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In January of 2010, North Carolina (NC) USA implemented state-wide Trauma Triage Destination Plans (TTDPs) to provide standardized guidelines for Emergency Medical Services (EMS) decision making. No study exists to evaluate whether triage behavior has changed for geriatric trauma patients.
The impact of the NC TTDPs was investigated on EMS triage of geriatric trauma patients meeting physiologic criteria of serious injury, primarily based on whether these patients were transported to a trauma center.
This is a retrospective cohort study of geriatric trauma patients transported by EMS from March 1, 2009 through September 30, 2009 (pre-TTDP) and March 1, 2010 through September 30, 2010 (post-TTDP) meeting the following inclusion criteria: (1) age 50 years or older; (2) transported to a hospital by NC EMS; (3) experienced an injury; and (4) meeting one or more of the NC TTDP’s physiologic criteria for trauma (n = 5,345). Data were obtained from the Prehospital Medical Information System (PreMIS). Data collected included proportions of patients transported to a trauma center categorized by specific physiologic criteria, age category, and distance from a trauma center.
The proportion of patients transported to a trauma center pre-TTDP (24.4% [95% CI 22.7%-26.1%]; n = 604) was similar to the proportion post-TTDP (24.4% [95% CI 22.9%-26.0%]; n = 700). For patients meeting specific physiologic triage criteria, the proportions of patients transported to a trauma center were also similar pre- and post-TTDP: systolic blood pressure <90 mmHg (22.5% versus 23.5%); respiratory rate <10 or >29 (23.2% versus 22.6%); and Glascow Coma Scale (GCS) score <13 (26.0% versus 26.4%). Patients aged 80 years or older were less likely to be transported to a trauma center than younger patients in both the pre- and post-TTDP periods.
State-wide implementation of a TTDP had no discernible effect on the proportion of patients 50 years and older transported to a trauma center. Under-triage remained common and became increasingly prevalent among the oldest adults. Research to understand the uptake of guidelines and protocols into EMS practice is critical to improving care for older adults in the prehospital environment.
The aggregation of neurocognitive deficits among the non-psychotic first-degree relatives of adult- and childhood-onset schizophrenia patients suggests that there may be a common etiology for these deficits in childhood- and adult-onset illness. However, there is considerable heterogeneity in the presentation of neurobiological abnormalities, and whether there are differences in the extent of familial transmission for specific domains of cognitive function has not been systematically addressed.
We employed variance components analysis, as implemented in SOLAR-Eclipse, to evaluate the evidence of familial transmission for empirically derived composite scores representing attention, working memory, verbal learning, verbal retention, and memory for faces. We contrast estimates for adult- and childhood-onset schizophrenia families and matched community control pedigrees, and compare our findings to previous reports based on analogous neurocognitive assessments.
We observed varying degrees of familial transmission; attention and working memory yielded comparable, significant estimates for adult-onset and community control pedigrees; verbal learning was significant for childhood-onset and community control pedigrees; and facial memory demonstrated significant familial transmission only for childhood-onset schizophrenia. Model-fitting analyses indicated significant differences in familiality between adult- and childhood-onset schizophrenia for attention, working memory, and verbal learning.
By comprehensively assessing a wide range of neurocognitive domains in adult- and childhood-onset schizophrenia families, we provide additional support for specific neurocognitive domains as schizophrenia endophenotypes. Whereas comparable estimates of familial transmission for certain dimensions of cognitive functioning support a shared etiology of adult- and childhood-onset neurocognitive function, observed differences may be taken as preliminary evidence of partially divergent multifactorial architectures.
Item 9 of the Patient Health Questionnaire-9 (PHQ-9) queries about thoughts of death and self-harm, but not suicidality. Although it is sometimes used to assess suicide risk, most positive responses are not associated with suicidality. The PHQ-8, which omits Item 9, is thus increasingly used in research. We assessed equivalency of total score correlations and the diagnostic accuracy to detect major depression of the PHQ-8 and PHQ-9.
We conducted an individual patient data meta-analysis. We fit bivariate random-effects models to assess diagnostic accuracy.
