Analysis of antibiotic utilization review at Landspitalinn, the University Hospital in Iceland

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenObjective: To describe the application of and analyze the cost effects of antibiotic utilization review at Landspitalinn, the National University Hospital in Iceland, and review the use of prophylactic antibiotics in a general surgical ward. Material and methods: The study was undertaken during a two month period in 1996. Patients in wards 11-A and 11-B (general medical floors), ward 12-G (general surgery service) and 11-E (hematology service) were enrolled. A specialist in infectious diseases and a clinical pharmacist reviewed the antibiotic treatment daily. If felt appropriate a recommendation to change treatment was forwarded. The number of patients treated with antibiotics, recommendations, recommendations accepted, and types of suggestions were recorded. Minimal savings per day were calculated by subtracting the cost of the antibiotic treatment after recommended modifications from the cost of the previous treatment. Prophylactic surgical treatment was examined in ward 12-G during an additional month. Results: One hundred and fifty patients were treated with antibiotics during January and February 1996. The percentage of cases where changes in antibiotic treatment was recommended was 74% in 12-G, 65% in 11-E but 33% and 32% in 11-A and 11-B respectively. In ward 11-E, 80% of the recommendations were accepted and appropriate changes made, corresponding figures for the other wards were 93-100%. The most frequently recommended changes were stopping antibiotics (33%), reducing doses (31%) and switching to oral agents (19%). The minimum savings were estimated at ISK 210 000 per month if the effects of recommendations that were accepted were presumed to have lasted three days. Four percent of prescribed prophylactic surgical treatment was according to approved standards. Conclusions: The results confirm the need to optimize the use of antibiotics at The National University Hospital. The antibiotic utilization review was well received and acceptance of recommendations was high. The application of antibiotic utilization review to the entire hospital could reduce antibiotic cost by as much as 30-36%.Markmið: Að gera grein fyrir framkvæmd og kanna kostnaðaráhrif sýklalyfjaeftirlits á Landspítalanum. Einnig var könnuð notkun sýklalyfja í varnandi skyni á skurðdeild. Efniviður og aðferðir: Rannsóknin var framkvæmd í janúar til mars 1996. Fylgst var með sýklalyfjameðferð hjá sjúklingum á deild-um 11-A og 11-B (almennar lyflækningadeildir), 12-G (almenn handlækningadeild) og 11-E (blóðfræðideild). Sérfræðingur í smitsjúkdómum og klínískur lyfjafræðingur fóru yfir sýklalyfjameðferðina daglega. Ef ástæða þótti til var lögð fram ráðlegging um breytingu á sýklalyfjameðferð. Læknar sjúklings ákváðu hvort ráðleggingum var fylgt. Skráður var fjöldi sjúklinga á sýklalyfjum, fjöldi ráðlegginga, eðli þeirra og hlutfall sem var fylgt. Lágmarkssparnaður var fundinn með því að draga kostnað við sýklalyfjameðferð eftir breytingu frá kostnaði fyrir breytingu. Skráð var varnandi sýklalyfjameðferð sem beitt var á deild 12-G í mars 1996 og hún borin saman við samþykktar leiðbeiningar um slíka meðferð í lyfjalista Landspítalans.Niðurstöður: Eitthundrað og fimmtíu sjúklingar voru meðhöndlaðir með sýklalyfjum í janúar og febrúar 1996. Hlutfall ráðlegginga um breytingu á meðferð var 74% á deild 12-G, 65% á 11-E en 33% og 32% á 11-A og 11-B. Fylgt var 80% ráðlegginga á deild 11-E en 93-100% á öðrum deildum. Algengustu ástæður ráðlegginga um breytingar á sýklalyfjameðferð voru: stöðvun meðferðar (33%), lækkun skammta (31%) og breytingar á meðferð úr stungulyfi í meðferð um munn (19%). Lágmarkssparnaður var metinn 70-210.000 krónur á mánuði ef reiknað var með að ráðleggingar hefðu áhrif í einn til þrjá daga. í mars voru 4% varnandi meðferðar fyrir skurðaðgerðir á deild 12-G í samræmi við samþykktar leiðbeiningar. Ályktanir: Niðurstöður okkar styðja nauðsyn þess að bæta sýklalyfjameðferð á Landspítalanum. Sýklalyfjaeftirliti var vel tekið og ráðleggingum fylgt í 80-100% tilvika. Eftirlit með sýklalyfjanotkun á Landspítalanum öllum gæti leitt til sparnaðar sem næmi allt að 30-36% sýklalyfjakostnaðar

