[show abstract][hide abstract] ABSTRACT: A substantial proportion of patients referred for plasma vitamin B12 (cobalamin [Cbl]) measurement present with high Cbl levels, which have been reported in patients with different cancer types. However, the cancer risk among patients with newly diagnosed high Cbl levels has not been adequately examined.
We conducted this cohort study using population-based Danish medical registries. Patients referred for Cbl measurement with levels greater than the lower reference limit (≥200 pmol/L) were identified from the population of Northern Denmark during the period of 1998 to 2009 using a database of laboratory test results covering the entire population. Data on cancer incidence (follow-up 1998-2010), Cbl treatment, and prior diagnoses were obtained from medical registries. Patients receiving Cbl treatment were excluded. Cancer risks were calculated as standardized incidence ratios (SIRs) with 95% confidence intervals (CIs), stratified by plasma Cbl levels. All statistical tests were two-sided.
We identified 333 667 persons without prevalent cancer and not receiving Cbl treatment. Six percent had Cbl levels greater than the upper reference limit (≥601 pmol/L). Cancer risk increased with higher Cbl levels and was highest during the first year of follow-up (Cbl 601-800 pmol/L: SIR = 3.44, 95% CI = 3.14 to 3.76; Cbl >800 pmol/L: SIR = 6.27, 95% CI = 5.70 to 6.88; both P < .001). The risks were particularly elevated for hematological and smoking- and alcohol-related cancers for persons with high Cbl levels.
High Cbl levels were associated with the risk of subsequently diagnosed cancer, mostly within the first year of follow-up. This may have clinical implications for the interpretation of high Cbl levels.
[show abstract][hide abstract] ABSTRACT: PURPOSETo estimate associations between use of β-blockers, angiotensin-converting enzyme (ACE) inhibitors, or angiotensin receptor blockers (ARBs) and breast cancer recurrence in a large Danish cohort. PATIENTS AND METHODS
We enrolled 18,733 women diagnosed with nonmetastatic breast cancer between 1996 and 2003. Patient, treatment, and 10-year recurrence data were ascertained from the Danish Breast Cancer Cooperative Group registry. Prescription and medical histories were ascertained by linkage to the National Prescription Registry and Registry of Patients, respectively. β-Blocker exposure was defined in aggregate and according to solubility, receptor selectivity, and individual drugs. ACE inhibitor and ARB exposures were defined in aggregate. Recurrence associations were estimated with multivariable Cox regression models in which time-varying drug exposures were lagged by 1 year.ResultsCompared with never users, users of any β-blocker had a lower recurrence hazard in unadjusted models (unadjusted hazard ratio [HR] = 0.91; 95% CI, 0.81 to 1.0) and a slightly higher recurrence hazard in adjusted models (adjusted HR = 1.3; 95% CI, 1.1 to 1.5). Associations were similar for exposures defined by receptor selectivity and solubility. Although most individual β-blockers showed no association with recurrence, metoprolol and sotalol were associated with increased recurrence rates (adjusted metoprolol HR = 1.5, 95% CI, 1.2 to 1.8; adjusted sotalol HR = 2.0, 95% CI, 0.99 to 4.0). ACE inhibitors were associated with a slightly increased recurrence hazard, whereas ARBs were not associated with recurrence (adjusted ACE inhibitor HR = 1.2, 95% CI, 0.97 to 1.4; adjusted ARBs HR = 1.1, 95% CI, 0.85 to 1.3). CONCLUSION
Our data do not support the hypothesis that β-blockers attenuate breast cancer recurrence risk.