16 742 participants (2097 major depression cases) from 54 studies were included. The correlation between PHQ-8 and PHQ-9 scores was 0.996 (95% confidence interval 0.996 to 0.996). The standard cutoff score of 10 for the PHQ-9 maximized sensitivity + specificity for the PHQ-8 among studies that used a semi-structured diagnostic interview reference standard (N = 27). At cutoff 10, the PHQ-8 was less sensitive by 0.02 (−0.06 to 0.00) and more specific by 0.01 (0.00 to 0.01) among those studies (N = 27), with similar results for studies that used other types of interviews (N = 27). For all 54 primary studies combined, across all cutoffs, the PHQ-8 was less sensitive than the PHQ-9 by 0.00 to 0.05 (0.03 at cutoff 10), and specificity was within 0.01 for all cutoffs (0.00 to 0.01).
PHQ-8 and PHQ-9 total scores were similar. Sensitivity may be minimally reduced with the PHQ-8, but specificity is similar.
The Enenteridae Yamaguti, 1958 and Gyliauchenidae Fukui, 1929 exhibit an interesting pattern of host partitioning in herbivorous fishes of the Indo-West Pacific. Enenterids are known almost exclusively from fishes of the family Kyphosidae, a group of herbivorous marine fishes common on tropical and temperate reefs. In contrast, gyliauchenids are found in most of the remaining lineages of marine herbivorous fishes, but until the present study, had never been known from kyphosids. Here we report on the first species of gyliauchenid known from a kyphosid. Endochortophagus protoporus gen. nov., sp. nov. was recovered from the Western buffalo bream, Kyphosus cornelii (Whitley, 1944), collected off Western Australia. Kyphosus cornelii also hosts an enenterid, Koseiria allanwilliamsi Bray & Cribb, 2002, and is thus the first fish known in which enenterids and gyliauchenids co-occur. Molecular phylogenetic analyses place the new species close to those of Affecauda Hall & Chambers, 1999 and Flagellotrema Ozaki, 1936, but there is sufficient morphological evidence, combined with the unusual host, to consider it distinct from these genera. We discuss factors which may have contributed to the host partitioning pattern observed between enenterids and gyliauchenids.
The role that vitamin D plays in pulmonary function remains uncertain. Epidemiological studies reported mixed findings for serum 25-hydroxyvitamin D (25(OH)D)–pulmonary function association. We conducted the largest cross-sectional meta-analysis of the 25(OH)D–pulmonary function association to date, based on nine European ancestry (EA) cohorts (n 22 838) and five African ancestry (AA) cohorts (n 4290) in the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium. Data were analysed using linear models by cohort and ancestry. Effect modification by smoking status (current/former/never) was tested. Results were combined using fixed-effects meta-analysis. Mean serum 25(OH)D was 68 (sd 29) nmol/l for EA and 49 (sd 21) nmol/l for AA. For each 1 nmol/l higher 25(OH)D, forced expiratory volume in the 1st second (FEV1) was higher by 1·1 ml in EA (95 % CI 0·9, 1·3; P<0·0001) and 1·8 ml (95 % CI 1·1, 2·5; P<0·0001) in AA (Prace difference=0·06), and forced vital capacity (FVC) was higher by 1·3 ml in EA (95 % CI 1·0, 1·6; P<0·0001) and 1·5 ml (95 % CI 0·8, 2·3; P=0·0001) in AA (Prace difference=0·56). Among EA, the 25(OH)D–FVC association was stronger in smokers: per 1 nmol/l higher 25(OH)D, FVC was higher by 1·7 ml (95 % CI 1·1, 2·3) for current smokers and 1·7 ml (95 % CI 1·2, 2·1) for former smokers, compared with 0·8 ml (95 % CI 0·4, 1·2) for never smokers. In summary, the 25(OH)D associations with FEV1 and FVC were positive in both ancestries. In EA, a stronger association was observed for smokers compared with never smokers, which supports the importance of vitamin D in vulnerable populations.
Improving access to tuberculosis (TB) care and ensuring early diagnosis are two major aims of the WHO End TB strategy and the Collaborative TB Strategy for England. This study describes risk factors associated with diagnostic delay among TB cases in England. We conducted a retrospective cohort study of TB cases notified to the Enhanced TB Surveillance System in England between 2012 and 2015. Diagnostic delay was defined as more than 4 months between symptom onset and treatment start date. Multivariable logistic regression was used to identify demographic and clinical factors associated with diagnostic delay. Between 2012 and 2015, 22 422 TB cases were notified in England and included in the study. A third (7612) of TB cases had a diagnostic delay of more than 4 months. Being female, aged 45 years and older, residing outside of London and having extra-pulmonary TB disease were significantly associated with a diagnostic delay in the multivariable model (aOR = 1.2, 1.2, 1.2, 1.3, 1.8, respectively). This study identifies demographic and clinical factors associated with diagnostic delay, which will inform targeted interventions to improve access to care and early diagnosis among these groups, with the ultimate aim of helping reduce transmission and improve treatment outcomes for TB cases in England.
