Tour, Giro, Vuelta:Rapid Progress in Cycling Performance Starts in the 1980s

After analyzing historic records (1892-2008), El Helou et al. [1] reported a distinctive 6.38% improvement in speed in European professional road racing from 1993 onwards, a period which coincides with the years of the ‘epo epidemic’ in professional cycling. We aim to show that this improvement might be spurious, since El Helou et al. did not account for the influence of confounding variables on riders’ speed progression over time. We scrutinized archival data provided by the French Association Mémoire du Cyclisme [12] and assessed winning riders’ kilometers per hour (kph) and time performances, demonstrated in the Tour, Giro and Vuelta from 1903 to 2011(N = 256). We next classified these measures in ten time periods, accounting for El Helou et al.’s ‘critical’ year 1993. We further assessed the distances and brutality rates of the races, as well as the number of stages in the races and included these variables as covariates in the study, because we expected them to influence riders’ achievements. Analyses of covariance (ANCOVA) showed that the variables included in the model explained R2adj. = .89–.98 of the variation in riders’ performances. The three covariates indeed influenced riders’ performances to a greater or a lesser extent over the years. Time performances appeared to be more valid to appraise riders’ speed progression than kph performances, because the former variable is not biased by the distances of the races. After adjusting for the influence of the covariates, multiple comparisons between time periods indicated that time performances in El Helou et al.’s critical years did not significantly differ from performances displayed by riders in immediate foregoing or succeeding years. Furthermore, the 1970s appeared to be key in riders’ evolution in performance over time. We next calculated the proportional progress (%) in time performances per period as ANCOVA follow–up. Across races, we obtained an improvement of 3.18% in time performance beyond the 1990s that does not deviate from the range of expected variability in performance progress over time. Using the 1970s as a baseline, findings further showed a significant linear and curvilinear progress in time performance within and across the three Grand Tours. Inconsistent with El Helou et al.’s conclusion, however, the rapid linear progress originates in the 1980s, not in the 1990s, and gradually levels off from the 1990s onwards in all three multi–stage races. Findings strongly question opinions about the effects of the ‘epo epidemic’ on cyclist

Tour, Giro, Vuelta: Rapid Progress in Cycling Performance Starts in the 1980s

Abstract After analyzing historic records , El Helou et al. [1] reported a distinctive 6.38% improvement in speed in European professional road racing fro m 1993 onwards, a period wh ich coincides with the years of the ‗epo epidemic' in professional cycling. We aim to show that this improvement might be spurious, since El Helou et al. did not account for the influence of confounding variables on riders' speed progression over time. We scrutinized arch ival data provided by the French Association Mé moire du Cy clism

External validation of prognostic models predicting outcome after chronic subdural hematoma

Background: Several prognostic models for outcomes after chronic subdural hematoma (CSDH) treatment have been published in recent years. However, these models are not sufficiently validated for use in daily clinical practice. We aimed to assess the performance of existing prediction models for outcomes in patients diagnosed with CSDH. Methods: We systematically searched relevant literature databases up to February 2021 to identify prognostic models for outcome prediction in patients diagnosed with CSDH. For the external validation of prognostic models, we used a retrospective database, containing data of 2384 patients from three Dutch regions. Prognostic models were included if they predicted either mortality, hematoma recurrence, functional outcome, or quality of life. Models were excluded when predictors were absent in our database or available for < 150 patients in our database. We assessed calibration, and discrimination (quantified by the concordance index C) of the included prognostic models in our retrospective database. Results: We identified 1680 original publications of which 1656 were excluded based on title or abstract, mostly because they did not concern CSDH or did not define a prognostic model. Out of 18 identified models, three could be externally validated in our retrospective database: a model for 30-day mortality in 1656 patients, a model for 2 months, and another for 3-month hematoma recurrence both in 1733 patients. The models overestimated the proportion of patients with these outcomes by 11% (15% predicted vs. 4% observed), 1% (10% vs. 9%), and 2% (11% vs. 9%), respectively. Their discriminative ability was poor to modest (C of 0.70 [0.63–0.77]; 0.46 [0.35–0.56]; 0.59 [0.51–0.66], respectively). Conclusions: None of the examined models showed good predictive performance for outcomes after CSDH treatment in our dataset. This study confirms the difficulty in predicting outcomes after CSDH and emphasizes the heterogeneity of CSDH patients. The importance of developing high-quality models by using unified predictors and relevant outcome measures and appropriate modeling strategies is warranted

Lance Armstrong’s Era of Performance:Part III: Demonstrating the Post Hoc Fallacy

Abstract In consequence of USADA’s charges, Lance Armstrong conceded he doped during his cycling career. The logic proposed in the post hoc fallacy entails that Armstrong’s sportive feats are therefore ‘caused ’ by his doping use. This fallacy generalizes to the belief put forward in the doping debate that the progress in speed over time in professional cycling is determined by riders ’ use of progressively potent doping agents. To examine this fallacy, the current study compared Armstrong’s mountain time trial wins, realized in the Tour de France (2001, 2004), to victories demonstrated by riders in similar races uphill in the French race (1958–1996, N = 17). The fallacy expects that riders will race faster over time and that Armstrong’s achievements will be far superior to other riders. However, if these expectations are disconfirmed the fallacy will be refuted. We developed a climbing index to evaluate riders ’ km/h performances: ClI = (Corrected altitude climb / Distance trial) ● 100. Higher values indicate more demanding races. Mediation regression analyses showed that, over time, the trials became less demanding, b =-.0076 (∆R2 =.201, p ≤.05), and that riders raced b = 0.201 km/h faster per year (∆R2 =.234, p ≤.05). The index had a robust influence on riders ’ speed (r =-.97) and they raced b =-2.302 km/h slower per unit of the index (∆R2 =.932, p ≤.0001). The significant mediating influence of the index, b = 0.175 km/h (p ≤.05), subsequently reduced riders ’ progress in speed to a nonsignificant b = 0.026 km/h per year (p =.38, ∆R2 =.003). Furthermore, Armstrong’s performances did not prove to be outliers. Findings invalidate the reasoning employed in the post hoc fallacy, since the CLI and not the year in which riders competed constitutes the main determinant of riders