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Syrine Boucherabine,1,* Rania Nassar,1,2,* Lobna Mohamed,1 Matthew Olsen,3 Fatma Alqutami,1 Shroque Zaher,1 Mahmood Hachim,1 Abdulmajeed Alkhajeh,4 Simon McKirdy,5 Rashed Alghafri,3,5– 7 Lotti Tajouri,3,5,7 Abiola Senok1 1College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates; 2Oral and Biomedical Sciences, School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Cardiff, UK; 3Faculty of Health Sciences and Medicine, Bond University, Robina, QLD, Australia; 4Dubai Health Authority, Dubai, United Arab Emirates; 5Harry Butler Institute, Murdoch University, Murdoch, WA, Australia; 6General Department of Forensic Sciences and Criminology, Dubai Police, Dubai, United Arab Emirates; 7Dubai Police Scientists Council, Dubai, United Arab Emirates*These authors contributed equally to this workCorrespondence: Abiola Senok, Mohammed Bin Rashid University of Medicine and Health Sciences, Building 14, Dubai Healthcare City, P. O. Box 505055, Dubai, United Arab Emirates, Tel +97143838717, Email abiola.senok@mbru.ac.aeBackground: As high touch wearable devices, the potential for microbial contamination of smart watches is high. In this study, microbial contamination of smart watches of healthcare workers (HCWs) was assessed and compared to the individual’s mobile phone and hands.Methods: This study was part of a larger point prevalence survey of microbial contamination of mobile phones of HCWs at the emergency unit of a tertiary care facility. Swabs from smart watches, mobile phones and hands were obtained from four HCWs with dual ownership of these digital devices. Bacterial culture was carried out for all samples and those from smart watches and mobile phones were further assessed using shotgun metagenomic sequencing.Results: Majority of the participants were females (n/N = 3/4; 75%). Although they all use their digital devices at work and believe that these devices could harbour microbes, cleaning in the preceding 24 hours was reported by one individual. Predominant organisms identified on bacterial culture were multidrug resistant Staphylococcus hominis and Staphylococcus epidermidis. At least one organism identified from the hands was also detected on all mobile phones and two smart watches. Shotgun metagenomics analysis demonstrated greater microbial number and diversity on mobile phones compared to smart watches. All devices had high signatures of Pseudomonas aeruginosa and associated bacteriophages and antibiotic resistance genes. Almost half of the antibiotic resistance genes (n/N = 35/75;46.6%) were present on all devices and majority were related to efflux pumps. Of the 201 virulence factor genes (VFG) identified, majority (n/N = 148/201;73%) were associated with P. aeruginosa with 96% (n/N = 142/148) present on smart watches and mobile phones.Conclusion: This first report on microbial contamination of smart watches using metagenomics next generation sequencing showed similar pattern of contamination with microbes, VFG and antibiotic resistance genes across digital devices. Further studies on microbial contamination of wearable digital devices are urgently needed.Keywords: smart watches, mobile phones, microbial contamination, shotgun sequencing

Marie Olsen,1,2 Camilla Udo,1,3 Lena Dahlberg,1,4 Anne-Marie Boström2,5,6 1School of Health and Welfare, Dalarna University, Falun, Sweden; 2Department of Neurobiology, Care Sciences and Society, Division of Nursing, Karolinska Institutet, Stockholm, Sweden; 3Center for Clinical Research Dalarna-Uppsala University, Falun, Sweden; 4Department of Neurobiology, Care Sciences and Society, Ageing Research Centre, Karolinska Institutet, Stockholm, Sweden; 5Theme Inflammation and Ageing, Karolinska University Hospital, Huddinge, Sweden; 6R&D Unit, Stockholms Sjukhem, Stockholm, SwedenCorrespondence: Marie Olsen, School of Health and Welfare, Dalarna University, Falun, SE-788 91, Sweden, Tel +46 23 778453, Email moe@du.seIntroduction: Knowledge of older person’s experiences of important values in home care service can facilitate the development and delivery of high-quality services supporting their well-being, dignity and participation in the care provided. To date, few studies have explored older person’s values and experiences of home care services.Purpose: This study aimed to explore values that older person holds regarding home care services and their experiences of how these values manifest in home care service delivery.Participants and Methods: The study has a qualitative exploratory design. Semi-structured interviews were conducted with 16 older persons aged 74– 90 who received home care service. Data were analysed using qualitative content analysis.Results: Two themes (each with sub-themes) of values relating to the experience of home care service from the perspective of the 16 older persons were identified: to be supported as an autonomous person and to be supported as a relational being. The participants experience that these two values were only partly manifested in the home care services they received. They also noted that their well-being was negatively affected when staff failed to implement these values. The fundamental values identified in study related to the older person feeling safe, being autonomous, maintaining control and independence, and having relationships. The values constitute help to guide practice from the perspective of older persons who receive home care services.Conclusion: The identified values are primarily interpersonal-level values. However, such values are also of importance for home care service organisations when promoting delivery of person-centred care. Taking such a position implies adopting a relation-oriented rather than a task-oriented approach in providing home care services for older persons.Keywords: dignity, home care service, older persons, person-centered care, value, well-being