Analysis of antibiotic utilization review at Landspitalinn, the University Hospital in Iceland

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenObjective: To describe the application of and analyze the cost effects of antibiotic utilization review at Landspitalinn, the National University Hospital in Iceland, and review the use of prophylactic antibiotics in a general surgical ward. Material and methods: The study was undertaken during a two month period in 1996. Patients in wards 11-A and 11-B (general medical floors), ward 12-G (general surgery service) and 11-E (hematology service) were enrolled. A specialist in infectious diseases and a clinical pharmacist reviewed the antibiotic treatment daily. If felt appropriate a recommendation to change treatment was forwarded. The number of patients treated with antibiotics, recommendations, recommendations accepted, and types of suggestions were recorded. Minimal savings per day were calculated by subtracting the cost of the antibiotic treatment after recommended modifications from the cost of the previous treatment. Prophylactic surgical treatment was examined in ward 12-G during an additional month. Results: One hundred and fifty patients were treated with antibiotics during January and February 1996. The percentage of cases where changes in antibiotic treatment was recommended was 74% in 12-G, 65% in 11-E but 33% and 32% in 11-A and 11-B respectively. In ward 11-E, 80% of the recommendations were accepted and appropriate changes made, corresponding figures for the other wards were 93-100%. The most frequently recommended changes were stopping antibiotics (33%), reducing doses (31%) and switching to oral agents (19%). The minimum savings were estimated at ISK 210 000 per month if the effects of recommendations that were accepted were presumed to have lasted three days. Four percent of prescribed prophylactic surgical treatment was according to approved standards. Conclusions: The results confirm the need to optimize the use of antibiotics at The National University Hospital. The antibiotic utilization review was well received and acceptance of recommendations was high. The application of antibiotic utilization review to the entire hospital could reduce antibiotic cost by as much as 30-36%.Markmið: Að gera grein fyrir framkvæmd og kanna kostnaðaráhrif sýklalyfjaeftirlits á Landspítalanum. Einnig var könnuð notkun sýklalyfja í varnandi skyni á skurðdeild. Efniviður og aðferðir: Rannsóknin var framkvæmd í janúar til mars 1996. Fylgst var með sýklalyfjameðferð hjá sjúklingum á deild-um 11-A og 11-B (almennar lyflækningadeildir), 12-G (almenn handlækningadeild) og 11-E (blóðfræðideild). Sérfræðingur í smitsjúkdómum og klínískur lyfjafræðingur fóru yfir sýklalyfjameðferðina daglega. Ef ástæða þótti til var lögð fram ráðlegging um breytingu á sýklalyfjameðferð. Læknar sjúklings ákváðu hvort ráðleggingum var fylgt. Skráður var fjöldi sjúklinga á sýklalyfjum, fjöldi ráðlegginga, eðli þeirra og hlutfall sem var fylgt. Lágmarkssparnaður var fundinn með því að draga kostnað við sýklalyfjameðferð eftir breytingu frá kostnaði fyrir breytingu. Skráð var varnandi sýklalyfjameðferð sem beitt var á deild 12-G í mars 1996 og hún borin saman við samþykktar leiðbeiningar um slíka meðferð í lyfjalista Landspítalans.Niðurstöður: Eitthundrað og fimmtíu sjúklingar voru meðhöndlaðir með sýklalyfjum í janúar og febrúar 1996. Hlutfall ráðlegginga um breytingu á meðferð var 74% á deild 12-G, 65% á 11-E en 33% og 32% á 11-A og 11-B. Fylgt var 80% ráðlegginga á deild 11-E en 93-100% á öðrum deildum. Algengustu ástæður ráðlegginga um breytingar á sýklalyfjameðferð voru: stöðvun meðferðar (33%), lækkun skammta (31%) og breytingar á meðferð úr stungulyfi í meðferð um munn (19%). Lágmarkssparnaður var metinn 70-210.000 krónur á mánuði ef reiknað var með að ráðleggingar hefðu áhrif í einn til þrjá daga. í mars voru 4% varnandi meðferðar fyrir skurðaðgerðir á deild 12-G í samræmi við samþykktar leiðbeiningar. Ályktanir: Niðurstöður okkar styðja nauðsyn þess að bæta sýklalyfjameðferð á Landspítalanum. Sýklalyfjaeftirliti var vel tekið og ráðleggingum fylgt í 80-100% tilvika. Eftirlit með sýklalyfjanotkun á Landspítalanum öllum gæti leitt til sparnaðar sem næmi allt að 30-36% sýklalyfjakostnaðar

