Trend Analyses in Multifactor Designs

1992 ◽  
pp. 265-306
Author(s):  
Harold R. Lindman
Keyword(s):  
Trend Analyses

Improved Survival after Stroke: Is Admission to Hospital the Major Explanation? Trend Analyses of the Auckland Regional Community Stroke Studies

2006 ◽  
Vol 23 (2-3) ◽  
pp. 162-168 ◽  
Author(s):  
Kristie N. Carter ◽  
Craig S. Anderson ◽  
Maree L. Hackett ◽  
P. Alan Barber ◽  
Ruth Bonita
Keyword(s):  
Trend Analyses ◽  
Regional Community

Trend Analyses of Seasonal Streamflows of the Tapi Basin

2018 ◽  
Vol 4 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Ganesh D. Kale ◽  
D. Nagesh Kumar
Keyword(s):  
Trend Analyses ◽  
Tapi Basin

Trends in the Surgical Management and Outcomes of Complicated Peptic Ulcer Disease

2020 ◽  
Vol 86 (7) ◽  
pp. 856-864
Author(s):  
Olubode A. Olufajo ◽  
Amanda Wilson ◽  
Bruke Yehayes ◽  
Ahmad Zeineddin ◽  
Edward E. Cornwell ◽  
...  
Keyword(s):  
Peptic Ulcer ◽  
Peptic Ulcer Disease ◽  
Surgical Management ◽  
Postoperative Care ◽  
National Inpatient Sample ◽  
Trend Analyses ◽  
Ulcer Disease ◽  
Preoperative Optimization ◽  
Obstruction Group ◽  
Perforation Group

Background Older data indicate that less patients undergo surgery for complicated peptic ulcer disease (PUD). We evaluated contemporary trends in the surgical management and outcomes of patients with complicated PUD. Methods The National Inpatient Sample (2005-2014) was queried for patients with complicated PUD (hemorrhage, perforation, or obstruction). Trend analyses were used to evaluate changes in management and outcomes. Results There were 1 570 696 admissions for complicated PUD during the study period. Majority (87.0%) presented with hemorrhage, 10.6% presented with perforation, and 2.4% had an obstruction. The average age was 67 years. Overall, admissions with complicated PUD decreased from 180 054 in 2005 to 150 335 in 2014. The proportion of patients managed operatively decreased from 2.5% to 1.9% in the hemorrhage group, 75.0% to 67.4% in the perforation group, and 26.0% to 20.2% in the obstruction group (all P-trend < .05). Overall, among patients managed operatively, the use of acid-reducing procedures decreased from 25.9% to 13.9%, mortality decreased from 11.9% to 9.4% (both P-trend < .001), while complications remained stable (10.4% to 10.3%, P-trend = .830). Conclusions There are fewer admissions with complicated PUD and more patients are treated nonoperatively. Despite subtle improvements, significant proportions of patients still die from complicated PUD indicating the need for improved preoperative optimization and postoperative care among these patients.

New insights into survival trend analyses in cancer population-based studies

2017 ◽  
Vol 26 ◽  
pp. S9-S15 ◽  
Author(s):  
Zoé Uhry ◽  
Nadine Bossard ◽  
Laurent Remontet ◽  
Jean Iwaz ◽  
Laurent Roche
Keyword(s):  
Population Based ◽  
Trend Analyses

scholarly journals Multidimensional penalized splines for incidence and mortality-trend analyses and validation of national cancer-incidence estimates

2020 ◽  
Vol 49 (4) ◽  
pp. 1294-1306 ◽  
Author(s):  
Zoé Uhry ◽  
Edouard Chatignoux ◽  
Emmanuelle Dantony ◽  
Marc Colonna ◽  
Laurent Roche ◽  
...  
Keyword(s):  
Cancer Incidence ◽  
Estimation Method ◽  
Penalized Splines ◽  
Registry Data ◽  
Testis Cancer ◽  
Mortality Trend ◽  
Validation Process ◽  
Trend Analyses ◽  
Incidence Trends ◽  
Incidence And Mortality

