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Adjustment for misclassification in studies of familial aggregation of disease using routine register data.

https://arctichealth.org/en/permalink/ahliterature187750
Source
Stat Med. 2002 Dec 15;21(23):3595-607
Publication Type
Article
Date
Dec-15-2002
Author
Elisabeth Wreford Andersen
Per Kragh Andersen
Author Affiliation
Danish Epidemiology Science Centre, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark. eo@biostat.ku.dk
Source
Stat Med. 2002 Dec 15;21(23):3595-607
Date
Dec-15-2002
Language
English
Publication Type
Article
Keywords
Adolescent
Bias (epidemiology)
Case-Control Studies
Cluster analysis
Computer simulation
Denmark - epidemiology
Female
Humans
Male
Models, Statistical
Mothers
Registries
Regression Analysis
Risk factors
Schizophrenia - classification - epidemiology
Abstract
This paper discusses the misclassification that occurs when relying solely on routine register data in family studies of disease clustering. A register study of familial aggregation of schizophrenia is used as an example. The familial aggregation is studied using a regression model for the disease in the child including the disease status of the parents as a risk factor. If all the information is found in the routine registers then the disease status of the parents is only known from the time when the register started and if this information is used unquestioningly the parents who have had the disease before this time are misclassified as disease-free. Two methods are presented to adjust for this misclassification: regression calibration and an EM-type algorithm. These methods are used in the schizophrenia example where the large effect of having a schizophrenic mother hardly shows any signs of bias due to misclassification. The methods are also studied in simulations showing that the misclassification problem increases with the disease frequency.
PubMed ID
12436458 View in PubMed
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Does lithium protect against dementia?

https://arctichealth.org/en/permalink/ahliterature98084
Source
Bipolar Disord. 2010 Feb;12(1):87-94
Publication Type
Article
Date
Feb-2010
Author
Lars Vedel Kessing
Julie Lyng Forman
Per Kragh Andersen
Author Affiliation
Department of Psychiatry, University Hospital of Copenhagen. Copenhagen, Denmark. lars.kessing@rh.dk
Source
Bipolar Disord. 2010 Feb;12(1):87-94
Date
Feb-2010
Language
English
Publication Type
Article
Keywords
Adult
Aged
Antidepressive Agents - therapeutic use
Antimanic Agents - therapeutic use
Antipsychotic Agents - therapeutic use
Bipolar Disorder - complications - drug therapy
Dementia - etiology - prevention & control
Denmark
Evidence-Based Medicine
Female
Follow-Up Studies
Humans
Lithium Chloride - therapeutic use
Male
Middle Aged
Registries - statistics & numerical data
Regression Analysis
Retrospective Studies
Abstract
OBJECTIVE: To investigate whether treatment with lithium in patients with mania or bipolar disorder is associated with a decreased rate of subsequent dementia. METHODS: Linkage of register data on prescribed lithium in all patients discharged from psychiatric health care service with a diagnosis of mania or bipolar disorder and subsequent diagnoses of dementia in Denmark during a period from 1995 to 2005. RESULTS: A total of 4,856 patients with a diagnosis of a manic or mixed episode or bipolar disorder at their first psychiatric contact were included in the study. Among these patients, 2,449 were exposed to lithium (50.4%), 1,781 to anticonvulsants (36.7%), 4,280 to antidepressants (88.1%), and 3,901 to antipsychotics (80.3%) during the study period. A total of 216 patients received a diagnosis of dementia during follow-up (103.6/10,000 person-years). During the period following the second prescription of lithium, the rate of dementia was decreased compared to the period following the first prescription. In contrast, the rates of dementia during multiple prescription periods with anticonvulsants, antidepressants, or antipsychotics, respectively, were not significantly decreased compared to the rate of dementia during the period with one prescription of these drugs. CONCLUSIONS: Continued treatment with lithium was associated with a reduced rate of dementia in patients with bipolar disorder in contrast to continued treatment with anticonvulsants, antidepressants, or antipsychotics. Methodological reasons for these findings cannot be excluded due to the nonrandomized nature of the data.
PubMed ID
20148870 View in PubMed
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Does the association between broken partnership and first time myocardial infarction vary with time after break-up?