Measurements of plasma HIV-1 RNA in Iceland

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenObjective: First to measure plasma HIV-1 RNA in Icelandic HIV infected individuals and second to evaluate the initial effects of new combination regimens on viral load and CD4+ cell counts in HIV infected patients in Iceland. Material and methods: The cohort studied consis¬ted of all HIV infected individuals we received samples from during the period September 1995 to November 1996. HIV-1 RNA and CD4+ cells were measured initially and subsequently every three to six months except when a change was made in the antiretroviral regimen, when samples were measured before the change, three to four weeks later and then every three to six months. The quantitative measurement of viral RNA was performed using the Amplicor HIV Monitor™ Test (Roche Diagnostic Sys¬tems). CD4+ cell counts were measured by flow cytometry. Results: A total of 44 patients were evaluated. The initial RNA ranged from < 2.6 logio to 6.13 logio with a mean of 5.02 log. CD4+ cell counts ranged from 2 to 641 per mm3 (mean 230 cells/mm3). Eleven patients had never been treated with antiretroviral drugs and had greater than 10 000 viral copies per mL of plasma. Twenty five of the patients were evaluated following a change in or initiation of a new treatment. The initial change in treatment led to a +0.7 to -2.88 log change in plasma RNA (mean -0.9 log) and a mean of 6.9 cells per mm3 increase in CD4+ cells. Saquinavir was added to two reverse transcriptase (RT) inhibitors in 11 patients with a resulting mean of 0.23 log fall in RNA levels (range +0.70 log to -0.78 log). Saquinavir plus one RT inhibitor were added to one RT inhibitor in six patients with a subsequent mean of 0.65 log reduction in viral load (range +0.24 to -2.26 log). Saquinavir plus two RT inhibitors were given to four antiretroviral naive patients with a resulting mean of 2.37 log reduction in viral load (range -1.8 log to -2.67 log). Conclusions: 1. In a mixed cohort of RT inhibitor naive and treated patients, the viral RNA ranged throughout the range of the RNA assay. 2. Changes in viral load following changes in treatment were quite variable. 3. Saquinavir alone added to two RT inhibitors did not lead to a significant reduction in viral load. 4. In antiretroviral naive patients the viral load was reduced 100 fold following treatment with saquinavir and two RT inhibitors.Markmið: Annars vegar að mæla HIV-1 (human immunodeficiency virus) RNA í plasma HIV sýktra einstaklinga á Íslandi og hins vegar að meta áhrif nýrra lyfjasamsetninga á magn veiru í plasma og fjölda CD4+ frumna í blóði. Aðferðir: Fylgst var með öllum HIV sýktum einstaklingum sem sýni bárust frá á tímabilinu September 1995 til nóvember 1996. Blóð var dregið til mælinga á RNA í plasma og oftast einnig talningar á CD4+ frumum á þriggja til sex mánaða fresti nema þegar lyfjameðferð var breytt, en þá voru sýni mæld fyrir breytingu, þremur til fjórum vikum síðar og á þriggja til sex mánaða fresti í kjölfarið. Magn veiru í plasma var ákvarðað með Amplicor HIV Monitor™ prófi frá Roche. Fjöldi CD4+ frumna var greindur með flúrljómandi mótefnamerkingu og talningu í flæðifrumusjá. Niðurstöður: Fylgst var með 44 sjúklingum. Upphafsgildi RNA var frá 2,6 logio til 6,13 logio; að meðaltali 5,02 log. Fjöldi CD4+ frumna var á bilinu 2-641 fruma/mm3; að meðaltali 230 frumur/mm3. Ellefu einstaklingar höfðu ekki verið meðhöndlaðir með HIV bælandi lyfjum og greindust með fleiri en 10.000 veirueintök í mL plasma. Meðferð var breytt hjá 25 sjúklingum. Breyting veirumagns hjá öllum hópnum fyrir og eftir meðferð var allt frá 0,7 log aukningu (+0,7 log) niður í 2,88 log lækkun (-2,88), sem er að meðaltali minnkun um 0,9 log. Breyting á fjölda CD4+ frumna spannaði fækkun um 195 frumur/mm3 í aukn¬ingu um 143 frumur/mm3. Meðaltalið var aukn-ing um 6,9 frumur/mm3. Hjá 11 sjúklingum sem meðhöndlaðir voru með tveimur bakritahemlum var sakvínavír, próteasahemli, bætt við meðferðina. Breyting á veirumagni spann-aði frá +0,7 til -0,78 log og meðaltalið var -0,23 log. Sex sjúklingar voru meðhöndlaðir með einum bakritahemli. Sakvínavír og öðrum bakritahemli var bætt við þá meðferð. Breyting veirumagns var frá +0,24 log í -2,26 log; meðaltal -0,65 log. Fjórir einstaklingar höfðu ekki verið meðhöndlaðir áður. Hafin var meðferð með tveimur bakritahemlum og sakvínavír. Magn veiru lækkaði frá -1,8 til -2,67 log; meðaltalið var -2,37 log. Ályktanir: 1. RNA gildi HIV sýktra spönnuðu allt svið mælingaraðferðarinnar. 2. Breytingar veirumagns í kjölfar breytinga á meðferð voru töluvert einstaklingsbundnar. 3. Ekki mældist marktæk lækkun veiru þegar sakvínavír einu sér var bætt við tvo bakritahemla. 4. Veirumagn í blóði sjúklinga sem ekki höfðu fengið meðferð áður lækkaði að meðaltali rúmlega hundraðfalt í kjölfar meðferðar með sakvínavír og tveimur bakritahemlum

