WHAT FACTORS AFFECT SECONDARY SCHOOL STUDENTS’ PERFORMANCE IN SCIENCE IN THE DEVELOPING COUNTRIES? A CONCEPTUAL MODEL FOR AN EXPLORATION

This paper develops a conceptual framework to explore the factors affecting secondary school students’ performance in science in the developing countries. While the various factors are related to the increased academic performance, the specific mechanisms through which those factors exert their influence on a child's academic performance are not yet fully understood. Based on both sociological and psychological theories and empirical studies, socioeconomic status, parental involvement, school resources and teacher quality as independent variables and motivation towards learning science as a mediating variable were incorporated into the proposed framework. Appropriate instruments for the exploration are suggested. While the conceptual framework developed in the present study lessening the knowledge gap pertaining to the factors affecting students’ performance in science, especially in the developing countries, it paves a path to explore the effect of those factors on students’ performance.  Article visualizations

Measurement of D-s(+) and D-s(*+) production in B meson decays and from continuum e(+)e(-) annihilation at root s=10.6 GeV

New measurements of D-s(+) and D-s(*+) meson production rates from B decays and from q(q) over bar continuum events near the Y(4S) resonance are presented. Using 20.8 fb(-1) of data on the Y(4S) resonance and 2.6 fb(-1) off-resonance, we find the inclusive branching fractions B(B-->Ds+X) = (10.93+/-0.19+/-0.58+/-2.73)% and B(B-->Ds*+X) = (7.9+/-0.8+/-0.7+/-2.0)%, where the first error is statistical, the second is systematic, and the third is due to the D-s(+)-->phipi(+) branching fraction uncertainty. The production cross sections sigma(e(+)e(-)-->Ds+X)xB(D-s(+)-->phipi(+)) = 7.55+/-0.20+/-0.34 pb and sigma(e(+)e(-)-->Ds*+/-X)xB(D-s(+)-->phipi(+)) = 5.8+/-0.7+/-0.5 pb are measured at center-of-mass energies about 40 MeV below the Y(4S) mass. The branching fractions SigmaB(B-->D-s((*)+)(D) over bar ((*))) = (5.07+/-0.14+/-0.30+/-1.27)% and SigmaB(B-->D-s(*+)(D) over bar ((*))) = (4.1+/-0.2+/-0.4+/-1.0)% are determined from the D-s((*)+) momentum spectra. The mass difference m(D-s(+)) -m(D+) = 98.4+/-0.1+/-0.3 MeV/c(2) is also measured

Measurement of Ds+ and Ds*+ production in B meson decays and from continuum e+e- annihilation at √s=10.6 GeV

New measurements of Ds+ and Ds*+ meson production rates from B decays and from qq̅ continuum events near the Υ(4S) resonance are presented. Using 20.8 fb-1 of data on the Υ(4S) resonance and 2.6 fb-1 off-resonance, we find the inclusive branching fractions B(B⃗Ds+X)=(10.93±0.19±0.58±2.73)% and B(B⃗Ds*+X)=(7.9±0.8±0.7±2.0)%, where the first error is statistical, the second is systematic, and the third is due to the Ds+→φπ+ branching fraction uncertainty. The production cross sections σ(e+e-→Ds+X)×B(Ds+→φπ+)=7.55±0.20±0.34pb and σ(e+e-→Ds*±X)×B(Ds+→φπ+)=5.8±0.7±0.5pb are measured at center-of-mass energies about 40 MeV below the Υ(4S) mass. The branching fractions ΣB(B⃗Ds(*)+D(*))=(5.07±0.14±0.30±1.27)% and ΣB(B⃗Ds*+D(*))=(4.1±0.2±0.4±1.0)% are determined from the Ds(*)+ momentum spectra. The mass difference m(Ds+)-m(D+)=98.4±0.1±0.3MeV/c2 is also measured

Measurement of D+(s) and D*+(s) production in B meson decays and from continuum e+ e- annihilations at s**(1/2) = 10.6-GeV.