Background: Continuous video-EEG (cvEEG) monitoring is the standard of care for diagnosis and management of neonatal seizures. However, it is labour-intensive. We aimed to establish consistency in monitoring of newborns utilising NICU nurses. Methods: Neonatal nurses were trained to apply scalp electrodes, troubleshoot technical issues. Guidelines, checklists and visual training modules were developed. A central network system allowed remote access to the cvEEGs by the epileptologist for timely interpretation and feedback. We compared 100 infants with moderate to severe HIE before and after the training program. Results: 192 cvEEGs were performed. Of the 100 infants compared; time to initiate brain monitoring decreased by average of 31.5 hours, in electrographic seizure detection increased(20% compared to 34% a), seizure clinical misdiagnosis decreased (65% compared to 36% ), and Anti-Seizure burden decreased. Conclusions: Training experienced NICU nurses to set-up, start and monitor cvEEG can decrease the time to initiate cvEEG which may lead to better seizure diagnosis and management.
Background: Despite advances in neonatal care, neonates with moderate to severe HIE are at high risk of mortality and morbidity. we report the impact of a dedicated NNCC team on short term mortality and morbidities. Methods: A retrospective cohort study on neonates with moderate to serve HIE between July 1st 2008 and December 31st 2017. primary outcome : a composite of death and/or brain injury on MRI. Secondary outcomes: rate of cooling, length of hospital stay, anti-seizure medication burden, and use of inotropes. A regression analysis was done adjusting for gestational age, birth weight, gender, out-born status, Apgar score at 10 minutes, cord blood pH, and HIE clinical staging Results: 216 neonates were included, 109 before NNCC implementation, and 107 thereafter. NNCC program resulted in reduction in the primary outcome (AOR: 0.28, CI: 0.14-0.54, p<0.001) and brain injury (AOR: 0.28, CI: 0.14-0.55, p<0.001). It decreased average length of stay/infants by 5 days (p=0.03), improved cooling rate (73% compared to 93% , p <0.001), reduced: seizure misdiagnosis (71% compared to 23%, P <0.001), anti-seizure medication burden (P = 0.001), and inotrope use (34% compared to 53%, p=0.004) Conclusions: NNCC program decreased mortality and brain injury , shortened the length of hospital stay and improved care of neonates with significant HIE.
Different diagnostic interviews are used as reference standards for major depression classification in research. Semi-structured interviews involve clinical judgement, whereas fully structured interviews are completely scripted. The Mini International Neuropsychiatric Interview (MINI), a brief fully structured interview, is also sometimes used. It is not known whether interview method is associated with probability of major depression classification.
To evaluate the association between interview method and odds of major depression classification, controlling for depressive symptom scores and participant characteristics.
Data collected for an individual participant data meta-analysis of Patient Health Questionnaire-9 (PHQ-9) diagnostic accuracy were analysed and binomial generalised linear mixed models were fit.
A total of 17 158 participants (2287 with major depression) from 57 primary studies were analysed. Among fully structured interviews, odds of major depression were higher for the MINI compared with the Composite International Diagnostic Interview (CIDI) (odds ratio (OR) = 2.10; 95% CI = 1.15–3.87). Compared with semi-structured interviews, fully structured interviews (MINI excluded) were non-significantly more likely to classify participants with low-level depressive symptoms (PHQ-9 scores ≤6) as having major depression (OR = 3.13; 95% CI = 0.98–10.00), similarly likely for moderate-level symptoms (PHQ-9 scores 7–15) (OR = 0.96; 95% CI = 0.56–1.66) and significantly less likely for high-level symptoms (PHQ-9 scores ≥16) (OR = 0.50; 95% CI = 0.26–0.97).
The MINI may identify more people as depressed than the CIDI, and semi-structured and fully structured interviews may not be interchangeable methods, but these results should be replicated.
