Time Series Analysis Of Trends Research Articles

An interrupted time series analysis of trends in opioid-related emergency department visits from pre-COVID-19 pandemic to pandemic, from the Canadian Hospitals Injury Reporting and Prevention Program

BackgroundOpioid-related emergency department (ED) visits in Canada increased during the COVID-19 pandemic, but how trends in volume and case severity changed from pre-pandemic times through the pandemic is not known. Trends in ED visits related to specific types of opioids also remain unclear. Our objective was to describe pre-pandemic trends and how they changed with the onset of COVID-19 and thereafter.MethodsBased on data from the Canadian Hospitals Injury Reporting and Prevention Program, we identified opioid-related ED visits and constructed a time series from March 12, 2018 through March 7, 2021—two pre-COVID periods and one COVID period. We used an interrupted time series (ITS) analysis to examine trends in volume and case severity. We compared medians and means of monthly counts and percentages of severe cases between the periods, by sex, age, and opioid type.ResultsBefore the pandemic, there was an increasing trend in fentanyl-related visits for males, females and 25- to 64-year-olds, and a decreasing trend in heroin-related visits for males and 18- to 64-year-olds. Fentanyl-related visits for 18- to 24-year-olds showed an immediate increase at the start of the pandemic and a decreasing trend during the pandemic. Heroin-related visits for 12- to 17-year-olds had an immediate increase at the start of the pandemic; for 18- to 24-year-olds and 45- to 64-year-olds, the prior decreasing pre-pandemic trend ceased. For pooled opioid-related visits, no significant trend in the percentage of severe cases was observed throughout the entire study period.ConclusionThis study shows that an ITS approach in trend analysis is a valuable supplement to comparisons of before and after measures (with or without controlling seasonal effects). The findings provide evidence on how ED presentations for opioid use evolved in Canada from 2018 to 2021. The results can inform policies designed to reduce opioid-related harm in the context of a public health emergency.

Time-series analysis of trends in the incidence rates of successful and attempted suicides in Thailand in 2013–2019 and their predictors

BackgroundSuicide rates are of increasing concern worldwide. There are approximately 4000–5000 deaths by suicide each year in Thailand. This study examined trends in annual incidence rates and predictors of successful and attempted suicides in Thailand (2013–2019).MethodsSecondary data analysis was conducted on data from two national-level databases: The National Health Security Office and the National Death Certification Registry System. Time-related trends and predictors of successful and attempted suicides were calculated using joinpoint regression and multivariable logistic regression analyses, respectively.ResultsOf all successful suicide cases from 2013 to 2019, about 80% involved men, with an average age of 45.37 (± 16.43) years. Predictors of successful suicide included male sex, older age, using highly lethal methods, and no prior psychiatric treatment. Among individuals admitted to hospitals following a suicide attempt from 2013– to 2019, the average age at first admission was 38.83 ± 22.47 years, with women more heavily represented than men. Only 2.3% of these patients received psychiatric treatment in the hospital. Predictors of attempted suicide included female sex; adolescent or adult; and mental, alcohol, or substance-related disorder(s). Age-standardized annual rates per 100,000 people showed that, through 2019, suicide incidence increased slightly, and attempts decreased.ConclusionsThere was a significantly increasing trend in successful suicide during the 7 years; the increase was more notable among men. The study highlights sex-related gaps in public health owing to an identified higher incidence of suicide among men, and a higher incidence of suicide attempts in women adolescents, emphasizing the need to consider sex-sensitive issues in individual as well as societal contexts.

Police-reported suicides during the first 16 months of the COVID-19 pandemic in Ecuador: A time-series analysis of trends and risk factors until June 2021

