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Regionalt kunnskapssenter for barn og unge – psykisk helse og barnevern
Institutt for psykisk helse
NTNU
Forfatterbidrag: utforming/design av statistiske analyser, tolking av data, litteratursøk, revisjon av manus og godkjenning av innsendt manus.
Stian Lydersen er dr.ing. og professor i medisinsk statistikk ved Regionalt kunnskapssenter for barn og unge – psykisk helse og barnevern (RKBU Midt-Norge) ved Institutt for psykisk helse, NTNU.
Articles by Stian Lydersen
Data quality in the Norwegian Myocardial Infarction Registry
- Ida Almenning Kiel,
- Ragna Elise Støre Govatsmark,
- Veronica Bendiktsen Berge,
- Kari Krizak Halle,
- Stian Lydersen,
- Cecilie Risøe,
- Bjørn Haug,
- Jarle Jortveit,
- Siri Malm,
- Gard Frodahl Tveitevåg Svingen,
- Miriam Wiksnes,
- Christian Engelsen Berg-Hansen,
- Lars Håvard Nilsen,
- Espen Ellingsen Moe,
- Kaare Harald Bønaa
26.03.2025:
In Norway, 61 national medical quality registries have been established, based on diagnoses, procedures or services (1). The main purpose of these registries is to contribute to better patient treatment (1, 2). They are also used for research and administration. In many medical fields, the national...
Autism diagnoses in school-age children in southern Trøndelag 2016–2019
- Anne Berit Røe,
- Sidsel Jullumstrø,
- Kristin Brobakken Eig,
- Stian Lydersen,
- Terje Nærland,
- Anne Lise Høyland
11.12.2024:
The prevalence of autism spectrum disorders is rising, and the reason why is not clear (1). Changes to the diagnostic criteria and increased awareness of the diagnosis may explain much of the increase, but a genuine rise in prevalence cannot be ruled out (2). Autism spectrum diagnoses cover a broad...
Percentages in rows or columns?
- Stian Lydersen
09.09.2024:
When reporting counts and comparing proportions, it can be useful to present the figures in a contingency table. But should the percentages be reported in the rows or the columns? To answer this question, we can ask ourselves what is exposure and what is outcome, and report percentages within each...
Machine learning in medical research
- Guro F. Giskeødegård,
- Stian Lydersen
29.05.2023:
Machine learning is used to find underlying patterns in data. This can be useful in medical research. Machine learning is a form of artificial intelligence that is used to find underlying patterns in data. It can be based on statistical methods, or other techniques from mathematics or informatics...
Do we need all the decimals?
- Stian Lydersen,
- Eva Skovlund
05.05.2023:
If we use too few decimal places, the result will be imprecisely reported. On the other hand, if we use too many decimals, we give the impression that the result is more precise than it really is. How many decimals to use should be a conscious choice. Using more decimals than necessary is not wrong...
Attrition analysis
- Stian Lydersen
24.10.2022:
Attrition will occur in most clinical studies. If those who drop out differ substantially from those who participate, the generalisability of the study's results may suffer. Attrition can occur because not all of the invited participants choose to take part in the study, or because some of the...
Measurements below the detection limit
- Guro F. Giskeødegård,
- Stian Lydersen
19.09.2022:
Many methods for measuring levels of a substance in a sample have a lower detection limit. Data from these measurements must be handled in a way that avoids systematic errors. Let's start with an example: Figure 1 shows a fictional dataset of measurements of serum levels of a substance in two...
Internal consistency: from alpha to omega?
- Kenneth Stensen,
- Stian Lydersen
29.08.2022:
Questionnaires often consist of scales composed of different questions and are intended to measure a given factor, for example anxiety or depression. Internal consistency is a measure of the strength of the relationship between questions in the same scale. When developing questionnaires and scales...