Measurements of plasma HIV-1 RNA in Iceland

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenObjective: First to measure plasma HIV-1 RNA in Icelandic HIV infected individuals and second to evaluate the initial effects of new combination regimens on viral load and CD4+ cell counts in HIV infected patients in Iceland. Material and methods: The cohort studied consis¬ted of all HIV infected individuals we received samples from during the period September 1995 to November 1996. HIV-1 RNA and CD4+ cells were measured initially and subsequently every three to six months except when a change was made in the antiretroviral regimen, when samples were measured before the change, three to four weeks later and then every three to six months. The quantitative measurement of viral RNA was performed using the Amplicor HIV Monitor™ Test (Roche Diagnostic Sys¬tems). CD4+ cell counts were measured by flow cytometry. Results: A total of 44 patients were evaluated. The initial RNA ranged from < 2.6 logio to 6.13 logio with a mean of 5.02 log. CD4+ cell counts ranged from 2 to 641 per mm3 (mean 230 cells/mm3). Eleven patients had never been treated with antiretroviral drugs and had greater than 10 000 viral copies per mL of plasma. Twenty five of the patients were evaluated following a change in or initiation of a new treatment. The initial change in treatment led to a +0.7 to -2.88 log change in plasma RNA (mean -0.9 log) and a mean of 6.9 cells per mm3 increase in CD4+ cells. Saquinavir was added to two reverse transcriptase (RT) inhibitors in 11 patients with a resulting mean of 0.23 log fall in RNA levels (range +0.70 log to -0.78 log). Saquinavir plus one RT inhibitor were added to one RT inhibitor in six patients with a subsequent mean of 0.65 log reduction in viral load (range +0.24 to -2.26 log). Saquinavir plus two RT inhibitors were given to four antiretroviral naive patients with a resulting mean of 2.37 log reduction in viral load (range -1.8 log to -2.67 log). Conclusions: 1. In a mixed cohort of RT inhibitor naive and treated patients, the viral RNA ranged throughout the range of the RNA assay. 2. Changes in viral load following changes in treatment were quite variable. 3. Saquinavir alone added to two RT inhibitors did not lead to a significant reduction in viral load. 4. In antiretroviral naive patients the viral load was reduced 100 fold following treatment with saquinavir and two RT inhibitors.Markmið: Annars vegar að mæla HIV-1 (human immunodeficiency virus) RNA í plasma HIV sýktra einstaklinga á Íslandi og hins vegar að meta áhrif nýrra lyfjasamsetninga á magn veiru í plasma og fjölda CD4+ frumna í blóði. Aðferðir: Fylgst var með öllum HIV sýktum einstaklingum sem sýni bárust frá á tímabilinu September 1995 til nóvember 1996. Blóð var dregið til mælinga á RNA í plasma og oftast einnig talningar á CD4+ frumum á þriggja til sex mánaða fresti nema þegar lyfjameðferð var breytt, en þá voru sýni mæld fyrir breytingu, þremur til fjórum vikum síðar og á þriggja til sex mánaða fresti í kjölfarið. Magn veiru í plasma var ákvarðað með Amplicor HIV Monitor™ prófi frá Roche. Fjöldi CD4+ frumna var greindur með flúrljómandi mótefnamerkingu og talningu í flæðifrumusjá. Niðurstöður: Fylgst var með 44 sjúklingum. Upphafsgildi RNA var frá 2,6 logio til 6,13 logio; að meðaltali 5,02 log. Fjöldi CD4+ frumna var á bilinu 2-641 fruma/mm3; að meðaltali 230 frumur/mm3. Ellefu einstaklingar höfðu ekki verið meðhöndlaðir með HIV bælandi lyfjum og greindust með fleiri en 10.000 veirueintök í mL plasma. Meðferð var breytt hjá 25 sjúklingum. Breyting veirumagns hjá öllum hópnum fyrir og eftir meðferð var allt frá 0,7 log aukningu (+0,7 log) niður í 2,88 log lækkun (-2,88), sem er að meðaltali minnkun um 0,9 log. Breyting á fjölda CD4+ frumna spannaði fækkun um 195 frumur/mm3 í aukn¬ingu um 143 frumur/mm3. Meðaltalið var aukn-ing um 6,9 frumur/mm3. Hjá 11 sjúklingum sem meðhöndlaðir voru með tveimur bakritahemlum var sakvínavír, próteasahemli, bætt við meðferðina. Breyting á veirumagni spann-aði frá +0,7 til -0,78 log og meðaltalið var -0,23 log. Sex sjúklingar voru meðhöndlaðir með einum bakritahemli. Sakvínavír og öðrum bakritahemli var bætt við þá meðferð. Breyting veirumagns var frá +0,24 log í -2,26 log; meðaltal -0,65 log. Fjórir einstaklingar höfðu ekki verið meðhöndlaðir áður. Hafin var meðferð með tveimur bakritahemlum og sakvínavír. Magn veiru lækkaði frá -1,8 til -2,67 log; meðaltalið var -2,37 log. Ályktanir: 1. RNA gildi HIV sýktra spönnuðu allt svið mælingaraðferðarinnar. 2. Breytingar veirumagns í kjölfar breytinga á meðferð voru töluvert einstaklingsbundnar. 3. Ekki mældist marktæk lækkun veiru þegar sakvínavír einu sér var bætt við tvo bakritahemla. 4. Veirumagn í blóði sjúklinga sem ekki höfðu fengið meðferð áður lækkaði að meðaltali rúmlega hundraðfalt í kjölfar meðferðar með sakvínavír og tveimur bakritahemlum