Journal of Clinical Oncology 05/2013; · 18.04 Impact Factor
[show abstract][hide abstract] ABSTRACT: BACKGROUND: Colorectal cancer (CRC) is common, with surgery as the main curative treatment. The prevalence of chronic liver disease has increased, but knowledge is limited on postoperative mortality in patients with liver disease who undergo CRC surgery. Hence, we examined 30-day mortality after CRC surgery in patients with liver disease compared to those without liver disease. METHODS: We used medical databases to conduct a nationwide cohort study of all patients undergoing CRC surgery in Denmark from 1996 through 2009. We further identified patients diagnosed with any liver disease before CRC surgery and categorized them into two cohorts: patients with non-cirrhotic liver disease and patients with liver cirrhosis. Patients without liver disease were defined as the comparison cohort. Using the Kaplan-Meier method, we computed 30-day mortality after CRC surgery in each cohort. We used a Cox regression model to compute hazard ratios as measures of the relative risk (RR) of death, controlling for potential confounders including comorbidities. In order to examine the impact of liver disease in different subgroups, we stratified patients by gender, age, cancer stage, cancer site, timing of admission, type of surgery, comorbidity level, and non-hepatic alcohol-related disease. RESULTS: Overall, 39,840 patients underwent CRC surgery: 369 (0.9%) had non-cirrhotic liver disease and 158 (0.4 %) had liver cirrhosis. Thirty-day mortality after CRC surgery was 8.7% in patients without liver disease and 13.3% in patients with non-cirrhotic liver disease (adjusted RR of 1.49 (95% confidence interval (CI): 1.12-1.98)). Among patients with liver cirrhosis, mortality was 24.1%, corresponding to an adjusted RR of 2.59 (95% CI: 1.86-3.61). The negative impact of liver disease on postoperative mortality was found in all subgroups. CONCLUSIONS: Pre-existing liver disease was associated with a markedly increased 30-day mortality following CRC surgery.
[show abstract][hide abstract] ABSTRACT: BACKGROUND: Concerns have been raised about the risk of dementia associated with anti-estrogen adjuvant therapy in breast cancer, but study results have been inconsistent. We examined whether tamoxifen or other endocrine therapy was associated with dementia risk in a large population of breast cancer patients. METHODS: We used Danish nationwide medical registries to identify breast cancer patients diagnosed between 1990 and 2004, use of endocrine therapy and subsequent diagnoses of dementia. We used Cox regression to estimate the risk of dementia among patients who received five years of tamoxifen or other endocrine therapies. RESULTS: The study included 16,419 breast cancer patients. In this cohort, 37% were unexposed to endocrine therapy, 9% had five years of tamoxifen therapy and 54% had other endocrine regimens, some of them containing tamoxifen for less than five years with subsequent aromatase inhibitor therapy. Tamoxifen therapy was associated with a near-null risk of dementia (hazard ratio (HR): 1.4, 95% CI: 1.0, 1.9), and a null association was observed after death was taken into account as a competing risk (Sub-HR=1.0, 95%CI: 0.76, 1.4). CONCLUSIONS: No clinically relevant association between use of tamoxifen or other endocrine therapy and risk of dementia was observed.
Cancer Epidemiology Biomarkers & Prevention 04/2013; · 4.56 Impact Factor
[show abstract][hide abstract] ABSTRACT: IMPORTANCE Excess endogenous cortisol has been linked to venous thromboembolism (VTE) risk, but whether this relationship applies to exogenous glucocorticoids remains uncertain. Because the prevalence of glucocorticoid use and the incidence of VTE are high, an increased risk of VTE associated with glucocorticoid use would have important implications. BACKGROUND To examine the association between glucocorticoid use and VTE. DESIGN Population-based case-control study using nationwide databases. SETTING Denmark (population 5.6 million). PARTICIPANTS We identified 38 765 VTE cases diagnosed from January 1, 2005, through December 31, 2011, and 387 650 population controls included through risk-set sampling and matched by birth year and sex. The VTE diagnosis date for the case was the index date for cases and matched controls. EXPOSURE We classified individuals who filled their most recent glucocorticoid prescription 90 days or less, 91 to 365 days, and more than 365 days before the index date as present, recent, and former users, respectively. Present users were subdivided into new (first-ever prescription 90 days or less before the index date) and continuing users (others). MAIN OUTCOMES AND MEASURES We used conditional logistic regression adjusted for VTE risk factors to estimate incidence rate ratios (IRRs) and 95% CIs for glucocorticoid users vs nonusers. RESULTS Systemic glucocorticoids increased VTE risk among present (adjusted IRR, 2.31; 95% CI, 2.18-2.45), new (3.06; 2.77-3.38), continuing (2.02; 1.88-2.17), and recent (1.18; 1.10-1.26) users but not among former users (0.94; 0.90-0.99). The adjusted IRR increased from 1.00 (95% CI, 0.93-1.07) for a prednisolone-equivalent cumulative dose of 10 mg or less to 1.98 (1.78-2.20) for more than 1000 to 2000 mg, and to 1.60 (1.49-1.71) for doses higher than 2000 mg. New use of inhaled (adjusted IRR, 2.21; 95% CI, 1.72-2.86) and intestinal-acting (2.17; 1.27-3.71) glucocorticoids also increased VTE risk. CONCLUSIONS AND RELEVANCE The risk of VTE is increased among glucocorticoid users. Although residual confounding may partly explain this finding, we consider a biological mechanism likely because the association followed a clear temporal gradient, persisted after adjustment for indicators of severity of underlying disease, and existed also for noninflammatory conditions. Hence, our observations merit clinical attention.