BackgroundThere are widespread concerns that the COVID-19 pandemic may increase suicides. Few studies have analysed effects beyond the pandemic's early months or examined changes in known suicide risk factors.MethodsUsing time series models fit with Poisson regression, we analysed monthly police-reported suicides in Ecuador from January 2015 to June 2021. Treating March 2020 as the start of the pandemic, we calculated rate ratios (RRs) comparing the observed to the expected number of suicides for the total population and by age and sex groups. We investigated changes in risk factors, precipitants, geographic distribution, and suicide methods.FindingsThere was no evidence that suicide rates were higher than expected during the pandemic (RR 0·97 [95% CI 0·92–1·02]). There was some evidence of fewer than expected male suicides (RR 0·95 [95% CI 0·90–1·00]). The proportion of suicides occurring in urban and coastal areas increased but decreased amongst indigenous and other minorities. The proportions of suicides with evidence of alcohol consumption, disability, and amongst married and cohabiting individuals decreased, whereas suicides where mental health problems were considered contributory increased. There were relative increases in the proportion of suicides by hanging but decreases in self-poisoning and other suicide methods.InterpretationThe pandemic did not appear to adversely impact overall suicide numbers nationwide during the first 16 months of the pandemic. Reduced alcohol consumption may have contributed to the decline in male suicides.FundingNone.

Pediatric Prescriptions of Proton Pump Inhibitors in France (2009-2019): A Time-Series Analysis of Trends and Practice Guidelines Impact

To describe the ambulatory proton pump inhibitor (PPI) prescription in French children, its trends, and the impact of French (2014) and international (2018) clinical guidelines. We described PPI prescription rates based on national dispensation data in French children (IQVIA's Xponent database, 2009-2019). Using a segmented linear regression, we assessed the impact of clinical guidelines on PPI prescription rates. Analyses were performed for the overall pediatric population and by age subgroups (infants <2years old, children 2-11years old, adolescents 12-17years old). During the study period, 8 060 288 pediatric PPI prescriptions were filled, with a mean PPI prescription rate of 52.5 per 1000 inhabitants per year. Between 2009 and 2019, the PPI prescription rate increased by 41% in the overall pediatric population (+110% in infants). The PPI prescription rate showed seasonal patterns with peaks in winter. After the release of French guidelines, significant decreases in trends of prescription rates occurred overall (change in trend -0.28, 95% CI -0.34;-0.23) and across all age groups. In infants, this change in trend was not sufficient to reverse the PPI prescription rate that was still increasing over time. In children, the PPI prescription rate slightly decreased and in adolescents, it was stable. After the release of international guidelines, a significant decrease in trend occurred in adolescents only (change in trend -0.26, 95% CI -0.47; -0.04). The pediatric PPI prescription rate in France was high, displayed a major increase over the last decade, mainly among infants, and was modestly affected by clinical guidelines.

Decoupling wastewater impacts from hydrogeochemical trends in impacted groundwater resources

In the urban environment, anthropogenic activities provide numerous potential sources of contamination, which can often lead to difficulties in identifying the processes impacting groundwater quality (natural and anthropogenic). This is particularly relevant at Wastewater Treatment Plants (WWTPs) that are often subject to changes in land use and composition of contaminant sources over time and space, as well as multiple potential hydrogeochemical interactions. To help address this issue, we demonstrate how long-term time-series analysis of major ions and key contaminants of concern, which are routinely collected by WWTP operators, can be analysed using hydrogeochemical plotting tools, multivariate statistics and targeted isotopic analysis, to provide a means of better characterising key hydrogeochemical influences and anthropogenic inputs. Application of this approach to a WWTP in south-eastern Australia indicated that anthropogenic impacts were the primary driver influencing the local hydrogeochemical environment and groundwater quality. However, secondary processes, including mineral (particularly calcite) dissolution, ion exchange and possible dedolomitisation, as well as natural degradation/transformation of contaminants were also important. Long-term, time-series analysis of trends in NO3-N, NH4-N, Ca2+, SO42−, HCO3− and K+ in conjunction with the other lines of evidence, allowed for enhanced separation between individual contaminant sources, particularly when paired with a detailed site history and Conceptual Site Model (CSM). This indicated that off-site agricultural impacts post-date most site derived impacts, and to date, have not significantly added to the identified contaminant plume. The outcomes of this work have significant global application in the identification, assessment, and control of environmental and health risks at complex sites and show how significant value (rarely obtained) can be derived from the analysis of routine monitoring datasets, particularly when analysed using a multiple lines of evidence approach.