Henrik Solli,1 Morten Olsen,1 Finn Breinholt Larsen,2 Lars Pedersen,1 Morten Schmidt1,3 1Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; 2DEFACTUM, Social & Health Services and Labour Market, Central Denmark Region, Aarhus, Denmark; 3Department of Cardiology, Aarhus University Hospital, Aarhus, DenmarkCorrespondence: Henrik SolliDepartment of Clinical Epidemiology, Aarhus University Hospital, Olof Palmes Allé 43-45, Aarhus 8200 Aarhus N, DenmarkEmail henrsoll@rm.dkPurpose: Obesity is an established risk factor for venous thromboembolism (VTE), while studies on physical inactivity and VTE risk show conflicting results. We examined whether physical activity modified the association between obesity and VTE.Patients and Methods: We conducted a population-based cohort study by combining data on outcome diagnoses, comorbidities and medication from nationwide registries with self-reported lifestyle data from an extensive Danish lifestyle questionnaire (2001– 2015). We computed incidence rates (IRs) and hazard ratios (HRs) of VTE for categories of body mass index (BMI), among the total study population (n=57,523) and for physically active (n=25,387) and inactive individuals (n=30,902) separately.Results: Obesity (BMI ≥ 30 kg/m2) was as expected associated with increased VTE risk compared with normal weight (HR 1.62, 95% confidence interval (CI): 1.26– 2.09). Independent of BMI category, the rate of VTE was higher for inactive than active individuals. Thus, among obese individuals, the IR per 1000 person-years was 2.03 (95% CI: 1.60– 2.57) for inactive and 1.44 (95% CI: 0.97– 2.15) for active individuals. In contrast, the HR for VTE comparing obese with normal weight individuals were higher for active (HR 2.19, 95% CI: 1.35– 3.58) than inactive individuals (HR 1.36, 95% CI: 1.00– 1.84).Conclusion: Physical activity acts as an effect measure modifier of the association between obesity and VTE. Thus, physical activity reduced the absolute rate of VTE among obese individuals but increased the relative rate of VTE among obese compared with normal weight individuals.Keywords: venous thromboembolism, obesity, exercise, epidemiology, surveys and questionnaires

Priscila Corraini,1 Morten Olsen,1 Lars Pedersen,1 Olaf M Dekkers,1,2 Jan P Vandenbroucke1–3 1Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark; 2Leiden University Medical Center, Leiden, the Netherlands; 3Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK Abstract: We revisited the three interrelated epidemiological concepts of effect modification, interaction and mediation for clinical investigators and examined their applicability when using research databases. The standard methods that are available to assess interaction, effect modification and mediation are explained and exemplified. For each concept, we first give a simple “best-case” example from a randomized controlled trial, followed by a structurally similar example from an observational study using research databases. Our explanation of the examples is based on recent theoretical developments and insights in the context of large health care databases. Terminology is sometimes ambiguous for what constitutes effect modification and interaction. The strong assumptions underlying the assessment of interaction, and particularly mediation, require clinicians and epidemiologists to take extra care when conducting observational studies in the context of health care databases. These strong assumptions may limit the applicability of interaction and mediation assessments, at least until the biases and limitations of these assessments when using large research databases are clarified. Keywords: methods, epidemiology, effect modifiers, stratified analyses, health care administrative claims

