Can analyses of electronic patient records be independently and externally validated? The effect of statins on the mortality of patients with ischaemic heart disease: a cohort study with nested case-control analysis

Objective To conduct a fully independent and external validation of a research study based on one electronic health record database, using a different electronic database sampling the same population. Design Using the Clinical Practice Research Datalink (CPRD), we replicated a published investigation into the effects of statins in patients with ischaemic heart disease (IHD) by a different research team using QResearch. We replicated the original methods and analysed all-cause mortality using: (1) a cohort analysis and (2) a case-control analysis nested within the full cohort. Setting Electronic health record databases containing longitudinal patient consultation data from large numbers of general practices distributed throughout the UK. Participants CPRD data for 34 925 patients with IHD from 224 general practices, compared to previously published results from QResearch for 13 029 patients from 89 general practices. The study period was from January 1996 to December 2003. Results We successfully replicated the methods of the original study very closely. In a cohort analysis, risk of death was lower by 55% for patients on statins, compared with 53% for QResearch (adjusted HR 0.45, 95% CI 0.40 to 0.50; vs 0.47, 95% CI 0.41 to 0.53). In case-control analyses, patients on statins had a 31% lower odds of death, compared with 39% for QResearch (adjusted OR 0.69, 95% CI 0.63 to 0.75; vs OR 0.61, 95% CI 0.52 to 0.72). Results were also close for individual statins. Conclusions Database differences in population characteristics and in data definitions, recording, quality and completeness had a minimal impact on key statistical outputs. The results uphold the validity of research using CPRD and QResearch by providing independent evidence that both datasets produce very similar estimates of treatment effect, leading to the same clinical and policy decisions. Together with other non-independent replication studies, there is a nascent body of evidence for wider validity

“It’s like a safety net for when things go wrong”: key stakeholder and program user perspectives on a peer-led safe space program in Sydney, Australia

Background: Safe Spaces are a harm reduction approach commonly utilised in nightlife and festival settings to address alcohol and other drug-related harms. Despite increasing use, there has been little independent evaluation of safe space programs. This study aimed to explore (1) program user satisfaction with and use of a safe space program implemented in Sydney, Australia (The Take Kare Safe Space (TKSS)), and (2) the strengths and weaknesses of TKSS from the perspective of key stakeholders. Methods: Semi-structured, in-depth, interviews lasting between 30 min to 1 h were conducted with 38 key program stakeholders, including staff from police (n = 4), ambulance (n = 4), a local hospital accident and emergency room (n = 4), local council (n = 2), city ‘rangers’ (n = 2), the TKSS program (n = 4), licensed venues and other nightlife service providers (n = 4), and program users (n = 14). Purposive sampling was used to identify key stakeholders to participate in interviews. Results: Stakeholders stated that the TKSS program had a number of core benefits, including that it filled a service gap in nightlife settings; improved the efficiency and effectiveness of emergency services and other stakeholders operating in nightlife precincts; provided welfare services through proactive and non-judgmental interventions; and facilitated a means to de-escalate conflict without engaging police. Perceived weaknesses of the program included a lack of public awareness about the program; staff and volunteer levels; and misunderstandings regarding the scope and function of the TKSS program by some stakeholders. Conclusion: This study demonstrates the complex relationships that exist around the delivery of harm reduction in nightlife settings. In particular, it highlights the relative lack of servicing of public nightlife settings and the value of safe spaces/peer-to-peer safety ambassador programs in linking up care and filling this service gap. Further, it documents the extended benefit across key stakeholder groups of delivering proactive and non-judgemental harm reduction services and, in doing so, provides critical evidence around their efficacy in reducing AOD-related harms in the night-time economy

The Positional Match Running Performance of Elite Gaelic Football.