https://arctichealth.org/en/permalink/ahliterature258323
Source
Int J Epidemiol. 2013 Dec;42(6):1811-9
Publication Type
Article
Date
Dec-2013
Author
Margit Kriegbaum
Ulla Christensen
Per Kragh Andersen
Merete Osler
Rikke Lund
Author Affiliation
Department of Public Health, University of Copenhagen, Copenhagen, Denmark and Glostrup University Hospital, Copenhagen, Denmark.
Source
Int J Epidemiol. 2013 Dec;42(6):1811-9
Date
Dec-2013
Language
English
Publication Type
Article
Keywords
Adult
Aged
Case-Control Studies
Denmark - epidemiology
Divorce - statistics & numerical data
Female
Humans
Life Change Events
Male
Middle Aged
Myocardial Infarction - epidemiology
Regression Analysis
Spouses - statistics & numerical data
Time Factors
Abstract
Marriage is associated with lower risk of coronary heart disease, but it is unknown if the association depends on time since break-up with a partner. In this study we included both married and unmarried couples to study if the association between broken partnership (BP) and first time incident myocardial infarction (MI) changes with time since BP.
Register study of the entire Danish population: the population was restricted to those aged 30 to 65 years with follow-up for incident MI between 1985 and 2006 with an annual record on each individual; in total 43 million records. The register data were used to identify MI events. Poisson regression was used to study associations between time since BP and MI adjusted for socio-demographic confounders and hospital admissions. Analyses were stratified by sex.
Compared with unexposed (no BP), the incidence rate ratio (IRR) of MI in men with BP in the same year was 0.97 [95% confidence interval (CI) 0.90-1.05], year before BP was 1.25 (95% CI 1.17-1.34), 2-3 years after BP was 1.12 (95% CI 1.06-1.18), 4-8 years after BP was 1.09 (95% CI 1.05-1.14) and 9+ years since BP was 1.09 (95% CI 1.05-1.12). In women, the IRR same year as BP was 1.45 (95% CI 1.26-1.66), the year after BP was 1.30 (95% CI 1.14-1.50), 2-3 years after BP was 1.26 (95% CI 1.13-1.39), 4-8 years after BP was 1.17 (95% CI 1.08-1.26) and 9+ years since BP was 1.24 (95% CI 1.17-1.32).
We found both a short-term elevated risk of first time MI following BP and a weaker long-term elevated risk, in both men and women.
PubMed ID
24415614 View in PubMed
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Fever in pregnancy and risk of fetal death: a cohort study.

https://arctichealth.org/en/permalink/ahliterature63590
Source
Lancet. 2002 Nov 16;360(9345):1552-6
Publication Type
Article
Date
Nov-16-2002
Author
Anne-Marie Nybo Andersen
Pernille Vastrup
Jan Wohlfahrt
Per Kragh Andersen
Jørn Olsen
Mads Melbye
Author Affiliation
Department of Epidemiology Research, Danish Epidemiology Science Centre, Statens Serum Institut, Copenhagen, Denmark. a.nybo@socmed.ku.dk
Source
Lancet. 2002 Nov 16;360(9345):1552-6
Date
Nov-16-2002
Language
English
Publication Type
Article
Keywords
Abortion, Spontaneous - etiology
Adult
Female
Fetal Death - etiology
Fever - complications
Gestational Age
Humans
Pregnancy
Pregnancy Complications
Pregnancy outcome
Pregnancy Trimester, First
Pregnancy Trimester, Second
Prospective Studies
Regression Analysis
Research Support, Non-U.S. Gov't
Risk factors
Abstract
BACKGROUND: Hyperthermia acts as a teratogen in some animals where it can induce resorption of the fetus and fetal death. Fever during pregnancy, especially in the period of embryogenesis, is also suspected as being a risk factor for fetal death in human beings. We did a large cohort study in Denmark to investigate this possibility. METHODS: We interviewed 24040 women who were recruited in the first half of pregnancy to the Danish National Birth Cohort Study, and obtained information on the number of fever incidents during the first 16 weeks of pregnancy. For each fever episode, the highest measured body temperature, duration of incident, and gestational age were recorded. Outcomes of pregnancies were identified through linkage with the Civil Registration System and the National Discharge Registry. Cox's regression with time-dependent variables was used to estimate the relative risk of fetal death, taking delayed entry into account. FINDINGS: 1145 pregnancies resulted in a miscarriage or stillbirth (4.8%). During the first 16 pregnancy weeks 18.5% of the women experienced at least one episode of fever. However, we found no association between fever in pregnancy and fetal death before or after adjustment for known risk factors of fetal death (relative risk 0.95 [95% CI 0.80-1.13]). This finding was consistent irrespective of measured maximum temperature, duration and number of fever incidents, or the gestational time of the fever incident, and was observed for fetal death in all three trimesters of pregnancy. INTERPRETATION: We found no evidence that fever in the first 16 weeks of pregnancy is associated with the risk of fetal death in clinically recognised pregnancies.
