OBJECTIVES : To conduct a scoping review on the literature of mental health symptoms and disorders in elite female athletes globally, identify geographic research gaps, and summarise key contributing factors and methodologies. DESIGN : Scoping review. METHODS : While focusing on mental health symptoms and disorders among elite female athletes, studies including both female and male participants were considered to provide a comprehensive overview. A search was conducted in PubMed, PsycINFO, CINAHL, and Scopus databases. Two reviewers independently screened studies, extracted data, and charted results on study characteristics, descriptive study-level prevalence estimates, associated factors, and methodologies. RESULTS : Fifty-nine studies were included. Only seven investigated elite female athletes, 22 reported sex-disaggregated prevalence estimates, and 30 presented aggregated results. Most studies (88.1%) were cross-sectional. Only three studies investigated disorders, and the remaining 56 investigated symptoms such as depression, anxiety, and disordered eating. Risk associations included injury, illness, career dissatisfaction, financial stress, and gender. Research originated mainly from Europe (n = 27), with only one study from Africa and three from South America. CONCLUSIONS : Mental health symptoms are prevalent among elite female athletes, yet evidence is skewed toward high-income regions and often lacks female-specific data. More geographically inclusive, longitudinal, and sex-disaggregated research is needed, particularly in Africa and South America, to ensure the development of equitable interventions and policies.
Factors associated with return-to-sport outcomes following pathogen-confirmed acute respiratory infections in athletes : AWARE X study
Jooste, Marcel; Sewry, Nicola Ann; Valtonen, Maarit; Dyer, Marlise; Jordaan, Esme; Schwellnus, Martin Peter (BMJ Publishing Group, 2026-07)
OBJECTIVE : To identify factors associated with return-to-sport (RTS) outcomes following confirmed acute respiratory infections (ARinf) in athletes. METHODS : This prospective cohort study included 114 confirmed ARinf cases among athletic individuals. Causative pathogens were identified using multiplex PCR testing, and illness severity was classified per International Olympic Committee consensus (mild, moderate and severe). RTS outcomes included time (days) to return-to-training (RTT), return-to-full-training (RTFT) and return-to-full-performance (RTFP). Cox regression models (HRs) assessed associations between RTS outcomes and demographics, sport participation, pathogen groups and illness severity. RESULTS : The median (IQR) days to RTT were 3.5 (0–7), RTFT 8 (6–11) and RTFP 11 (7–14). Amateur athletes had prolonged RTS outcomes (HR range=0.51–0.59; p≤0.03) compared with professional athletes. RTS outcomes differed between the most common pathogen groups: influenza and SARS-CoV-2 had longer RTS than rhinovirus (HR range=0.11–0.23; p≤0.003). Severe illness was associated with prolonged RTS outcomes compared with mild and moderate illnesses (HR range=0.17–0.31; p<0.0001). Pathogen-related differences in RTS persisted within each severity group. Within mild/moderate illnesses, the influenza/SARS-CoV-2 subgroup had longer RTS than rhinovirus (HRs: RTT=0.35; RTFT=0.05; RTFP=0.06; p<0.05) and within severe illnesses (HRs: RTT=0.23; RTFT=0.21; RTFP=0.13; p≤0.01). CONCLUSION : Factors associated with RTS outcomes following ARinf in athletes are level of sport participation, illness severity at presentation and the causative pathogen. Clinical assessment of illness severity remains valuable in RTS decision-making, particularly in low-resource settings. However, identifying the causative pathogen may provide additional predictive value and refine RTS clinical decision-making.