none622Bernard Aubert; D. Boutigny; J.M. Gaillard; A. Hicheur; Y. Karyotakis; J.P. Lees; P. Robbe; V. Tisserand; A. Palano; G.P. Chen; J.C. Chen; N.D. Qi; G. Rong; P. Wang; Y.S. Hz; G. Eigen; P.L. Reinertsen; B. Stugu; B. Abbott; G.S. Abrams; A.W. Borgland; A.B. Breon; David Nathan Brown; Janice Button-Shafer; R.N. Cahn; A.R. Clark; M.S. Gill; A.V. Gritsan; Y. Groysman; R.G. Jacobsen; R.W. Kadel; J. Kadyk; L.T. Kerth; S. Kluth; Yu.G. Kolomensky; J.F. Kral; C. LeClerc; M.E. Levi; T. Liu; G. Lynch; A.B. Meyer; M. Momayezi; P.J. Oddone; A. Perazzo; M. Pripstein; N.A. Roe; A. Romosan; M.T. Ronan; V.G. Shelkov; A.V. Telnov; W.A. Wenzel; P.G. Bright-Thomas; T.J. Harrison; C.M. Hawkes; D.J. Knowles; S.W. O'Neale; R.C. Penny; A.T. Watson; N.K Watson; T. Deppermann; K. Goetzen; H. Koch; J. Krug; M. Kunze; B. Lewandowski; K. Peters; H. Schmuecker; M. Steinke; J.C. Andress; N.R. Barlow; W. Bhimji; N. Chevalier; P.J. Clark; W.N. Cottingham; N. De Groot; N. Dyce; B. Foster; J.D. McFall; D. Wallom; F.F. Wilson; K. Abe; C. Hearty; T.S. Mattison; J.A. McKenna; D. Thiessen; S. Jolly; A.K. McKemey; Jane S. Tinslay; V.E. Blinov; A.D. Bukin; D.A. Bukin; A.R. Buzykaev; V.B. Golubev; V.N. Ivanchenko; A.A. Korol; E.A. Kravchenko; A.P. Onuchin; A.A. Salnikov; S.I. Serednyakov; Yu.I. Skovpen; Valery I. Telnov; A.N. Yushkov; D. Best; A.J. Lankford; M. Mandelkern; S. McMahon; D.P. Stoker; A. Ahsan; K. Arisaka; C. Buchanan; S. Chun; J.G. Branson; D.B. MacFarlane; Soeren A. Prell; S. Rahatlou; G. Raven; V. Sharma; C. Campagnari; B. Dahmes; P.A. Hart; N. Kuznetsova; S.L. Levy; O. Long; A. Lu; J.D. Richman; W. Verkerke; Michael S. Witherell; S. Yellin; J. Beringer; D.E. Dorfan; A.M. Eisner; A. Frey; A.A. Grillo; M. Grothe; C.A. Heusch; R.P. Johnson; W. Kroeger; William S. Lockman; T. Pulliam; H. Sadrozinski; T. Schalk; R.E. Schmitz; B.A. Schumm; A. Seiden; M. Turri; W. Walkowiak; D.C. Williams; M.G. Wison; E. Chen; G.P. Dubois-Felsmann; A. Dvoretskii; D.G. Hitlin; S. Metzler; J. Oyang; F.C. Porter; A. Ryd; A. Samuel; M. Weaver; S. Yang; R.Y. Zhu; S. Devmal; T.L. Geld; S. Jayatilleke; G. Mancinelli; B.T. Meadows; M.D. Sokoloff; T. Barillari; P. Bloom; M.O. Dima; S. Fahey; William T. Ford; D.R. Johnson; U. Nauenberg; A. Olivas; H. Park; P. Rankin; J. Roy; S. Sen; James G. Smith; W.C. van Hoek; D.L. Wagner; J. Blouw; John L. Harton; M. Krishnamurthy; A. Soffer; W.H. Toki; R.J. Wilson; J. Zhang; T. Brandt; J. Brose; T. Colberg; G. Dahlinger; M. Dickopp; R.S. Dubitzky; A. Hauke; E. Maly; R. Muller-Pfefferkorn; S. Otto; Klaus R. Schubert; R. Schwierz; B. Spaan; L. Wilden; L. Behr; Denis Bernard; 1; G.R. Bonneaud; F. Brochard; J. Cohen-Tanugi; S. Ferrag; E. Roussot; S. T'Jampens; C. Thiebaux; G. Vasileiadis; M. Verderi; A. Anjomshoaa; R. Bernet; A. Khan; D. Lavin; F. Muheim; S. Playfer; J.E. Swain; M. Falbo; C. Borean; C. Bozzi; S. Dittongo; M. Folegani; L. Piemontese; E. Treadwell; F. Anulli; R. Baldini-Ferroli; A. Calcaterra; R. de