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In this article a Bayesian hierarchical model (BHM) for observed monthly precipitation is proposed. This BHM incorporates covariates based on an output on a fine grid from a regional meteorological model. At the data level of the BHM, the observed monthly precipitation is transformed using the Box-Cox transformation, and each month is modeled separately. To capture spatial correlation at the data level, a Gaussian field with Matérn correlation function is used. It is assumed that the data are subject to measurement error. The location and log-scale parameters at the latent level are also modeled with Gaussian fields with Matérn correlation functions. An output from a regional meteorological model on a fine grid is used to construct spatial covariates for the latent parameters of the BHM for each month of the year. These covariates are then projected onto each of the observed sites for each month and incorporated into the BHM. Markov chain Monte Carlo simulation is used for posterior inference and Bayesian kriging is used to predict the latent parameters on the grid. This BHM was applied to observed data on monthly precipitation, which come from forty sites across Iceland from the years 1958 to 2006. The data were corrected for wind, wetting, and evaporation loss. An output from a linear model of orographic precipitation defined on a 1 km by 1 km grid over Iceland was used to construct the covariates for the BHM. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Discharge in rivers is commonly estimated by the use of a rating curve constructed from pairs of measured water elevations and discharges at a specific location. The Bayesian approach has been successfully applied to estimate discharge rating curves that are based on the standard power-law. In this paper the standard power-law model is extended by adding a B-spline function. The extended model is compared to the standard power-law model by applying the models to discharge data sets from sixty one different rivers. In addition four rivers are analyzed in detail to demonstrate the benefit of the extended model. The models are compared using two measures, the Deviance Information Criterion (DIC) and Bayes factor. The former provides robust comparison of fit adjusting for the different complexity of the models and the latter measures the evidence of one model against the other. The extended model captures deviations in the data from the standard power-law but reduces to the standard powerlaw when that model is adequate. The extended model provides substantially better fit than the standard power-law model for about 30% of the rivers and performs better for 60% of the rivers when extrapolating large discharge values. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the association of potential risk factors for urinary tract infections (UTI) caused by E. coli producing ESBL vs. not producing ESBL in Iceland., Methods: Observational, case-control study including a cohort of 27,747 patients (22,800 females, 4,947 males; 1207 cases, 26,540 controls) of all ages with UTI caused by E. coli in 2012 to 2021 at the clinical microbiology laboratory covering about 2/3 of the Icelandic population. Clinical patient data was obtained from three national databases. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) as a measure of association between ESBL and exposure variables., Results: The proportion of samples with ESBL-producing E. coli increased during the study period, from 2.6% in 2012 to 7.6% in 2021 (p < 0.001). ESBL-positive strains were detected in 1207 individuals (4.4%), 905 females (4.0%) and 302 males (6.1%). The following risk factors were identified: Male sex, higher age, institution type (hospital, nursing home), hospital-associated UTI, Charlson comorbidity index score ≥ 3, history of cystitis or hospitalization in the past year, and prescriptions for certain antibiotics or proton pump inhibitors (PPIs: OR 1.51) in the past half year. The antibiotic associated with the highest risk was ciprofloxacin (OR 2.45)., Conclusion: The prevalence of UTIs caused by ESBL-producing E. coli has been increasing in Iceland. The strongest risk factors for ESBL production were previous antibiotic use, especially ciprofloxacin, and previous PPI use, both considered to be overprescribed. It is important to promote the prudent use of these drugs., (© 2024. The Author(s).)

Introduction: Streptococcus pneumoniae is a cause of infections that range in severity from acute otitis media (AOM) to pneumonia and invasive pneumococcal disease (IPD). The 10-valent pneumococcal conjugate vaccine (PHiD-CV10) was introduced into the Icelandic paediatric immunisation programme in 2011. The aim was to estimate the population impact and cost-effectiveness of PHiD-CV10 introduction., Methods: Data on primary care visits from 2005-2015 and hospitalisations from 2005-2017 were obtained from population-based registries. A Bayesian time series analysis with synthetic controls was employed to estimate the number of cases of AOM, pneumonia and IPD that would have occurred between 2013-2017, had PHiD-CV10 not been introduced. Prevented cases were calculated by subtracting the observed number of cases from this estimate. The cost of the programme was calculated accounting for cost-savings due to prevented cases., Results: The introduction of PHiD-CV10 prevented 13,767 (95% credible interval [CI] 2,511-29,410) visits for AOM from 2013-2015, and prevented 1,814 (95%CI -523-4,512) hospitalisations for pneumonia and 53 (95%CI -17-177) admissions for IPD from 2013-2017. Visits for AOM decreased both among young children and among children 4-19 years of age, with rate ratios between 0.72-0.89. Decreases were observed in both pneumonia hospitalisations (rate ratios between 0.67-0.92) and IPD (rate ratios between 0.27-0.94). The total cost of implementing PHiD-CV10 in Iceland was -7,463,176 United States Dollars (USD) (95%CI -16,159,551-582,135) with 2.1 USD (95%CI 0.2-4.7) saved for every 1 USD spent., Conclusions: The introduction of PHiD-CV10 was associated with large decreases in visits and hospitalisations for infections commonly caused by pneumococcus and was cost-saving during the first five years of the immunisation programme., Competing Interests: An investigator-initiated study funded by GlaxoSmithKline Biologicals SA. Additionally, a grant was received from the Landspitali University Hospital Research Fund. GlaxoSmithKline Biologicals SA was provided the opportunity to review a draft version of this manuscript, but the authors are solely responsible for final content and interpretation. The authors received no financial support or other form of compensation related to the development of the manuscript. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Introduction: Pneumococcus is an important respiratory pathogen. The 10-valent pneumococcal vaccine (PHiD-CV) was introduced into the Icelandic vaccination programme in 2011. The aim was to estimate the impact of PHiD-CV on paediatric hospitalisations for respiratory tract infections and invasive disease., Methods: The 2005-2015 birth-cohorts were followed until three years of age and hospitalisations were recorded for invasive pneumococcal disease (IPD), meningitis, sepsis, pneumonia and otitis media. Hospitalisations for upper- and lower respiratory tract infections (URTI, LRTI) were used as comparators. The 2005-2010 birth-cohorts were defined as vaccine non-eligible cohorts (VNEC) and 2011-2015 birth-cohorts as vaccine eligible cohorts (VEC). Incidence rates (IR) were estimated for diagnoses, birth-cohorts and age groups, and incidence rate ratios (IRR) between VNEC and VEC were calculated assuming Poisson variance. Cox regression was used to estimate the hazard ratio (HR) of hospitalisation between VNEC and VEC., Results: 51,264 children were followed for 142,315 person-years, accumulating 1,703 hospitalisations for the respective study diagnoses. Hospitalisations for pneumonia decreased by 20% (HR 0.80, 95%CI:0.67-0.95) despite a 32% increase in admissions for LRTI (HR 1.32, 95%CI:1.14-1.53). Hospital admissions for culture-confirmed IPD decreased by 93% (HR 0.07, 95%CI:0.01-0.50) and no hospitalisations for IPD with vaccine-type pneumococci were observed in the VEC. Hospitalisations for meningitis and sepsis did not change. A decrease in hospital admissions for otitis media was observed, but did not coincide with PHiD-CV introduction., Conclusion: Following the introduction of PHiD-CV in Iceland, hospitalisations for pneumonia and culture confirmed IPD decreased. Admissions for other LRTIs and URTIs increased during this period., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020. Published by Elsevier Ltd.)