There is currently limited information available on match running performance in Gaelic football. The objective of the current study was to report on the match running profile of elite male Gaelic football and assess positional running performance. In this observational study 50 elite male Gaelic football players wore 4-Hz GPS units (VXsports, New Zealand) across 30 competitive games with a total of 212 full game data sets collected. Activity was classed according to total distance, high speed distance (≥17 km.h), sprint distance (≥22 km.h), mean velocity (km.h), peak velocity (km.h) and number of accelerations. The average match distance was 8160 ± 1482 m, reflective of a relative distance of 116 ± 21 m.min, with 1731 ± 659 m covered at high speed which is reflective of a relative high speed distance of 25 ± 9 m.min. The observed sprint distance was 445 ± 169 m distributed across 44 sprint actions. The peak velocity was 30.3 ± 1.8 km.h with a mean velocity of 6.5 ± 1.2 km.h. Players completed 184 ± 40 accelerations which represent 2.6 ± 0.5 a.min. There were significant differences between positional groups for both total running distance, high speed running distance and sprint distance, with midfielders covering more total and high speed running distance, compared to other positions (p<0.001). There was a reduction in high speed and sprint distance between the first and second half (p<0.001). Reductions in running performance were position dependant with the middle three positions experiencing the highest decrement in performance. The current study is the first to communicate a detailed description of match running performance during competitive elite Gaelic football match play

Aerobic Fitness and Playing Experience Protect Against Spikes in Workload: The Role of the Acute:Chronic Workload Ratio on Injury Risk in Elite Gaelic Football.

PURPOSE: To examine the association between combined session-RPE workload measures and injury risk in elite Gaelic footballers. METHODS: Thirty-seven elite Gaelic footballers (mean ± SD age of 24.2 ± 2.9 yr) from one elite squad were involved in a single season study. Weekly workload (session-RPE multiplied by duration) and all time-loss injuries (including subsequent week injuries) were recorded during the period. Rolling weekly sums and week-to-week changes in workload were measured, allowing for the calculation of the 'acute:chronic workload ratio' that was calculated by dividing acute workload (i.e. 1-week workload) by chronic workload (i.e. rolling average 4-weekly workload). Workload measures were then modelled against all injury data sustained using a logistic regression model. Odds ratios (OR) were reported against a reference group. RESULTS: High 1-weekly workloads (≥2770 AU, OR = 1.63 - 6.75) were associated with significantly higher risk of injury compared to a low training load reference group (1.5), players with 1 year experience had a higher risk of injury (OR = 2.22) and players with 2-3 (OR = 0.20) and 4-6 years (OR = 0.24) of experience had a lower risk of injury. Players with poorer aerobic fitness (estimated from a 1 km time trial) had a higher injury risk compared to players with higher aerobic fitness (OR = 1.50-2.50). An acute:chronic workload ratio of (≥2.0) demonstrated the greatest risk of injury. CONCLUSIONS: These findings highlight an increased risk of injury for elite Gaelic football players with high (>2.0) acute:chronic workload ratios and high weekly workloads. A high aerobic capacity and playing experience appears to offer injury protection against rapid changes in workload and high acute:chronic workload ratios. Moderate workloads, coupled with moderate-high changes in the acute:chronic workload ratio appear to be protective for Gaelic football players

The metabolic power and energetic demands of elite Gaelic football match play.

BACKGROUND: Metabolic power has not yet been investigated within elite Gaelic football. The aim of the current investigation was to compare the metabolic power demands between positional groups and examine the temporal profile of elite Gaelic football match play. METHODS: Global positional satellite system (GPS) data were collected from 50 elite Gaelic football players from 4 inter-county teams during 35 elite competitive matches over a three season period. A total of 351 complete match samples were obtained for final analysis. Players were categorised based on positional groups; full-back, half-back, midfield, half- forward and full-forward. Instantaneous raw velocity data was obtained from the GPS and exported to a customised spreadsheet which provided estimations of both speed based, derived metabolic power and energy expenditure variables (total distance, high speed distance, average metabolic power, high power distance and total energy expenditure). RESULTS: Match mean distance was 9222 ± 1588 m, reflective of an average metabolic power of 9.5-12.5 W∙kg-1, with an average energy expenditure of 58-70 Kj∙kg-1 depending on position. There were significant differences between positional groups for both speed-based and metabolic power indices. Midfielders covered more total and high-speed distance, as well as greater average and overall energy expenditure compared to other positions (p < 0.001). A reduction in total, high-speed, and high-power distance, as well as average metabolic power throughout the match (p < 0.001) was observed. CONCLUSIONS: Positional differences exist for both metabolic power and traditional running based variables. The middle three positions (midfield, half-back and half-forward) possess greater activity profiles when compared to other positional groups. The reduction in metabolic power and traditional running based variables are comparable across match play. The current study demonstrates that metabolic power may contribute to our understanding of Gaelic football match-play

High chronic training loads and exposure to bouts of maximal velocity running reduce injury risk in elite Gaelic football.