Sangro; D. Falciai; G. Finocchiaro; P. Patteri; I.M. Peruzzi; M. Piccolo; Y. Xie; A. Zallo; S. Bagnasco; A. Buzzo; R. Contri; G. Crosetti; P. Fabbricatore; S. Farinon; M. Lo Vetere; M. Macri; M.R. Monge; R. Musenich; M. Pallavicini; R. Parodi; S. Passaggio; F.C. Pastore; C. Patrignani; M.G. Pia; C. Priano; E. Robutti; A. Santroni; M. Morii; R. Bartoldus; T. Dignan; R. Hamilton; U. Mallik; J. Cochran; H.B. Crawley; P.A. Fischer; J. Lamsa; W.T. Meyer; E.I. Rosenberg; M. Benkebil; G. Grosdidier; C. Hast; Andreas Hocker; H.M. Lacker; S. Laplace; V. Lepeltier; A.M. Lutz; S. Plaszczynski; M.H. Schune; S. Trincaz-Duvoid; A. Valassi; G. Wormser; R.M. Bionta; V. Brigljevic; D.J. Lange; M. Mugge; X. Shi; K. van Bibber; T.J. Wenaus; D.M. Wright; C.R. Wuest; M. Carroll; J.R. Fry; E. Gabathuler; R. Gamet; M. George; M. Kay; D.J. Payne; R.J. Sloane; C. Touramanis; M.L. Aspinwall; D.A. Bowerman; Paul D. Dauncey; U. Egede; Ivo M. Gough Eschrich; N.J.W. Gunawardane; J.A. Nash; P. Sanders; D. Smith; D.E. Azzopardi; J.J. Back; P. Dixon; P.F. Harrison; R.J.L. Potter; H.W. Shorthouse; P. Strother; P.B. Vidal; M.I. Williams; G. Cowan; S. George; M.G. Green; A. Kurup; C.E. Marker; P. McGrath; T.R. McMahon; S. Ricciardi; F. Salvatore; I. Scott; G. Vaitsas; David Norvil Brown; C.L. Davis; John Allison; Roger J. Barlow; J.T. Boyd; A.C. Forti; J. Fullwood; F. Jackson; G.D. Lafferty; N. Savvas; E.T. Simopoulos; J.H. Weatherall; A. Farbin; A. Jawahery; V. Lillard; J. Olsen; D.A. Roberts; J.R. Schieck; G. Blaylock; C. Dallapiccola; K.T. Flood; Stanley S. Hertzbach; R. Kofler; T.B. Moore; H. Staengle; Stephane Willocq; B. Brau; R. Cowan; G. Sciolla; F. Taylor; R.K. Yamamoto; M. Milek; P.M. Patel; J. Trischuk; F. Lanni; F. Palombo; J.M. Bauer; M. Booke; L. Cremaldi; V. Eschenburg; R. Kroeger; J. Reidy; D.A. Sanders; D.J. Summers; J.P. Martin; J.Y. Nief; R. Seitz; P. Taras; A. Woch; V. Zacek; H. Nicholson; C.S. Sutton; C. Cartaro; N. Cavallo; G. De Nardo; F. Fabozzi; C. Gatto; L. Lista; P. Paolucci; D. Piccolo; C. Sciacca; J.M. LoSecco; J.R.G. Alsmiller; T.A. Gabriel; T. Handler; J. Brau; R. Frey; M. Iwasaki; N.B. Sinev; David M. Strom; F. Colecchia; F. Dal Corso; A. Dorigo; F. Galeazzi; M. Margoni; G. Michelon; M. Morandin; M. Posocco; M. Rotondo; F. Simonetto; R. Stroili; E. Torassa; C. Voci; Maurice Benayoun; H. Briand; J. Chauveau; P. David; C. de la Vaissiere; L. Del Buono; O. Hamon; F. Le Diberder; P Leruste; J. Lory; L. Roos; J. Stark; S. Versille; P. Manfredi; V. Re; V. Speziali; E.D. Frank; Larry