This study assesses spatiotemporal and sex-specific growth of Atlantic cod Gadus morhua in Icelandic waters. We use a Bayesian approach which lends itself to fitting and comparing nested models such as these. We then compare fitted parameters of these models to potential explanatory variables using a redundancy analysis (RDA) to look for drivers of growth in G. morhua. Results indicate that models that incorporate differences in growth among time, space and sex are the best-fitting models according to deviance information criterion (DIC). Results from RDA indicate that capelin Mallotus villosus recruitment and biomass is highly correlated with deviations in the von Bertalannfy growth parameter k and that L ∞ is correlated with G. morhua landings in the model that uses year to account for time-varying growth and estimated G. morhua recruitment in the model that uses cohort to account for time-varying growth., (© 2019 The Fisheries Society of the British Isles.)

Aim: The aim was to estimate the impact of the 10-valent pneumococcal vaccine (PHiD-CV) on tympanostomy tube placements (TTP) in children under five years of age in Iceland., Methods: This population-based observational cohort study followed 11 consecutive birth-cohorts 2005-2015 from birth until their fifth birthday. Population registries were merged using national identification numbers. The risk of TTP was compared between birth-cohorts adjusted for the number of previous otitis media diagnoses and antimicrobial prescriptions. A Cox regression model was applied and the hazard ratio (HR) of TTP was estimated between each birth-cohort and the last vaccine non-eligible birth-cohort. The vaccine impact of PHiD-CV10 on TTP was estimated as 1-HR ×100%., Results: In total, 51 247 children were followed for 210 724 person-years, of which 14 351 underwent 20 373 procedures. The estimated vaccine impact on TTP was -6% (95% CI -16% to 2.7%). Children in the vaccine-eligible cohorts had fewer previous otitis media diagnoses and had been prescribed fewer antimicrobials prior to the procedure than children in the vaccine non-eligible cohorts., Conclusion: Despite high uptake of PHiD-CV10, tympanostomy procedures increased in Iceland during the study period. Vaccine-eligible children had milder disease prior to the procedure. The reason underlying these findings are speculative., (©2019 The Authors. Acta Paediatrica published by John Wiley & Sons Ltd on behalf of Foundation Acta Paediatrica.)

Vaccinations with the 10-valent pneumococcal conjugated vaccine (PHiD-CV) started in Iceland in 2011. Protein D (PD) from H. influenzae , which is coded for by the hpd gene, is used as a conjugate in the vaccine and may provide protection against PD-positive H. influenzae We aimed to evaluate the effect of PHiD-CV vaccination on H. influenzae in children, both in carriage and in acute otitis media (AOM). H. influenzae was isolated from nasopharyngeal swabs collected from healthy children attending 15 day care centers in 2009 and from 2012 to 2017 and from middle ear (ME) samples from children with AOM collected from 2012 to 2017. All isolates were identified using PCR for the hpd and fucK genes. Of the 3,600 samples collected from healthy children, 2,465 were culture positive for H. influenzae (68.5% carriage rate); of these, 151 (6.1%) contained hpd -negative isolates. Of the 2,847 ME samples collected, 889 (31.2%) were culture positive for H. influenzae ; of these, 71 (8.0%) were hpd negative. Despite the same practice throughout the study, the annual number of ME samples reduced from 660 in 2012 to 330 in 2017. The proportions of hpd -negative isolates in unvaccinated versus vaccinated children were 5.6% and 7.0%, respectively, in healthy carriers, and 5.4% and 7.8%, respectively, in ME samples. The proportion of hpd -negative isolates increased with time in ME samples but not in healthy carriers. The number of ME samples from children with AOM decreased. The PHiD-CV had no effect on the proportion of the hpd gene in H. influenzae from carriage, but there was an increase in hpd -negative H. influenzae in otitis media. The proportions of hpd -negative isolates remained similar in vaccinated and unvaccinated children., (Copyright © 2019 Sveinsdóttir et al.)