Agnethe Berglund,1 Morten Olsen,2 Marianne Andersen,3 Eigil Husted Nielsen,4 Ulla Feldt-Rasmussen,5 Caroline Kistorp,6 Claus Højbjerg Gravholt,1,7 Kirstine Stochhholm1,8 1Department of Endocrinology and Internal Medicine, 2Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, 3Department of Endocrinology, Odense University Hospital, Odense, 4Department of Endocrinology, Aalborg University Hospital, Aalborg, 5Department of Endocrinology, Rigshospitalet, Copenhagen University, Copenhagen, 6Department of Endocrinology, Herlev Hospital, Herlev, 7Department of Molecular Medicine, 8Department of Pediatrics, Center of Rare Diseases, Aarhus University Hospital, Aarhus, Denmark Objective: Routinely collected health data may be valuable sources for conducting research. This study aimed to evaluate the validity of algorithms detecting hypopituitary patients in the Danish National Patient Registry (DNPR) using medical records as reference standard. Study design and setting: Patients with International Classification of Diseases (10th edition [ICD-10]) diagnoses of hypopituitarism, or other diagnoses of pituitary disorders assumed to be associated with an increased risk of hypopituitarism, recorded in the DNPR during 2000–2012 were identified. Medical records were reviewed to confirm or disprove hypopituitarism. Results: Hypopituitarism was confirmed in 911 patients. In a candidate population of 1,661, this yielded an overall positive predictive value (PPV) of 54.8% (95% confidence interval [CI]: 52.4–57.3). Using algorithms searching for patients recorded at least one, three or five times with a diagnosis of hypopituitarism (E23.0x) and/or at least once with a diagnosis of postprocedural hypopituitarism (E89.3x), PPVs gradually increased from 73.3% (95% CI: 70.6–75.8) to 83.3% (95% CI: 80.7–85.7). Completeness for the same algorithms, however, decreased from 90.8% (95% CI: 88.7–92.6) to 82.9% (95% CI: 80.3–85.3) respectively. Including data of hormone replacement in the same algorithms PPVs increased from 73.2% (95% CI: 70.6–75.7) to 82.6% (95% CI: 80.1–84.9) and completeness decreased from 94.3% (95% CI: 92.6–95.7) to 89.7% (95% CI: 87.5–91.6) with increasing records of E23.0x. Conclusion: The DNPR is a valuable data source to identify hypopituitary patients using a search criteria of at least five records of E23.0x and/or at least one record of E89.3x. Completeness is increased when including hormone replacement data in the algorithm. The consequences of misclassification must, however, always be considered. Keywords: ICD-10 algorithms, registry health data, hypopituitarism

Sumitra Shantakumar,1 Morten Olsen,2 Thao T Vo,3 Mette Nørgaard,2 Lars Pedersen,21Worldwide Epidemiology Department, GlaxoSmithKline Pte Ltd, Singapore; 2Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; 3Worldwide Epidemiology, GlaxoSmithkline, Research Triangle Park, USA Purpose: Soft tissue sarcoma (STS) patients may experience post-treatment cardiotoxicity, yet no population-based data exist. We examined the incidence of left ventricular ejection fraction (LVEF) decline, heart failure, and cardiac death following STS diagnosis among adults, using Danish patient registries and medical record review. Patients and methods: LVEF decline was examined in a regional cohort of STS patients diagnosed during 1997–2011 in Western Denmark for whom cardiac imaging data were available. LVEF decline was defined as an absolute decline from baseline to follow-up of 10% or more, or, where baseline imaging was not available, a decline below the lower limit of normal (or 40%) for a follow-up LVEF. Heart failure and cardiac death were investigated in a national Danish cohort of all STS patients diagnosed from 2000 to 2009. We followed patients from STS diagnosis until heart failure, cardiac death, emigration or December 31, 2012 (whichever occurred first). Results: The incidence rate of LVEF decline for the regional cohort with follow-up data (N=100, five events) or baseline and follow-up measurements (N=75, 19 events) was 16.8 (95% confidence interval [CI]: 7.0–40.3) and 108 (95% CI: 69–170), respectively, per 1,000 person-years. In the national cohort (N=1,187), the incidence of heart failure (40 events) and cardiac death (15 events) was 7.3 (95% CI: 5.4–10.0) and 2.7 (95% CI: 1.6–4.5), respectively, per 1,000 person-years. The strongest predictors of heart failure were doxorubicin treatment (hazard ratio [HR] =2.2, 95% CI: 0.5–10.2) and pre-existing cardiovascular disease (HR=6.3, 95% CI: 0.98–40.6). Conclusion: LVEF decline occurred more frequently compared to heart failure or cardiac death in a nationally representative cohort of Danish STS patients.Keywords: sarcoma, heart failure, LVEF, cardiac death

