Showing papers by "Anders H. Riis published in 2010"
TL;DR: The results confirm previous studies showing reduced fertility in overweight and obese women, and the association between underweight and fecundability varied by parity.
Abstract: BACKGROUND: Recent studies have shown that both female and male obesity may delay time-to-pregnancy (TTP). Little is known about central adiposity or weight gain and fecundability in women. METHODS: We examined the association between anthropometric factors and TTP among I65I Danish women participating in an inter-net-based prospective cohort study of pregnancy planners (2007―2008). We categorized body mass index (BMI = kg/m 2 ) as underweight (<20), normal weight (20-24), overweight (25-29), obese (30-34) and very obese (≥35). We used discrete-time Cox regression to estimate fecundability ratios (FRs) and 95% confidence intervals (CI), controlling for potential confounders. RESULTS: We found longer TTPs for overweight (FR = 0.83, 95% CI = 0.70―I.00), obese (FR = 0.75, 95% CI = 0.58-0.97), and very obese (FR = 0.61, 95% CI = 0.42―0.88) women, compared with normal weight women. After further control for waist circumference, FRs for overweight, obese, and very obese women were 0.72 (95% CI = 0.58―0.90), 0.60 (95% CI = 0.42-0.85) and 0.48 (95% CI = 0.3I-0.74), respectively. Underweight was associated with reduced fecundability among nulliparous women (FR = 0.82, 95% CI = 0.63- I.06) and increased fecundability among parous women (FR = 1.61, 95% CI = 1.08-2.39). Male BMI was not materially associated with TTP after control for female BMI. Compared with women who maintained a stable weight since age I7 (―5 to 4 kg), women who gained ≥ 15 kg had longer TTPs (FR = 0.72, 95% CI = 0.59-0.88) after adjustment for BMI at age I7. Associations of waist circumference and waist-to-hip ratio with TTP depended on adjustment for female BMI: null associations were observed before adjustment for BMI and weakly positive associations were observed after adjustment for BMI. CONCLUSIONS: Our results confirm previous studies showing reduced fertility in overweight and obese women. The association between underweight and fecundability varied by parity.
216 citations
TL;DR: NTM disease incidence has remained unchanged in Denmark over the past 12 years and negative prognostic factors include high levels of comorbidity, advanced age, male sex, and M. xenopi.
Abstract: Rationale: Few population-based data are available regarding nontuberculous mycobacteria (NTM) pulmonary disease epidemiology and prognosis.Objectives: To examine NTM pulmonary colonization incidence, disease incidence, and prognostic factors.Methods: All adults in Denmark with at least one NTM-positive pulmonary specimen during 1997 to 2008 were identified using national medical databases and were categorized as having possible or definite NTM disease or colonization.Measurements and Main Results: We calculated annual age-standardized NTM incidence rates and adjusted hazard ratios (HR) of death associated with patient age, sex, comorbidity, NTM species, and NTM disease status. Of 1,282 adults with 2,666 NTM-positive pulmonary specimens, 335 (26%) had definite NTM disease, 238 (19%) possible disease, and 709 (55%) colonization only. NTM incidence rates decreased until 2002, followed by an increase from 2003 to 2008 (mean annual rate per 100,000 person-years: NTM colonization, 1.36; NTM disease, 1.08). Fiv...
216 citations
TL;DR: Several categories of THA patients had a higher risk of revision due to infection within the total follow-up time, and more attention should be paid by clinicians to infection prevention strategies in patients with THA, particularly those with increased risk.
Abstract: Background and purpose There has been a limited amount of research on risk factors for revision due to infection following total hip arthroplasty (THA), probably due to low absolute numbers of revisions. We therefore studied patient- and surgery-related risk factors for revision due to infection after primary THA in a population-based setting.Materials and methods Using the Danish Hip Arthroplasty Registry, we identified 80,756 primary THAs performed in Denmark between Jan 1, 1995 and Dec 31, 2008. We used Cox regression analysis to compute crude and adjusted relative risk (RR) of revision due to infection. Revision was defined as extraction or exchange of any component due to infection. The median follow-up time was 5 (0–14) years.Results 597 primary THAs (0.7%) were revised due to infection. Males, patients with any co-morbidity, patients operated due to non-traumatic avascular femoral head necrosis, and patients with long duration of surgery had an increased RR of revision due to infection within the t...
131 citations
TL;DR: The aim of the study was to examine whether exposure to abacavir increases the risk for myocardial infarction and to investigate the mechanism behind this risk increase.
Abstract: Objective
The aim of the study was to examine whether exposure to abacavir increases the risk for myocardial infarction (MI).