The introduction of pneumococcal conjugate vaccines (PCVs) into childhood vaccination programs has reduced carriage of vaccine serotypes and pneumococcal disease. The 10-valent PCV was introduced in Iceland in 2011. The aim of this study was to determine PCV impact on the prevalence of serotypes, genetic lineages, and antimicrobial-resistant pneumococci isolated from the lower respiratory tract (LRT) of adults. Pneumococci isolated between 2009 and 2017 at the Landspitali University Hospital were included ( n  = 797). The hospital serves almost three-quarters of the Icelandic population. Isolates were serotyped and tested for antimicrobial susceptibility, and the genome of every other isolate collected between 2009 and 2014 was sequenced ( n  = 275). Serotypes and multilocus sequence types (STs) were extracted from the genome data. Three study periods were defined, 2009 to 2011 (PreVac), 2012 to 2014 (PostVac-I), and 2015 to 2017 (PostVac-II). The total number of isolates and vaccine-type (VT) pneumococci decreased from PreVac to PostVac-II ( n  = 314 versus n  = 230 [ p  = 0.002] and n  = 170 versus n  = 33 [ p  < 0.001], respectively), but non-vaccine-type (NVT) pneumococci increased among adults 18 to 64 years old ( n  = 56 versus n  = 114 [ p  = 0.008]). Serotype 19F decreased in the PostVac-II period; these isolates were all multidrug resistant (MDR) and were members of the Taiwan 19F -14 PMEN lineage. Serotype 6A decreased among adults ≥65 years old in the PostVac-II period ( p  = 0.037), while serotype 6C increased ( p  = 0.021) and most serotype 6C isolates were MDR. Nonencapsulated Streptococcus pneumoniae (NESp) isolates increased among adults 18 to 64 years old in the PostVac-II period, and the majority were MDR ( p  = 0.028). An overall reduction in the number of LRT samples and pneumococcus-positive cultures and significant changes in the serotype distribution became evident within 4 years, thereby demonstrating a significant herd effect., (Copyright © 2019 Quirk et al.)

Vaccination with pneumococcal conjugate vaccines (PCVs) disrupts the pneumococcal population. Our aim was to determine the impact of the 10-valent PCV on the serotypes, genetic lineages, and antimicrobial susceptibility of pneumococci isolated from children in Iceland. Pneumococci were collected between 2009 and 2017 from the nasopharynges of healthy children attending 15 day care centers and from the middle ears (MEs) of children with acute otitis media from the greater Reykjavik capital area. Isolates were serotyped and tested for antimicrobial susceptibility. Whole-genome sequencing (WGS) was performed on alternate isolates from 2009 to 2014, and serotypes and multilocus sequence types (STs) were extracted from the WGS data. Two study periods were defined: 2009 to 2011 (PreVac) and 2012 to 2017 (PostVac). The overall nasopharyngeal carriage rate was similar between the two periods (67.3% PreVac and 61.5% PostVac, P = 0.090). Vaccine-type (VT) pneumococci decreased and nonvaccine-type (NVT) pneumococci (serotypes 6C, 15A, 15B/C, 21, 22F, 23A, 23B, 35F, and 35B) significantly increased in different age strata post-PCV introduction. The total number of pneumococci recovered from ME samples significantly decreased as did the proportion that were VTs, although NVT pneumococci (6C, 15B/C, 23A, and 23B) increased significantly. Most serotype 6C pneumococci were multidrug resistant (MDR). Serotype 19F was the predominant serotype associated with MEs, and it significantly decreased post-PCV introduction: these isolates were predominantly MDR and of the Taiwan 19F -14 PMEN lineage. Overall, the nasopharyngeal carriage rate remained constant and the number of ME-associated pneumococci decreased significantly post-PCV introduction; however, there was a concomitant and statistically significant shift from VTs to NVTs in both collections of pneumococci., (Copyright © 2018 Quirk et al.)

Background: Antimicrobial resistance is a public-health threat and antimicrobial consumption is the main contributor. The ten-valent pneumococcal conjugate vaccine (PHiD-CV10) was introduced into the Icelandic vaccination program in 2011. The aim was to estimate the vaccine impact of PHiD-CV10 on outpatient antimicrobial prescriptions in children., Methods: Eleven Icelandic birth-cohorts (2005-2015) were followed from birth until three years of age or to the end of the study period (December 31, 2016). Birth-cohorts were grouped as vaccine non-eligible (VNEC, 2005-2010) or vaccine eligible (VEC, 2011-2015). Data on primary care visits for respiratory infections and antimicrobial prescriptions were extracted from two national registers. Using national identification numbers, prescriptions were linked to physician visits if filled within three days of the visit. Incidence rates and incidence rate ratios between VNEC and VEC were calculated. An Andersen-Gill model was used to model the individual level data, accounting for repeated events and censoring. Vaccine impact was calculated as (1 - Hazard Ratio) × 100%., Results: Included were 53,510 children who contributed 151,992 person-years of follow-up and filled 231,660 antimicrobial prescriptions. The incidence rate was significantly lower in the VEC compared to the VNEC, 144.5 and 157.2 prescriptions per 100 person-years respectively (IRR 0.92, 95%CI 0.91-0.93). Children in VEC were more likely to have filled zero (IRR 1.16 (95%CI 1.10-1.23) and 1-4 (IRR 1.08 95%CI 1.06-1.11) prescriptions compared to children in VNEC. The vaccine impact of PHiD-CV10 against all-cause antimicrobial prescriptions was 5.8% (95%CI 1.6-9.8%).When only considering acute otitis media-associated prescriptions, the vaccine impact was 21.8% (95%CI 11.5-30.9%)., Conclusion: The introduction of PHiD-CV10 lead to reduced antimicrobial use in children, mainly by reducing acute otitis media episodes. This intervention therefore reduces both disease burden and could slow the spread of antimicrobial resistance.