Notes
Comment In: Lancet. 2002 Nov 16;360(9345):152612443584
PubMed ID
12443593 View in PubMed
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How do macro-level contexts and policies affect the employment chances of chronically ill and disabled people? Part II: The impact of active and passive labor market policies.

https://arctichealth.org/en/permalink/ahliterature132184
Source
Int J Health Serv. 2011;41(3):415-30
Publication Type
Article
Date
2011
Author
Paula Holland
Lotta Nylén
Karsten Thielen
Kjetil A van der Wel
Wen-Hao Chen
Ben Barr
Bo Burström
Finn Diderichsen
Per Kragh Andersen
Espen Dahl
Sharanjit Uppal
Stephen Clayton
Margaret Whitehead
Author Affiliation
Division of Health Research, Lancaster University, England.
Source
Int J Health Serv. 2011;41(3):415-30
Date
2011
Language
English
Publication Type
Article
Keywords
Adult
Canada
Chronic Disease
Disabled Persons
Educational Status
Employment - statistics & numerical data - trends
Europe
Female
Health Surveys
Humans
Male
Middle Aged
Organizational Culture
Organizational Policy
Public Policy
Regression Analysis
Social Justice
Social Welfare
Abstract
The authors investigate three hypotheses on the influence of labor market deregulation, decommodification, and investment in active labor market policies on the employment of chronically ill and disabled people. The study explores the interaction between employment, chronic illness, and educational level for men and women in Canada, Denmark, Norway, Sweden, and the United Kingdom, countries with advanced social welfare systems and universal health care but with varying types of active and passive labor market policies. People with chronic illness were found to fare better in employment terms in the Nordic countries than in Canada or the United Kingdom. Their employment chances also varied by educational level and country. The employment impact of having both chronic illness and low education was not just additive but synergistic. This amplification was strongest for British men and women, Norwegian men, and Danish women. Hypotheses on the disincentive effects of tighter employment regulation or more generous welfare benefits were not supported. The hypothesis that greater investments in active labor market policies may improve the employment of chronically ill people was partially supported. Attention must be paid to the differential impact of macro-level policies on the labor market participation of chronically ill and disabled people with low education, a group facing multiple barriers to gaining employment.
PubMed ID
21842571 View in PubMed
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Lithium treatment and risk of dementia.

https://arctichealth.org/en/permalink/ahliterature154426
Source
Arch Gen Psychiatry. 2008 Nov;65(11):1331-5
Publication Type
Article
Date
Nov-2008
Author
Lars Vedel Kessing
Lars Søndergård
Julie Lyng Forman
Per Kragh Andersen
Author Affiliation
Department of Psychiatry, University Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, DK 2100 Copenhagen, Denmark. lars.kessing@rh.dk
Source
Arch Gen Psychiatry. 2008 Nov;65(11):1331-5
Date
Nov-2008
Language
English
Publication Type
Article
Keywords
Adult
Aged
Alzheimer Disease - diagnosis - epidemiology - prevention & control - psychology
Bipolar Disorder - drug therapy - epidemiology
Cohort Studies
Dementia - diagnosis - epidemiology - prevention & control - psychology
Denmark
Drug Prescriptions - statistics & numerical data
Female
Humans
Lithium Compounds - adverse effects - therapeutic use
Male
Middle Aged
Registries
Regression Analysis
Risk
Abstract
It has been suggested that lithium may have neuroprotective abilities, but it is not clear whether lithium reduces the risk of dementia.