Design, setting and subjects
This was a prospective nationwide cohort study which included all Danish HIV-infected patients on highly active antiretroviral therapy (HAART) from 1995 to 2005 (N=2952). Data on hospitalization for MI and comorbidity were obtained from Danish medical databases. Hospitalization rates for MI after HAART initiation were calculated for patients who used abacavir and those who did not. We used Cox's regression to compute incidence rate ratios (IRR) as a measure of relative risk for MI, while controlling for potential confounders (as separate variables and via propensity score) including comorbidity.
Main outcome
Relative risk of hospitalization with MI in abacavir users compared with abacavir nonusers.
Results
Hospitalization rates for MI were 2.4/1000 person-years (PYR) [95% confidence interval (CI) 1.7–3.4] for abacavir nonusers and 5.7/1000 PYR (95% CI 4.1–7.9) for abacavir users. The risk of MI increased after initiation of abacavir [unadjusted IRR=2.22 (95% CI 1.31–3.76); IRR adjusted for confounders=2.00 (95% CI 1.10–3.64); IRR adjusted for propensity score=2.00 (95% CI 1.07–3.76)]. This effect was also observed among patients initiating abacavir within 2 years after the start of HAART and among patients who started abacavir as part of a triple nucleoside reverse transcriptase inhibitor (NRTI) regimen.
Conclusions
We confirmed the association between abacavir use and increased risk of MI. Further studies are needed to control for potential confounding not measured in research to date.
129 citations
TL;DR: Risk of venous thromboembolism in splenectomization patients compared with the general population and appendectomized patients: a 10-year nationwide cohort study.
95 citations
TL;DR: The successful conduct of this pilot study suggests that the internet may be a useful tool to recruit and follow subjects in prospective cohort studies.
Abstract: The attraction of being able to use the internet for the recruitment of an epidemiologic cohort stems mainly from cost efficiency and convenience. The pregnancy planning study (‘Snart-Gravid’)—a prospective cohort study of Danish women planning a pregnancy—was conducted to evaluate the feasibility and cost efficiency of using internet-based recruitment and follow-up. Feasibility was assessed by examining patient accrual data over time, questionnaire-specific response rates and losses to follow-up. The relative cost efficiency was examined by comparing the study costs with those of an alternative non internet-based study approach. The target recruitment of 2,500 participants over 6 months was achieved using advertisements on a health-related website, supported by a coordinated media strategy at study initiation. Questionnaire cycle-specific response rates ranged from 87 to 90% over the 12-month follow-up. At 6 months, 87% of women had a known outcome or were still under follow-up; at 12 months the figure was 82%. The study cost of $400,000 ($160 per enrolled subject) compared favorably with the estimated cost to conduct the same study using a conventional non-internet based approach ($322 per subject). The gain in efficiency with the internet-based approach appeared to be even more substantial with longer follow-up and larger study sizes. The successful conduct of this pilot study suggests that the internet may be a useful tool to recruit and follow subjects in prospective cohort studies.
80 citations
15 Jun 2010
TL;DR: In this article, the authors examined the association between anthropometric factors and TTP among I65I Danish women participating in an inter-net-based prospective cohort study of pregnancy planners (2007―2008).
Abstract: BACKGROUND: Recent studies have shown that both female and male obesity may delay time-to-pregnancy (TTP). Little is known about central adiposity or weight gain and fecundability in women. METHODS: We examined the association between anthropometric factors and TTP among I65I Danish women participating in an inter-net-based prospective cohort study of pregnancy planners (2007―2008). We categorized body mass index (BMI = kg/m 2 ) as underweight (<20), normal weight (20-24), overweight (25-29), obese (30-34) and very obese (≥35). We used discrete-time Cox regression to estimate fecundability ratios (FRs) and 95% confidence intervals (CI), controlling for potential confounders. RESULTS: We found longer TTPs for overweight (FR = 0.83, 95% CI = 0.70―I.00), obese (FR = 0.75, 95% CI = 0.58-0.97), and very obese (FR = 0.61, 95% CI = 0.42―0.88) women, compared with normal weight women. After further control for waist circumference, FRs for overweight, obese, and very obese women were 0.72 (95% CI = 0.58―0.90), 0.60 (95% CI = 0.42-0.85) and 0.48 (95% CI = 0.3I-0.74), respectively. Underweight was associated with reduced fecundability among nulliparous women (FR = 0.82, 95% CI = 0.63- I.06) and increased fecundability among parous women (FR = 1.61, 95% CI = 1.08-2.39). Male BMI was not materially associated with TTP after control for female BMI. Compared with women who maintained a stable weight since age I7 (―5 to 4 kg), women who gained ≥ 15 kg had longer TTPs (FR = 0.72, 95% CI = 0.59-0.88) after adjustment for BMI at age I7. Associations of waist circumference and waist-to-hip ratio with TTP depended on adjustment for female BMI: null associations were observed before adjustment for BMI and weakly positive associations were observed after adjustment for BMI. CONCLUSIONS: Our results confirm previous studies showing reduced fertility in overweight and obese women. The association between underweight and fecundability varied by parity.