Background: The 10-valent pneumococcal conjugate vaccine (PHiD-CV10) was introduced in Iceland in 2011, without catch-up. The aim of this study was to estimate vaccine impact (VI) on acute otitis media (AOM)., Methods: In this whole-population study, all primary care visits due to AOM from 2005 to 2015 in children <3 years of age were included. Birth cohorts were grouped as vaccine noneligible (VNEC) or vaccine eligible (VEC). Crude incidence rates (IRs) were compared between the VNEC and VEC. A Cox regression model for repeated events was used to model the individual-level data. VI was calculated as (hazard ratio [HR] - 1) × 100%., Results: Included were 53150 children, with 140912 person-years of follow-up and 58794 AOM episodes. Both IR and the mean number of episodes differed significantly between VNEC and VEC; 43 compared to 38 episodes per 100 person-years and 1.61 episodes per child compared to 1.37. IR was significantly reduced in all age brackets, with the largest reduction in children <4 months of age (40% [95% confidence interval {CI}, 31%-49%). The VI on all-cause AOM was 22% (95% CI, 12%-31%). The impact was mediated through its effect on the first (HR, 0.84 [95% CI, .82-.86]) and second (HR, 0.95 [95% CI, .93-.98]) episodes., Conclusions: The impact of PHiD-CV10 on all-cause AOM was considerable, mediated mainly by preventing the first two episodes of AOM. A decrease in the IR of AOM in children too young to receive direct vaccine protection was demonstrated, suggesting herd effect.

Background: Acute otitis media (AOM) nonresponsive to antibiotics is most commonly caused by antibiotic-resistant Streptococcus pneumoniae and Haemophilus influenzae. A strategy for treating these infections with parenteral ceftriaxone was adopted at the Children's Hospital Iceland. The 10-valent pneumococcal H. influenzae protein D-conjugate vaccine was introduced into the vaccination program in Iceland in 2011. The aim was to study its effect on the incidence of AOM with treatment failure., Methods: This retrospective observational study included children who visited the Children's Hospital Iceland because of AOM or received ceftriaxone, regardless of indication from 2008-2015. Incidence rate was calculated for prevaccine (2008-2011) and postvaccine (2012-2015) periods using person-years at risk within the hospital's referral region. Incidence rate ratio of ceftriaxone treatment episodes of AOM was calculated using the Mantel-Haenzel method adjusting for age. Incidence risk ratio of ceftriaxone treatment if presenting to the hospital with AOM was calculated to adjust for rate of AOM visits., Results: Visits for AOM decreased from 47.5 to 33.9 visits per 1000 person-years, incidence rate ratio (IRR) 0.86 (95% confidence interval [CI]: 0.81-0.91), P < 0.001. Fewer AOM episodes were treated with ceftriaxone, decreasing from 6.49 to 2.96 treatment episodes per 1000 person-years, with an overall Mantel-Haenzel adjusted IRR 0.45 (95% CI: 0.37-0.54; P < 0.001). This remained significant after adjusting for the decrease in AOM visits, IRR 0.53 (95% CI: 0.44-0.63; P < 0.001)., Conclusions: Visits for AOM and ceftriaxone use decreased significantly after H. influenzae protein D-conjugate vaccine introduction. The observed decrease in ceftriaxone use is presumed to represent a decline in AOM with treatment failure, secondary to a decrease in resistant infections.