SO2 emission rates and incorporation into the air pollution dispersion forecast during the 2021 eruption of Fagradalsfjall, Iceland

During the low-effusion rate Fagradalsfjall eruption (19 March – 18 September 2021), the emission of sulfur dioxide (SO2) was frequently measured using ground-based UV spectrometers. The total SO2 emitted during the entire eruption was 970 ± 540 kt, which is only about 6% of the SO2 emitted during the similar length Holuhraun eruption (2014–2015). The eruption was divided into five phases based on visual observations, including the number of active vents and the occurrence of lava fountaining. The SO2 emission rate ranged from 44 ± 19 kg/s in Phase 2 to 85 ± 29 kg/s in Phase 5, with an average of 64 ± 34 kg/s for the entire eruption. There was notable variability in SO2 on short timescales, with measurements on 11 August 2021 ranging from 17 to 78 kg/s. SO2 flux measurements were made using scanning DOAS instruments located at different distances from and orientations relative to the eruption site augmented by traverses. Four hundred and forty-four scan and traverse measurements met quality criteria and were used, along with plume height and meteorological data, to calculate SO2 fluxes while accounting for wind-related uncertainties. A tendency for stronger SO2 flux concurrent with higher amplitude seismic tremor and the occurrence of lava fountaining was observed during Phases 4 and 5 which were characterized by intermittent crater activity including observable effusion of lava and gas release interspersed with long repose times. This tendency was used to refine the calculation of the amount of SO2 emitted during variably vigorous activity. The continuous seismic tremor time series was used to quantify how long during these eruption phases strong/weak activity was exhibited to improve the calculated SO2 flux during these Phases. The total SO2 emissions derived from field measurements align closely with results obtained by combining melt inclusion and groundmass glass analyses with lava effusion rate measurements (910 ± 230 kt SO2). Specifically, utilizing the maximum S content found in evolved melt inclusions and the least remaining S content in accompanying quenched groundmasses provides an identical result between field measurements and the petrological calculations. This suggests that the maximum SO2 release calculated from petrological estimates should be preferentially used to initialize gas dispersion models for basaltic eruptions when other measurements are lacking. During the eruption, the CALPUFF dispersion model was used to forecast ground-level exposure to SO2. The SO2 emission rates measured by DOAS were used as input for the dispersion model, with updates made when a significant change was measured. A detailed analysis of one mid-distance station over the entire eruption shows that the model performed very well at predicting the presence of volcanic SO2 when it was measured. However, it frequently predicted the presence of SO2 that was not measured and the concentrations forecasted had no correlation with the concentrations measured. Various approaches to improve the model forecast were tested, including updating plume height and SO2 flux source terms based on measurements. These approaches did not unambiguously improve the model performance but suggest that improvements might be achieved in more-polluted conditions.Peer reviewe

