Time Trend Effects Research Articles

Trends in smoking initiation and cessation over a century in two Australian cohorts

Background Historical data on smoking can enhance our comprehension of the effectiveness of past tobacco control policies and play a key role in developing targeted public health interventions. This study was undertaken to assess trends in smoking initiation and cessation in Australia for the period 1910–2005. Methods Rates of smoking initiation and cessation were calculated for participants in two population-based cohorts, the Busselton Health Study and the Tasmanian Longitudinal Health Study. The effects of time trends, gender and age group were evaluated. Results Of the 29,971 participants, 56.8% ever smoked. In males, over the period 1910–1999, the rate of smoking initiation in young adolescents remained high with a peak in the 1970s; in older adolescents it peaked in the 1940s and then declined; in young adults it showed a steady decline. In females, the rate of smoking initiation in young adolescents rose sharply in the 1960s and peaked in the 1970s, in older adolescents it increased throughout the period, and in young adults it declined after 1970. In the period 1930–2005, 27.3% of 9,605 people aged 36–50 years who smoked ceased smoking. Rates of cessation in this age group increased throughout but decreased in males after 1990 and plateaued around 2000 in females. Conclusion Our findings show substantial variation in the efficacy of tobacco control policies across age groups, with a notable lack of success among the younger population.

Women in academic publishing: Descriptive trends from authors to editors across 33 years of management science

Traditionally, leadership scholars often study snapshots of leaders in organizations. However, academic publishing offers a unique, more controlled context to study leadership with implications for leadership scholars and scholarship. Hence, we present a descriptive overview of women’s representation across 33 years in 11 top management journals across levels of leaders in academic publishing (i.e., editors, associate editors, and editorial board members) and authors. To do so, we curated an archival dataset tracking women’s representation over time and across these four levels (i.e., 21,510 authors and 4,173 leaders) with 51,360 data entries for the authors and 320,545 for the leaders. Overall, women’s representation increased over time, which was explained by simple time trend effects. Only 32 of 135 editors were women (i.e., 23.7 %), and the share of women associate editors showed particularly drastic fluctuations. We did not observe a “leaky pipeline” except from the associate editor to editor step, as well as notable fluctuations—particularly after new editor appointments—and between journals. We discuss the influential roles editors and publishers have on women’s representation in academic publishing and science more broadly as well as implications for future research and policy.

Effects of Allocation Method and Time Trends on Identification of the Best Arm in Multi-Arm Trials

Many trial designs, such as dose-finding trials, shared-control designs, or adaptive platform trials, investigate multiple therapies simultaneously. Often these trials seek to identify the best arm and compare it to a control. Adaptive trials are commonly considered in this space, focusing on methods that drop arms or adjust allocation in response to accumulating information. These methods continue to be compared in the literature, most recently with an emphasis on the effect of time trends during the experiment. Here we compare several methods, considering their performance with and without time trends present. The four procedures are: (a) fixed allocation, (b) arm dropping based on p-values (two variants), (c) arm dropping based on the posterior probability each arm is best (two variants), and (d) response-adaptive randomization. These procedures are compared in terms of their ability to identify the best arm, statistical power, accuracy of estimation, and potential benefit to participants inside the trial. We find arm dropping based on the probability each arm is best and RAR among the best options from the methods considered. Arm dropping based on p-values performs moderately worse, and fixed allocation is much worse on all metrics within this context.

Time-trend treatment effect of cardiac resynchronization therapy with or without defibrillator on mortality: a systematic review and meta-analysis.