Navigating adversity : non-completion and evacuation of trail runners at the 2022 Magoebaskloof Forest Marathon
Maleka, Thabo; Jansen van Rensburg, Audrey; Viljoen, Carel Thomas; Ramkilawon, Gopika Devi; Ramagole, Dimakatso Althea; Nair, Anoop; Janse van Rensburg, Dina Christina (South African Sports Medicine Association, 2026-04-22)
BACKGROUND : Trail running occurs on natural, uneven terrain. The literature is limited in exploring factors that contribute to trail runners not completing a race. OBJECTIVES : This study firstly investigated self-reported reasons for runners who did not finish (DNF) the 2022 Magoebaskloof Forest Marathon across 10km, 20km, 34km, and 50km distances, and secondly assessed runners' evacuation methods. METHODS: A descriptive cross-sectional study of consenting trail runners (n=429) who completed the post-race DNF survey (10km, 20km, 34km and 50km distances). Within two weeks post-race, runners reported whether they finished, reasons for discontinuing and evacuation methods. We report numbers (n) and point prevalence (%). RESULTS : Of the 228 runners who completed the post-race survey, 16 (7%) DNF. DNF runners entered the 34 km (19%) and 50 km distance (81%) and were aged 31–50 years (94%). No DNFs occurred in the 10km and 20km races. Approximately 27% did not meet cut-off times, while 19% got lost despite trail directions. Other contributing factors included pre-existing and new injuries (23%), illnesses (15%), and inadequate training (8%). While 50% of the DNF group had >5 years total running experience, only 19% had >5 years of trail running experience. Runners who finished the trail race had significantly more trail running experience than those who DNF (p=0.0082). The primary evacuation method was hiking back to the nearest aid station (63%), with 19% subsequently transported by shuttle. CONCLUSION : Multiple factors may have contributed to the race non-completion. Many DNF runners started with injuries or illnesses, inadequate training, or limited trail-running experience. Event planners should improve measures to prevent runners from getting lost. These findings emphasise the importance of preparation, navigation skills, and race management in ensuring trail running safety and success.
Elevating the game : pathway structures and the operationalisation of talent identification and development systems across world netball
Rongen, Fieke; Till, Kevin; Hill, Megan; Backhouse, Susan H.; Janse van Rensburg, Dina Christina; Hayburn, Jess; Navin, Anita; Whitehead, Sarah (Routledge, 2026)
Sporting pathways and talent identification and development systems (TIDS) are commonly used worldwide to identify and develop future elite athletes. However, limited research explores the structure of sporting pathways and the operationalisation of TIDS as part of them globally, especially in women’s sports, including netball. Therefore, representatives from 10 global netball governing bodies participated in semi-structured interviews to help describe the structure of their netball pathway and operationalisation of their TIDS. Utilising reflexive thematic analysis three themes were generated: ‘Netball pathways are multilayered but not always consistently connected’, ‘Traditional and forward-thinking talent identification and development practices’, and ‘Limited resources make talent identification and development challenging’. These findings provide organisations with an understanding of the structure of sporting pathways, and the operationalisation of TIDS in netball and the challenges of optimising them. To address these challenges, prioritising coach and practitioner education across the pathway to deliver inclusive, ethical, and appropriate practices to maximise player retention and player development is needed. Organisations are encouraged to consider how they can collaborate to maximise the use of resources within the sport.
The reporting of injury epidemiology and risk factors in women's rugby : a scoping review
Bellingan, Lenel; Sewry, Nicola Ann; MacMillan, Candice; Viljoen, Carel (Elsevier, 2026-03)
OBJECTIVES : To map the methodology in currently available scientific literature on injury epidemiology and injury risk factors in women’s rugby union. DESIGN : A scoping review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines. METHODS : Studies reporting injury epidemiology or injury risk factors in women’s rugby union were included through a search across nine databases. Studies were screened based on the eligibility criteria, and data were extracted and analysed from the studies that were included. RESULTS : Out of 3259 records produced, 55 studies met the inclusion criteria. There was an increase in publications over the last decade, but a lack of studies across Africa and South America. Most studies (n = 17; 31 %) used unique injury definitions, and collected injury data using clinical assessment (n = 26; 47 %). Twenty-five different injury incidence measures were reported, and 33 (60 %) studies reported injury prevalence. Thirty-one (56%) studies investigated risk factors associated with injury in women’s rugby. Sixteen (52 %) studies pooled the data for males and females or rugby fifteens, sevens, and tens. CONCLUSIONS : Current research on women’s rugby injuries highlights several gaps, including limited research across certain countries, pooled data reporting, and univariate risk factor analysis without injured-uninjured player comparisons. Despite existing consensus statements for injury in female sports, studies used varied reporting of injury incidence and prevalence, with most studies using their own study definitions and reporting methods. Future research should follow published guidelines and focus specifically on women’s rugby.
