| 1. |
- Bergström, Göran, 1964, et al.
(författare)
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Prevalence of Subclinical Coronary Artery Atherosclerosis in the General Population
- 2021
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Ingår i: Circulation. - Philadelphia : American Heart Association. - 0009-7322 .- 1524-4539. ; 144:12, s. 916-929
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Tidskriftsartikel (refereegranskat)abstract
- Background: Early detection of coronary atherosclerosis using coronary computed tomography angiography (CCTA), in addition to coronary artery calcification (CAC) scoring, may help inform prevention strategies. We used CCTA to determine the prevalence, severity, and characteristics of coronary atherosclerosis and its association with CAC scores in a general population.Methods: We recruited 30 154 randomly invited individuals age 50 to 64 years to SCAPIS (the Swedish Cardiopulmonary Bioimage Study). The study includes individuals without known coronary heart disease (ie, no previous myocardial infarctions or cardiac procedures) and with high-quality results from CCTA and CAC imaging performed using dedicated dual-source CT scanners. Noncontrast images were scored for CAC. CCTA images were visually read and scored for coronary atherosclerosis per segment (defined as no atherosclerosis, 1% to 49% stenosis, or ≥50% stenosis). External validity of prevalence estimates was evaluated using inverse probability for participation weighting and Swedish register data.Results: In total, 25 182 individuals without known coronary heart disease were included (50.6% women). Any CCTA-detected atherosclerosis was found in 42.1%; any significant stenosis (≥50%) in 5.2%; left main, proximal left anterior descending artery, or 3-vessel disease in 1.9%; and any noncalcified plaques in 8.3% of this population. Onset of atherosclerosis was delayed on average by 10 years in women. Atherosclerosis was more prevalent in older individuals and predominantly found in the proximal left anterior descending artery. Prevalence of CCTA-detected atherosclerosis increased with increasing CAC scores. Among those with a CAC score >400, all had atherosclerosis and 45.7% had significant stenosis. In those with 0 CAC, 5.5% had atherosclerosis and 0.4% had significant stenosis. In participants with 0 CAC and intermediate 10-year risk of atherosclerotic cardiovascular disease according to the pooled cohort equation, 9.2% had CCTA-verified atherosclerosis. Prevalence estimates had excellent external validity and changed marginally when adjusted to the age-matched Swedish background population.Conclusions: Using CCTA in a large, random sample of the general population without established disease, we showed that silent coronary atherosclerosis is common in this population. High CAC scores convey a significant probability of substantial stenosis, and 0 CAC does not exclude atherosclerosis, particularly in those at higher baseline risk.
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| 2. |
- Koski, Timo, et al.
(författare)
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Towards field-adjusted production : Estimating research productivity from a zero-truncated distribution
- 2016
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Ingår i: Journal of Informetrics. - : Elsevier. - 1751-1577 .- 1875-5879. ; 10:4, s. 1143-1152
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Tidskriftsartikel (refereegranskat)abstract
- Measures of research productivity (e.g. peer reviewed papers per researcher) is a fundamental part of bibliometric studies, but is often restricted by the properties of the data available. This paper addresses that fundamental issue and presents a detailed method for estimation of productivity (peer reviewed papers per researcher) based on data available in bibliographic databases (e.g. Web of Science and Scopus). The method can, for example, be used to estimate average productivity in different fields, and such field reference values can be used to produce field adjusted production values. Being able to produce such field adjusted production values could dramatically increase the relevance of bibliometric rankings and other bibliometric performance indicators. The results indicate that the estimations are reasonably stable given a sufficiently large data set.
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| 3. |
- Sandström, Erik, et al.
(författare)
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The P-model : An indicator that accounts for field adjusted production as well as field normalized citation impact.