Corraini P, Olsen M, Pedersen L, Dekkers OM, Vandenbroucke JP, Clin Epidemiol. 2017;9:331–338.For clarification, on page 334, Interaction section, left column, last paragraph, the interpretation of the relative risk due to interaction should read “This excess relative risk due to interaction indicates that the probability of serious upper gastrointestinal bleeding following combined use of aspirin and clopidogrel is much higher than the probability expected from the addition of the effects of the two drugs.” where it previously read “By obtaining this relative risk due to interaction, the likelihood of serious upper gastrointestinal bleeding from the combined use of aspirin and clopidogrel was eight times higher than the likelihood expected by the addition of the two drugs.”Read the original article

Corraini P, Olsen M, Pedersen L, Dekkers OM, Vandenbroucke JP, Clin Epidemiol. 2017;9:331–338.On pages 333–334, the interaction contrast appeared incorrectly as 1.5 per 1,000 person-years, where it should read –1.5 per 1,000 person-years. This occurred from an inversion between the result of the rate reduction of heart disease due to aspirin among those receiving warfarin (10.3–8.7=1.6) and the result of the rate reduction due to aspirin among those not receiving warfarin (13.3–10.2=3.1).The interpretation of the interaction contrast should then read in page 334 as: “As the interaction contrast was below zero, it could be concluded that the effect of combining warfarin and aspirin in reducing ischemic heart disease was lower than that expected by the sum of the effects of either agent on its own.”Read the original article

Sandra Kruchov Thygesen, Morten Olsen, Christian Fynbo ChristiansenDepartment of Clinical Epidemiology, Aarhus University Hospital, Aarhus, DenmarkBackground: Infant respiratory distress syndrome (IRDS) is the most common respiratory disease in preterm infants, and is associated with considerable morbidity and mortality. Valid data on IRDS are important in clinical epidemiological research.Objectives: The objective of this study was to estimate the positive predictive value (PPV) of the IRDS diagnosis registered in the population-based Danish National Patient Registry according to the International Classification of Diseases, 8th and 10th revisions.Methods: Between January 1, 1977 and December 31, 2008, we randomly selected three patients per year, 96 in total, who were registered with an IRDS diagnosis in the Danish National Patient Registry and living in the northern part of Denmark. Data on the infants included information on the presence of predefined clinical symptoms. We defined IRDS as the presence of at least two of four clinical symptoms (tachypnea, retractions or nasal flaring, grunting, and central cyanosis), which had to be present for more than 30 minutes. Using medical record review as the reference standard, we computed the positive predictive value of the registered IRDS diagnosis including 95% confidence intervals (CIs).Results: We located the medical record for 90 of the 96 patients (94%), and found an overall PPV of the IRDS diagnosis of 81% (95% CI 72%–88%). This did not vary substantially between primary and secondary diagnoses. The PPV was higher, at 89% (95% CI 80%–95%), for preterm infants born before 37 weeks of gestation.Conclusion: The PPV of the IRDS diagnosis in the Danish National Patient Registry is reasonable when compared with symptoms described in the corresponding medical records. The Danish National Patient Registry is a useful data source for studies of IRDS, particularly if restricted to preterm infants. Nonetheless, the potential impact of misclassification of the IRDS diagnosis must be considered.Keywords: epidemiology, data quality, validity, positive predictive value, hospital diagnosis, respiratory distress syndrome

Inès Ben Ghezala, Johan Frederik Berg Arendt, Rune Erichsen, Jihen Zalfani, Henrik Gammelager, Trine Frøslev, Morten OlsenDepartment of Clinical Epidemiology, Aarhus University Hospital, Aarhus, DenmarkPurpose: The aim of this validation study was to assess the positive predictive value (PPV) of the International Classification of Diseases, 10th revision (ICD-10) diagnosis of vitamin B12 (cobalamin [Cbl]) deficiency anemia in the Danish National Patient Register (DNPR).Patients and methods: We identified all patients above 18 years of age recorded in the DNPR with a diagnosis of Cbl deficiency anemia (ICD-10 code: D51) admitted to two Danish university hospitals and one Danish regional hospital from 2000 through 2009. We assessed the PPV using biochemical parameters on Cbl deficiency with or without anemia as reference standards. These data were obtained from the Laboratory Information Systems Database. Data on prescriptions with Cbl supplementation drugs were obtained from the Aarhus University Prescription Database.Results: We identified 1089 patients coded with a Cbl deficiency anemia diagnosis in the DNPR. The PPV was 31.5% (95% confidence interval [CI]: 28.8%–34.3%) and 36.8% (95% CI: 34.0%–39.7%) depending on definitions of Cbl deficiency with anemia. When using Cbl deficiency without anemia as a reference standard, the PPV was 51.3% (95% CI: 48.4%–54.3%). The PPV for Cbl supplemented patients was 22.2% (95% CI: 18.0%–26.9%) and for non-Cbl supplemented patients 63.9% (95% CI: 60.5%–67.3%).Conclusion: The PPVs of the ICD-10 diagnosis coding for Cbl deficiency anemia were generally low in the DNPR. Therefore, this register should be used with caution to study patients with Cbl deficiency anemia.Keywords: vitamin B12 deficiency anemia, Danish National Patient Register, Laboratory Information Systems Database, International Classification of Diseases, positive predictive value, validation study

