{"entity": "researcher", "timestamp": "2026-09-23T21:54:42.485Z", "family": "Reutfors", "given": "Johan", "initials": "J", "orcid": "0000-0003-1372-4262", "affiliations": ["Centre for Pharmacoepidemiology, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden."], "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/researcher/dbc162955acf4b2ba0b4dade363d4592.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/researcher/dbc162955acf4b2ba0b4dade363d4592"}}, "publications": [{"entity": "publication", "iuid": "84132b483bd742ef925ba567ab364bc6", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/84132b483bd742ef925ba567ab364bc6.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/84132b483bd742ef925ba567ab364bc6"}}, "title": "The use of uncertain exposure-A method to define switching and add-on in pharmacoepidemiology.", "authors": [{"family": "Pazzagli", "given": "Laura", "initials": "L", "orcid": "0000-0002-1908-6073", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/a1238a7c151343afb5daf301a63b63c2.json"}}, {"family": "Linder", "given": "Marie", "initials": "M", "orcid": "0000-0003-2619-2189", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/2caaaaa0836e48948cc20734a68c4e22.json"}}, {"family": "Reutfors", "given": "Johan", "initials": "J", "orcid": "0000-0003-1372-4262", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/dbc162955acf4b2ba0b4dade363d4592.json"}}, {"family": "Brandt", "given": "Lena", "initials": "L"}], "type": "journal article", "published": "2022-01-00", "journal": {"title": "Pharmacoepidemiol Drug Saf", "issn": "1099-1557", "volume": "31", "issue": "1", "pages": "28-36", "issn-l": null}, "abstract": "When defining exposure to pharmacological treatments in pharmacoepidemiology, register data often do not provide information regarding if a pharmacological treatment is a switch or an add-on. This study aims to compare two methods defining switching and add-on therapies and their impact on exposure-outcome associations. Additionally, to guide bias reduction, it aims to describe how the methods relate to immortal time bias and selection bias.\n\nCohort study using Swedish population-based health registers to identify antidepressant (AD) prescriptions as exposures while hospitalizations for psychiatric reasons were used as an empirical outcome example. The first method for exposure definition used conditioning on future exposure (FE), the second used the concept of uncertain exposure (UE). To estimate associations between outcome and exposure categories \"Use of one AD,\" \"Use of two or more ADs\", and \"UE\" compared to \"Unexposed,\" hazard ratios (HRs) and 95% confidence intervals were estimated using Cox regression adjusted for age and sex.\n\nUsing the UE method, 7.2% of time periods were classified as \"UE\" with a notable proportion of psychiatric hospitalizations (7.7%) occurring during this time, while when using the FE method these hospitalizations were distributed over unexposed time and AD use time. The FE method resulted in slightly higher associations than the UE method. The highest HR was found during \"UE\": HR (95% CI) 5.54 (5.06-6.07).\n\nThis study suggests that to reduce the potential immortal time bias, selection bias, and exposure misclassification inherent to the FE method, the UE method could be used for identifying switching and add-on therapies. If not used as a main exposure definition, the UE method may be used to investigate the impact of UE time in a sensitivity analysis.", "doi": "10.1002/pds.5363", "pmid": "34558772", "labels": [], "xrefs": [], "notes": [], "created": "2026-09-23T13:32:42.604Z", "modified": "2026-09-23T13:32:42.634Z"}, {"entity": "publication", "iuid": "7082e012404d45b18ee84d3636cd7299", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/7082e012404d45b18ee84d3636cd7299.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/7082e012404d45b18ee84d3636cd7299"}}, "title": "Use of hypnotic drugs among children, adolescents, and young adults in Scandinavia.", "authors": [{"family": "Wesselhoeft", "given": "Rikke", "initials": "R", "orcid": "0000-0001-9700-2739", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/29670ecb185844689260deb334d8ef10.json"}}, {"family": "Rasmussen", "given": "Lotte", "initials": "L"}, {"family": "Jensen", "given": "Peter Bj\u00f8dstrup", "initials": "PB"}, {"family": "Jennum", "given": "Poul J\u00f8rgen", "initials": "PJ", "orcid": "0000-0001-6986-5254", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/01b009348f0846beb1d0c60941b1ca28.json"}}, {"family": "Skurtveit", "given": "Svetlana", "initials": "S"}, {"family": "Hartz", "given": "Ingeborg", "initials": "I"}, {"family": "Reutfors", "given": "Johan", "initials": "J", "orcid": "0000-0003-1372-4262", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/dbc162955acf4b2ba0b4dade363d4592.json"}}, {"family": "Damkier", "given": "Per", "initials": "P", "orcid": "0000-0003-0591-7187", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/3220b6c562f2497f9122594f270ba2ab.json"}}, {"family": "Bliddal", "given": "Mette", "initials": "M"}, {"family": "Potteg\u00e5rd", "given": "Anton", "initials": "A", "orcid": "0000-0001-9314-5679", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/1daf4d9300f94bf6916f968437b52a80.json"}}], "type": "journal article", "published": "2021-08-00", "journal": {"title": "Acta Psychiatr Scand", "issn": "1600-0447", "volume": "144", "issue": "2", "pages": "100-112", "issn-l": null}, "abstract": "Hypnotic use in children and adolescents is controversial.\n\nTo describe the use of hypnotic drugs (melatonin, z-drugs, and sedating antihistamines) among 5- to 24-year-old Scandinavians during 2012 to 2018.\n\nAggregate-level data were obtained from public data sources in Sweden, Norway, and Denmark. We calculated annual prevalence (users/1000 inhabitants) stratified by age group, sex, and country. Quantity of use (Defined Daily Dose (DDD)/user/day) was estimated for Norway and Denmark.\n\nMelatonin was the most commonly used hypnotic, and its use increased markedly from 2012 to 2018, particularly among females and 15- to 24-year-old individuals. Sweden had the highest increase in use (6.5 to 25/1000) compared with Norway (10-20/1000) and Denmark (5.7-12/1000). The annual prevalence of sedating antihistamine use was also highest in Sweden, reaching 13/1000 in 2018 in comparison to 7.5/1000 in Norway and 2.5/1000 in Denmark. Z-drug use decreased in all countries toward 2018, dropping to 3.5/1000 in Sweden, 4.4/1000 in Norway, and 1.7/1000 in Denmark. The quantity of hypnotic use in Norway and Denmark was 0.8-1.0 DDD/user/day for melatonin in 2018, as compared to 0.1-0.3 for z-drugs and antihistamines.\n\nThe use of melatonin and sedating antihistamines increased among young Scandinavians during 2012-2018, and the increase was twice as high in Sweden compared with Norway and Denmark. In addition, Sweden had the highest use of sedating antihistamines. The Scandinavian variation of hypnotic use could reflect differences in frequency of sleep problems between populations or variation of healthcare access or clinical practice between countries.", "doi": "10.1111/acps.13329", "pmid": "34021908", "labels": [], "xrefs": [], "notes": [], "created": "2026-09-23T09:59:52.674Z", "modified": "2026-09-23T10:37:29.122Z"}]}