OBJECTIVES: To examine the relationship between chronic training loads, number of exposures to maximal velocity, the distance covered at maximal velocity, percentage of maximal velocity in training and match-play and subsequent injury risk in elite Gaelic footballers. DESIGN: Prospective cohort design. METHODS: Thirty-seven elite Gaelic footballers from one elite squad were involved in a one-season study. Training and game loads (session-RPE multiplied by duration in min) were recorded in conjunction with external match and training loads (using global positioning system technology) to measure the distance covered at maximal velocity, relative maximal velocity and the number of player exposures to maximal velocity across weekly periods during the season. Lower limb injuries were also recorded. Training load and GPS data were modelled against injury data using logistic regression. Odds ratios (OR) were calculated based on chronic training load status, relative maximal velocity and number of exposures to maximal velocity with these reported against the lowest reference group for these variables. RESULTS: Players who produced over 95% maximal velocity on at least one occasion within training environments had lower risk of injury compared to the reference group of 85% maximal velocity on at least one occasion (OR: 0.12, p=0.001). Higher chronic training loads (≥4750AU) allowed players to tolerate increased distances (between 90 to 120m) and exposures to maximal velocity (between 10 to 15 exposures), with these exposures having a protective effect compared to lower exposures (OR: 0.22 p=0.026) and distance (OR=0.23, p=0.055). CONCLUSIONS: Players who had higher chronic training loads (≥4750AU) tolerated increased distances and exposures to maximal velocity when compared to players exposed to low chronic training loads (≤4750AU). Under- and over-exposure of players to maximal velocity events (represented by a U-shaped curve) increased the risk of injury

The Integration of Internal and External Training Load Metrics in Hurling

The current study aimed to assess the relationship between the hurling player's fitness profile and integrated training load (TL) metrics. Twenty-five hurling players performed treadmill testing for VO2max, the speed at blood lactate concentrations of 2 mmol•L-1 (vLT) and 4 mmol•L-1 (vOBLA) and the heart rate-blood lactate profile for calculation of individual training impulse (iTRIMP). The total distance (TD; m), high speed distance (HSD; m) and sprint distance (SD; m) covered were measured using GPS technology (4-Hz, VX Sport, Lower Hutt, New Zealand) which allowed for the measurement of the external TL. The external TL was divided by the internal TL to form integration ratios. Pearson correlation analyses allowed for the assessment of the relationships between fitness measures and the ratios to performance during simulated match play. External measures of the TL alone showed limited correlations with fitness measures. Integrated TL ratios showed significant relationships with fitness measures in players. TD:iTRIMP was correlated with aerobic fitness measures VO2max (r = 0.524; p = 0.006; 95% CI: 0.224 to 0.754; large) and vOBLA (r = 0.559; p = 0.003; 95% CI: 0.254 to 0.854; large). HSD:iTRIMP also correlated with aerobic markers for fitness vLT (r = 0.502; p = 0.009; 95% CI: 0.204 to 0.801; large); vOBLA (r = 0.407; p = 0.039; 95% CI: 0.024 to 0.644; moderate). Interestingly SD:iTRIMP also showed significant correlations with vLT (r = 0.611; p = 0.001; 95% CI: 0.324 to 0.754; large). The current study showed that TL ratios can provide practitioners with a measure of fitness as external performance alone showed limited relationships with aerobic fitness measures. © Editorial Committee of Journal of Human Kinetics 2016

Addition of Caffeine to a Carbohydrate Feeding Strategy Prior to Intermittent Exercise