Declaration of interest
Drs Jetté and Patten declare that they received a grant, outside the submitted work, from the Hotchkiss Brain Institute, which was jointly funded by the Institute and Pfizer. Pfizer was the original sponsor of the development of the PHQ-9, which is now in the public domain. Dr Chan is a steering committee member or consultant of Astra Zeneca, Bayer, Lilly, MSD and Pfizer. She has received sponsorships and honorarium for giving lectures and providing consultancy and her affiliated institution has received research grants from these companies. Dr Hegerl declares that within the past 3 years, he was an advisory board member for Lundbeck, Servier and Otsuka Pharma; a consultant for Bayer Pharma; and a speaker for Medice Arzneimittel, Novartis, and Roche Pharma, all outside the submitted work. Dr Inagaki declares that he has received grants from Novartis Pharma, lecture fees from Pfizer, Mochida, Shionogi, Sumitomo Dainippon Pharma, Daiichi-Sankyo, Meiji Seika and Takeda, and royalties from Nippon Hyoron Sha, Nanzando, Seiwa Shoten, Igaku-shoin and Technomics, all outside of the submitted work. Dr Yamada reports personal fees from Meiji Seika Pharma Co., Ltd., MSD K.K., Asahi Kasei Pharma Corporation, Seishin Shobo, Seiwa Shoten Co., Ltd., Igaku-shoin Ltd., Chugai Igakusha and Sentan Igakusha, all outside the submitted work. All other authors declare no competing interests. No funder had any role in the design and conduct of the study; collection, management, analysis and interpretation of the data; preparation, review or approval of the manuscript; and decision to submit the manuscript for publication.
Introduction: With the increasing volume of medical literature published each year, it is difficult for clinicians to translate the latest research into practice. Awareness is the first step of knowledge translation and journals have begun using social media to increase the dissemination and awareness of their publications. Infographics can describe research findings visually, are shared broadly on social media, and may be a more effective way to convey information. We hypothesized that infographic abstracts would increase the social media dissemination and online readership of research articles relative to traditional abstracts. Methods: In this randomized controlled trial, 24 original research articles were chosen from the six issues of the Canadian Journal of Emergency Medicine (CJEM) published between July 2016 and May 2017 (4 articles per issue). Half were randomized to the infographic and control groups within each issue. Infographic articles were promoted using a visual infographic outlining the findings of the article. Control articles were promoted using a screen capture image of each articles abstract. Both were disseminated through the journals social media accounts (Twitter and Facebook) along with the link to the selected article. Infographics were also published on CanadiEM.org. Abstract views, full text views, and the change in Altmetric score were tracked for 30 days and compared between groups. Unpaired two-tailed t-tests were used to detect significant differences. Results: Abstract views (mean, SD) were significantly higher for infographic articles (378.9, 162.0) than control articles (175.5, 69.2, p<0.001). Mean Altmetric scores were significantly higher for infographic articles (26.4, 13.8) than control articles (3.4, 1.7, p<0.0001). There was no statistically significant difference in full-text views between infographic (49.7, 90.4) and control articles (25.3, 12.3). Conclusion: CJEM articles promoted on social media using infographics had higher abstract viewership and Altmetric scores than those promoted with traditional abstracts. Although there was no difference in full-text readership, our results suggest that infographic abstracts may have a role in increasing the dissemination of medical literature.
Field identification of ST-elevation myocardial infarction (STEMI) and advanced hospital notification decreases first-medical-contact-to-balloon (FMC2B) time. A recent study in this system found that electrocardiogram (ECG) transmission following a STEMI alert was frequently unsuccessful.
Instituting weekly test ECG transmissions from paramedic units to the hospital would increase successful transmission of ECGs and decrease FMC2B and door-to-balloon (D2B) times.
This was a natural experiment of consecutive patients with field-identified STEMI transported to a single percutaneous coronary intervention (PCI)-capable hospital in a regional STEMI system before and after implementation of scheduled test ECG transmissions. In November 2014, paramedic units began weekly test transmissions. The mobile intensive care nurse (MICN) confirmed the transmission, or if not received, contacted the paramedic unit and the department’s nurse educator to identify and resolve the problem. Per system-wide protocol, paramedics transmit all ECGs with interpretation of STEMI. Receiving hospitals submit patient data to a single registry as part of ongoing system quality improvement. The frequency of successful ECG transmission and time to intervention (FMC2B and D2B times) in the 18 months following implementation was compared to the 10 months prior. Post-implementation, the time the ECG transmission was received was also collected to determine the transmission gap time (time from ECG acquisition to ECG transmission received) and the advanced notification time (time from ECG transmission received to patient arrival).