D. Gladney; Q.H. Guo; J.H. Panetta; C. Angelini; G. Batignani; S. Bettarini; M. Bondioli; M. Carpinelli; F. Forti; M.A. Giorgi; A. Lusiani; F. Martinez-Vidal; M. Morganti; N. Neri; E. Paoloni; M. Rama; G. Rizzo; F. Sandrelli; G. Simi; G. Triggiani; J. Walsh; M. Haire; D. Judd; K. Paick; L. Turnbull; D.E. Wagoner; J. Albert; C. Bula; P. Elmer; C. Lu; K.T. McDonald; V. Miftakov; S.F. Schaffner; A.J.S. Smith; A. Tumanov; E.W. Varnes; G. Cavoto; D. del Re; R. Faccini; F. Ferrarotto; F. Ferroni; K. Fratini; E. Lamanna; Emanuele Leonardi; M.A. Mazzoni; Silvio Morganti; G. Piredda; F. Safai Tehrani; M. Serra; C. Voena; S. Christ; R. Waldi; P.F. Jacques; M. Kalelkar; R.J. Plano; T. Adye; B. Franek; N.I. Geddes; G.P. Gopal; S.M. Xella; R. Aleksan; G. De Domenico; S. Emery; A. Gaidot; S.F. Ganzhur; P.F. Giraud; W. Kozanecki; M. Langer; G.W. London; B. Mayer; B. Serfass; G. Vasseur; C. Yeche; M. Zito; N. Copty; M.V. Purohit; H. Singh; F.X. Yumiceva; I. Adam; P.L. Anthony; D. Aston; K. Baird; J.P. Berger; Elliott D. Bloom; A.M. Boyarski; F. Bulos; G. Calderini; R. Claus; M.R. Convery; D.P. Coupal; D.H. Coward; J. Dorfan; M. Doser; W. Dunwoodie; R.C. Field; T. Glanzman; G.L. Godfrey; S.J. Gowdy; P. Grosso; T. Himel; Tetiana Berger-Hryn'ova; M.E. Huffer; Walter R. Innes; C.P. Jessop; M.H. Kelsey; P. Kim; M.L. Kocian; Urs Langenegger; David W.G.S. Leith; S. Luitz; V. Luth; H.L. Lynch; H. Marsiske; S. Menke; R. Messner; K.C. Moffeit; R. Mount; D.R. Muller; C.P. O'Grady; M. Perl; S. Petrak; Helen R. Quinn; B.N. Ratcliff; S.H. Robertson; L.S. Rochester; A. Roodman; T. Schietinger; R.H. Schindler; J. Schwiening; V.V. Serbo; A. Snyder; A. Soha; S.M. Spanier; J. Stelzer; D. Su; M.K. Sullivan; H.A. Tanaka; J. Va'vra; S.R. Wagner; A.J.R. Weinstein; William J. Wisniewski; D.H. Wright; C.C. Young; P.R. Burchat; C.H. Cheng; David P. Kirkby; T.I. Meyer; C. Roat; R. Henderson; W. Bugg; H. Cohn; A.W. Weidemann; J.M. Izen; I. Kitayama; X.C. Lou; m. Turcotte; F. Bianchi; Marcella Bona; B. Di Girolamo; D. Gamba; A. Smol; D. Zanin; L. Bosisio; G. Della Ricca; L. Lanceri; A. Pompili; P. Poropat; M. Prest; E. Vallazza; G. Vuagnin; R.S. Panvini; C. Brown; Asoka S. De Silva; Robert V. Kowalewski; J.M. Roney; H.R. Band; E. Charles; S. Dasu; F. Di Lodovico; A.M. Eichenbaum; H. Hu; J.R. Johnson; R. Liu; J. Nielsen; Y. Pan; R. Prepost; I.J. Scott; J.H. von Wimmersperg-Toeller; S.L. Wu; Z. Yu; H. Zobernig; T.M.B. Kordich; H. NealBernard, Aubert; D., Boutigny; J. M., Gaillard; A., Hicheur; Y., Karyotakis; J. P., Lees; P., Robbe; V., Tisserand; A., Palano; G. P., Chen; J. C., Chen; N. D., Qi; G., Rong; P., Wang; Y. S., Hz; G., Eigen; P. L., Reinertsen; B., Stugu; B., Abbott; G. S., Abrams; A. W., Borgland; A. B., Breon; David Nathan, Brown; Janice