[show abstract][hide abstract] ABSTRACT: X-linked hypohidrotic ectodermal dysplasia (XLHED) is characterized by hypohidrosis, sparse hair, and teeth abnormalities. Infants with XLHED have an increased risk of death by hyperpyrexia. XLHED is the most common form of hypohidrotic ectodermal dysplasia (HED); however, no population-based prevalence estimates are available. We aimed to: 1) estimate the prevalence of XLHED in the Danish population per January 1, 2011; 2) identify the most frequent age at time of diagnosis; and 3) quantify the most frequent clinical feature associated with XLHED. MATERIALS AND METHODS: We conducted a nationwide cross-sectional study (1995-2010). We leveraged national medical registries and data from clinical departments to categorize XLHED cases into three groups: 1) Molecularly-confirmed XLHED; 2) Clinically-diagnosed HED (registered with ICD-10 Q82.4); and 3) Possible HED (registered with sufficient clinical features based on a clinical algorithm that we designed). RESULTS: We identified 90 molecularly-confirmed XLHED, 146 clinically-diagnosed HED, and 988 possible HED cases between 1995 and 2010 (total n= 1224). The prevalence was 21.9 per 100,000 overall and 1.6 per 100,000 when restricting to molecularly-confirmed XLHED cases. The most frequent age at time of XLHED diagnosis occurred between the ages of 11-18 years. Teeth abnormalities occurred in 79% of all cases and 52% of molecularly-confirmed cases as a primary clinical marker. CONCLUSION: We present the first ever population-based prevalence estimates of XLHED and suggest that the prevalence of XLHED may be higher than previously estimated. Diagnosis occurs most frequently during adolescence and teeth abnormalities were the most frequent clinical marker of XLHED.
European journal of medical genetics 02/2013; · 1.57 Impact Factor
[show abstract][hide abstract] ABSTRACT: To develop and validate a case definition of eosinophilic esophagitis (EoE) in the linked Danish health registries.
For case definition development, we queried the Danish medical registries from 2006-2007 to identify candidate cases of EoE in Northern Denmark. All International Classification of Diseases-10 (ICD-10) and prescription codes were obtained, and archived pathology slides were obtained and re-reviewed to determine case status. We used an iterative process to select inclusion/exclusion codes, refine the case definition, and optimize sensitivity and specificity. We then re-queried the registries from 2008-2009 to yield a validation set. The case definition algorithm was applied, and sensitivity and specificity were calculated.