Background: Since the introduction of pneumococcal conjugate vaccines, vaccine type pneumococcal carriage and disease has decreased world-wide. The aim was to monitor changes in the nasopharyngeal carriage of pneumococci, the distribution of serotypes and antimicrobial resistance in children before and after initiation of the 10-valent pneumococcal vaccination in 2011, in a previously unvaccinated population., Methods: Repeated cross-sectional study at 15day-care centres in greater Reykjavik area. Nasopharyngeal swabs were collected yearly in March from 2009 to 2015. The swabs were selectively cultured for pneumococci, which were serotyped using latex agglutination and/or PCR and antimicrobial susceptibility determined. Two independent studies were conducted. In study 1, on total impact, isolates from children aged <4years were included. The vaccine-eligible-cohort (birth-years: 2011-2013, sampled in 2013-2015) was compared with children at the same age born in 2005-2010 and sampled in 2009-2012. In study 2 on herd effect, isolates from older non-vaccine-eligible children (3.5-6.3years) were compared for the periods before and after the vaccination (2009-2011 vs 2013-2015. Vaccine impact was determined using 1-odds-ratio., Results: Following vaccination, the vaccine impact on vaccine type acquisition was 94% (95% CI: 91-96%) in study 1 and 56% (95% CI: 44-65%) in study 2. The impact on serotype 6A was 33% (95% CI: -9%; 59%) in study 1 and 42% (95% CI: 10-63%) in study 2 with minimal effect on 19A. The non-vaccine serotypes/groups 6C, 11, 15 and 23B were the most common serotypes/groups after vaccination. Isolates from the vaccine-eligible-cohort had lower penicillin MICs, less resistance to erythromycin and co-trimoxazole and less multi resistance than isolates from the control-group., Conclusions: The efficacy of the vaccination on vaccine serotypes was high, and a milder effect on vaccine-associated-serotype 6A was observed for the vaccine-eligible-cohort. There was a significant herd effect on vaccine types in older non-vaccine-eligible children. Overall antimicrobial non-susceptibility was reduced., (Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Evidence is mixed on whether society-wide economic conditions affect cardiovascular health and the reasons for the suggested relationship are largely untested. We explore whether a short-term increase in labor supply affects the probability of acute myocardial infarctions, using a natural experiment in Iceland. In 1987 personal income taxes were temporarily reduced to zero, resulting in an overall increase in labor supply. We merge and analyze individual-level, registry-based data on earnings and AMIs including all Icelandic men and women aged 45-74 during the period 1982-1992. The results support the prominent hypothesis of increased work as a mechanism explaining worsening heart health in upswings, for men aged 45-64 who were self-employed. We furthermore find a larger increase in probability of AMIs during the tax-free year in men aged 45-54 than men aged 55-64., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Introduction: Respiratory tract infections (RTIs) and antibiotic usage are common in children, increasing the risk of antibacterial resistance. The introduction of protein-conjugated pneumococcal vaccines has led to reduction in pneumococcal infections. In 2011, pneumococcal protein-conjugated vaccine-10 was introduced into the national childhood vaccination in Iceland, a population not earlier vaccinated against pneumococcus, with 95% vaccine uptake in the first year. The aim of the study was to evaluate the number of children visiting the Children's Hospital Iceland for RTIs before and after the introduction of the vaccine., Methods: Admissions and visits to the Children's Hospital because of RTIs were recorded, and children aged 3 months to 2 years in the nonvaccine eligible cohort (born 2008-2010) were compared with the vaccine eligible cohort (born in 2011). Statistical analysis was done using large sample Z test and incidence rate ratios (IRRs) were calculated., Results: A significant reduction in incidence rate was found when comparing the nonvaccine eligible cohort with the vaccine eligible cohort, both for acute otitis media (AOM) (IRR: 0.76; 95% confidence interval: 0.67-0.87; P < 0.0001) and for pneumonia (IRR: 0.77; 95% confidence interval: 0.64-0.95; P < 0.01)., Conclusion: A significant reduction in hospital visits because of AOM and pneumonia in children vaccinated with pneumococcal protein-conjugated vaccine-10 was established. The abrupt and significant reduction of AOM is unusually clear. This reduction was noted very early after initiation of the vaccination.

Aims: To evaluate the effectiveness of a 6-month, partnership-based self-management programme for patients with mild and moderate chronic obstructive pulmonary disease., Background: Self-management is a widely valued concept used to address contemporary issues of chronic health problems. Findings of self-management programmes for people with chronic obstructive pulmonary disease are inconclusive., Design: Pragmatic randomized control trial., Methods: Patients, 45-65 years old, with mild and moderate chronic obstructive pulmonary disease were invited with a family member. Experimental group (n = 48) participated in a 6-month, partnership-based self-management programme consisting of: (a) three to four conversations between nurse and patient-family member; (b) 6 months of smoking cessation; and (c) interdisciplinary team-patient-family member group meeting. Control group (n = 52) received usual care. Data were collected at months zero, six and 12. The trial lasted from June 2009-March 2013., Results: Patients with mild and moderate chronic obstructive pulmonary disease who participated in the partnership-based self-management programme perceived less intrusiveness of the disease and its treatment than patients in the control group. Patients in the experimental group did not have better health-related quality of life, less anxiety or depression, increased physical activity, fewer exacerbations or better smoking status than patients in the control group. Patients in both groups found participation in the research useful and important., Conclusion: The partnership-based self-management programme had benefits concerning perception of the intrusiveness of chronic obstructive pulmonary disease and its treatment on lifestyles, activities and interests for young patients with the disease in its early stages. High satisfaction in control group, low family attendance and the relatively short treatment period may explain the less than expected benefits of the programme., (© 2015 John Wiley & Sons Ltd.)

Smoking is related to health deterioration through increased risk of various diseases. Changes in this health behavior could contribute to the documented health improvements during economic downturns. Furthermore, the reasons for changes in behavior are not well understood. We explore smoking behavior in Iceland before and after the sudden and unexpected economic crisis in 2008. Furthermore, to explore the mechanisms through which smoking could be affected we focus on the role of labor-market changes. Both real income and working hours fell significantly and economic theory suggests that such changes can affect health behaviors which in turn affect health. We use individual longitudinal data from 2007 to 2009, incidentally before and after the crisis hit. The data originates from a postal survey, collected by The Public Health Institute in Iceland. Two outcomes are explored: smoking participation and smoking intensity, using pooled ordinary least squares (OLS) and linear probability models. The detected reduction in both outcomes is not explained by the changes in labor-market variables. Other factors in the demand function for tobacco play a more important role. The most notable are real prices which increased in particular for imported goods because of the devaluation of the Icelandic currency as a result of the economic collapse.