To investigate whether continued treatment with lithium reduces the risk of dementia in a nationwide study.
An observational cohort study with linkage of registers of all patients prescribed lithium and diagnosed as having dementia in Denmark from January 1, 1995, through December 31, 2005.
We identified all patients treated with lithium in Denmark within community psychiatry, private specialist, and general practices and a random sample of 30% of the general population. Subjects A total of 16,238 persons who purchased lithium at least once and 1,487,177 persons from the general population who did not purchase lithium. Main Outcome Measure Diagnosis of dementia or Alzheimer disease during inpatient or outpatient hospital care.
Persons who purchased lithium at least once had an increased rate of dementia compared with persons not exposed to lithium (relative risk, 1.47; 95% confidence interval, 1.22-1.76). For persons who continued to take lithium, the rate of dementia decreased to the same level as the rate for the general population. The rate of dementia decreased early after the consumption of lithium tablets corresponding to 1 prescription (typically 100 tablets) and stayed at a low level, although with a slight increase according to the number of subsequent prescriptions. The association between the number of prescriptions for lithium and dementia was unique and different from the association between the number of prescriptions for anticonvulsants and dementia. All findings were replicated in subanalyses with Alzheimer disease as the outcome.
Continued lithium treatment was associated with reduction of the rate of dementia to the same level as that for the general population. Methodological reasons for this finding cannot be excluded, owing to the nonrandomized nature of data.
PubMed ID
18981345 View in PubMed
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Repeated events and total time on test.

https://arctichealth.org/en/permalink/ahliterature157947
Source
Stat Med. 2008 Aug 30;27(19):3817-32
Publication Type
Article
Date
Aug-30-2008
Author
Kajsa Kvist
Per Kragh Andersen
Jules Angst
Lars Vedel Kessing
Author Affiliation
Department of Biostatistics, University of Copenhagen, Copenhagen, Denmark. kakv@biostat.ku.dk
Source
Stat Med. 2008 Aug 30;27(19):3817-32
Date
Aug-30-2008
Language
English
Publication Type
Article
Keywords
Bias (epidemiology)
Computer simulation
Denmark - epidemiology
Female
Humans
Male
Models, Statistical
Mood Disorders - epidemiology
Proportional Hazards Models
Recurrence
Registries
Regression Analysis
Retrospective Studies
Statistics, nonparametric
Switzerland - epidemiology
Time Factors
Abstract
We adopt the total time on test procedure to investigate monotone time trends in the intensity in a repeated event setting. The correct model is assumed to be a proportional hazards model, with a random effect to account for dependence within subjects. The method offers a simple routine for testing relevant hypotheses for recurrent event processes, without making distributional assumptions about the frailty. Such assumptions may severely affect conclusions concerning regression coefficients and cause bias in the estimated heterogeneity. The method is illustrated by re-analyzing Danish registry data and a long-term Swiss clinical study on recurrence in affective disorder.
Notes
Cites: Stat Methods Med Res. 2002 Apr;11(2):141-6612040694
Cites: Eur Arch Psychiatry Clin Neurosci. 2003 Oct;253(5):236-4014504992
Cites: Acta Psychiatr Scand. 2004 May;109(5):339-4415049770
Cites: Biometrics. 2004 Sep;60(3):764-7315339300
Cites: Am J Epidemiol. 1999 Mar 1;149(5):404-1110067899
Cites: Br J Psychiatry. 2004 Nov;185:372-715516544
Cites: Stat Med. 2006 May 30;25(10):1672-8416252271
PubMed ID
18381708 View in PubMed
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Socioeconomic status and survival of cirrhosis patients: a Danish nationwide cohort study.

https://arctichealth.org/en/permalink/ahliterature150909
Source
BMC Gastroenterol. 2009;9:35
Publication Type
Article
Date
2009
Author
Peter Jepsen
Hendrik Vilstrup
Per Kragh Andersen
Henrik Toft Sørensen
Author Affiliation
Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark. pj@dce.au.dk.