This study aimed to investigate the impact of cardiac resynchronization therapy with a defibrillator (CRT-D) on mortality, comparing it with CRT with a pacemaker (CRT-P). Additionally, the study sought to identify subgroups, evaluate the time trend in treatment effects, and analyze patient characteristics, considering the changing indications over the past decades. PubMed, CENTRAL, and Embase up to October 2021 were screened for studies comparing CRT-P and CRT-D, focusing on mortality. Altogether 26 observational studies were selected comprising 128 030 CRT patients, including 55 469 with CRT-P and 72 561 with CRT-D device. Cardiac resynchronization therapy with defibrillator was able to reduce all-cause mortality by almost 20% over CRT-P [adjusted hazard ratio (HR): 0.85; 95% confidence interval (CI): 0.76-0.94; P < 0.01] even in propensity-matched studies (HR: 0.83; 95% CI: 0.80-0.87; P < 0.001) but not in those with non-ischaemic aetiology (HR: 0.95; 95% CI: 0.79-1.15; P = 0.19) or over 75 years (HR: 1.08; 95% CI 0.96-1.21; P = 0.17). When treatment effect on mortality was investigated by the median year of inclusion, there was a difference between studies released before 2015 and those thereafter. Time-trend effects could be also observed in patients' characteristics: CRT-P candidates were getting older and the prevalence of ischaemic aetiology was increasing over time. The results of this systematic review of observational studies, mostly retrospective with meta-analysis, suggest that patients with CRT-D had a lower risk of mortality compared with CRT-P. However, subgroups could be identified, where CRT-D was not superior such as non-ischaemic and older patients. An improved treatment effect of CRT-D on mortality could be observed between the early and late studies partly related to the changed characteristics of CRT candidates.

Global prevalence of Helicobacter pylori infection among individuals with obesity: A protocol for a systematic review and meta-analysis.

Modern populations are prone to obesity, as sedentary lifestyles prevail globally. Previous research has shown that obesity and Helicobacter pylori are mutually associated. However, the global prevalence of H. pylori among individuals with obesity is not yet determined. A comprehensive search will be conducted in PubMed, Scopus, and Web of Science online databases for studies that have reported the prevalence of H. pylori infection among individuals with obesity. Cross-sectional, case-control, and cohort studies will be included if reported sufficient data. Records screening, data extraction, and quality assessment will be done by independent reviewers. Joanna Bridge Institute checklist for prevalence studies will be used to appraise the included studies. Prevalence will be pooled using random effect models. Heterogeneity will be quantified by I 2 and p value. Subgroup analyses and meta-regression will be utilized to address the sources of residual between-study heterogeneity. Understanding the regional and global occurrence of H. pylori infection in individuals with obesity can provide valuable insights for health policymakers and clinicians to devise proficient diagnostic and eradication strategies, thereby enhancing postoperative outcomes for patients undergoing bariatric surgery. The study's strength will lie in not being restricted to language and time of publication, comprehensive investigation of regional and pre- and posteradication estimates, and the effects of time trends and sociodemographic indices on H. pylori prevalence. However, potential heterogeneity in methodologies used across prevalence studies could affect the interpretation of the results. Additionally, the study relies on previously published studies, limiting data quality and completeness.

A Generalized Linear Mixed Model for Data Breaches and Its Application in Cyber Insurance

Data breach incidents result in severe financial loss and reputational damage, which raises the importance of using insurance to manage and mitigate cyber related risks. We analyze data breach chronology collected by Privacy Rights Clearinghouse (PRC) since 2001 and propose a Bayesian generalized linear mixed model for data breach incidents. Our model captures the dependency between frequency and severity of cyber losses and the behavior of cyber attacks on entities across time. Risk characteristics such as types of breach, types of organization, entity locations in chronology, as well as time trend effects are taken into consideration when investigating breach frequencies. Estimations of model parameters are presented under Bayesian framework using a combination of Gibbs sampler and Metropolis–Hastings algorithm. Predictions and implications of the proposed model in enterprise risk management and cyber insurance rate filing are discussed and illustrated. We find that it is feasible and effective to use our proposed NB-GLMM for analyzing the number of data breach incidents with uniquely identified risk factors. Our results show that both geological location and business type play significant roles in measuring cyber risks. The outcomes of our predictive analytics can be utilized by insurers to price their cyber insurance products, and by corporate information technology (IT) and data security officers to develop risk mitigation strategies according to company’s characteristics.