Of the 51 and 49 candidate cases identified in both the development and validation sets, 21 and 24 had EoE, respectively. Characteristics of EoE cases in the development set [mean age 35 years; 76% male; 86% dysphagia; 103 eosinophils per high-power field (eos/hpf)] were similar to those in the validation set (mean age 42 years; 83% male; 67% dysphagia; 77 eos/hpf). Re-review of archived slides confirmed that the pathology coding for esophageal eosinophilia was correct in greater than 90% of cases. Two registry-based case algorithms based on pathology, ICD-10, and pharmacy codes were successfully generated in the development set, one that was sensitive (90%) and one that was specific (97%). When these algorithms were applied to the validation set, they remained sensitive (88%) and specific (96%).
Two registry-based definitions, one highly sensitive and one highly specific, were developed and validated for the linked Danish national health databases, making future population-based studies feasible.
World Journal of Gastroenterology 01/2013; 19(4):503-10. · 2.55 Impact Factor
[show abstract][hide abstract] ABSTRACT: Enlarged lymph nodes may be a marker of occult cancer, but accurate data on cancer risk are limited. We used population-based Danish medical registries to assess cancer risk in a cohort of patients with a first-time inpatient or outpatient hospital contact for enlarged lymph nodes during 1994-2008. Observed cancer incidences were compared with that expected in the general population. We observed 1750 cancers among 11 284 patients with enlarged lymph nodes during median follow up of 4·7 years. Only 389 cases were expected. Cancer risk was 11·5% [95% confidence interval (CI): 10·9-12·1%] during the first year of follow up, corresponding to an age- and sex-standardized incidence ratio (SIR) of 21·1 (95% CI: 20·0-22·3). One-year SIRs were more than 100 times increased for head and neck cancer and lymphomas. Beyond one year of follow up, overall cancer risk remained 1·4-fold (95% CI: 1·3-1·5-fold) higher than expected, while risk of lymphoma remained six to 10 times higher. Cancer risk was also elevated among patients with other conditions known to be associated with enlarged lymph nodes, such as infections and rheumatic disorders. We conclude that enlarged lymph nodes are a marker of occult cancer and long-term risk of cancer.
British Journal of Haematology 12/2012; · 4.94 Impact Factor
[show abstract][hide abstract] ABSTRACT: Clin Microbiol Infect 2012; 18: 963-969 ABSTRACT: Seasonal variation in occurrence is a common feature of many diseases, especially those of infectious origin. Studies of seasonal variation contribute to healthcare planning and to the understanding of the aetiology of infections. In this article, we provide an overview of statistical methods for the assessment and quantification of seasonality of infectious diseases, as exemplified by their application to meningococcal disease in Denmark in 1995-2011. Additionally, we discuss the conditions under which seasonality should be considered as a covariate in studies of infectious diseases. The methods considered range from the simplest comparison of disease occurrence between the extremes of summer and winter, through modelling of the intensity of seasonal patterns by use of a sine curve, to more advanced generalized linear models. All three classes of method have advantages and disadvantages. The choice among analytical approaches should ideally reflect the research question of interest. Simple methods are compelling, but may overlook important seasonal peaks that would have been identified if more advanced methods had been applied. For most studies, we suggest the use of methods that allow estimation of the magnitude and timing of seasonal peaks and valleys, ideally with a measure of the intensity of seasonality, such as the peak-to-low ratio. Seasonality may be a confounder in studies of infectious disease occurrence when it fulfils the three primary criteria for being a confounder, i.e. when both the disease occurrence and the exposure vary seasonally without seasonality being a step in the causal pathway. In these situations, confounding by seasonality should be controlled as for any confounder.