From GPT-4 to expert-endorsed athlete guidance : a Delphi consensus on sleep and jet lag
Vitale, Jacopo; McCall, Alan; Athlete Travel & Sleep Interest Group (ATSIG); Halson, Shona; Janse van Rensburg, Dina Christina (Springer, 2026)
BACKGROUND : Large language models (LLMs) like GPT-4 are increasingly used to generate health information, but concerns persist about their accuracy and relevance, particularly for elite athletes. OBJECTIVE : This study used GPT-4-generated frequently asked question (FAQ) responses on sleep and jet lag as the starting material for expert evaluation and consensus development, with the goal of producing consensus-based, athlete-specific guidance while identifying the limitations of AI-generated content. METHODS : Between November 2024 and March 2025, n=17 international sleep and circadian experts from the Athlete Travel & Sleep Interest Group (ATSIG) participated in a two-round Delphi process. Experts rated 20 GPT-4-generated FAQ responses (10 on sleep, 10 on jet lag) for appropriateness using a 6-point Likert scale and provided qualitative feedback. Items were revised after Round 1 using inductive thematic coding. Consensus was defined as ≥70% of participants rating an item as appropriate (scores 5–6) and ≤15% as non-appropriate (scores 1–2). Statistical analyses included Wilcoxon signed-rank tests, convergence metrics, and dissent detection (outlier and bipolarity analysis). RESULTS : In Round 1, 15 of 20 items (75%) met consensus; by Round 2, 18 of 20 (90%) achieved consensus. For sleep items, 7 of 10 reached consensus in Round 1 and 9 in Round 2; for jet lag, 8 items reached consensus in Round 1 and 9 in Round 2. Sleep Q6 (sleep and injury risk) narrowly missed the consensus threshold with 64.7% agreement, while Jet Lag Q9 (melatonin and sleep aids) remained below the 70% threshold. No item showed bimodal score distributions, suggesting no polarized disagreement. Descriptive rating patterns, increased consensus, and qualitative expert feedback indicated improved clarity, accuracy, and athlete-specific relevance after the Delphi process, although item-level statistical comparisons did not remain significant after Bonferroni correction for multiple testing. Qualitative analysis identified common concerns: for sleep items—imprecise or misleading content (55%), lack of athlete-specific relevance (30%), and outdated evidence (11%); for jet lag—outdated evidence (36%), imprecise or misleading content (34%), and formatting issues (17%). CONCLUSION : GPT-4-derived content may serve as useful preliminary material for expert discussion but should not be used as standalone guidance. Expert evaluation improved the clarity, safety, and athlete-specific relevance of most sleep and jet-lag responses, while the final outputs should be interpreted as consensus-based guidance rather than definitive proof of correctness. KEY POINTS 1. Expert-endorsed, consensus-based guidance on athlete sleep and jet lag was developed through a structured Delphi process using GPT-4-derived FAQ draft material as the starting point. 2. Consensus was achieved on 90% of items, suggesting improved expert agreement on most responses; however, this should be interpreted as consensus-based guidance rather than definitive proof of correctness. 3. The study shows that large language models can effectively support sports science communication when their outputs are reviewed and validated by domain experts.