The incidence of childhood-onset type 1 diabetes, time trends and association with the population composition in Sweden: a 40 year follow-up

Aims/hypothesisDuring the 1980s and 1990s, the incidence of childhood-onset type 1 diabetes more than doubled in Sweden, followed by a plateau. In the present 40 year follow-up, we investigated if the incidence remained stable and whether this could be explained by increased migration from countries reporting lower incidences.MethodsWe used 23,143 incident cases of childhood-onset type 1 diabetes reported between 1978 and 2019 to the nationwide, population-based Swedish Childhood Diabetes Registry and population data from Statistics Sweden. Generalised additive models and ANOVA were applied to analyse the effects of onset age, sex, time trends and parental country of birth and interaction effects between these factors.ResultsThe flattening of the incidence increase seems to remain over the period 2005–2019. When comparing the incidence of type 1 diabetes for all children in Sweden with that for children with both parents born in Sweden, the trends were parallel but at a higher level for the latter. A comparison of the incidence trends between individuals with Swedish backgrounds (high diabetes trait) and Asian backgrounds (low diabetes trait) showed that the Asian subpopulation had a stable increase in incidence over time.Conclusions/interpretationIn Sweden, the increase in incidence of childhood-onset type 1 diabetes in the late 20th century has been approaching a more stable albeit high level over the last two decades. Increased immigration from countries with lower incidences of childhood-onset type 1 diabetes does not provide a complete explanation for the observed levelling off.Graphical abstract

Effect of online quotation platform on container shipping orders

ABSTRACT In the digital era, major shipping lines are developing instant quote and online booking platforms. In one of the first attempts to investigate the post-event effects of this trend, we evaluate how a shipping line’s online quote platform impacts its shipper portfolio and the ordered container volume. In order to control for unobserved, time-varying effects that could be correlated with the platform’s implementation, we apply the regression discontinuity design (RDD) method to the import trade data from 2016 to 2019 of a top shipping line that released its platform in August 2018. We also adopt global polynomial regression and local liner regression so as to control for the effects of different polynomial time trends. We find the container volume assigned to the shipping line declined slightly after the online platform was launched. The container orders of small shippers increase by 3.97 TEU on average after online platform adoption. The volume of assigned containers from other shippersdeclines. These findings hold fruitful implications for shipping lines. A significant increase in the number of small shippers and their container volumes demonstrate administrative cost saving and risk mitigation for a shipping line. However, it also leads to possible loss of large customers.

Heightened religiosity proactively and reactively responds to the COVID-19 pandemic across the globe: Novel insights from the parasite-stress theory of sociality and the behavioral immune system theory

According to the parasite-stress theory of sociality and the behavioral immune system theory, heightened religiosity serves an anti-pathogen function by promoting in-group assortative sociality. Thus, highly religious countries/territories could have better control of the COVID-19 (proactively avoids disease-threat), and heightened COVID-19 threat could increase religiosity (reactively responds to disease-threat). As expected, country-level religiosity (religion-related online searches (Allah, Buddhism, Jesus, etc.) and number of total religions/ethnoreligions) negatively and significantly predicted COVID-19 severity (a composite index of COVID-19 susceptibility, reproductive rate, morbidity, and mortality rates) (Study 1a), after accounting for covariates (e.g., socioeconomic factors, ecological factors, collectivism index, cultural tightness-looseness index, COVID-19 policy response, test-to-case ratio). Moreover, multilevel analysis accounting for daily- (e.g., time-trend effect, season) and macro-level (same as in Study 1a) covariates showed that country-level religious searches, compared with the number of total religions/ethnoreligions, were more robust in negatively and significantly predicting daily-level COVID-19 severity during early pandemic stages (Study 1b). At weekly level, perceived coronavirus threat measured with coronavirus-related searches (corona, covid, covid-19, etc.), compared with actual COVID-19 threat measured with epidemiological data, showed larger effects in positively predicting religious searches (Study 2), after accounting for weekly- (e.g., autocorrelation, time-trend effect, season, religious holidays, major-illness-related searches) and macro-level (e.g., Christian-majority country/territory and all country-level variables in Study 1) covariates. Accordingly, heightened religiosity could proactively and reactively respond to the COVID-19 pandemic across the globe.