Background: Day care attendance and antibiotic consumption are major risk factors for carriage of antibiotic-susceptible and non-susceptible pneumococci. We describe the nasopharyngeal carriage of antibiotic-susceptible and non-susceptible pneumococci among children at day care centres (DCCs), analyse the association of potential risk factors with carriage, and examine the effects of a hygiene intervention on carriage., Methods: Thirty DCCs in 2 communities were included in a cohort intervention trial. Nasopharyngeal cultures and information on the children were obtained every 6 months. The study lasted 2.5 y and the hygiene intervention was introduced at half of the DCCs during the last 1.5 y of the study. The results were analysed using a mixed effects logistic regression model., Results: A total of 5663 cultures were obtained from 2399 children, of which 55.6% grew pneumococci. Of the pneumococci, 27.9% were penicillin-non-susceptible (PNSP). The hygiene intervention was associated with a decreased risk of pneumococcal carriage, but this did not reach statistical significance for PNSP carriage. Pneumococcal and PNSP carriage was negatively associated with age, varied significantly between DCCs, and was positively associated with the number of preceding colds. Individual antibiotic use (mainly penicillin/amoxicillin) at the time of sampling and/or during the preceding month was associated with a decreased risk of pneumococcal and PNSP carriage. Individual use of cephalosporins was associated with an increased risk of carriage of penicillin and TMP-SMX-non-susceptible pneumococci., Conclusion: The hygiene intervention at the DCCs reduced the risk of pneumococcal carriage and the individual use of antibiotics was found to affect carriage in a complex manner.

Objectives: The needs of patients with uncompleted visits to the emergency department (ED) are uncertain. The aim was to evaluate ED patients who leave against medical advice (AMA) and who leave without being seen (WBS) regarding repeat ED visits, hospitalisation and mortality within 30 days., Methods: The National University Hospital operates the only ED for adults in the capital area of Reykjavik. The source of data was the electronic records for patients 18 years or older, who left AMA, who left WBS, who had the ICD-10 code Z53.2, or who completed their visits. ED visits, hospital admissions and the death registry are filed with the personal identification number, which enabled recognition of the index visit, and the outcomes, rates of return visits, hospitalisation and death., Results: Of 107 119 patients, 77 left AMA, 4471 left WBS and 423 had code Z53.2. The HR for returning to the ED within 30 days was 4.79 for AMA patients, 4.84 for WBS patients and 3.67 for Z53.2 patients. The HR for hospitalisation within 30 days was 6.90 for AMA patients, 1.09 for WBS patients and 1.07 for Z53.2 patients. The HR for death within 30 days was 10.97 for AMA patients, 0.84 for WBS and no deaths occurred among Z53.2 patients., Discussion: During 30 days follow-up, AMA and WBS patients had an increased rate of repeat ED visits compared with those patients who completed their ED visits. AMA patients also had an increased rate of hospitalisations.

Background: Day care attendance is a major risk factor for respiratory and gastrointestinal illnesses in preschool children. In this study, we describe the results of a hygiene intervention cohort trial at day care centres (DCCs) on the rates of febrile, respiratory, and gastrointestinal illnesses in preschool children., Methods: Thirty DCCs in 2 communities were included. The number of illness episodes was registered for each child every 6 months, as well as potential risk factors. The hygiene intervention was introduced in half of the DCCs and the results analysed using a multivariate mixed effects hierarchical Poisson regression model., Results: The study lasted 2.5 y, of which the hygiene intervention lasted 1.5 y. Two thousand three hundred and forty-nine children participated, delivering 2832 person-y. Adjusted incidence rate ratios of the illnesses at the intervention and non-intervention DCCs were not significantly different for any of the illnesses. The intervention was not more effective in children less than 3 y of age than in older children and no significant effects were seen with time. Compliance with the hygiene protocol was good as measured by the use of hygiene products and by a survey among the staff at the DCCs., Conclusions: The most likely explanation for the lack of effects of the intervention is that the baseline standard of hygiene at the DCCs was probably too high for the intervention to demonstrate significant results, but recall bias cannot be excluded. Even though hygiene is important for minimizing the spread of microbes at DCCs, other risk factors need to be studied.

Valid and reliable instruments are needed to measure how family members perceive support from nurses when a family member is experiencing serious illness. The purpose of this article is to describe the development and psychometric testing of a new instrument, the Iceland-Family Perceived Support Questionnaire (ICE-FPSQ). The concepts in the original version of the ICE-FPSQ (suggesting 24 items and 4 categories) were developed from the Calgary Family Intervention Model. In the first phase of the instrument construction, 179 family members answered the original ICE-FPSQ, and 236 answered the questionnaire in the second phase of testing. Principal Component Analysis (PCA) reduced the original questionnaire to 21 items. Cronbach's α = .959 explained 68% of the total variance, with three factors emerging: (a) emotional support (α = .925), (b) recognition of families' strengths (α = .926), and (c) cognitive support (α = .841). Confirmatory Factor Analyses (CFA) resulted in a final version of the questionnaire containing 14 items with total alpha of .961 and two factors: (a) cognitive support (α = .881) and (b) emotional support (α = .952). The instrument measures family's perceptions of support provided by nurses and will be helpful in examining the usefulness of family nursing interventions.

Instruments that are able to capture changes related to an intervention are of great value to the scientific as well as to the clinical community. The Iceland-Expressive Family Functioning Questionnaire (ICE-EFFQ) measures expressive emotions, collaboration, problem solving, communication, and behavior in families experiencing a chronic or an acute illness. The conceptual framework of the Calgary Family Assessment Model (Wright & Leahey, 2009) was used to construct the original questionnaire of 45 items and 10 subcategories. A total of 557 family members with a recent illness experience of a close relative answered the ICE-EFFQ in three different studies. Principal component factor analysis reduced the original questionnaire to 22 items with five factors emerging and a total Cronbach's alpha coefficient of α = 0.912 accounting for 60.3% of the total variability. Confirmatory factor analysis from two studies produced the final version of the questionnaire consisting of 17 items and four factors.