- 2019
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Ingår i: Proceedings of the 17th International Conference of the International Society for Scientometrics and Informetrics. ; , s. 2326-2331
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Konferensbidrag (refereegranskat)abstract
- Any type of scientific study or evaluation of research quality and impact enters into two types of problems if thereis more than one topic area involved in the study: (1) How to account for differences in (paper) production? (2)How to account for differences in citation impact, i.e. influence over subsequent literature? This paper aims toshow that these questions can be answered with the help of two methods; the Field Adjusted Production (FAP)indicator and a percentile indicator which is designed to include the FAP. Consequently, they are used incombination in order to express a score that includes both paper production an impact into one figure. Thereby isconstructed a score that can be used for ranking of universities, departments, individuals. The paper first explainsthe background of the method, and then how to calculate the indicators belonging to the P-Model. Then the paperindicates some examples and will discuss methods for validation of the proposed indicator.
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| 4. |
- Sandström, Ulf, 1953-, et al.
(författare)
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Meeting the Micro-Level Challenges : Bibliometrics at the Individual Level
- 2009
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Ingår i: PROCEEDINGS OF ISSI 2009 - 12TH INTERNATIONAL CONFERENCE OF THE INTERNATIONAL SOCIETY FOR SCIENTOMETRICS AND INFORMETRICS, VOL 2. ; , s. 846-856
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Konferensbidrag (refereegranskat)abstract
- The aim of this paper is to demonstrate a method for bibliometric evaluation of individuals, i.e. research staff currently employed within a university department or other knowledge organisations with research purposes. Based on methods for citation analysis and methods for clustering of papers into research lines ( using bibliographic coupling) we present an analysis of one researcher in three dimensions: 1) publication and citation indicators; 2) publication profile, and 3) research lines. One of the features of the method is the benchmark against other researchers within the same research line, i.e. researchers that use the same references and, accordingly, are active in the same field of research. The paper suggests this method as a means to avoid the fallacies of evaluation solely dependent on sub-field categories in the Web of Science in advanced citation analysis. The method was used in a Research Assessment Exercise accomplished in the autumn of 2008 at Royal Institute of Technology.
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| 5. |
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| 6. |
- Sandström, Ulf, 1953-, et al.
(författare)
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Modell för beräkning av direktanslag till svenska lärosäten baserad på forskningsproduktion och citeringsgrad
- 2007
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Ingår i: Resurser för kvalitet. Betänkande av Resursutreningen. - Stockholm : Fritzes. - 9789138228272 ; , s. 389-443
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Resursutredningen har haft i uppdrag att göra en översyn av resurstilldelningssystemet för den grundläggande högskoleutbildningen. Utifrån översynen skulle eventuella förändringar av systemet föreslås. Utgångspunkten för uppdraget har varit att åstadkomma ett resurstilldelningssystem som möjliggör ett utbildningsutbud med hög kvalitet som efterfrågas av studenter och arbetsmarknaden.Resursutredningens förslag innebär att de direkta anslagen fördelas utifrån akademins egna kriterier för vad som är god utbildning och forskning och utifrån studenternas egna informerade val. Det resulterar i att staten varken kan eller bör styra hur resurserna fördelas mellan lärosätena. Det blir därför viktigt att denna modell sköts och kvalitetssäkras av ett akademiskt väl kvalificerat mellanliggande organ utanför Regeringskansliet.
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| 7. |
- Sandström, Ulf, 1953-, et al.
(författare)
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The field factor : Towards a Metric for Academic Institutions
- 2009
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Ingår i: Research Evaluation. - : BEECH TREE PUBLISHING. - 0958-2029 .- 1471-5449. ; 18:3, s. 243-250
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Tidskriftsartikel (refereegranskat)abstract
- We present a new model for performance-related funding of universities in Sweden. The model is based oil number of papers in international scientific journals, but relies oil an estimation of field-adjusted production per scientific/technological area Author counts are based oil potential authors using the Waring distribution for 34 areas of science (Schubert and Braun, 1992) We apply this model to the Swedish university system and illustrate with the reallocations that Would follow from a complete implementation. Next, we test the accuracy of the method using publication data from six Swedish universities and four Norwegian universities. In conclusion we discuss advantages and drawbacks with the method.