Clinical Microbiology and Infection 06/2012; 18(10):963-9. · 4.58 Impact Factor
[show abstract][hide abstract] ABSTRACT: OBJECTIVES: To examine the familial risk of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), including juvenile rheumatoid/idiopathic arthritis (JRA), in a population-based setting; and to determine whether patterns of transmission differ according to the sex of the parent or offspring, in order to provide insight into the potential impact of X-chromosomal factors on sex disparities in these autoimmune diseases.METHODS: A population-based cohort of parent-offspring triads from Denmark (1977-2010) was established. SLE and RA incidence rates among offspring were calculated, and Cox regression was performed to assess the sex-specific risk of disease in offspring according to maternal or paternal disease history.RESULTS: Among 3 513 817 parent-offspring triads, there were 1258 SLE cases among offspring (1095 female, 163 male) and 9118 cases of RA/JRA (6086 female, 3032 male). Among female offspring, SLE risk was nearly the same according to maternal (HR 14.1) or paternal (HR 14.5) history (p=NS); likewise among male offspring, risk according to maternal (HR 5.5) and paternal (no cases) history were similar (p=NS). For RA, all risk estimates were similar, regardless of the sex of the offspring or parent (HR 2.6-2.9; p=NS).CONCLUSIONS: The authors quantified the familial risk of SLE and RA in a nationwide cohort study. For both diseases, transmission was comparable among both female and male offspring of maternal and paternal cases. These data provide evidence at the population level that X-chromosomal factors do not play a major role in sex disparities associated with the risk of SLE and RA.
Annals of the rheumatic diseases 05/2012; · 8.11 Impact Factor
[show abstract][hide abstract] ABSTRACT: Proton pump inhibitors (PPIs) are increasingly used in reflux disease treatment also among pregnant women. Hypospadias prevalence is increasing and the birth defect is diagnosed in 0.3%-0.8% of male births, but the association with maternal PPI use during pregnancy is virtually unknown. Therefore, we decided to estimate the hypospadias risk in male offspring after maternal PPI use during pregnancy. We used Danish nationwide registries to conduct a population-based prevalence study including all live-born boys from 1997 through 2009. Maternal PPI use was classified according to exposure time: early pregnancy (30 days before conception through the end of the first trimester) and entire pregnancy (30 days before and throughout pregnancy). Outcome was defined as a hospital hypospadias diagnosis recorded any time after delivery. We calculated prevalence ratios and 95% confidence intervals associating maternal PPI use with hypospadias in male offspring using Cox proportional hazard regression analysis and adjusted for confounding factors. We identified a total of 430,569 live-born boys of whom 2926 were exposed to maternal PPI use during early pregnancy. Among the exposed boys, 20 (0.7%) were diagnosed with hypospadias, whereas 2683 (0.6%) of the nonexposed had hypospadias (adjusted prevalence ratio = 1.1; 95% confidence interval, 0.7-1.7). A total of 5227 boys were exposed during the entire pregnancy, and 32 (0.6%) had hypospadias corresponding to a prevalence ratio of 1.0 (95% confidence interval, 0.7-1.4). The subanalysis restricted to omeprazole exposure showed similar results. We thus conclude that maternal PPI use during pregnancy was not associated with hypospadias in boy offspring.
American journal of therapeutics 02/2012; · 1.29 Impact Factor
[show abstract][hide abstract] ABSTRACT: Glucocorticoids are widely prescribed drugs. In the human body, glucocorticoid is the main stress hormone and controls a variety of physiological and cellular processes, including metabolism and immune response. It belongs to the same steroid superfamily as estrogens, which are known to play a role in breast cancer. However, the effect of glucocorticoid use on the risk of breast cancer is not clear.
We conducted a case-control study using population-based medical databases from Northern Denmark (1.8 million inhabitants) to investigate the association between glucocorticoid prescriptions and breast cancer risk. The study included 9,488 incident breast cancer cases diagnosed between 1994 and 2008 and 94,876 population controls. We estimated the odds ratios (ORs) and 95% confidence intervals (CIs) associating glucocorticoid use with breast cancer occurrence, controlling for prescriptions of postmenopausal hormone replacement therapy, anti-diabetics, immunosuppressive drugs, and hospital diagnosis of obesity, diabetes, chronic pulmonary diseases and autoimmune diseases.
We found no effect on breast cancer risk in ever users (> 2 prescriptions) of any glucocorticoids (adjusted odds ratio (aOR) = 1.0; 95% CI: 0.96, 1.1), systemic glucocorticoids (aOR = 1.0; 95% CI: 0.96, 1.1), or inhaled glucocorticoids (aOR = 1.0; 95% CI: 0.95, 1.1), each compared to never users of any glucocorticoids. Associations for recent use (preceding two years) and former use (more than two years earlier) were near null in all dose categories (low, medium and high number of prescriptions). Intensity of systemic glucocorticoid use (cumulative prednisolone equivalent doses), regardless of duration (< 1, 1 to 5, 5+ years), was also not associated with breast cancer risk.