Covid-19 pandemic and activity patterns in Milan. Wi-Fi sensors and location-based data

The recent development of location detection systems allows to monitor, understand and predict the activity patterns of the city users. In this framework, the research focuses on the analysis of a sample of aggregated traffic data, based on the number of mobile devices detected through a network of 55 Wi-Fi Access Points in Milan. Data was collected over 7 months (January to July 2020), allowing for a study on the impact of the Covid-19 pandemic on activity patterns. Data analysis was based on merging: (i) time series analysis of trends, peak hours and mobility profiles;(ii) GIS-based spatial analysis of land data and Public Transport data. Results showed the effectiveness of Wi-Fi location data to monitor and characterize long-term trends about activity patterns in large scale urban scenarios. Results also showed a significant correlation between Wi-Fi data and the density distribution of residential buildings, service and transportation facilities, entertainment, financial amenities, department stores and bike-sharing docking stations. In this context, a Suitability Analysis Index is proposed, aiming at identifying the areas of Milan which could be exploited for more extensive data collection campaigns by means of the installation of additional Wi-Fi sensors. Future work is based on the development of Wi-Fi sensing applications for monitoring mobility data in real time.

Reduction in the Incidence of Urological Cancers after the Ban on Chinese Herbal Products Containing Aristolochic Acid: An Interrupted Time-Series Analysis

Cancer is a public health problem worldwide. Taiwan has a higher incidence rate of urological cancers than many Asian countries do. Aristolochic acid has been considered a potent carcinogen. In this study, we examined whether the cessation of the sales and preparation of aristolochic acid-containing Chinese herbal products (AA-CHPs) in Taiwan contributed to a decline in the incidence rates of bladder cancer, carcinomas of the renal pelvis and other urinary organs, and kidney cancer. We conducted an interrupted time-series analysis of long-term trends in the incidence rates of the aforementioned cancers between 1995 and 2013 in Taiwan. The incidence rates of bladder cancer and carcinomas of the renal pelvis and other urinary organs decreased considerably after 2008 and 2011, respectively. Notably, these change-of-slope time points occurred after the year 2003, when a ban on AA-CHPs was imposed in Taiwan. The ban on AA-CHPs in Taiwan was possibly associated with the reduction in the incidence of bladder cancer and carcinomas of the renal pelvis and other urinary organs.

Carbapenem resistant organisms: A 9-year surveillance and trends at Saint George University Medical Center

IntroductionCarbapenem resistant organisms (CRO) constitute a large group of bacteria with different mechanisms of resistance and recently increasing global incidence. This rise has ambiguous dynamics and essential local epidemiologic data is lacking. Materials and methodsIn this retrospective study at the 400-bed Saint George Hospital (SGH) in Beirut, Lebanon, we retrieved electronic laboratory records of all intrinsic and acquired CRO isolates from January 1, 2010 until June 30, 2018. Isolation density was calculated as: number of isolates/1000PD. Analysis carried out using WHOnet with a trend time series analysis. ResultsDuring the study period, a total of 2150 non-duplicate CRO were isolated. While Acinetobacter baumanii (AB), Pseudomonas aeruginosa (CRPa), and Stenotrophomonas maltophilia (Sm) constituted 85% of total CRO in the study period, the carbapenem resistant enterobacteriaceae (CRE) rose from few sporadic cases before 2016 to a solid 32% of total CRO in 2018. Our most concrete trends were as follows. The rate of AB bacteremia was at an average of 0.114/1000 PD from 2011 to 2014. In 2015, a sudden doubling of AB bacteremia to 0.23/1000 PD. In 2017, there was a significant decrease to 0.113/1,000PD (p < 0.0001) to reach 0.097/1000PD in 2018 with a continuously declining trend. The peak of Sm bacteremia was in 2016 at 0.121/1000PD after which it significantly decreased by 21% in 2017 to disappear in 2018 (p < 0.0001). There were no significant trends observed in the isolation density of the CRPa group from 2010 until June 2018. Klebsiella pneumonia (CRKp) bacteremia was isolated first in 2013, then in 2016 and continued to rise (p = 0.028). In 2017, carbapenem resistant KP bacteremia rate doubled to 0.05/1,000PD from 0.024/1000 (p = 0.0139). ConclusionIn conclusion, this 9-year study at SGH depicts the major trends and dynamics of local CRO isolation, mainly A. baumanii, P. aeruginosa and CRKp. Further efforts are warranted both locally and internationally for a richer understanding of this trend. Bearing in mind that understanding antimicrobial resistance is a complex, multifaceted process that is only feasible when all its aspects are combined: molecular, phenotypic and clinical.