Changes in public satisfaction with GP services in Britain between 1998 and 2019: a repeated cross-sectional analysis of attitudinal data

BackgroundBetween 1998 and 2019, the structure and process of general practitioner services in Britain underwent a series of reforms and experienced distinct funding environments. This paper examines changes in satisfaction with GP services over time against this backdrop.MethodsData were extracted from the British Social Attitudes Survey for the period 1998–2019. Logistic regression analyses investigated changes in overall satisfaction and among specific population sub-groups differentiated by socio-demographic characteristics whilst taking account of time trend and interaction effects between sub-group membership and time trend.ResultsSustained and significant changes in satisfaction coincided closely with changes to the funding environment. Distinct patterns were evident among sub-groups. Satisfaction appeared to fall more sharply during austerity for low income groups, older people and people who had fewer formal qualifications/years in education.ConclusionWhile a series of policy initiatives were adopted over the period examined, public satisfaction seemed to move in a manner consistent with levels of government expenditure rather than exhibiting distinct breaks that coincided with policy initiatives. As services recover from the pandemic it will be necessary to invest in a significant and sustained way to rebuild public satisfaction.

Universal Thermal Climate Index (UTCI) and adverse pregnancy outcomes in Ahvaz, Iran

BackgroundClimate change may jeopardize the health of mothers and their offspring. There are few studies on the association between increasing temperature and pregnancy outcomes. The aim of this study was to investigate the relation between Universal Thermal Climate Index (UTCI) and adverse pregnancy outcomes including stillbirth, low birth weight (LBW), preterm labor (PTL), spontaneous abortion (SA), preeclampsia and hypertension in Ahvaz, Iran.MethodsDistributed Lag Non-linear Models (DLNM) combined with quasi-Poisson regression were used to research the effect of UTCI on adverse pregnancy outcomes. The effect of time trend, air pollutants (NO2, SO2 and PM10), and weekdays were adjusted.ResultsThe results showed that the low values of UTCI index (11.6 °C, in lags 0–6, 0–13) caused significant increase in the risk of preterm labor. However, hot thermal stress (high UTCI) significantly increased the risk of stillbirth in lag 0–13. We did not observe any significant relation between UTCI and other pregnancy outcomes in this study.ConclusionsIt seems like both hot and cold weathers can be associated with adverse pregnancy outcomes.

Spatio-temporal modeling for malnutrition in tribal population among states of India a Bayesian approach

Exploring Bayesian spatio-temporal methods to analyze spatial dependence in malnutrition at the state level for tribal children (less than 3 years) population of India and change over time (three rounds of NFHS-2(1998-99),3(2005-06) and 4(2015-16)). The Bayesian model, fitted by Markov chain Monte Carlo simulation using OpenBUGS, for spatial autocorrelation (through spatial random effects modeling). The model estimated (1) mean time trend and (2) spatial random effects. Results of spatio-temporal modeling for stunting, wasting and underweight exhibited a declining mean trend across the study region from NFHS-2 to NFHS-4. Spatial random effects exhibited spatial dependence for various states in stunting, wasting and underweight tribal children. Future research should analyze spatio-temporal distribution for malnutrition at district level which will require NFHS-5 data. Also, analysis can be done capturing spatio-temporal interaction and identifying hot spots and cold spots at district level.

Successful virologic outcomes over time among HAART-treated HIV-infected patients

ABSTRACT Few large studies evaluated the effects of time trends on virologic suppression in people living with HIV/AIDS (PLWHA) in China. To address this, An retrospective observational longitudinal study was conducted. We examined annual trends in the rate of virologic suppression, the viral load at the time of virologic suppression, and other determinants of virologic suppression in Zhejiang Province, China in PLWHA between January 2013 and July 2018. Patients who received a treatment regimen for at least 24 weeks were included. Virologic suppression was defined as VL ≤50 copies/mL. Generalized estimating equation logistic regression models were used to adjust for covariates. We included 16,265 patients with 45023 tests. The proportion of patients who experienced an unsuccessful virologic outcome decreased continuously throughout the observation period (18.14% to 6.64%). Time was significantly negatively associated with detectable VL (all ORs <1). Other factors were positively associated with detectable VL, including patients <30 years of age, single, non-adherent to treatment, and with a follow-up CD4 count <200 cells/µL. Patients infected through homosexual transmission and those with a longer ART duration were more likely to reach virologic suppression. We demonstrated outstanding time trend improvements in the virological outcomes of PLWHA in China.