Overall, our study provides no evidence that glucocorticoid use affects the risk of breast cancer.
Breast cancer research: BCR 02/2012; 14(1):R21. · 5.87 Impact Factor
[show abstract][hide abstract] ABSTRACT: Multiple sclerosis (MS) patients may be at increased risk of venous thromboembolism (VTE), but evidence is limited.
To examine long-term risk of VTE among MS patients.
We conducted a population-based cohort study among 17,418 Danish MS patients and 87,090 comparison cohort members from the general population. Data on MS, VTE and comorbidities were obtained from the Danish National Registry of Patients including all admissions to Danish hospitals since 1977. We computed cumulative risks for VTE and adjusted incidence rate ratios (IRRs).
A total of 34 (0.2%) MS patients and 36 (0.04%) comparison cohort members had a deep venous thrombosis (DVT) within 1 year following the date of initial MS diagnosis/index date [adjusted IRR = 3.02 (95% CI: 2.14-4.27)]. During this period, 16 (0.09%) MS patients and 26 (0.03%) comparison cohort members had a documented pulmonary embolism (PE) [adjusted IRR = 2.85 (95% CI: 1.72-4.70)]. During the subsequent up to 29 years, 315 (1.9% of MS patients alive at year 1) MS patients had a record of a DVT [adjusted IRR = 2.28 (95% CI: 2.01-2.59)] and 129 (0.8%) had PE [IRR = 1.58 (95% CI: 1.31-1.92].
MS is a risk factor for VTE, but the absolute risk is low.
[show abstract][hide abstract] ABSTRACT: Gastroesophageal reflux disease is a strong risk factor for esophageal adenocarcinoma, but it is not clear whether the mucosal inflammation that develops in patients with reflux disease promotes this cancer. We determined the development of adenocarcinoma among patients who underwent esophagogastroduodenoscopy and were found to have erosive (with esophagitis) or nonerosive (without esophagitis) reflux.
We performed a nationwide cohort study using data from 33,849 patients with reflux disease (52% men; median age, 59.3 y) from population-based Danish medical registries, from 1996 through 2008. The observed incidences of adenocarcinoma were compared with the expected incidence for the general population, standardized by age, sex, and calendar time. Absolute risks were estimated using Kaplan-Meier methods.
In the study cohort, 26,194 of the patients (77%) had erosive reflux disease and 37 subsequently developed esophageal adenocarcinoma after a mean follow-up time of 7.4 years. Their absolute risk after 10 years was 0.24% (95% confidence interval [CI], 0.15%-0.32%). The incidence of cancer among patients with erosive reflux disease was significantly greater than that expected for the general population (standardized incidence ratio, 2.2; 95% CI, 1.6-3.0). In contrast, of the 7655 patients with nonerosive reflux disease, only 1 was diagnosed with esophageal adenocarcinoma after 4.5 years of follow-up evaluation (standardized incidence ratio, 0.3; 95% CI, 0.01-1.5).
Erosive reflux disease, but not nonerosive disease, increased the risk of esophageal adenocarcinoma, based on analysis of population-based Danish medical registries. Inflammation therefore might be an important factor in the progression from reflux to esophageal adenocarcinoma.
Clinical gastroenterology and hepatology: the official clinical practice journal of the American Gastroenterological Association 01/2012; 10(5):475-80.e1. · 5.64 Impact Factor
[show abstract][hide abstract] ABSTRACT: Alcoholic patients comprise a large proportion of patients in intensive care units (ICUs). However, data are limited on the impact of alcoholism on mortality after intensive care.