Abstract Background Cancer-incidence and mortality-trend analyses require appropriate statistical modelling. In countries without a nationwide cancer registry, an additional issue is estimating national incidence from local-registry data. The objectives of this study were to (i) promote the use of multidimensional penalized splines (MPS) for trend analyses; (ii) estimate the national cancer-incidence trends, using MPS, from only local-registry data; and (iii) propose a validation process of these estimates. Methods We used an MPS model of age and year for trend analyses in France over 1990–2015 with a projection up to 2018. Validation was performed for 22 cancer sites and relied essentially on comparison with reference estimates that used the incidence/health-care ratio over the period 2011–2015. Alternative estimates that used the incidence/mortality ratio were also used to validate the trends. Results In the validation assessment, the relative differences of the incidence estimates (2011–2015) with the reference estimates were &lt;5% except for testis cancer in men and &lt; 7% except for larynx cancer in women. Trends could be correctly derived since 1990 despite incomplete histories in some registries. The proposed method was applied to estimate the incidence and mortality trends of female lung cancer and prostate cancer in France. Conclusions The validation process confirmed the validity of the national French estimates; it may be applied in other countries to help in choosing the most appropriate national estimation method according to country-specific contexts. MPS form a powerful statistical tool for trend analyses; they allow trends to vary smoothly with age and are suitable for modelling simple as well as complex trends thanks to penalization. Detailed trend analyses of lung and prostate cancers illustrated the suitability of MPS and the epidemiological interest of such analyses.

scholarly journals Temporal and spatial changes of rainfall and streamflow in the Upper Tekezē–Atbara river basin, Ethiopia

2017 ◽  
Vol 21 (4) ◽  
pp. 2127-2142 ◽  
Author(s):  
Tesfay G. Gebremicael ◽  
Yasir A. Mohamed ◽  
Pieter v. Zaag ◽  
Eyasu Y. Hagos
Keyword(s):  
Change Point ◽  
Statistical Tests ◽  
Catchment Management ◽  
Trend Analyses ◽  
Temporal And Spatial Variability ◽  
Spatial Changes ◽  
Changing Patterns ◽  
Temporal And Spatial ◽  
Using Data ◽  
Streamflow Trends

Abstract. The Upper Tekezē–Atbara river sub-basin, part of the Nile Basin, is characterized by high temporal and spatial variability of rainfall and streamflow. In spite of its importance for sustainable water use and food security, the changing patterns of streamflow and its association with climate change is not well understood. This study aims to improve the understanding of the linkages between rainfall and streamflow trends and identify possible drivers of streamflow variabilities in the basin. Trend analyses and change-point detections of rainfall and streamflow were analysed using Mann–Kendall and Pettitt tests, respectively, using data records for 21 rainfall and 9 streamflow stations. The nature of changes and linkages between rainfall and streamflow were carefully examined for monthly, seasonal and annual flows, as well as indicators of hydrologic alteration (IHA). The trend and change-point analyses found that 19 of the tested 21 rainfall stations did not show statistically significant changes. In contrast, trend analyses on the streamflow showed both significant increasing and decreasing patterns. A decreasing trend in the dry season (October to February), short season (March to May), main rainy season (June to September) and annual totals is dominant in six out of the nine stations. Only one out of nine gauging stations experienced significant increasing flow in the dry and short rainy seasons, attributed to the construction of Tekezē hydropower dam upstream this station in 2009. Overall, streamflow trends and change-point timings were found to be inconsistent among the stations. Changes in streamflow without significant change in rainfall suggests factors other than rainfall drive the change. Most likely the observed changes in streamflow regimes could be due to changes in catchment characteristics of the basin. Further studies are needed to verify and quantify the hydrological changes shown in statistical tests by identifying the physical mechanisms behind those changes. The findings from this study are useful as a prerequisite for studying the effects of catchment management dynamics on the hydrological variabilities in the basin.

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