Unpacking the impact of travel and jet lag on sleep and performance of athletes : a narrative review
Fabunmi, Oyesanmi A.; Jansen van Rensburg, Audrey; Vitale, Jacopo A.; Stevens, David; Lenting, Andrea; Janse van Rensburg, Dina Christina (Springer, 2026-04-22)
PURPOSE OF REVIEW : Travel is an essential aspect of an athlete's professional career. Yet, the embodiment of travel can lead to travel fatigue and jet lag, leading to a cascade of undesirable outcomes related to sleep and athletic performance. This review aims to synthesize the current evidence on the impact of long-haul travel and jet lag on the sleep and performance of athletes. RECENT FINDINGS : Emerging evidence suggests that travel fatigue and jet lag negatively impact sleep, particularly total sleep time, efficiency, and onset latency, and impair the cognitive and physical performance of elite athletes. However, some studies report neutral or positive effects, often due to prior travel experience, targeted interventions, or favorable conditions like business class seating. SUMMARY : Jet lag and travel fatigue pose a multifactorial risk to both sleep and performance in athletes. Implementing proactive, evidence-based travel management strategies is vital for optimizing athlete readiness, well-being and competitive success.
Improving social support among sports medicine practitioners : a call to action
Hendricks, Sharief; Zondi, Phathokuhle Cele; Janse van Rensburg, Dina Christina; Gordon, Leigh; Rotunno, Adrian; Ganda, Janesh; Naidoo, Dhavina; Dalton, Caroline; Isaacs, Natheema; Jones, Ben; Patricios, Jon S. (BMJ Publishing Group, 2026-05)
No abstract available.
Orthostatic blood pressure changes among adults in Ekiti state, Nigeria :impact of socio-demographic, anthropometric, and biophysical factors
Fabunmi, Oyesanmi A.; Adeniyi, Mayowa J.; Lenting, Andrea; Masilela, Thulani; Janse van Rensburg, Dina Christina (Wiley, 2026-02)
Orthostatic intolerance is the inability to maintain upright posture, a key manifestation of autonomic dysfunction that can lead to orthostatic hypotension (OH). We aimed to investigate orthostatic blood pressure (BP) changes among cohorts living in Ekiti State and to explore plausible underlying factors. We encompassed 140 participants (28% male; 72% female; age range: 18–70 years) in our preliminary study. Socio-demographic and anthropometric indices were collected using appropriate tools. Orthostatic responses were assessed at baseline, standing, and sitting following standardized protocols. Systolic (BP) decreased significantly by 4% after 1-min standing (130 ± 22 mmHg) compared to baseline (137 ± 20 mmHg). Diastolic (BP) increased significantly by 6.1% at 3 min (87 ± 13 mmHg) and 4.8% at 5 min (86 ± 12 mmHg) compared to baseline (82 ± 11 mmHg) (p < 0.001). Occupation (traders) and education level (secondary) are positively associated with mean arterial pressure (MAP) at 1- and 3-min standing times (p < 0.05). Orthostatic MAP at 1, 3, and 5 min correlated negatively with height but positively with body mass index (BMI), hip, and waist circumference (p < 0.05). These preliminary findings suggest a potential role for body composition and lifestyle in regulating autonomic cardiovascular function in response to postural changes.
Clinical manifestations of different viral respiratory infections in athletes : implications for risk assessment and return-to-sport - AWARE VII study in 116 cases
Jooste, Marcel; Sewry, Nicola Ann; Valtonen, Maarit; Dyer, Marlise; Jordaan, Esme; Schwellnus, Martin Peter (Taylor and Francis, 2026)
OBJECTIVES : The aims of this study were to describe the etiology of acute respiratory infections (ARinf) in athletic individuals, and to identify differences in the clinical presentation, evidence of possible multi-organ involvement, and illness classification between common pathogen groups. METHODS : One-hundred-and-sixteen cases of confirmed ARinf in athletic individuals were evaluated ≤ 5 days of the onset of an ARinf. Nasopharyngeal swab multiplex PCR testing was performed to identify a causative pathogen. Symptomatology, clinical examination findings, results of selected blood tests, and the clinical syndrome and illness severity classifications were compared between four common pathogen groups. RESULTS : The etiologies of ARinf in this cohort were: rhinovirus = 34(29%), influenza = 17(15%), SARS-CoV-2 = 15(13%), common coronavirus = 13(11%), 'unidentified' = 16(14%), 'dual pathogen' = 9(8%), and 'other' = 12(10%). Clinical presentation differed among the four common pathogen groups as follows: Influenza had more total symptoms, lower respiratory & regional symptoms, and systemic & non-respiratory symptoms than rhinovirus (p ≤ 0.002) and common coronavirus (p < 0.05). Influenza and SARS-CoV-2 had higher total symptoms and systemic & non-respiratory symptom severity scores than rhinovirus (p ≤ 0.0006 and p < 0.03 respectively) and common coronavirus (p ≤ 0.03 and p = 0.02 respectively). Evidence of other non-respiratory organ involvement on clinical examination was highest for influenza (53%). Illness classification for pathogen groups differed: common coronavirus had the highest percentage (%) of rhinitis-like ('common cold') illnesses (69%), and influenza had the highest % of 'flu-like' illnesses (82%). Influenza had the highest % of severe illnesses (88%) and common coronavirus the lowest (31%). 