Aim: Evaluation of long-term outcome of extremely low-birthweight (ELBW) teenagers born in Iceland in 1991-1995., Method: Participants, 30 of 35 ELBW survivors and 30 full term control teenagers (14-19 years), were assessed for disabilities, health problems and learning difficulties. Results of national standardized tests in mathematics and Icelandic language were compared with results of neurodevelopmental assessment at 5 years of age., Results: A quarter of the ELBW teenagers had disabilities. All were initially diagnosed with neurodevelopmental disorders early in life and neurosensory and/or intellectual disabilities were confirmed later in childhood. Chronic lung disorders, neurological problems and psychiatric disorders were most common health problems. Growth parameters were within normal limits for most of the ELBW teenagers. Learning difficulties affected 57% of the ELBW teenagers, 20% attended special education classes and 37% required special teaching. Results of national standardized tests were significantly lower for ELBW survivors and were significantly related to the results of neurodevelopmental assessment at 5 years of age., Interpretation: A quarter of ELBW teenagers have disabilities albeit most of them mild. Chronic health problems and learning difficulties affect many ELBW survivors. Changes with time emphasize need of long-term follow-up., (© 2011 The Author(s)/Acta Paediatrica © 2011 Foundation Acta Paediatrica.)

Introduction: Allergic disorders are an increasing health problem in many countries, in particular among children. We have evaluated the prevalence and manifestations of allergy in a cohort of young Icelanders for more than two decades. Variations in the epidemiology and clinical expression of allergy in different communities may help to identify etiological factors contributing to these disorders., Methods: A cohort of 179 children has been monitored for allergic manifestations for two decades, at the ages of two, four, eight, and 15 years, and most recently at the age of 21 years involving 120 of the participants., Results: Cumulative prevalences of 40%, 45%, and 29% have been observed, respectively, for rhinoconjunctivitis, eczema, and asthma during the study period. None had developed rhinoconjunctivitis at the age of about 2 years, but the point prevalence gradually increased to 33% at the age of 21 years. Conversely, the prevalence of eczema was 31% at the age of 2 years, but gradually declined to 8% at the age of 21 years. The prevalence of asthma peaked at 28% at the age of 4 years, but declined thereafter and has remained stable at about 13% from the age of eight to 21 years., Discussion: The prevalence of allergic diseases is high in Iceland among children and young individuals. Asthma and atopic eczema are very common in childhood, but decreases with age while the prevalence of rhinoconjunctivitis increases markedly. The very high and increasing prevalence of rhinoconjunctivitis among 15- to 21-year-old individuals is noteworthy., (© 2012 John Wiley & Sons A/S.)

Background: The risk factors for febrile, respiratory, and gastrointestinal illnesses in preschool children at day care centres have not been adequately identified and may differ between countries., Methods: In this repeated cross-sectional and longitudinal study of children at day care centres, we analyzed various potential risk factors for infectious illnesses using a mixed effect hierarchical Poisson regression model. The results of the analyses and the incidence rates of these illnesses are reported herein., Results: The study lasted 2.5 y (2000-2003) and was divided into five 6-month periods (seasons). Nine hundred and seventeen children participated, and their mean age within each season was 3.6-4.1 y. The only consistent risk factors identified were young age and winter season. No consistent risk factors at the day care centres (facilities or hygiene practices) were identified. The incidences of the febrile, respiratory, and gastrointestinal illnesses varied significantly between seasons (winter/summer) and between age groups., Conclusions: Risk factors of infectious illnesses are difficult to identify and because they may vary between countries, international recommendations on expensive intervention strategies are not justifiable. Rates of respiratory illnesses in Icelandic preschool children appear higher than in other countries, but rates of gastrointestinal illnesses lower.

Background: Air pollutants in Iceland's capital area include hydrogen sulfide (H2S) emissions from geothermal power plants, particle pollution (PM10) and traffic-related pollutants. Respiratory health effects of exposure to PM and traffic pollutants are well documented, yet this is one of the first studies to investigate short-term health effects of ambient H2S exposure., Objectives: The aim of this study was to investigate the associations between daily ambient levels of H2S, PM10, nitrogen dioxide (NO2) and ozone (O3), and the use of drugs for obstructive pulmonary diseases in adults in Iceland's capital area., Methods: The study period was 8 March 2006 to 31 December 2009. We used log-linear Poisson generalized additive regression models with cubic splines to estimate relative risks of individually dispensed drugs by air pollution levels. A three-day moving average of the exposure variables gave the best fit to the data. Final models included significant covariates adjusting for climate and influenza epidemics, as well as time-dependent variables., Results: The three-day moving average of H2S and PM10 levels were positively associated with the number of individuals who were dispensed drugs at lag 3-5, corresponding to a 2.0% (95% confidence interval [CI] 0.4, 3.6) and 0.9% (95% CI 0.1, 1.8) per 10 μg/m3 pollutant concentration increase, respectively., Conclusion: Our findings indicated that intermittent increases in levels of particle matter from traffic and natural sources and ambient H2S levels were weakly associated with increased dispensing of drugs for obstructive pulmonary disease in Iceland's capital area. These weak associations could be confounded by unevaluated variables hence further studies are needed., (Copyright © 2012 Elsevier Inc. All rights reserved.)