Source
BMC Gastroenterol. 2009;9:35
Date
2009
Language
English
Publication Type
Article
Keywords
Cohort Studies
Denmark - epidemiology
Employment
Female
Humans
Income
Liver Cirrhosis - diagnosis - economics - mortality
Male
Marital status
Middle Aged
Prognosis
Regression Analysis
Social Class
Survival Rate
Abstract
Low socioeconomic status is a risk factor for liver cirrhosis, but it is unknown whether it is a prognostic factor after cirrhosis diagnosis. We examined whether marital status, employment, and personal income were associated with the survival of cirrhosis patients.
Using registry-data we conducted a population-based cohort study of 1,765 Danish cirrhosis patients diagnosed in 1999-2001 at age 45-59 years. Follow-up ended on 31 December 2003. With Cox regression we examined the associations between marital status (never married, divorced, married), employment (employed, disability pensioner, unemployed), personal income (0-49, 50-99, 100+ percent of the national average) and survival, controlling for gender, age, cirrhosis severity, comorbidity, and substance abuse.
Five-year survival was higher for married patients (48%) than for patients who never married (40%) or were divorced (34%), but after adjustment only divorced patients had poorer survival than married patients (adjusted hazard ratio for divorced vs. married = 1.22, 95% CI 1.04-1.42). Five-year survival was lower for disability pensioners (31%) than for employed (46%) or unemployed patients (48%), also after adjustment (adjusted hazard ratio for disability pensioners vs. employed = 1.35, 95% CI 1.09-1.66). Personal income was not associated with survival.
Marital status and employment were associated with the survival of cirrhosis patients. Specifically, divorced cirrhosis patients and cirrhosis patients who never married had a poorer survival than did married cirrhosis patients, and cirrhosis patients who were disability pensioners had a poorer survival than did employed or unemployed cirrhosis patients. The poorer survival for the divorced and for the disability pensioners could not be explained by differences in other socioeconomic factors, gender, age, cirrhosis severity, substance abuse, or comorbidity. Personal income was not associated with survival.
Notes
Cites: Science. 2000 Mar 31;287(5462):2398-910766613
Cites: Ann Intern Med. 2006 Jan 17;144(2):82-9316418407
Cites: Ugeskr Laeger. 2001 Dec 31;164(1):33-711810794
Cites: J Epidemiol Community Health. 2003 Dec;57(12):981-614652266
Cites: Alcohol Clin Exp Res. 2004 Jan;28(1):64-7714745303
Cites: Arch Intern Med. 2004 Jul 26;164(14):1514-815277281
Cites: Liver Int. 2004 Aug;24(4):277-8015287849
Cites: J Chronic Dis. 1987;40(5):373-833558716
Cites: Am J Public Health. 1989 Jan;79(1):52-62818707
Cites: Alcohol Clin Exp Res. 1995 Aug;19(4):984-917485850
Cites: J Med Syst. 1997 Feb;21(1):11-209172066
Cites: Stroke. 1998 Nov;29(11):2285-919804635
Cites: BMJ. 1999 May 29;318(7196):1460-710346775
Cites: Dan Med Bull. 1999 Jun;46(3):263-810421985
Cites: Med Care. 2005 Nov;43(11):1130-916224307
Cites: J Hepatol. 2006 Jan;44(1):217-3116298014
Cites: Int J Cardiol. 2006 Nov 10;113(2):181-716343668
Cites: J Addict Dis. 2006;25(4):49-5817088225
Cites: Drug Alcohol Rev. 2007 May;26(3):273-817454016
Cites: BMC Public Health. 2007;7:17217650304
Cites: Natl Vital Stat Rep. 2007 Nov 20;56(5):1-9518092547
Cites: Hepatology. 2008 Jul;48(1):214-2018537190
Cites: Eur J Cancer. 2008 Sep;44(14):2074-8518674895
Cites: Eur J Cancer. 2008 Sep;44(14):1938-4918684615
Cites: Int J Cancer. 2009 Jan 1;124(1):180-718844231
Cites: Soc Sci Med. 2001 Feb;52(3):357-6811330771
PubMed ID
19450284 View in PubMed
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8 records – page 1 of 1.