Button, Shafer; R. N., Cahn; A. R., Clark; M. S., Gill; A. V., Gritsan; Y., Groysman; R. G., Jacobsen; R. W., Kadel; J., Kadyk; L. T., Kerth; S., Kluth; Kolomensky, Y. u. G.; J. F., Kral; C., Leclerc; M. E., Levi; T., Liu; G., Lynch; A. B., Meyer; M., Momayezi; P. J., Oddone; A., Perazzo; M., Pripstein; N. A., Roe; A., Romosan; M. T., Ronan; V. G., Shelkov; A. V., Telnov; W. A., Wenzel; P. G., Bright Thomas; T. J., Harrison; C. M., Hawkes; D. J., Knowles; S. W., O'Neale; R. C., Penny; A. T., Watson; N. K., Watson; T., Deppermann; K., Goetzen; H., Koch; J., Krug; M., Kunze; B., Lewandowski; K., Peters; H., Schmuecker; M., Steinke; J. C., Andress; N. R., Barlow; W., Bhimji; N., Chevalier; P. J., Clark; W. N., Cottingham; N., De Groot; N., Dyce; B., Foster; J. D., Mcfall; D., Wallom; F. F., Wilson; K., Abe; C., Hearty; T. S., Mattison; J. A., Mckenna; D., Thiessen; S., Jolly; A. K., Mckemey; Jane S., Tinslay; V. E., Blinov; A. D., Bukin; D. A., Bukin; A. R., Buzykaev; V. B., Golubev; V. N., Ivanchenko; A. A., Korol; E. A., Kravchenko; A. P., Onuchin; A. A., Salnikov; S. I., Serednyakov; Skovpen, Y. u. I.; Valery I., Telnov; A. N., Yushkov; D., Best; A. J., Lankford; M., Mandelkern; S., Mcmahon; D. P., Stoker; A., Ahsan; K., Arisaka; C., Buchanan; S., Chun; J. G., Branson; D. B., Macfarlane; Soeren A., Prell; S., Rahatlou; G., Raven; V., Sharma; C., Campagnari; B., Dahmes; P. A., Hart; N., Kuznetsova; S. L., Levy; O., Long; A., Lu; J. D., Richman; W., Verkerke; Michael S., Witherell; S., Yellin; J., Beringer; D. E., Dorfan; A. M., Eisner; A., Frey; A. A., Grillo; M., Grothe; C. A., Heusch; R. P., Johnson; W., Kroeger; William S., Lockman; T., Pulliam; H., Sadrozinski; T., Schalk; R. E., Schmitz; B. A., Schumm; A., Seiden; M., Turri; W., Walkowiak; D. C., Williams; M. G., Wison; E., Chen; G. P., Dubois Felsmann; A., Dvoretskii; D. G., Hitlin; S., Metzler; J., Oyang; F. C., Porter; A., Ryd; A., Samuel; M., Weaver; S., Yang; R. Y., Zhu; S., Devmal; T. L., Geld; S., Jayatilleke; G., Mancinelli; B. T., Meadows; M. D., Sokoloff; T., Barillari; P., Bloom; M. O., Dima; S., Fahey; William T., Ford; D. R., Johnson; U., Nauenberg; A., Olivas; H., Park; P., Rankin; J., Roy; S., Sen; James G., Smith; W. C., van Hoek; D. L., Wagner; J., Blouw; John L., Harton; M., Krishnamurthy; A., Soffer; W. H., Toki; R. J., Wilson; J., Zhang; T., Brandt; J., Brose; T., Colberg; G., Dahlinger; M., Dickopp; R. S., Dubitzky; A., Hauke; E., Maly; R., Muller Pfefferkorn; S., Otto; Klaus R., Schubert; R., Schwierz; B., Spaan; L., Wilden; L., Behr; Denis, Bernard; 1, ; G. R., Bonneaud; F., Brochard; J., Cohen Tanugi; S., Ferrag; E., Roussot; S., T'Jampens; C., Thiebaux; G., Vasileiadis; M., Verderi; A., Anjomshoaa; R., Bernet; A., Khan; D., Lavin; F., Muheim; S., Playfer; J. E., Swain; M., Falbo; C., Borean; C., Bozzi; S., Dittongo; M., Folegani; L., Piemontese; E., Treadwell; F., Anulli; R., Baldini