We conducted a cohort study among 16,848 first-time ICU patients between 2001 and 2007 to examine 30-day and 3-year mortality among alcoholic patients. Alcoholic patients with and without complications of alcohol misuse (for example, alcoholic liver disease) were identified from previous hospital contacts for alcoholism-related conditions or redemption of a prescription for alcohol deterrents. Data on medication use, demographics, hospital diagnoses, and comorbidity were obtained from medical databases. We computed 30-day and 3-year mortality and mortality rate ratios (MRRs) by using Cox regression analysis, controlling for covariates.
In total, 1,229 (7.3%) ICU patients were current alcoholics. Among alcoholic patients without complications of alcoholism (n=785, 4.7% of the cohort), 30-day mortality was 15.9% compared with 19.7% among nonalcoholic patients. Compared with nonalcoholic patients, the adjusted 30-day MRR was 1.04 (95% confidence interval (CI), 0.87 to 1.25). Three-year mortality was 36.2% compared with 40.9% among nonalcoholic patients, corresponding to an adjusted 3-year MRR of 1.16 (95% CI, 1.03 to 1.31). For alcoholic patients with complications (n=444, 2.6% of the cohort), 30-day mortality was 33.6%, and 3-year mortality was 64.5%, corresponding to adjusted MRRs, with nonalcoholics as the comparator, of 1.64 (95% CI, 1.38 to 1.95) and 1.67 (95% CI, 1.48 to 1.90), respectively.
Alcoholic ICU patients with chronic complications of alcoholism have substantially increased 30-day and 3-year mortality. In contrast, alcoholics without complications have no increased 30-day and only slightly increased 3- year mortality.
Critical care (London, England) 01/2012; 16(1):R5. · 4.72 Impact Factor
[show abstract][hide abstract] ABSTRACT: Epidemiologic studies often rely on drug dispensation records to measure medication intake. We aimed to estimate correspondence between general practitioner (GP)-reported treatment and timing of prescription dispensation. From seven GPs in northern Denmark, we obtained 317 prescription records for 286 patients treated with ten commonly prescribed medication types for chronic diseases. We linked the GP-reported information to the regional prescription database to retrieve patients' prescription records both prospectively and retrospectively in relation to the GP-reported date of treatment (index date, August 20, 2008 for all patients). We computed overall and medication-specific correspondence between GP-reported treatment and the timing of dispensation. We computed correspondence based on both exact medication and therapeutic subgroup agreement. The correspondence for dispensation within ±90 days of GP-reported treatment was 0.81 (95% confidence interval = 0.76-0.85) with variation by medication type, ranging from 0.55 for ACE-inhibitors to 1.00 for oral glucose-lowering agents. The correspondence was greater when analyzed within therapeutic groups than when analyzed for exact medications within these groups.
[show abstract][hide abstract] ABSTRACT: The Danish health care system provides partial reimbursement of most prescription medications in Denmark. The dispensation of prescription medications is registered in administrative databases. Each time a prescription is redeemed at a pharmacy, an electronic record is generated with information related to the user, prescriber, the pharmacy, and the dispensed drug. The National Health Service gathers this information for administration of the drug reimbursement plan. Recently, this information became the basis for the establishment of a new research database, the Danish National Database of Reimbursed Prescriptions (DNDRP). In this paper, we review the content, coverage, quality, linkage, access, and research possibilities of this new database. The database encompasses the reimbursement records of all reimbursed drugs sold in community pharmacies and hospital-based outpatient pharmacies in Denmark since 2004. On average, approximately 3.5 million users are recorded in the database each year. During the coverage period, the number of annual prescription redemptions increased by 15%. Most dispensed prescriptions are in the categories "alimentary tract and metabolism", "cardiovascular system", "nervous system", and "respiratory system". Individuals are identified by the unique central personal registration (CPR) number assigned to all persons born in or immigrating to Denmark. The new database fully complies with Denmark's Act on Processing of Personal Data, while avoiding additional restrictions imposed on data use at the Danish National Prescription Registry, administered by Statistics Denmark. Most importantly, CPR numbers are reversibly encrypted, which allows re-identification of drug users; furthermore, the data access is possible outside the servers of Statistics Denmark. These features open additional opportunities for international collaboration, validation studies, studies on adverse drug effects requiring review of medical records, studies involving contact to general practitioners, and linkage of prescription data to other clinical and research databases. The DNDRP thus is a valuable data source for pharmacoepidemiological research.