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| 8. |
- Van Den Besselaar, Peter, et al.
(författare)
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Do observations have any role in science policy studies? A reply
- 2017
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Ingår i: Journal of Informetrics. - : Elsevier. - 1751-1577 .- 1875-5879. ; 11:3, s. 941-944
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Tidskriftsartikel (refereegranskat)abstract
- In Van den Besselaar et al. (2017) we tested the claim of Linda Butler (2003) that funding systems based on output counts have a negative effect on impact as well as quality. Using new data and improved indicators, we indeed reject the claim of Butler. The impact of Australian research improved after the introduction of such a system, and did not decline as Butler states. In their comments on our findings, Linda Butler, Jochen Gläser, Kaare Aagaard & Jesper Schneider, Ben Martin, and Diana Hicks put forward a lot of arguments, but do not dispute our basic finding: citation impact of Australian research went up, immediately after the output based performance system was introduced. It is important to test the findings of Butler about Australia – as these findings are part of the accepted knowledge in the field, heavily cited, often used in policy reports, but hardly confirmed in other studies. We found that the conclusions of Butler are wrong, and that many of the policy implications based on it simply are unfounded. In our study, we used better indicators, and a similar causality concept as our opponents. And our findings are independent of the exact timing of the policy intervention. Furthermore, our commenters have not addressed our main conclusions at all, and some even claim that observations do not really matter in the social sciences. We find this position problematic − why would the taxpayer fund science policy studies, if it is merely about opinions? Let’s take science seriously − including our own field Do observations have any role in science policy studies? A reply. Available from: https://www.researchgate.net/publication/318312568_Do_observations_have_any_role_in_science_policy_studies_A_reply [accessed Sep 11, 2017].
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| 9. |
- Van Den Besselaar, Peter, et al.
(författare)
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Perverse effects of output-based research funding? Butler's Australian case revisited
- 2017
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Ingår i: Journal of Informetrics. - : Elsevier. - 1751-1577 .- 1875-5879. ; 11:3, s. 905-918
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Tidskriftsartikel (refereegranskat)abstract
- More than ten years ago, Linda Butler (2003a) published a well-cited article claiming that the Australian science policy in the early 1990s made a mistake by introducing output based funding. According to Butler, the policy stimulated researchers to publish more but at the same time less good papers, resulting in lower total impact of Australian research compared to other countries. We redo and extend the analysis using longer time series, and show that Butlers’ main conclusions are not correct. We conclude in this paper (i) that the currently available data reject Butler’s claim that “journal publication productivity has increased significantly… but its impact has declined”, and (ii) that it is hard to find such evidence also with a reconstruction of her data. On the contrary, after implementing evaluation systems and performance based funding, Australia not only improved its share of research output but also increased research quality, implying that total impact was greatly increased. Our findings show that if output based research funding has an effect on research quality, it is positive and not negative. This finding has implications for the discussions about research evaluation and about assumed perverse effects of incentives, as in those debates the Australian case plays a major role.
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| 10. |
- van den Besselaar, Peter, et al.
(författare)
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Science policy through stimulating scholarly output. Reanalyzing the Australian case
- 2016
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Ingår i: STI2016 - Proceedings of the 21ST international conference on science and technology indicators. - : UNIV POLITECNICA VALENCIA. - 9788490485194 - 8490485194 ; , s. 531-540
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Konferensbidrag (refereegranskat)abstract
- There is a long standing debate about perverse effects of performance indicators. A main target is science policy using stimulation of output as instrument. The criticism is to a large extent based on a study of the Australian science policy in the early 1990s. Linda Butler studied the effects and argued that the effect was an growth of output, but also a decrease of average quality of the output. These results have been cited many times. In this paper we reanalyze this case and show that the analysis of Butler was wrong: the new Australian science policy did not only increase the output of the system, but also the quality went up. We discuss the implications.
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