49 citations
TL;DR: The overall survival of primary THAs in RA patients is similar to THA survival in OA patients, while survival of the total THA concept did not show any statistically significant differences between the two groups.
Abstract: Background and purpose There has been a limited amount of research on survival of total hip arthroplasties (THAs) in rheumatoid arthritis (RA). We therefore performed a population-based, nationwide study to compare the survival of primary THAs in RA patients and in osteoarthritis (OA) patients. We also wanted to identify predictors of THA failure in RA patients.Methods Using the Danish Hip Arthroplasty Registry, we identified 1,661 primary THAs in RA patients and 64,858 in OA patients, all of which were inserted between 1995 and 2008. The follow-up period was up to 14 years for both groups.Results Regarding overall THA survival, the adjusted RR for RA patients compared to OA patients was 0.81 (95% CI: 0.65–1.01). We found no difference in survival of cups between primary THAs in RA and OA patients. In contrast, there was better overall survival of stems in RA patients than in OA patients, both regarding revision due to aseptic loosening (adjusted RR = 0.58; 95% CI: 0.34–0.99) and for any reason (adjusted ...
48 citations
TL;DR: The adjusted short- and long-term risk of death for splenectomised patients was higher than the general population, and most of this risk seems to be due to the underlyingsplenectomy indication and not to splenectomy alone.
39 citations
TL;DR: Any risk of amyotrophic lateral sclerosis associated with statin use probably is small, so outweighed by the important clinical advantages of statin medications to prevent and treat cardiovascular diseases.
Abstract: Background Use of statins has been associated with an amyotrophic lateral sclerosis-like syndrome in 2 analyses of overlapping surveillance databases that record adverse events potentially related to prescription drug use. We assessed whether statin use is associated with the occurrence of amyotrophic lateral sclerosis and other motor neuron disorders. Methods and Results We conducted a population-based case-control study in Northern Denmark, with a population of 1.8 million. From the Danish National Registry of Patients, we identified incident cases coded with amyotrophic lateral sclerosis or other motor neuron syndromes during the period from 1999 to 2008. We selected 10 population control subjects matched to cases on sex, birth year, and calendar time. Statin use was ascertained in the prescription database in the region—and so recorded before diagnosis—and associated with disease occurrence by conditional logistic regression adjusting for covariates. We identified 556 cases of amyotrophic lateral sclerosis or other motor neuron syndromes and 5560 population control subjects. The odds ratio associating disease occurrence with statin use was 0.96 (95% confidence interval, 0.73 to 1.28). Recent users of statins, former users, and users of short or long duration had similarly near-null associations. Conclusions Any risk of amyotrophic lateral sclerosis associated with statin use probably is small, so outweighed by the important clinical advantages of statin medications to prevent and treat cardiovascular diseases.
36 citations
TL;DR: Although there is a weak inverse association between ever use of statins and CRC incidence, there was no trend with increasing duration of use, so statins do not appear to reduce CRC risk.
TL;DR: Preadmission use of systemic glucocorticoids was associated with increased 30-day mortality following PUB, and increased mortality was most pronounced when glucoc Corticoids were used in high doses or were combined with other ulcer-related drugs.
Abstract: Systemic glucocorticoid use is associated with an increased risk for peptic ulcer bleeding (PUB); however, little is known about whether glucocorticoid use is associated with PUB outcome. We conducted a population-based cohort study to examine the association between preadmission use of systemic glucocorticoids and 30-day mortality following PUB. We identified all patients (n = 7,486) hospitalized with a first-time diagnosis of PUB in Western Denmark between 1991 and 2004. Data on PUB; systemic glucocorticoid use (n = 574; 7.7%), including cumulative dose; use of other ulcer-related drugs; previous uncomplicated ulcer; comorbidities; and complete follow-up for mortality were obtained from population-based medical databases. We computed 30-day mortality and mortality rate ratios (MRRs) comparing glucocorticoid users and nonusers, controlling for potential confounding factors. Thirty-day mortality was 14.0% among users of systemic glucocorticoids and no other ulcer-related drugs and 8.7% among nonusers of glucocorticoids, corresponding to an adjusted MRR of 1.30 (95% confidence interval [CI], 0.81-2.08). Among users of systemic glucocorticoids in combination with other ulcer-related drugs, 30-day mortality was 18.9%, corresponding to an adjusted MRR of 1.54 (95% CI, 1.20-1.99). Among both short-term and long-term users, high-dose glucocorticoid use was associated with a greater increase in mortality than low-dose use. Former use of systemic glucocorticoids was not associated with increased mortality. Thus, preadmission use of systemic glucocorticoids was associated with increased 30-day mortality following PUB. Increased mortality was most pronounced when glucocorticoids were used in high doses or were combined with other ulcer-related drugs.