Background: Short-term forecasts of infectious disease burden can contribute to situational awareness and aid capacity planning. Based on best practice in other fields and recent insights in infectious disease epidemiology, one can maximise the predictive performance of such forecasts if multiple models are combined into an ensemble. Here, we report on the performance of ensembles in predicting COVID-19 cases and deaths across Europe between 08 March 2021 and 07 March 2022.Methods: We used open-source tools to develop a public European COVID-19 Forecast Hub. We invited groups globally to contribute weekly forecasts for COVID-19 cases and deaths reported by a standardised source for 32 countries over the next 1–4 weeks. Teams submitted forecasts from March 2021 using standardised quantiles of the predictive distribution. Each week we created an ensemble forecast, where each predictive quantile was calculated as the equally-weighted average (initially the mean and then from 26th July the median) of all individual models’ predictive quantiles. We measured the performance of each model using the relative Weighted Interval Score (WIS), comparing models’ forecast accuracy relative to all other models. We retrospectively explored alternative methods for ensemble forecasts, including weighted averages based on models’ past predictive performance.Results: Over 52 weeks, we collected forecasts from 48 unique models. We evaluated 29 models’ forecast scores in comparison to the ensemble model. We found a weekly ensemble had a consistently strong performance across countries over time. Across all horizons and locations, the ensemble performed better on relative WIS than 83% of participating models’ forecasts of incident cases (with a total N=886 predictions from 23 unique models), and 91% of participating models’ forecasts of deaths (N=763 predictions from 20 models). Across a 1–4 week time horizon, ensemble performance declined with longer forecast periods when forecasting cases, but remained stable over 4 weeks for incident death forecasts. In every forecast across 32 countries, the ensemble outperformed most contributing models when forecasting either cases or deaths, frequently outperforming all of its individual component models. Among several choices of ensemble methods we found that the most influential and best choice was to use a median average of models instead of using the mean, regardless of methods of weighting component forecast models.Conclusions: Our results support the use of combining forecasts from individual models into an ensemble in order to improve predictive performance across epidemiological targets and populations during infectious disease epidemics. Our findings further suggest that median ensemble methods yield better predictive performance more than ones based on means. Our findings also highlight that forecast consumers should place more weight on incident death forecasts than incident case forecasts at forecast horizons greater than 2 weeks.Funding: AA, BH, BL, LWa, MMa, PP, SV funded by National Institutes of Health (NIH) Grant 1R01GM109718, NSF BIG DATA Grant IIS-1633028, NSF Grant No.: OAC-1916805, NSF Expeditions in Computing Grant CCF-1918656, CCF-1917819, NSF RAPID CNS-2028004, NSF RAPID OAC-2027541, US Centers for Disease Control and Prevention 75D30119C05935, a grant from Google, University of Virginia Strategic Investment Fund award number SIF160, Defense Threat Reduction Agency (DTRA) under Contract No. HDTRA1-19-D-0007, and respectively Virginia Dept of Health Grant VDH-21-501-0141, VDH-21-501-0143, VDH-21-501-0147, VDH-21-501-0145, VDH-21-501-0146, VDH-21-501-0142, VDH-21-501-0148. AF, AMa, GL funded by SMIGE - Modelli statistici inferenziali per governare l'epidemia, FISR 2020-Covid-19 I Fase, FISR2020IP-00156, Codice Progetto: PRJ-0695. AM, BK, FD, FR, JK, JN, JZ, KN, MG, MR, MS, RB funded by Ministry of Science and Higher Education of Poland with grant 28/WFSN/2021 to the University of Warsaw. BRe, CPe, JLAz funded by Ministerio de Sanidad/ISCIII. BT, PG funded by PERISCOPE European H2020 project, contract number 101016233. CP, DL, EA, MC, SA funded by European Commission - Directorate-General for Communications Networks, Content and Technology through the contract LC-01485746, and Ministerio de Ciencia, Innovacion y Universidades and FEDER, with the project PGC2018-095456-B-I00. DE., MGu funded by Spanish Ministry of Health / REACT-UE (FEDER). DO, GF, IMi, LC funded by Laboratory Directed Research and Development program of Los Alamos National Laboratory (LANL) under project number 20200700ER. DS, ELR, GG, NGR, NW, YW funded by National Institutes of General Medical Sciences (R35GM119582; the content is solely the responsibility of the authors and does not necessarily represent the official views of NIGMS or the National Institutes of Health). FB, FP funded by InPresa, Lombardy Region, Italy. HG, KS funded by European Centre for Disease Prevention and Control. IV funded by Agencia de Qualitat i Avaluacio Sanitaries de Catalunya (AQuAS) through contract 2021-021OE. JDe, SMo, VP funded by Netzwerk Universitatsmedizin (NUM) project egePan (01KX2021). JPB, SH, TH funded by Federal Ministry of Education and Research (BMBF; grant 05M18SIA). KH, MSc, YKh funded by Project SaxoCOV, funded by the German Free State of Saxony. Presentation of data, model results and simulations also funded by the NFDI4Health Task Force COVID-19 (https://www.nfdi4health.de/task-force-covid-19-2) within the framework of a DFG-project (LO-342/17-1). LP, VE funded by Mathematical and Statistical modelling project (MUNI/A/1615/2020), Online platform for real-time monitoring, analysis and management of epidemic situations (MUNI/11/02202001/2020); VE also supported by RECETOX research infrastructure (Ministry of Education, Youth and Sports of the Czech Republic: LM2018121), the CETOCOEN EXCELLENCE (CZ.02.1.01/0.0/0.0/17-043/0009632),...