41% of rhinovirus presented with severe illness. CONCLUSION : Influenza and SARS-CoV-2 had greater number and severity of symptoms than rhinovirus and common coronavirus. Among the four common pathogen groups, influenza had the highest percentage of abnormal clinical examination and serological findings and severe illnesses. Knowledge of the causative pathogen and the clinical presentation may add value to the risk assessment and guide clinical decision-making in return-to-sport following ARinf in athletic individuals.
Beyond the 24-hour norm : PM2.5 air quality challenges at athletics events in South Africa
Havenga, Henno; Verster, Jean; Schwellnus, Martin Peter; Burger, Roelof; Sewry, Nicola Ann (Taylor and Francis, 2026)
The health implications of particulate matter 2.5 (PM2.5) exposure are well documented, particularly its penetration into the respiratory tract, posing serious health risks. This prospective longitudinal study investigates PM2.5 exposure levels during athletics events in South Africa, highlighting the short-term exposure risks for athletes. PM2.5 concentrations were measured at four events across rural, central metropolitan, and industrial metropolitan settings in 2023. Results indicated significant variations in PM2.5 levels, with mean concentrations ranging from 28.6 μg/m3 in rural areas to 132.7 μg/m3 in industrial metropolitan regions, exceeding WHO 24-hour exposure recommendations. Factors such as local industries and cooking methods at event sites contributed to these elevated levels. The findings underscore the need for establishing short-term PM2.5 exposure standards for outdoor activities, where added respiratory stress from exercise could exacerbate underlying conditions; we also highlight the importance of location selection to mitigate health risks for athletes.
Preseason injury epidemiology and associated injury risk factors among South African junior provincial rugby players : a prospective cohort study
Meyer, Kyle; Garnett, Daniel; Janse van Rensburg, Dina Christina; Fletcher, Lizelle; Viljoen, Carel Thomas (Taylor and Francis, 2026)
BACKGROUND : The preseason period in rugby plays a key role in athlete preparation for the demands of the sport during the in-competition period. Epidemiological data pertaining to rugby have focused mainly on senior elite professional with little evidence available for junior elite professionals, and even less during the preseason period. This may limit the ability of stakeholders in the sport to understand the effects of injury on participants during the preseason period. OBJECTIVE : To determine the epidemiology, clinical characteristics, and associated risk factors for injury among elite male junior provincial rugby players in South Africa during a 14-week preseason period. DESIGN : A prospective cohort study. METHODS : Data collection procedures were in-line with consensus statements in sports and rugby. Prospective injury data related to 53 male participants were collected. Descriptive statistics was used to describe clinical characteristics of injury, cross-tabulations were created to investigate risk factor associations, and logistic regression was used to model the risk factors. RESULTS : The overall injury prevalence was 75.5%. The incidence of match play injuries (149.26/1000 h) were higher than training injuries (23.32/1000 h). Injuries to the lower limb (48.8%) and muscle/tendon injuries (48.2%) were most commonly reported injuries by anatomical region and tissue type during the preseason period. When controlling for age and playing position, baseline injury was associated with a higher risk of sustaining a subsequent injury during preseason. Age, baseline injury, and playing position showed no statistically significant association with injury risk. CONCLUSION : A high number of training and match play injury incidence were recorded for elite male junior provincial rugby players. Baseline injury was associated with a higher risk of sustaining a subsequent injury during preseason when controlling for playing position and age.