Jihen Zalfani, Trine Frøslev, Morten Olsen, Inès Ben Ghezala, Henrik Gammelager, Johan FB Arendt, Rune ErichsenDepartment of Clinical Epidemiology, Aarhus University Hospital, Aarhus, DenmarkObjective: Valid data on anemia caused by bleeding are needed for epidemiological research and monitoring health care. The Danish National Registry of Patients (DNRP) is a nationwide medical database with information on all Danish residents' hospital history. We aimed to assess the positive predictive value (PPV) of the diagnostic coding of anemia caused by bleeding in the DNRP.Methods: In the DNRP, we identified all patients with International Classification of Disease, 10th edition codes for anemia caused by bleeding (acute: D50.0; chronic: D62.6) at three Danish hospitals from 2000 through 2009. For these patients we computed the PPV using hemoglobin level data, from Aarhus University laboratory database, as reference standard. Anemia was defined by a hemoglobin level less than 7.0 mmol/L for women and less than 8.0 mmol/L for men.Results: We identified 3391 patients in the DNRP with a diagnosis of anemia caused by bleeding. The overall PPV was 95.4% (95% confidence interval [CI]: 94.6%–96.0%). The PPV was 97.6% (95% CI: 96.6%–98.3%) for men and 94.0% (95% CI: 92.9%–94.9%) for women, and the PPV increased with age at diagnosis. The PPV varied according to type of discharging departments, from 89.2% (95% CI: 83.4%–93.4%) in gynecology to 96.8% (95% CI: 94.9%–98.2%) in surgery, and was lower for outpatients compared with inpatients.Conclusion: We found a high PPV of the coding for anemia caused by bleeding in the DNRP. The registry is a valid source of data on anemia caused by bleeding for various purposes including research and monitoring health care.Keywords: anemia, Danish National Registry of Patients, International Classification of Diseases, predictive value, laboratory database, validation

Physical habitat is important in determining the carrying capacity of juvenile brown trout, and within freshwater management. Summer daytime physical habitat selection for the parr lifestage (7–20 cm) juvenile brown trout (Salmo trutta) was assessed in 6 small lowland streams. Habitat preference was determined for the four variables; water velocity, water depth, substrate and cover, and the preferences for physical habitat selection were expressed in terms of habitat suitability indices (HSI’s). The statistical confidence of HSI’s was evaluated using power analysis. It was found that a minimum of 22 fish observations was needed to have statistical confidence in the HSIs for water depth, and a minimum of 92 fish observations for water velocity during daytime summer conditions. Generally parr were utilising the deeper habitats, indicating preference for deeper water. Cover was also being selected for at all sites, but selection was inconsistent among sites for the variables substrate and velocity. The results indicate that during daytime summer conditions water depth is a significant variable for parr habitat selection in these small lowland streams, with cover also being important. Therefore, daytime refugia may be a critical limiting factor for parr in small lowland streams, and important for stream management actions under the Water Framework Directive.

[This corrects the article DOI: 10.1186/s13007-018-0317-4.].

BackgroundGrain yield, ear and kernel attributes can assist to understand the performance of maize plant under different environmental conditions and can be used in the variety development process to address farmer's preferences. These parameters are however still laborious and expensive to measure.ResultsA low-cost ear digital imaging method was developed that provides estimates of ear and kernel attributes i.e., ear number and size, kernel number and size as well as kernel weight from photos of ears harvested from field trial plots. The image processing method uses a script that runs in a batch mode on ImageJ; an open source software. Kernel weight was estimated using the total kernel number derived from the number of kernels visible on the image and the average kernel size. Data showed a good agreement in terms of accuracy and precision between ground truth measurements and data generated through image processing. Broad-sense heritability of the estimated parameters was in the range or higher than that for measured grain weight. Limitation of the method for kernel weight estimation is discussed.ConclusionThe method developed in this work provides an opportunity to significantly reduce the cost of selection in the breeding process, especially for resource constrained crop improvement programs and can be used to learn more about the genetic bases of grain yield determinants.