The ergogenic effect of caffeine is well established, although no investigations providing a high carbohydrate feeding strategy (pre-exercise meal=2 g/kg BM) co-ingested with caffeine exist for soccer. This investigation examines the effect of caffeine in addition to a pre-exercise carbohydrate meal and drink mid-way through a soccer simulation. Eight recreational soccer players completed an 85-minute soccer simulation followed by an exercise capacity test (Yo-yo Intermittent Endurance test level 2) on two occasions. Prior to exercise participants consumed a high carbohydrate meal, with placebo or 5 mg/kg BM-1 caffeine. No significant performance effect was identified (p=0.099) despite a 12.8% (109 m) improvement in exercise capacity following caffeine. Rates of carbohydrate and fat oxidation did not differ between conditions and nor were differences apparent for plasma glucose, fatty acids, glycerol, β-hydroxybutyrate (p>0.05). However, an increase in lactate was observed for caffeine (p=0.039). A significant condition effect on rating of perceived exertion was identified (p<0.001), with the overall mean for the protocol lowered to 11.7±0.9 au for caffeine compared to 12.8±1.3 au. Caffeine supplementation with a carbohydrate feeding strategy failed to affect metabolic and metabolite responses, although reductions in perception of exercise were observed. While a 12.8% increase in exercise capacity was noted the findings were not significant, possibly due to the small sample size

Anthropometric and Performance Characteristics of Elite Hurling Players

The purpose of the present study was to examine variations in the anthropometric and performance characteristics of elite hurling players in relation to playing position. Forty-one male, elite intercounty hurlers (25 ± 4 years), 4 goalkeepers, 8 full-backs, 8 halfback, 6 midfielders, 8 half-forwards and 7 full-forwards underwent measurements of standard anthropometric (stature, body mass, sum of five skinfolds and adipose tissue percentage estimates (%AT)) and performance characteristics (counter-movement jump (CMJ), CMJ peak power, CMJ relative peak power, 5-, 10-, 20-m sprint times and estimated V•O2max) during the later stages of the competitive season. A clear hierarchical anthropometric profile is evident with goalkeepers being the taller (184.3 ± 3.7 m), possessing the highest body mass (88.7 ± 5.7 kg) and adiposity (13.2 ± 3.1 %AT) than their outfield colleagues. Half-backs (47.4 ± 2.4 cm) and half-forwards (50.7 ± 5.9 cm) produced the highest CMJ scores; a similar profile was evident for sprint times. Midfielders (60.1 ± 1.4 mL.kg-1.min-1) exhibited a significantly (p<0.05) greater maximal oxygen uptake than all other playing positions. Differences in the anthropometric and performance characteristics of other playing positions whilst evident were non-significant. This study provides novel data, as it is the first report to present normative anthropometric and performance data for elite hurling players which to date has not been present in the literature. The enhanced maximal oxygen uptake in midfield players is likely due to different performance, technical and tactical demands associated with this position

Impact and return on investment of the take kare safe space program—a harm reduction strategy implemented in Sydney, Australia

Safe spaces are increasingly utilized to reduce alcohol-related harm, violence, crime and improve public safety in nightlife settings. This study aimed to determine the impact and return on investment of the Take Kare Safe Space (TKSS) program—a harm reduction program implemented to address alcohol-related violence and disorder in three locations in Sydney’s night-time economy between 2014 and 2019. TKSS ambassadors provided support at static safe spaces and patrolled designated nightlife precincts to provide practical assistance to vulnerable and intoxicated people. Ambassadors recorded information relating to these interactions including ‘client’ age, gender, perceived level of intoxication, time and length of engagement with the program. Costs of program implementation and benefits of major incidents averted were obtained to allow calculation of return on investment. From December 2014 to April 2019, 66,455 people were supported by TKSS ambassadors. Most users were male (62%) and aged 18–25 years (66%). Of 3633 interventions by ambassadors, serious risk of harm was averted in 735 cases (20%). The program’s return on investment is estimated at 2.67, suggesting that a $1 investment results in$2.67 in benefits. Safe Spaces are extensively utilized, particularly by young males with high levels of intoxication, and represent a positive return on investment. Despite the growth of such services, there remains a notable absence of rigorous, independent evaluation regarding the outcomes and/or social benefit of safe space programs. From a policy perspective, there is a need for more high-quality economic evaluations to better inform decisions about competing uses of limited resources