Minimal cost multifactor experiments for agricultural research involving hard-to-change factors

Multifactor experiments are very common in agricultural research. Randomizing run orders in multifactor experiments often witness in large number of factorwise level changes which will increase the cost and time of the experiments. Minimal cost multifactor experiments are such experiments where the cost of the experiment is minimum which can be achieved by choosing a factorial run order where the total number of factor level change is minimum as cost of the experiment is directly proportional to the number of level changes of factors. Here, a method of constructing minimal cost 2-level multifactor experiments with minimum number of factorwise level changes has been proposed. As for a same factorial combination, there may exist more than one minimally changed factorial run order, an exhaustive search was also performed to obtain all possible minimally changed run order for two level multifactorial experiments with three factors. Due to restricted randomization, adaption of these run orders may witness the effect of systematic time trend. Hence, the usual method of analysis may not be a feasible solution due to lack of randomization. Here, the analytical procedure of experiments using minimal cost multifactorial run order has also been highlighted based on a real experimental data. The work has been carried out at ICAR-Indian Agricultural Statistics Research Institute, New Delhi during 2019-20. The data from the real experiment used for explaining the analysis procedure has been collected from Climate Change Facility of ICAR-Indian Agricultural Research Institute farm, New Delhi, India based on experiments conducted during 2014-15.

Physiological equivalent temperature (PET) and non-accidental, cardiovascular and respiratory disease mortality in Ahvaz, Iran.

Climate change may be associated with human morbidity and mortality through direct and indirect effects. Ahvaz is one of the hottest cities in the world. The aim of this study was to investigate the relation between physiological Equivalent Temperature (PET) and non-accidental, cardiovascular and respiratory disease mortality in Ahvaz, Iran. Distributed Lag Non-linear Models (DLNM) combined with quasi-Poisson regression were used to investigate the effect of PET on death. The effect of time trend, air pollutants (NO2, SO2 and PM10), and weekdays were adjusted.The results showed that in cold stress [1st percentile of PET (2.7°C) relative to 25th percentile (11.9°C)] the risk of total respiratory mortality, respiratory mortality in men, and mortality in people under 65year olds, significantly decreased in the cumulative lags of 0-2, 0-6 and 0-13; but the risk of respiratory mortality increased in the elderly and in the final lags. In contrast, heat stress [99th percentile of PET (44.9°C) relative to 75th percentile (43.4°C)] significantly increased the risk of total cardiovascular mortality (CVD), cardiovascular mortality in men, ischemic heart disease and cerebrovascular disease mortality in lags 0 and 0-2. It seems that high PET values increase the risk of cardiovascular mortality, while low PET values increase respiratory mortality only among the elderly in Ahvaz.

The net effect of the travel restriction policy on tourism demand: evidence from Greece

PurposeThe purpose of this study is to provide up-to-date evidence on the net effect of COVID-19 pandemic on international arrivals and occupancy rates in Greece. Analysis and forecasting point out the demand for 2020, and thus yielding more concrete evidence on the pure effect of the pandemic on the tourism industry.Design/methodology/approachMonthly observations from January 2000 to December 2020 were extracted from the Tourist Enterprises Association (SETE) for Athens, Thessaloniki, Kalamata, Rhodes, Mytilene, Santorini, Zante, Kefalonia and Crete. To model and forecast the volatility and the time trend effect of tourist arrivals individually, the study applies the autoregressive integrated moving average (ARIMA) (p,d,q) and the error, trend, seasonality (ETS) model.FindingsEmpirical results suggested that Athens, Thessaloniki and Crete were three destinations with the worst losses in international tourist arrivals. Specifically, Athens was expecting to have (without the existence of COVID-19) more than 330,000 tourist arrivals in December 2020 while instead only 73,000 international tourists visited Athens that period. Similarly, Thessaloniki and the island of Crete lost more than 150,000 international visitors during December 2020.Originality/valueThe author’s study adds to a growing number of studies regarding the impact of COVID-19 by incorporating monthly international arrival data and occupancy rate data for the whole 2020 reflecting differences in transportation or vacation choices. Also, the authors operationalized multiple time-series forecasting models (ETS and ARIMA) for reaching more concrete forecasts and estimates on the effect of COVID-19 on the Greek tourism sector.