Lower Limb Amputations in Patients With Diabetes and Peripheral Artery Disease: A Time-Series Analysis of Trends (2005-2016)

Lower Limb Amputations in Patients With Diabetes and Peripheral Artery Disease: A Time-Series Analysis of Trends (2005-2016)

Global Trends in Mineral Commodities for Advanced Technologies

The U.S. Geological Survey National Minerals Information Center (NMIC) is the U.S. Government agency tasked with the collection, analysis, and dissemination of information on the production, consumption, import, export, and other measures of the flows of non-fuel mineral commodities of importance to the U.S. economy and national security. The NMIC and its agency predecessors have maintained a database of this information, collected and published annually, dating back to the beginning of the twentieth century. Time series analysis of annual information from the NMIC provides the opportunity to identify trends in the supply chains of the minerals and metals which are increasingly in demand for advanced technologies. The identification of trends in data for net import reliance, country concentration of production, global demand, price volatility, and other measures, when combined with world governance indicators, can be used to focus attention on individual mineral commodities where supply chain restrictions may develop. Specific examples for U.S. net import reliance, global tantalum primary mining, and mineral criticality screening are presented to illustrate the utility of time series analysis of trends in mineral commodity supply and demand, the types of data required, and the limitations of currently available information.

What Role Do Changes in the Demographic Composition Play in the Declining Trends in Alcohol Consumption and the Increase of Non-drinkers Among Swedish Youth? A Time-series Analysis of Trends in Non-drinking and Region of Origin 1971-2012.

AimNon-drinkers among youth in Sweden have increased markedly during the last 15 years. The aim of this study is to investigate the temporal association between region of origin among Swedish youth and rates of non-drinking.Data and methodData on non-drinkers were obtained from The Swedish Council on Information and Other drugs (CAN) yearly school surveys among Swedish ninth-grade students over the period 1971–2013. Annual data of region of origin for 1968–2012 has been compiled from Statistics Sweden (SCB) and consists of all 15-year-olds in Sweden and their region of birth; Sweden, The Nordic Countries, Europe, The Middle East and the rest of the world. Autoregressive Integrated Moving Average (ARIMA) modelling was applied in order to estimate these associations.ResultsDescriptive results revealed a change in the demography of Swedish 15- to 16-year-olds. In the early 1990s 1% of Swedish 15- to 16–year-olds were born in a Middle East country, this proportion increased to 6% in 2012. Furthermore, those born in the rest of the world (non-European or non-Nordic countries) increased from 1% to almost 4%. Similarly, the trend of non-drinkers increased from about 20% to more than 40% among Swedish 15- to 16-year-olds during the same period. However, a more thorough analysis using ARIMA modelling revealed no significant association between rates of region of origin and non-drinking.ConclusionThe marked increase in non-drinkers during the last 15 years is not associated to changes in the demographic composition, in terms of region of origin, among Swedish youth.

Road Safety Trends at National Level in Europe: A Review of Time-series Analysis Performed during the Period 2000–12

This paper presents a review of time-series analysis of road safety trends, aggregated at a national level, which has been performed in the period 2000–12 and applied to European national data sets covering long time periods. It provides a guideline and set of best practices in the area of time-series modelling and identifies the latest methods and applications of national road safety trend analysis in Europe. The paper begins with the methodological framework adopted for aggregate time-series modelling that will be considered, and then discusses a number of relevant applications to long-period data aggregated at the national level, whether for countries alone, or for groups of countries. Some analyses, which were performed at the disaggregated level, are also provided, as they are being used more and more. Finally, the paper summarizes and discusses the significant changes in aggregate road safety trend analysis which occurred during the period and provides recommendations for continuing these research efforts.

Time series analysis of trends in malaria cases and deaths at hospitals and the effect of antimalarial interventions, 2001-2011, Ethiopia.