Psychological profile of trail runners associated with running-related injuries : a prospective study
Gajardo-Burgos, Rubén E.; Sánchez, Raimund; Besomi, M.; Viljoen, Carel Thomas; Janse van Rensburg, Dina Christina; Bascour-Sandoval, Claudio (Sage, 2026)
BACKGROUND : Trail running has increased in popularity due to the benefits of physical activity in nature. However, trail running has an inherent risk of running-related injuries (RRI). It is known that athletes with certain psychological traits have a greater tendency to suffer injuries; however, this is unknown in trail runners. The main objective of this study was to identify trail runners' psychological profiles and to compare the proportion of RRI across these profiles. HYPOTHESIS : Trail runners with psychological profiles of high stress, precompetitive anxiety, mental fatigue, competitiveness, and poor sleep quality are at increased risk of RRI. STUDY DESIGN : Prospective cohort study. LEVEL OF EVIDENCE : Level 2. METHODS : A Gaussian mixture model cluster analysis was performed on 202 trail runners (55.5% male; aged 38.7 [33.4-46.2] years) with psychological stress, cognitive and somatic anxiety, self-confidence, mental fatigue, sleep quality, and competitiveness measured 4 weeks before participating in a race. The proportion of RRI during the race was recorded and compared across clusters. RESULTS : Overall RRI proportion during competition was 11.3% (n = 24). The most common RRI were muscle (41.7%) and tendon/bursa (16.7%) injuries, affecting primarily the knee (33.3%) and lower leg (20.8%). Five psychological profiles were identified. Cluster 1 (competitive runners with moderate psychological stress and mental fatigue, low sleep quality and anxiety, and high self-confidence) had a higher RRI proportion than Cluster 3 (similar traits but lower psychological stress, mental fatigue, and higher self-confidence; 21.2% vs 3.2%; P = 0.02). CONCLUSION : Certain psychological profiles in trail runners were associated with higher RRI risk. CLINICAL RELEVANCE : The medical team or trail running coaches should monitor runners with psychological profiles with higher psychological stress, mental fatigue, and cognitive anxiety, as well as lower self-confidence and sleep quality, to design strategies to reduce their risk of RRI.
Beyond prescriptions : chronic medication adherence predicts mortality risk in a large-scale cohort study
Blanco, Jessica Hamuy; Janse van Rensburg, Dina Christina; Jansen van Rensburg, Audrey; Uys, Corrie; Schellack, Natalie (Frontiers Media, 2025-11-25)
OBJECTIVES : The Medication Adherence Risk Score (MARS) is a calculated score using pharmacy transactional data spanning 50% of the South African private pharmacy market. This study aims to demonstrate that the existing MARS model enhances risk stratification by identifying individuals at increased risk of mortality related to non-adherence to chronic medication. METHODS : This was a retrospective cohort study in which an analysis of the relative mortality experience was compared to a standard fully underwritten base was performed for each of the MARS categories (low, medium, high and very high). The actual-to-expected ratio (AER) and relative risk (RR) for each category were compared across age groups and gender. The least absolute shrinkage and selection operator (LASSO) regression analysis method was applied to determine the most important variables within the dataset, providing insight into whether MARS offered more benefit than traditional risk rating factors. A time-to-event analysis by MARS categories was performed using the Cox proportional hazards model. RESULTS : The mortality experience of the study population was higher than the expected fully underwritten base (AER = 175%). For the overall sample, increasing AER and RR did not correlate with increasing MARS categories. However, use of the MARS in addition to age band allowed for differentiation of risk within the 25 to 55 age bands, with a higher MARS score indicating a higher AER and RR. The time-to-event analysis showed a statistically significant difference in the mean number of months before death occurred between the different MARS categories (low = 26.53; medium = 8.93; high = 7.02; very high = 6.92; p < 0.001). CONCLUSION : The MARS is not generalisable across all groups, as evidenced by the absence of a monotonic trend in the overall sample. However, when combined with age, it effectively differentiated mortality risk for individuals aged 25–55. The standard fully underwritten model underestimated the number of deaths within this pharmacy population. The time-to-event analysis showed a significant inverse relationship between MARS category and survival time.