Ferroli; A., Calcaterra; R., de Sangro; D., Falciai; G., Finocchiaro; P., Patteri; I. M., Peruzzi; M., Piccolo; Y., Xie; A., Zallo; S., Bagnasco; A., Buzzo; Contri, Roberto; G., Crosetti; P., Fabbricatore; S., Farinon; LO VETERE, Maurizio; M., Macri; Monge, MARIA ROBERTA; R., Musenich; Pallavicini, Marco; R., Parodi; S., Passaggio; F. C., Pastore; Patrignani, Claudia; M. G., Pia; C., Priano; E., Robutti; Santroni, Alberto; M., Morii; R., Bartoldus; T., Dignan; R., Hamilton; U., Mallik; J., Cochran; H. B., Crawley; P. A., Fischer; J., Lamsa; W. T., Meyer; E. I., Rosenberg; M., Benkebil; G., Grosdidier; C., Hast; Andreas, Hocker; H. M., Lacker; S., Laplace; V., Lepeltier; A. M., Lutz; S., Plaszczynski; M. H., Schune; S., Trincaz Duvoid; A., Valassi; G., Wormser; R. M., Bionta; V., Brigljevic; D. J., Lange; M., Mugge; X., Shi; K., van Bibber; T. J., Wenaus; D. M., Wright; C. R., Wuest; M., Carroll; J. R., Fry; E., Gabathuler; R., Gamet; M., George; M., Kay; D. J., Payne; R. J., Sloane; C., Touramanis; M. L., Aspinwall; D. A., Bowerman; Paul D., Dauncey; U., Egede; Ivo M., Gough Eschrich; N. J. W., Gunawardane; J. A., Nash; P., Sanders; D., Smith; D. E., Azzopardi; J. J., Back; P., Dixon; P. F., Harrison; R. J. L., Potter; H. W., Shorthouse; P., Strother; P. B., Vidal; M. I., Williams; G., Cowan; S., George; M. G., Green; A., Kurup; C. E., Marker; P., Mcgrath; T. R., Mcmahon; S., Ricciardi; F., Salvatore; I., Scott; G., Vaitsas; David Norvil, Brown; C. L., Davis; John, Allison; Roger J., Barlow; J. T., Boyd; A. C., Forti; J., Fullwood; F., Jackson; G. D., Lafferty; N., Savvas; E. T., Simopoulos; J. H., Weatherall; A., Farbin; A., Jawahery; V., Lillard; J., Olsen; D. A., Roberts; J. R., Schieck; G., Blaylock; C., Dallapiccola; K. T., Flood; Stanley S., Hertzbach; R., Kofler; T. B., Moore; H., Staengle; Stephane, Willocq; B., Brau; R., Cowan; G., Sciolla; F., Taylor; R. K., Yamamoto; M., Milek; P. M., Patel; J., Trischuk; F., Lanni; F., Palombo; J. M., Bauer; M., Booke; L., Cremaldi; V., Eschenburg; R., Kroeger; J., Reidy; D. A., Sanders; D. J., Summers; J. P., Martin; J. Y., Nief; R., Seitz; P., Taras; A., Woch; V., Zacek; H., Nicholson; C. S., Sutton; C., Cartaro; N., Cavallo; G., De Nardo; F., Fabozzi; C., Gatto; L., Lista; P., Paolucci; D., Piccolo; C., Sciacca; J. M., Losecco; J. R. G., Alsmiller; T. A., Gabriel; T., Handler; J., Brau; R., Frey; M., Iwasaki; N. B., Sinev; David M., Strom; F., Colecchia; F., Dal Corso; A., Dorigo; F., Galeazzi; M., Margoni; G., Michelon; M., Morandin; M., Posocco; M., Rotondo; F., Simonetto; R., Stroili; E., Torassa; C., Voci; Maurice, Benayoun; H., Briand; J., Chauveau; P., David; C., de la Vaissiere; L., Del Buono; O., Hamon; F., Le