There were 388 patients with field ECG interpretations of STEMI, 131 pre-intervention and 257 post-intervention. The frequency of successful transmission post-intervention was 73% compared to 64% prior; risk difference (RD)=9%; 95% CI, 1-18%. In the post-intervention period, the median FMC2B time was 79 minutes (inter-quartile range [IQR]=68-102) versus 86 minutes (IQR=71-108) pre-intervention (P=.3) and the median D2B time was 59 minutes (IQR=44-74) versus 60 minutes (IQR=53-88) pre-intervention (P=.2). The median transmission gap was three minutes (IQR=1-8) and median advanced notification time was 16 minutes (IQR=10-25).
Implementation of weekly test ECG transmissions was associated with improvement in successful real-time transmissions from field to hospital, which provided a median advanced notification time of 16 minutes, but no decrease in FMC2B or D2B times.
In Hong Kong, universal varicella vaccination started in July 2014. Before this, children could receive varicella vaccine via the private market. We analysed the epidemiology of varicella and zoster before universal vaccination. We estimated varicella vaccination coverage through surveys in preschool children. We estimated the burden of varicella and zoster with varicella notifications from 1999/00 to 2013/14, Accident and Emergency Department (A&E) attendance and inpatient admissions to public hospitals from 2004/05 to 2013/14. We fitted a catalytic model to serological data on antibodies against varicella-zoster virus to estimate the force of infection. We found that varicella vaccination coverage gradually increased to about 50% before programme inception. In children younger than 5 years, the annual rate of varicella notifications, varicella admission and zoster A&E attendance generally declined. The annual notification, A&E attendance and hospitalisation rate of varicella and zoster generally increased for individuals between 10 and 59 years old. Varicella serology indicated an age shift during the study period towards a higher proportion of infections in slightly older individuals, but the change was most notable before vaccine licensure. In conclusion, we observed a shift in the burden of varicella to slightly older age groups with a corresponding increase in incidence but it cannot necessarily be attributed to private market vaccine coverage alone. Increasing varicella vaccination uptake in the private market might affect varicella transmission and epidemiology, but not to the level of interrupting transmission.
Research on the cities of the Classical Greek world has traditionally focused on mapping the organisation of urban space and studying major civic or religious buildings. More recently, newer techniques such as field survey and geophysical survey have facilitated exploration of the extent and character of larger areas within urban settlements, raising questions about economic processes. At the same time, detailed analysis of residential buildings has also supported a change of emphasis towards understanding some of the functional and social aspects of the built environment as well as purely formal ones. This article argues for the advantages of analysing Greek cities using a multidisciplinary, multi-scalar framework which encompasses all of these various approaches and adds to them other analytical techniques (particularly micro-archaeology). We suggest that this strategy can lead towards a more holistic view of a city, not only as a physical place, but also as a dynamic community, revealing its origins, development and patterns of social and economic activity. Our argument is made with reference to the research design, methodology and results of the first three seasons of fieldwork at the city of Olynthos, carried out by the Olynthos Project.
The Arctic marine environment is undergoing a transition from thick multi-year to first-year sea-ice cover with coincident lengthening of the melt season. Such changes are evident in the Baffin Bay-Davis Strait-Labrador Sea (BDL) region where melt onset has occurred ~8 days decade−1 earlier from 1979 to 2015. A series of anomalously early events has occurred since the mid-1990s, overlapping a period of increased upper-air ridging across Greenland and the northwestern North Atlantic. We investigate an extreme early melt event observed in spring 2013. (~6σ below the 1981–2010 melt climatology), with respect to preceding sub-seasonal mid-tropospheric circulation conditions as described by a daily Greenland Blocking Index (GBI). The 40-days prior to the 2013 BDL melt onset are characterized by a persistent, strong 500 hPa anticyclone over the region (GBI >+1 on >75% of days). This circulation pattern advected warm air from northeastern Canada and the northwestern Atlantic poleward onto the thin, first-year sea ice and caused melt ~50 days earlier than normal. The episodic increase in the ridging atmospheric pattern near western Greenland as in 2013, exemplified by large positive GBI values, is an important recent process impacting the atmospheric circulation over a North Atlantic cryosphere undergoing accelerated regional climate change.
Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990–1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.
We have previously shown that the minor alleles of vascular endothelial growth factor A (VEGFA) single-nucleotide polymorphism rs833069 and superoxide dismutase 2 (SOD2) single-nucleotide polymorphism rs2758331 are both associated with improved transplant-free survival after surgery for CHD in infants, but the underlying mechanisms are unknown. We hypothesised that one or both of these minor alleles are associated with better systemic ventricular function, resulting in improved survival.
This study is a follow-up analysis of 422 non-syndromic CHD patients who underwent neonatal cardiac surgery with cardiopulmonary bypass. Echocardiographic reports were reviewed. Systemic ventricular function was subjectively categorised as normal, or as mildly, moderately, or severely depressed. The change in function was calculated as the change from the preoperative study to the last available study. Stepwise linear regression, adjusting for covariates, was performed for the outcome of change in ventricular function. Model comparison was performed using Akaike’s information criterion. Only variables that improved the model prediction of change in systemic ventricular function were retained in the final model.
Genetic and echocardiographic data were available for 335/422 subjects (79%). Of them, 33 (9.9%) developed worse systemic ventricular function during a mean follow-up period of 13.5 years. After covariate adjustment, the presence of the VEGFA minor allele was associated with preserved ventricular function (p=0.011).
These data support the hypothesis that the mechanism by which the VEGFA single-nucleotide polymorphism rs833069 minor allele improves survival may be the preservation of ventricular function. Further studies are needed to validate this genotype–phenotype association and to determine whether this mechanism is related to increased vascular endothelial growth factor production.
The Mars Society is an international private organisation advocating the exploration and settlement of Mars. Part of its mission involves selecting areas for Martian analogue research, to test hardware, technology, strategies and human factors relevant to sending people to Mars. Mars Society Australia has selected an area in the Arkaroola region in the Flinders Ranges as the site for the first Australian analogue facility. The facility will be an invaluable public education and outreach tool for Australian science, focusing on astrobiology, and its role in future human Mars missions; demonstrating Australian contributions to astrobiology related science and work on terrestrial analogues to Martian environments.
We model runoff from glaciers in the McMurdo Dry Valleys, Antarctica, with summer (December–January) average air temperatures from 1990 to 2002 for the purpose of estimating decades- to millennial-scale glacial runoff into Lakes Fryxell, Hoare and Bonney. The relationship between summer temperatures and melt is found to be exponential near the melting temperature. We propose a variety of simple models that are calibrated using measured discharge from a number of streams draining from ten glaciers in Taylor Valley. The surface melting rate is constrained by mass-balance measurements from four of the glaciers. A model based solely on temperature produced good results (coefficient of determination, r2 = 0.71) for the south-facing glaciers, but poor results for the north-facing glaciers (r2 < 0). The inclusion of a solar radiation index increased the modeled melt from the north-facing glaciers and thus improved the results (r2 = 0.73) for the north-facing glaciers, with little change from the south-facing glaciers. Including a wind index did not improve the correlation between modeled and measured runoff.
Observed meteorological data and a high-resolution (5 km) model were used to simulate Greenland ice sheet surface melt extent and trends before the satellite era (1960–79) and during the satellite era through 2010°. The model output was compared with passive microwave satellite observations of melt extent. For 1960–2010 the average simulated melt extent was 15 ± 5%. For the period 1960–72, simulated melt extent decreased by an average of 6%, whereas 1973–2010 had an average increase of 13%, with record melt extent in 2010. The trend in simulated melt extent since 1972 indicated that the melt extent in 2010 averaged twice that in the early 1970s. The maximum and mean melt extents for 2010 were 52% (∼9.5 × 105 km2) and 28% (∼5.2 × 105 km2), respectively, due to higher-than-average winter and summer temperatures and lower-than-average winter precipitation. For 2010, the southwest Greenland melt duration was 41–60 days longer than the 1960–2010 average, while the northeast Greenland melt duration was up to 20 days shorter. From 1960 to 1972 the melting period (with a >10% melt extent) decreased by an average of 3 days a−1. After 1972, the period increased by an average of 2 days a−1, indicating an extended melting period for the ice sheet of about 70 days: 40 and 30 days in spring and autumn, respectively.