We propose two methods to evaluate the statistical significance of differences in linkage disequilibrium (LD) between populations, where LD is measured by the standardised parameter D'. The first method is based on bootstrapping individuals within populations in order to test LD differences for each pair of loci. Using this approach we propose a solution to the problem of testing multiple locus-pairs by means of a single test for the number of pairs that exhibit significant LD differences among populations. The second method provides the Bayesian posterior probability that one population has greater LD than the other for each locus pair. Both methods can handle genotypes with unknown phase, and are demonstrated using two data sets. For the purpose of demonstration, we apply the methods to two different sets of data from humans. First, we explore the issue of LD differences between reproductively isolated populations using a new data set of twelve Xq25 microsatellites, typed in four European populations. Second, we examine evidence for LD differences between Alzheimer cases and controls from the Icelandic population using 19 single nucleotide polymorphisms (SNPs) from a 97 kb region flanking the Apolipoprotein E (APOE) gene on chromosome 19.

Objective: The aim of this study was to investigate psychotropic drug use among children in Iceland between 2003 and 2007., Methods: A nationwide population-based drug use study covering the total pediatric population (ages 0-17) in Iceland. Information was obtained from the National Medicines Registry to calculate prevalence of use by year and psychotropic drug group; incidence by year, psychotropic drug group, child's age and sex, and medical specialty of prescriber; the most commonly used psychotropic chemical substances, off-label and unlicensed use and concomitant psychotropic drug use., Results: The overall prevalence of psychotropic drug use was 48.7 per 1000 Icelandic children in 2007. Stimulants and antidepressants increased in prevalence from 2003 to 2007 and were the two most prevalent psychotropic drug groups, respectively, 28.4 and 23.4 per 1000 children in 2007. A statistically significant trend of declining prevalence (p = 0.00013) and incidence (p = 0.0018) of antidepressant use occurred during the study period. Out of 21,986 psychotropic drugs dispensed in 2007, 25.4% were used off-label., Conclusions: With reference to reports from other European countries, the results indicate extensive psychotropic drug use among children in Iceland between 2003 and 2007. Further scrutiny is needed to assess the rationale behind this widespread use.

One of the key problems in the study of ancient DNA is that of authenticating sequences obtained from PCR amplifications of highly degraded samples. Contamination of ancient samples and postmortem damage to endogenous DNA templates are the major obstacles facing researchers in this task. In particular, the authentication of sequences obtained from ancient human remains is thought by many to be rather challenging. We propose a novel approach, based on the c statistic, that can be employed to help identify the sequence motif of an endogenous template, based on a sample of sequences that reflect the nucleotide composition of individual template molecules obtained from ancient tissues (such as cloned products from a PCR amplification). The c statistic exploits as information the most common form of postmortem damage observed among clone sequences in ancient DNA studies, namely, lesion-induced substitutions caused by cytosine deamination events. Analyses of simulated sets of templates with miscoding lesions and real sets of clone sequences from the literature indicate that the c-based approach is highly effective in identifying endogenous sequence motifs, even when they are not present among the sampled clones. The proposed approach is likely to be of general use to researchers working with DNA from ancient tissues, particularly from human remains, where authentication of results has been most challenging.

The impact of population structure on association studies undertaken to identify genetic variants underlying common human diseases is an issue of growing interest. Spurious associations of alleles with disease phenotypes may be obtained or true associations overlooked when allele frequencies differ notably among subpopulations that are not represented equally among cases and controls. Population structure influences even carefully designed studies and can affect the validity of association results. Most study designs address this problem by sampling cases and controls from groups that share the same nationality or self-reported ethnic background, with the implicit assumption that no substructure exists within such groups. We examined population structure in the Icelandic gene pool using extensive genealogical and genetic data. Our results indicate that sampling strategies need to take account of substructure even in a relatively homogenous genetic isolate. This will probably be even more important in larger populations.

Historical inferences from genetic data increasingly depend on assumptions about the genealogical process that shapes the frequencies of alleles over time. Yet little is known about the structure of human genealogies over long periods of time and how they depart from expectations of standard demographic models, such as that attributed to Wright and Fisher. To obtain such information and to examine the recent evolutionary history of mtDNA and Y-chromosome haplotypes in the Icelandic gene pool, we traced the matrilineal and patrilineal ancestry of all 131,060 Icelanders born after 1972 back to two cohorts of ancestors, one born between 1848 and 1892 and the other between 1798 and 1742. This populationwide coalescent analysis of Icelandic genealogies revealed highly positively skewed distributions of descendants to ancestors, with the vast majority of potential ancestors contributing one or no descendants and a minority of ancestors contributing large numbers of descendants. The expansion and loss of matrilines and patrilines has caused considerable fluctuation in the frequencies of mtDNA and Y-chromosome haplotypes, despite a rapid population expansion in Iceland during the past 300 years. Contrary to a widespread assumption, the rate of evolution caused by this lineage-sorting process was markedly faster in matrilines (mtDNA) than in patrilines (Y chromosomes). The primary cause is a 10% shorter matrilineal generation interval. Variance in the number of offspring produced within each generation was not an important differentiating factor. We observed an intergenerational correlation in offspring number and in the length of generation intervals in the matrilineal and patrilineal genealogies, which was stronger in matrilines and thus contributes to their faster evolutionary rate. These findings may have implications for coalescent date estimates based on mtDNA and Y chromosomes.