Research on esports activity usually captures it from the perspective of involvement in gaming. This study presents the results of the first research in Poland (N = 438) on esports betting (ESB). ESB is compared to other forms of e-gambling and involvement in pay-to-win games. The aim was to build a predictive model of gambling disorder among people betting on esports. A predictive model of gambling disorder based on ordinal regression was built, including sociodemographic variables, involvement in esports betting, involvement in other Internet activities connected to ESB, as well as psychological variables—motivation to gamble and coping strategies. The results showed that gambling disorder among esports bettors is associated with time spent on one game session, placing other forms of online gambling bets once a week or more often, and paying in pay-to-win games. Gambling disorder was also predicted by escape coping strategies and lower engaged strategies as well as financial and coping motivation to bet on esports results. The results show the crucial role of psychological factors (motivation, coping) in the development of esports betting addiction. Esports betting is an activity associated with both gambling and gaming—involvement in both activities explains the development of ESB addiction. There is a need for further research focused on the specificity of esports betting behavior to discover the direction of links among gaming, gambling, and esports gambling.

The centrality of religiosity scale (CRS) is a measure of the importance of religious constructs in personality. The Polish CRS has been applied in more than 40 published studies on the psychology of religion, with over 18,000 total participants. However, no comprehensive overview on the Polish CRS is available. This paper shows how using the CRS sheds light on different patterns in which religion integrates with other psychological variables. It consists of three parts: first, we introduce the Polish adaptation of the CRS; second, we present the review of the research using the Polish CRS; and finally, we provide research results that suggest a curvilinear mechanism for explaining the categories of the centrality of religiosity. Three measures were applied to the research: the CRS, emotions toward God scale, and content of prayer scale-revised. The results indicated that there is a curvilinear relationship between centrality of religiosity and emotions toward God, prayer types, and styles of request prayer (excluding passive request prayer). We determined the changepoints at which the relationship between the centrality of religiosity and the religious contents changes. This finding allowed us to provide empirical confirmation of Huber’s thesis (2003) that there is a different way of operating low, medium, and high scores in centrality, namely marginal, subordinated, and central religiosity. The study also broadens our understanding of each of these types of religiosity.

This study estimated the levels of involvement in e-gambling and problem e-gambling in Poland and identified selected sociodemographic variables associated with e-gambling activities. The study was conducted using a representative sample of the adult inhabitants of Poland (n = 2000). The survey contained questions measuring three aspects of gambling (involvement in e-gambling, types of e-gambling activity, and problematic e-gambling). Results suggested that 4.1% of respondents were involved in e-gambling and 26.8% of them could be classified as problem gamblers. The most popular e-gambling games were lotteries and sports betting. Gender, age, size of city of residence, level of education, and income were identified as significant predictors of involvement in e-gambling. The results indicated that men, younger people, and people who earnt less were more often involved in e-gambling. Having children, playing online scratch cards, and online sport betting—but not online lotteries—turned out to be typical for problem online gamblers. The prevalence of problem gambling among Polish e-gamblers suggests that extended research in this area is needed.

The empirical study of prayer has remained an underdeveloped field in the Polish psychology of religion. The lack of adequate and psychometrically sound methods to measure prayer has also been observed. The Polish adaptation of the Content of Prayer Scale (CoP) by Huber is designed to meet this gap. The CoP builds upon the theoretical approach, which combines theological and psychological concepts of prayer. The aim of this study was to translate, adapt and validate the CoP into Polish culture, as well as to examine whether there is the possibility of integrating these two concepts of prayer. In three studies (total N = 2488) the internal structure of the CoP was explored, revised version of the method was established, its internal structure was confirmed and cross-validated and its reliability and validity were examined. The shortcomings of the theoretical approach proposed by Huber are discussed.