Seismic and geodetic insights into magma accumulation at Katla subglacial volcano, Iceland: 1999 to 2005

International audienceKatla is one of Iceland's most active volcanoes with at least 20 eruptions in the last 1100 years. The volcano is covered mostly by the Mýrdalsjökull ice cap; consequently, Katla eruptions are phreato-magmatic and are capable of producing jökulhlaups. A jökulhlaup in July 1999, preceded by an episode of continuous seismic tremor, was the first sign of renewed magma movement under the volcano since 1955. Using seismic and geodetic observations, and insights into geothermal activity from ice-surface observations, we analyze this period of unrest and assess the present state of Katla volcano. From 1999 to 2004, GPS measurements on nunataks exposed on the caldera edge revealed steady inflation of the volcano. Our measurements show uplift and horizontal displacement of the nuntatak benchmarks at a rate of up to 2 cm a−1, together with horizontal displacement of far-field stations (>11 km) at about 0.5 cm a−1 away from the caldera centre. Using a point-source model, these data place the center of the magma chamber at 4.9 km depth beneath the northern part of the caldera. However, this depth may be overestimated because of a progressive decrease in the mass of the overlying ice cap. The depth may be only 2–3 km. About 0.01 km3 of magma has accumulated between 1999 and 2004; this value is considerably less than the estimated 1 km3 of material erupted during the last eruption of Katla in 1918. Presently, rates of crustal deformation and earthquake activity are considerably less than observed between 1999 and 2004; nonetheless, the volcano remains in an agitated state

Equalization of four cardiovascular risk algorithms after systematic recalibration: individual-participant meta-analysis of 86 prospective studies.

AIMS: There is debate about the optimum algorithm for cardiovascular disease (CVD) risk estimation. We conducted head-to-head comparisons of four algorithms recommended by primary prevention guidelines, before and after 'recalibration', a method that adapts risk algorithms to take account of differences in the risk characteristics of the populations being studied. METHODS AND RESULTS: Using individual-participant data on 360 737 participants without CVD at baseline in 86 prospective studies from 22 countries, we compared the Framingham risk score (FRS), Systematic COronary Risk Evaluation (SCORE), pooled cohort equations (PCE), and Reynolds risk score (RRS). We calculated measures of risk discrimination and calibration, and modelled clinical implications of initiating statin therapy in people judged to be at 'high' 10 year CVD risk. Original risk algorithms were recalibrated using the risk factor profile and CVD incidence of target populations. The four algorithms had similar risk discrimination. Before recalibration, FRS, SCORE, and PCE over-predicted CVD risk on average by 10%, 52%, and 41%, respectively, whereas RRS under-predicted by 10%. Original versions of algorithms classified 29-39% of individuals aged ≥40 years as high risk. By contrast, recalibration reduced this proportion to 22-24% for every algorithm. We estimated that to prevent one CVD event, it would be necessary to initiate statin therapy in 44-51 such individuals using original algorithms, in contrast to 37-39 individuals with recalibrated algorithms. CONCLUSION: Before recalibration, the clinical performance of four widely used CVD risk algorithms varied substantially. By contrast, simple recalibration nearly equalized their performance and improved modelled targeting of preventive action to clinical need