Pedal power : female cyclists at 94.7 Ride Joburg face fewer illnesses but more injuries and finishing challenges
Janse van Rensburg, Dina Christina; Swart, Xan; Ramagole, Dimakatso Althea; Du Toit, Francois Christiaan; Viljoen, Carel Thomas; Botha, Tanita; Phalane, Mahlane; Beeton, Ramona; Jansen van Rensburg, Audrey (Edizioni Minerva Medica, 2026-02)
BACKGROUND: Mass participation in amateur cycling events is popular, and ensuring participant safety is crucial. This study aimed to determine the epidemiology of medical encounters (MEs), including injury and illness, at mass-participation amateur cycling events and to explore associated risk factors. METHODS: We conducted a cross-sectional, descriptive, exploratory analysis of operational data collected during the 2015-2016 94.7 Ride Joburg cycling race. Outcomes include frequency (N., %), prevalence (%), incidence (injuries/1000 participants), did-not-finish (DNF, %), and Odds Ratio (OR, 95%CI). RESULTS: In total, 44849 individuals, mean age 40.06±11.68, participated in the 94.7 Ride Joburg cycling race during 2015-2016. We report the prevalence for MEs (5.3%) (injury: 1.7%, illness: 3.6%). The incidence of all MEs was 52.71 (50.61-54.88) (injury: 16.79 [15.61-18.03], illness: 35.92 [34.19-37.72]). Most race participants were male (79.0%), aged 31-50 (58.9%). Older age decreased the odds of injury, illness, or not finishing (P<0.001). Females had higher odds of injury (OR:1.43; 1.21-1.67; P<0.001) and for DNF (OR:1.57; 1.46-1.70; P<0.001) but lower odds of illness (OR:0.73; 0.64-0.64; P<0.001), compared to males. Overall, 7.9% of participants DNF, 6.9% had MEs, 3.2% were injured, and 3.8% were ill. Medical point location and distance were not significantly associated with medical encounters. CONCLUSIONS: Older participants have lower odds of injury and illness encounters. Females have higher odds of injury encounters and not finishing the race but lower odds of illness encounters than males. These findings offer insights into injury and illness at mass-participation amateur cycling events.
Physical activity implementation for cancer care and prevention in Sub-Saharan Africa : a call to action
Douryang, Maurice; Irma Belinda, Yossa Nzeuwa; Pillay, Lervasen (BMJ Publishing Group, 2026-02)
No abstract available.