Diberder; P., Leruste; J., Lory; L., Roos; J., Stark; S., Versille; P., Manfredi; V., Re; V., Speziali; E. D., Frank; Larry D., Gladney; Q. H., Guo; J. H., Panetta; C., Angelini; G., Batignani; S., Bettarini; M., Bondioli; M., Carpinelli; F., Forti; M. A., Giorgi; A., Lusiani; F., Martinez Vidal; M., Morganti; N., Neri; E., Paoloni; M., Rama; G., Rizzo; F., Sandrelli; G., Simi; G., Triggiani; J., Walsh; M., Haire; D., Judd; K., Paick; L., Turnbull; D. E., Wagoner; J., Albert; C., Bula; P., Elmer; C., Lu; K. T., Mcdonald; V., Miftakov; S. F., Schaffner; A. J. S., Smith; A., Tumanov; E. W., Varnes; G., Cavoto; D., del Re; R., Faccini; F., Ferrarotto; F., Ferroni; K., Fratini; E., Lamanna; Emanuele, Leonardi; M. A., Mazzoni; Silvio, Morganti; G., Piredda; F., Safai Tehrani; M., Serra; C., Voena; S., Christ; R., Waldi; P. F., Jacques; M., Kalelkar; R. J., Plano; T., Adye; B., Franek; N. I., Geddes; G. P., Gopal; S. M., Xella; R., Aleksan; G., De Domenico; S., Emery; A., Gaidot; S. F., Ganzhur; P. F., Giraud; W., Kozanecki; M., Langer; G. W., London; B., Mayer; B., Serfass; G., Vasseur; C., Yeche; M., Zito; N., Copty; M. V., Purohit; H., Singh; F. X., Yumiceva; I., Adam; P. L., Anthony; D., Aston; K., Baird; J. P., Berger; Elliott D., Bloom; A. M., Boyarski; F., Bulos; G., Calderini; R., Claus; M. R., Convery; D. P., Coupal; D. H., Coward; J., Dorfan; M., Doser; W., Dunwoodie; R. C., Field; T., Glanzman; G. L., Godfrey; S. J., Gowdy; P., Grosso; T., Himel; Tetiana Berger, Hryn'Ova; M. E., Huffer; Walter R., Innes; C. P., Jessop; M. H., Kelsey; P., Kim; M. L., Kocian; Urs, Langenegger; David W. G. S., Leith; S., Luitz; V., Luth; H. L., Lynch; H., Marsiske; S., Menke; R., Messner; K. C., Moffeit; R., Mount; D. R., Muller; C. P., O'Grady; M., Perl; S., Petrak; Helen R., Quinn; B. N., Ratcliff; S. H., Robertson; L. S., Rochester; A., Roodman; T., Schietinger; R. H., Schindler; J., Schwiening; V. V., Serbo; A., Snyder; A., Soha; S. M., Spanier; J., Stelzer; D., Su; M. K., Sullivan; H. A., Tanaka; J., Va'Vra; S. R., Wagner; A. J. R., Weinstein; William J., Wisniewski; D. H., Wright; C. C., Young; P. R., Burchat; C. H., Cheng; David P., Kirkby; T. I., Meyer; C., Roat; R., Henderson; W., Bugg; H., Cohn; A. W., Weidemann; J. M., Izen; I., Kitayama; X. C., Lou; M., Turcotte; F., Bianchi; Marcella, Bona; B., Di Girolamo; D., Gamba; A., Smol; D., Zanin; L., Bosisio; G., Della Ricca; L., Lanceri; A., Pompili; P., Poropat; M., Prest; E., Vallazza; G., Vuagnin; R. S., Panvini; C., Brown; Asoka S., De Silva; Robert V., Kowalewski; J. M., Roney; H. R., Band; E., Charles; S., Dasu; F., Di Lodovico; A. M., Eichenbaum; H., Hu; J. R., Johnson; R., Liu; J., Nielsen; Y., Pan; R., Prepost; I. J., Scott; J. H., von Wimmersperg Toeller; S. L., Wu; Z., Yu; H., Zobernig; T. M. B., Kordich; H., Nea