Association between Physiological Equivalent Temperature (PET) with adverse pregnancy outcomes in Ahvaz, southwest of Iran

BackgroundThere are few epidemiological studies on the relation between temperature changes and adverse pregnancy outcomes. The purpose of this study was to determine the relation between Physiological Equivalent Temperature (PET) with adverse pregnancy outcomes including stillbirth, low birth weight (LBW), preterm labor (PTL), spontaneous abortion (SA), preeclampsia and hypertension in Ahvaz, Iran.MethodsDistributed Lag Non-linear Models (DLNM) combined with quasi-Poisson regression were used to investigate the effect of PET on adverse pregnancy outcomes. In this study the effect of time trend, air pollutants (NO2, SO2 and PM10), and weekdays were adjusted.ResultsHigh PET (45.4 C°, lag = 0) caused a significant increase in risk of stillbirth. Also, high levels of PET (45.4, 43.6, 42.5 C°, lag = 0–6) and low levels of PET (9.9, 16.9 C°, lags = 0, 0–13, 0–21) significantly increased the risk of LBW. But, low levels of PET (6.4, 9.9, 16.9 C°, lags = 0–6, 0–13) reduced the risk of gestational hypertension.ConclusionThe results of this study showed that hot and cold thermal stress may be associated with increased risk of stillbirth, and LBW in Ahvaz.

Physiological equivalent temperature (PET) index and respiratory hospital admissions in Ahvaz, southwest of Iran.

Although Ahvaz is considered as one of the warmest cities around the world, few epidemiological studies have been conducted on the adverse effects of temperature on human health using thermal indices in this city. This study investigates the relation between physiologically equivalent temperature (PET) and respiratory hospital admissions in Ahvaz. Distributed lag non-linear models (DLNMs) combined with quasi-Poisson regression models were used to investigate the relation between PET and respiratory disease hospital admissions, adjusted for the effect of time trend, air pollutants (NO2, SO2, and PM10), and weekdays. The analysis was performed by utilizing R software. Low PET values significantly decreased the risk of hospital admissions for total respiratory diseases, respiratory diseases in men and women, chronic obstructive pulmonary diseases (COPD), and bronchiectasis. However, low PET (16.9°C) in all lags except lag 0-30 significantly increased the risk of hospital admissions for asthma. The results indicate that in Ahvaz, which has a warm climate, cold weather decreased overall respiratory hospital admissions, except for asthma.

The long-term impact of restricted access to abortion on children's socioeconomic outcomes.

We examine the long-term consequences of restricted access to abortion following a change in the Hungarian abortion law in 1974. Due to a change that restricted access to legal abortions, the number of induced abortions decreased from 169,650 to 102,022 between 1973 and 1974, whereas the number of live births increased from 156,224 to 186,288. We analyze the effects on the adult outcomes of the affected cohort of newborns (educational attainment, labor market participation, teen fertility). We use matched large-scale, individual-level administrative datasets of the Hungarian Central Statistical Office (population census 2011; live birth register), and we estimate the effects by comparing children born within a short timespan around the time the law change came into effect. We apply a difference-in-differences approach, building on the special rules of the new law that, despite the severe restriction, still made abortion permissible for selected groups of women. We control for the compositional change in the population of parents, rule out the effect of (unobserved) time trends and other potential behavioral responses to the law change, and draw causal inferences. We find that restricted access to abortion had, on average, a negative impact on the socioeconomic outcomes of the affected cohort of children. Children born after the law change have had worse educational outcomes, a greater likelihood of being unemployed at age 37, and a higher probability of being a teen parent.

Association between the COVID-19 pandemic and the risk for adverse pregnancy outcomes: a cohort study

ObjectivesThe secondary impacts of the COVID-19 pandemic on adverse maternal and neonatal outcomes remain unclear. In this study, we aimed to evaluate the association between the COVID-19 pandemic and the...