BackgroundThe Government of Ethiopia and its partners have deployed artemisinin-based combination therapies (ACT) since 2004 and long-lasting insecticidal nets (LLINs) since 2005. Malaria interventions and trends in malaria cases and deaths were assessed at hospitals in malaria transmission areas during 2001–2011.MethodsRegional LLINs distribution records were used to estimate the proportion of the population-at-risk protected by LLINs. Hospital records were reviewed to estimate ACT availability. Time-series analysis was applied to data from 41 hospitals in malaria risk areas to assess trends of malaria cases and deaths during pre-intervention (2001–2005) and post-interventions (2006–2011) periods.FindingsThe proportion of the population-at-risk potentially protected by LLINs increased to 51% in 2011. The proportion of facilities with ACTs in stock exceeded 87% during 2006–2011. Among all ages, confirmed malaria cases in 2011 declined by 66% (95% confidence interval [CI], 44–79%) and SPR by 37% (CI, 20%–51%) compared to the level predicted by pre-intervention trends. In children under 5 years of age, malaria admissions and deaths fell by 81% (CI, 47%–94%) and 73% (CI, 48%–86%) respectively. Optimal breakpoint of the trendlines occurred between January and June 2006, consistent with the timing of malaria interventions. Over the same period, non-malaria cases and deaths either increased or remained unchanged, the number of malaria diagnostic tests performed reflected the decline in malaria cases, and rainfall remained at levels supportive of malaria transmission.ConclusionsMalaria cases and deaths in Ethiopian hospitals decreased substantially during 2006–2011 in conjunction with scale-up of malaria interventions. The decrease could not be accounted for by changes in hospital visits, malaria diagnostic testing or rainfall. However, given the history of variable malaria transmission in Ethiopia, more data would be required to exclude the possibility that the decrease is due to other factors.

Prescribing patterns of novel oral anticoagulants following regulatory approval for atrial fibrillation in Ontario, Canada: apopulation-based descriptive analysis.

The clinical armamentarium for anticoagulation has expanded substantially since the recent approval of dabigatran, rivaroxaban and apixaban for the prevention of stroke in atrial fibrillation. However, patients in the general population often differ from participants in clinical trials. In this study, we assessed the uptake of these novel oral anticoagulants in Ontario, Canada, within the first 2 years after dabigatran's approval for this indication. Using data on province-wide prescription volumes, we conducted a time-series analysis of prescription trends between October 2010 and September 2012 for all orally administered anticoagulants (warfarin, dabigatran and rivaroxaban) that were available in this period. We stratified dabigatran prescription rates by age group (20-39, 40-59, 60-64, 65-84 and ≥ 85 yr). We compared the proportion of dabigatran prescriptions to patients aged 65 or older with similar data from the Randomized Evaluation of Long-Term Anticoagulation Therapy (RE-LY) study. Over the 24-month study period, we found that prescriptions for the novel anticoagulants rose more than 20-fold, to represent 21.1% of all prescriptions of oral anticoagulants by September 2012. The rise in prescriptions was due primarily to an increase in dabigatran use. Prescription rates of dabigatran were highest among people aged 85 years or more, a group at increased risk of bleeding who are markedly older than the average participant in the clinical trial in which the drug was tested (71 yr). In September 2012, most of the dabigatran prescriptions were for the lower-dose formulation (110 mg) in the older groups (58.8% of dabigatran prescriptions in the 65-84 age group and 93.6% in the oldest group). We observed rapid growth in the uptake of the novel oral anticoagulants since their approval for use in patients with atrial fibrillation, especially among those aged 85 years or more. This increase in use in the oldest group, a population at high risk of bleeding, signals the need to evaluate outcomes of use of novel oral anticoagulants in the clinical setting.

Labor Standards and Local Economic Development

In times of economic crisis, state and local governments increasingly turn to economic development incentive programs to jumpstart job growth. However, recent efforts to attach minimum labor standards to incentives are seen as a threat to traditional practice. Critics of such “business assistance living wage” laws assert that they may reduce employment or redevelopment activity. This paper measures the actual impact of living wage laws using a time-series analysis of employment and business establishment trends in large U.S. cities that have enacted such laws and finds no evidence that ordinances mandating stronger labor standards affect aggregate economic development outcomes.