Geoeconomic variations in epidemiology, ventilation management, and outcomes in invasively ventilated intensive care unit patients without acute respiratory distress syndrome: a pooled analysis of four observational studies

Background: Geoeconomic variations in epidemiology, the practice of ventilation, and outcome in invasively ventilated intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) remain unexplored. In this analysis we aim to address these gaps using individual patient data of four large observational studies. Methods: In this pooled analysis we harmonised individual patient data from the ERICC, LUNG SAFE, PRoVENT, and PRoVENT-iMiC prospective observational studies, which were conducted from June, 2011, to December, 2018, in 534 ICUs in 54 countries. We used the 2016 World Bank classification to define two geoeconomic regions: middle-income countries (MICs) and high-income countries (HICs). ARDS was defined according to the Berlin criteria. Descriptive statistics were used to compare patients in MICs versus HICs. The primary outcome was the use of low tidal volume ventilation (LTVV) for the first 3 days of mechanical ventilation. Secondary outcomes were key ventilation parameters (tidal volume size, positive end-expiratory pressure, fraction of inspired oxygen, peak pressure, plateau pressure, driving pressure, and respiratory rate), patient characteristics, the risk for and actual development of acute respiratory distress syndrome after the first day of ventilation, duration of ventilation, ICU length of stay, and ICU mortality. Findings: Of the 7608 patients included in the original studies, this analysis included 3852 patients without ARDS, of whom 2345 were from MICs and 1507 were from HICs. Patients in MICs were younger, shorter and with a slightly lower body-mass index, more often had diabetes and active cancer, but less often chronic obstructive pulmonary disease and heart failure than patients from HICs. Sequential organ failure assessment scores were similar in MICs and HICs. Use of LTVV in MICs and HICs was comparable (42·4% vs 44·2%; absolute difference -1·69 [-9·58 to 6·11] p=0·67; data available in 3174 [82%] of 3852 patients). The median applied positive end expiratory pressure was lower in MICs than in HICs (5 [IQR 5-8] vs 6 [5-8] cm H2O; p=0·0011). ICU mortality was higher in MICs than in HICs (30·5% vs 19·9%; p=0·0004; adjusted effect 16·41% [95% CI 9·52-23·52]; p<0·0001) and was inversely associated with gross domestic product (adjusted odds ratio for a US$10 000 increase per capita 0·80 [95% CI 0·75-0·86]; p<0·0001). Interpretation: Despite similar disease severity and ventilation management, ICU mortality in patients without ARDS is higher in MICs than in HICs, with a strong association with country-level economic status