[show abstract][hide abstract] ABSTRACT: This paper provides an overview of the baseline data collected in the nationwide Danish Centre for Strategic Research in Type 2 Diabetes (DD2) project. The paper presents descriptive data from the first 580 patients enrolled in the DD2. The DD2 database will contain detailed interview data, clinical examination data, and urine and blood samples from up to 10,000 patients newly diagnosed with type 2 diabetes each year, collected from general practitioners and hospital outpatient clinics in all of Denmark. Of the first DD2 patients enrolled, blood and urine samples have been obtained from 97%. The median age of the first 580 patients was 59 years and 322 (56%) were men. Median weight gain from age 20 to maximum lifetime weight was 29 kg for men and 31 kg for women, and 364 patients (63%) did not currently participate in regular sports activities. Two hundred and ninety two patients (50%) had a known family history of diabetes. Two hundred fifty (43%) of the 580 DD2 patients have also been enrolled in the Danish Diabetes Database for Adults from which additional clinical data can be obtained. Among these 250 patients (154 of whom were men, 96 women), 75 (49%) men were currently obese, and 63 (41%) were overweight, whereas 62 (65%) women were obese, and another 21 (22%) were overweight. Twenty-nine patients (12%) received insulin, 164 patients (66%) received oral antidiabetics only, and 57 (23%) received no antidiabetic treatment. Glycemic regulation was modest (the glycosylated hemoglobin A of 46% was ≥7.5%). Two thirds of the patients received antihypertensive and hypolipidemic treatment. Self-reported daily tobacco smoking (23%) and alcohol overuse (6%) seemed comparable to occurrence in the general Danish population. One quarter of the patients with newly diagnosed diabetes had a history of hospital-diagnosed comorbidity at baseline as included in the Charlson comorbidity index, in particular prior myocardial infarction (5%), cerebrovascular disease (5%), peripheral vascular disease (4%), chronic pulmonary disease (6%), and previous solid cancer (6%). In the future, the DD2 database represents a valuable source for outcome studies in type 2 diabetes.
[show abstract][hide abstract] ABSTRACT: In contrast to deep venous thrombosis and pulmonary embolism, superficial venous thrombosis has not been considered to be a marker of occult cancer. However, actual data regarding the association are very limited.
We identified all patients in Denmark from 1994 to 2009 with a diagnosis of superficial venous thrombosis, deep venous thrombosis in the legs or pulmonary embolism using population-based health registries. The occurrence of cancer in the three venous thromboembolism cohorts was compared with the expected numbers of cases estimated using national incidence rates to compute standardised incidence ratios (SIRs).
We identified a total of 7663 patients with superficial venous thrombosis, 45,252 with deep venous thrombosis and 24,332 with pulmonary embolism. In the first year of follow-up, very similar proportions of patients in the three cohorts were diagnosed with cancer. The SIR was 2.46 (95% CI, 2.10-2.86) for superficial venous thrombosis, 2.75 (95% CI, 2.60-2.90) for deep venous thrombosis, and 3.27 (95% CI, 3.03-3.52) for pulmonary embolism. After one year, the SIRs declined to 1.05 (95% CI, 0.96-1.16), 1.11 (95% CI 1.07-1.16) and 1.15 (95% CI, 1.09-1.22), respectively. For all three patient cohorts, particularly strong associations were found for cancers of the liver, lung, ovaries and pancreas as well as for non-Hodgkin's lymphoma.
Venous thrombosis, whenever it is seen in the lower limbs, is a preclinical marker of prevalent cancer, particularly during the first year after diagnosis.
European journal of cancer (Oxford, England: 1990) 11/2011; 48(4):586-93. · 4.12 Impact Factor