Why are suicide rates rising in young men but falling in the elderly?—a time-series analysis of trends in England and Wales 1950–1998

Suicide rates doubled in males aged <45 in England and Wales between 1950 and 1998, in contrast rates declined in older males and females of all ages. Explanations for these divergent trends are largely speculative, but social changes are likely to have played an important role. We undertook a time-series analysis using routinely available age- and sex-specific suicide, social, economic and health data, focussing on the two age groups in which trends have diverged most—25–34 and 60+ year olds. Between 1950 and 1998 there were unfavourable trends in many of the risk factors for suicide: rises in divorce, unemployment and substance misuse and declines in births and marriage. Whilst economic prosperity has increased, so too has income inequality. Trends in suicide risk factors were generally similar in both age–sex groups, although the rises in divorce and markers of substance misuse were most marked in 25–34 year olds and young males experienced the lowest rise in antidepressant prescribing. Statistical modelling indicates that no single factor can be identified as underlying recent trends. The factors most consistently associated with the rises in young male suicide are increases in divorce, declines in marriage and increases in income inequality. These changes have had little effect on suicide in young females. This may be because the drugs commonly used in overdose—their favoured method of suicide—have become less toxic or because they are less affected by the factors underlying the rise in male suicide. In older people declines in suicide were associated with increases in gross domestic product, the size of the female workforce, marriage and the prescribing of antidepressants. Recent population trends in suicide appear to be associated with by a range of social and health related factors. It is possible that some of the patterns observed are due to declining levels of social integration, but such effects do not appear to have adversely influenced patterns in older generations.

A time-series analysis of trends in firearm-related homicide and suicide.

In order to determine whether firearm use was an increasing component of the general pattern of homicide in Cape Town, South Africa, hidden Markov time-series models were used to examine a week-by-week count of firearm homicides, non-firearm homicides, firearm suicides and non-firearm suicides for the 6-year period from 1986 to 1991. Of several models fitted to the proportion of homicides that involved firearms, the one which incorporated a discrete upward shift in the middle of 1991 was the most successful. There was no evidence of a similar upward shift in the proportion of the suicides that involved firearms. The sharp increase in 1991 in the probability that a homicide involved the use of a firearm is consistent with a reported upsurge in violence related to the so-called 'taxi wars'. Hidden Markov models, as a general methodology for the analysis of discrete-valued time series, may be a useful and flexible means of identifying time trends or points of transition related to events or interventions in a wide range of public health contexts.

Partisan Change and Shifting Expenditure Priorities in the American States, 1945-1978

This article examines the impact of shifts in partisan control of the governorship and state legislatures on longitudinal patterns of expenditure priorities for 38 states from 1945 to 1978. I suggest that such partisan interventions should have an impact on patterns of spending priorities over time only under two circumstances: (1) when the political parties within governmental institutions differ systematically in policy-relevant ways, and (2) when the governmental institution undergoing partisan change has the institutional power relative to other policymaking bodies to translate spending priorities into outcomes. Using a multiple interrupted time series analysis of trends in spending priorities for education, highways, welfare, and health and hospitals, it is found that, in general, partisan interventions do have a nontrivial impact on patterns of spending priorities over time, both in terms of the level (intercept) and trend (slope) of the spending priorities time series. In sum, it would appear that there is more than modest support for the general partisan intervention model of change in spending priorities over time.

A study of regional trends in the labour force participation of married women in the UK, 1968–1977

This paper presents a quarterly time-series analysis of regional trends in the labour force participation rate of married women in the UK for the period 1968–1977, using sample estimates of participation rates from the Family Expenditure Survey (FES). The use of FES data provides access to incorporated into UK regional time-series analysis. Labour force participation rates of married women are found to be related to the rate of unemployment amongst their husbands, the rise in real earnings of married women and the decline in the number of young children in households during 1968–1977. It is suggested that the reduction in earnings differentials between the regions has been a major factor contributing to the observed convergence of regional labour force participation rates of married women towards the national average.