Independent risk factors associated with a history of exercise associated muscle cramps (EAMC) among 21460 cycling race entrants (SAFER XXXVI) : a descriptive cross-sectional study
Pohl, Carey; Schwellnus, Martin Peter; Sewry, Nicola Ann; Boer, Pieter; Jordaan, Esme; Viljoen, Carel Thomas (Elsevier, 2026-03)
BACKGROUND : There is limited research on cyclists with a history of exercise associated muscle cramps (hEAMC) defined as muscle cramping (painful, spontaneous, sustained spasm of a muscle) during or after cycling. OBJECTIVE : To determine the epidemiology, clinical characteristics, and risk factors associated with hEAMC in cyclists taking part in a mass participation cycling event. METHODS : 21,460 race entrants from the 2016 Cape Town Cycle Tour completed an online questionnaire, which is based on the guidelines for recreational exercise participation from the European Association of Cardiovascular Prevention and Rehabilitation [EACPR]. The main outcome measures were: the lifetime prevalence hEAMC (%; 95% confidence intervals), independent risk factors (adjusted for age and sex) associated with hEAMC (history of chronic disease, history of allergies, history of chronic medication use, history of medication use before and during race, history of cycling injuries, and cycling training/racing variables). Poisson regression was used to calculate the prevalence (%) of the variables of interest, with 95% confidence intervals. RESULTS : The retrospective lifetime prevalence of hEAMC was 30.51%. EAMC in cyclists affects mainly the quadriceps muscles and occurs in the 4th quarter during a race. Novel independent risk factors associated with an increased risk of hEAMC in cyclists were: increased number of years participating as a recreational cyclist (PR=1.03 per 5 years increase; p<0.0001), a higher chronic disease composite score (PR=1.36 times increased risk for every 2 additional chronic diseases; p<0.0001), a history of any allergies (PR=1.18; p<0.0001), medication use before or during event (PR=1.41; p<0.0001) a history of an acute (PR=1.30; p<0.0001) and gradual onset injury (PR=1.29; p<0.0001). CONCLUSION : Our study identified novel independent risk factors associated with a hEAMC. These results, in combination with other known risk factors, could assist future targeted prevention programmes and the management of EAMC in recreational cyclists. HIGHLIGHTS • Older cyclists and males have a significantly higher lifetime prevalence of hEAMC. • EAMC in cyclists affects mainly the quadriceps muscles. • EAMC in cyclists occurs mainly in the 4th quarter during a race. • Risk factors for hEAMC: experience, chronic disease, allergies, medications, past injury.
Illness is common in trail runners during training : a prospective cohort study
Janse van Rensburg, Dina Christina; Jansen van Rensburg; Audrey; Boer, Pieter Henk; Serero, Precious; Botha, Tanita; Schoeman, Marlene; Viljoen, Carel Thomas (Elsevier, 2026-05)
OBJECTIVES : Trail runners often experience illness during event preparation. We aimed to prospectively determine prevalence, incidence, clinical characteristics, severity (time-loss, burden) and associated illness risk factors amongst South African male and female recreational trail runners of different ages over a 30-week training period. DESIGN : Prospective cohort. METHODS : Illness and training data from 152 trail runners (120 males, 32 females) were collected every 14 days over 30 weeks using the updated OSTRC-H questionnaire. Illness prevalence (%), incidence (I: per 1000 trail running exposure-days), incidence ratio (IR), severity [% time-loss; illness burden (IB: days lost/1000 trail running exposure-days)], and associated risk factors are reported. RESULTS : Over 30 weeks, 52 % of runners reported illness, with a mean two-week all-illness prevalence of 10.1 %. The overall illness incidence was 7.2 (95 % CI: 5.7–9.2). The winter-to-summer IR was 1.6 (p = 0.022). Illness incidence in females (I = 9.7) was higher than in males (I = 6.6), with a female:male IR of 1.5 (p < 0.05). Most illnesses affected the respiratory (64.3 %), digestive (15.9 %) and musculoskeletal (5.7 %) systems. Moderate illness severity (8–28 days time-loss) occurred in 29.3 % of runners. The overall IB was 43.2 days lost. BMI ≥ 25 kg/m2 was associated with illness, but no significant illness risk factors were identified via Poisson regression. CONCLUSIONS : During a 30-week training period, 52 % of runners reported illness, with a higher incidence in females. The respiratory tract accounted for > 60 % of illnesses. One in three trail runners experienced > one week time-loss. A higher BMI > 25 kg/m2 was associated with illness. Further research is needed to identify risk factors and develop prevention strategies. PRACTICAL IMPLICATIONS • Prioritise respiratory health monitoring • Screen for high-risk profiles early • Tailor strategies for females and higher-BMI runners • Inform trail running guidelines HIGHLIGHTS • Trail runners show an illness prevalence of 10.1% during training. • Females experience significantly higher illness incidence than males. • Illness mainly affects the respiratory system of trail runners during training. • Approximately one-third of trail runners suffer from moderate to severe illness, resulting in > 8 days of time-loss in a 30-week training period. • Trail runners with a higher BMI (> 25 kg/m2) are more susceptible to illness.

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